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Biomedical subjects

C Can

Publications and source records attributed to C Can.

At least 37 records · Page 2Linked to original sources
PubMed1998

Differential expression of a senescence-enhanced metallothionein gene in Arabidopsis in response to isolates of Peronospora parasitica and Pseudomonas syringae.

The metallothionein gene, LSC54, shows increased expression during leaf senescence in Brassica napus and Arabidopsis thaliana. A number of abiotic and biotic stresses have been shown to induce senescence-like symptoms in plants and, to investigate this further, the promoter of the LSC54 gene was cloned and fused to the GUS gene and transformed into Arabidopsis. The promoter was highly induced during leaf senescence and also in response to wounding; histochemical analysis indicated that this induction was localised to a few cells close to the wound site. The transgenic Arabidopsis tissue was infected with compatible and incompatible isolates of both the fungal biotroph, Peronospora parasitica and the bacterial necrotroph, Pseudomonas syringae. Incompatible isolates induced rapid cell death (the hypersensitive response) at the site of infection and, with both pathogens, early, localised expression of the GUS gene was observed. In contrast, relatively slow induction of the GUS gene was seen in the compatible interaction and this was correlated with the appearance of senescence-like symptoms in the biotrophic interaction and cell death by necrosis that occurred in response to the necrotrophic pathogen. These results suggest that there are common steps in the signalling pathways that lead to cell death in the hypersensitive response, pathogen induced necrosis and senescence.

Arabidopsis↗
PubMed1998

Genetic characterization of RRS1, a recessive locus in Arabidopsis thaliana that confers resistance to the bacterial soilborne pathogen Ralstonia solanacearum.

The soilborne, vascular pathogen Ralstonia solanacearum, the causative agent of bacterial wilt, was shown to infect a range of Arabidopsis thaliana accessions. The pathogen was capable of infecting the Col-5 accession in an hrp-dependent manner, following root inoculation. Elevated bacterial population levels were found in leaves of Col-5, 4 to 5 days after root inoculation by the GMI1000 strain. Bacteria were found predominantly in the xylem vessels and spread systematically throughout the plant. The Nd-1 accession of A. thaliana was resistant to the GMI1000 strain of R. solanacearum. Bacterial concentrations detected in leaves of Nd-1, inoculated with an hrp+ strain of R. solanacearum, were only slightly higher than those detected in the susceptible accession, Col-5, following inoculation with a strain whose hrp gene cluster was deleted. Leaf inoculation of the GMI1000 strain on the resistant accession Nd-1 induced the formation of lesions in the older leaves of the rosette whereas the same strain of R. solanacearum provoked complete wilting of Col-5. Resistance to strain GMI1000 of R. solanacearum segregated as a simply inherited recessive trait in a genetic cross between Col-5 and Nd-1. F9 recombinant inbred lines generated between these two accessions were used to map a locus, RRS1, that was the major determinant of resistance between restriction fragment length polymorphism markers mi83 and mi61 on chromosome V. This region of the A. thaliana genome is known to contain many other pathogen recognition capabilities.

Arabidopsis↗
PubMed1998

Antrochoanal polyps: analysis of 16 cases.

Antrochoanal polyps are rare lesions. Several surgical techniques have been reported to provide complete cure of the disease. However, inadequate treatment may result in a high rate of recurrences. The aetiological as well as predisposing factors are not well understood. We present a literature review and discuss the clinical, pathological and histological features of 16 patients with antrochoanal polyps, who have been surgically treated by either an endoscopical or conventional approach. It has been found that allergy has no role in the aetiology of antrochoanal polyps. However, the majority of the patients have sinonasal disease. The most common pre-operative radiological finding is the mucocoele-like appearance, which has also been confirmed in surgery. It is remarkable that antrochoanal polyps have recurred in 4 out of 8 patients, who have underwent simple intranasal polypectomy and inferior turbinectomy. As compared to conventional technique, the endoscopic approach proves to be superior.

Adolescent↗
PubMed1995

Comparison of preoperative computed tomographic findings with postoperative histopathological findings in laryngeal cancers.

In this study of 22 patients with laryngeal cancer, computed tomographic (CT) scans in the axial plane were compared with histopathological sections prepared in the same plane. The value of the preoperative CT for evaluating tumor invasion, location and size was then investigated. Findings demonstrated that CT was most sensitive in determining tumor invasion to the paralaryngeal and preepiglottic spaces, anterior and posterior commissures and subglottis. In contrast, CT was less sensitive in determining actual tumor invasion to the laryngeal cartilages, extralaryngeal tissues and metastases to cervical lymph nodes.

Carcinoma, Squamous Cell↗
PubMed1995

Anastomosis of the freshly divided uterine horns of rats with the CO2 laser vs. microsurgery.

We used the CO2 laser (group 1) and conventional microsurgery (group 2) for anastomosis of the freshly divided uterine horns of rats and compared the two methods. Each group was then compared with a control group in whom only exploration was carried out at laparotomy. Comparison was done regarding the clinical and histologic results. In addition, serum levels and tissue concentrations of alkaline phosphatase (ALP) and lactic dehydrogenase (LDH) were measured, and the three groups were compared. No significant difference was found between the mean adhesion scores of groups 1 and 2; however, when the control group was compared with the other groups, the differences were statistically significant. The tubal patency rates in groups 1 and 2 and the control group were 83.3%, 79.2% and 100%, respectively, and the pregnancy rates in those groups were 54.5% (6/11), 45.5% (5/11) and 100% (10/10). The differences in tubal patency and pregnancy rates between groups 1 and 2 were not significant, but when each was compared with the control group, the differences were significant. The mean scores for mucosal regeneration and disruption of the muscularis layer in group 1 were significantly lower than those in group 2. Serum levels and tissue concentrations of ALP and LDH in the control group were lower than in groups 1 and 2, and the differences between the control group and each of the other groups were significant; however, no significant difference was found between groups 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1994

Comparative study of microepineural suture, microepineural suture-aided CO2 laser, and laser only anastomoses in rat sciatic nerves.

The cut sciatic nerves of 33 rats were anastomosed by three different methods under the operation microscope; microepineural suture technique, CO2 laser technique, and laser-aided microepineural suture technique. On histologic examination at the end of 3 months postoperatively, in the CO2 laser and suture-aided CO2 laser groups, the degrees of inflammation, fibrosis, and Schwann cell vacuolar degeneration were significantly higher than in the microepineural suture anastomosis group. At the end of 3 months sciatic nerve function was absent in 3 of 11 rats anastomosed by only CO2 laser, however, sciatic nerve functions were found to be normal in the other two groups.

Anastomosis, Surgical↗
PubMed1993

Extended vein ligation: a new aspect of the surgical treatment of varicocele.

Conventional varicocelectomy is complicated by a postoperative recurrence rate of 5-20% in patients with varicocele. On the other hand, the exact location and relationship of the internal, external and gubernacular veins, arteries and lymphatics within the inguinoscrotal portion of the spermatic cord have not been well described. The results of detailed intraoperative observations and surgical dissection of the spermatic cord and gubernaculum are presented in 32 patients with clinically palpable varicocele. Following the identification of all veins within and around the spermatic cord and gubernaculum, dilated veins originating from the testis and traversing the gubernaculum were observed in 31% of the patients. External spermatic veins were present in 70% of all spermatic cords evaluated. The majority of patients (> 65%) had more than 3 internal spermatic veins. An average of 3.1 lymphatics per spermatic cord was identified and preserved during dissection of the cord. A solitary testicular artery was observed in 55% of the patients treated. In 3 patients with recurrent varicocele, by using intraoperative venography, we tried to demonstrate the relationship between the gubernacular, external spermatic veins and the plexus pampiniformis. Our results indicate that by giving a precise attention to varicocele anatomy and performing an extended vein ligation, better results together with decreased recurrence rates may be obtained.

Adult↗
PubMed1993

The nature of ghost cells in calcifying odontogenic cyst: an immunohistochemical study.

Two solid and two cystic forms of calcifying odontogenic cysts were stained immunohistochemically to study keratin, carcinoembryonic antigen, epithelial membrane antigen, and S-100 protein expression in ghost cells. The patterns of immunoreactivity were compared with those of dentigerous cysts, odontogenic keratocysts, ameloblastomas, calcifying epitheliomas of Malherbe, and control samples. Immunostaining patterns of calcifying odontogenic cysts were found to be similar to the odontogenic lesions and different from calcifying epithelioma. It is concluded that ghost cells are "keratinizing" odontogenic cells showing aberrant differentiation. These cells should not be regarded as metaplastic. The similarity of the immunostaining patterns of cystic and solid calcifying odontogenic cysts supports the view that these lesions are two morphologic variants of the same entity.

Ameloblastoma↗
PubMed1992

Expression of S-100 protein, epithelial membrane antigen, carcinoembryonic antigen and alpha fetoprotein in normal salivary glands and primary salivary gland tumors.

The distribution of S-100 protein, epithelial membrane antigen, carcinoembryonic antigen and alpha fetoprotein was studied in 38 primary salivary gland tumors. S-100 protein, a useful marker of myoepithelial cells, was demonstrated in some benign tumors. Carcinoembryonic antigen expression was consistently positive in adenoid cystic carcinoma. Demonstration of epithelial membrane antigen helped to confirm the epithelial nature of some neoplastic cells. Alpha fetoprotein was not expressed in any of the cases examined. No correlation was found between immunopositivity and tumor behavior in the present series.

Adenoma↗