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Biomedical subjects

G Baretton

Publications and source records attributed to G Baretton.

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

The influence of p53 and associated factors on the outcome of patients with oral squamous cell carcinoma.

In several tumour entities the immunohistochemical detection of p53 has proved to be a predictive factor for the survival of the patients. In this study the effector waf1 and the regulator mdm2 responsible for the inactivation of p53 were also determined in 156 tissue samples of primary squamous cell carcinomas in the oral cavity and oropharynx, their lymph node metastases, and the epithelium outside the invasively growing tumour from 107 patients. In this latter epithelium there was a significant correlation between grade of dysplasia and staining for p53 (P<0.01). In the dysplastic epithelium a significant correlation between p53, waf1, and mdm2 was shown (P<0.05). Differences in the immunohistochemical staining between different blocks of the tumour tissue and also between primary tumours and their lymph node metastases were revealed in 11-44% of cases, but there was no correlation with other variables, such as formation of lymph node metastases. In contrast to the conventional tumour grading and staging, no influence of any of the variables determined on survival or recurrence-free survival could be detected. It seems that p53 and associated factors are important in the early stages of cancerogenesis but not in further tumour progression and metastatic spread.

Aged↗
PubMed1998

[Prognostic significance of apoptosis inducers/inhibitors in stomach carcinoma with/without adjuvant intraoperative radiotherapy (IORT)].

Several studies have tried to improve the surgical results after resection for gastric cancer by different adjuvant therapy protocols, including intraoperative radiotherapy (IORT). Since 1990 we have performed a randomized, prospective trial comparing surgery alone and surgery plus adjuvant IORT to evaluate the role of adjuvant intraoperative radiotherapy in the treatment of curative resected gastric carcinomas. In the present study, p53, bcl-2 immunoreactivity and DNA fragmentation as a typical marker of apoptosis were determined to investigate the predictive value of apoptosis-related factors and the observed response to radiotherapy. Preliminary data indicate that patients with tumors containing increased numbers of apoptotic tumor cells might derive benefit from adjuvant IORT.

Adenocarcinoma↗
PubMed1997

Endothelialized biological heart valve prostheses in the non-human primate model.

OBJECTIVE: The main disadvantage of implanted cardiac valve bioprostheses remains primarily tissue failure due to calcification. Coating of bioprostheses with viable autologous endothelial cells may delay or even eliminate tissue calcification and subsequent cardiac dysfunction. METHODS: Glutaraldehyde-preserved Hancock bioprostheses (n = 5), pretreated with glutamic acid (8%) and cryopreserved allografts (n = 5) were lined, using endothelial cells harvested from the external jugular vein. Coated specimens were cultivated for 9 days in Medium 199 supplemented with 20% fetal calf serum and basic fibroblast growth factor. Endothelialized grafts were anastomosed into the descending thoracal aorta of adult Chacma baboons. Untreated valve bioprostheses (n = 4) served as controls. Forty days after implantation the prostheses were examined morphologically and immunohistochemically. RESULTS: After implantation endothelialized prostheses showed a positive Factor VIII related antigen reaction by immunohistochemistry on all valve surfaces. Scanning electron microscopy showed confluently lined leaflets with transplanted endothelial cells and displayed cobblestone morphology on all coated allografts. In contrast, the surface of pretreated xenograft valves revealed uncoated areas with platelet and leucocyte aggregates. No endothelium was observed on the leaflets of untreated controls 40 days after implantation. CONCLUSION: In vitro endothelialization of cardiac valve bioprostheses with autologous endothelial cells is possible. The newly created endothelium is shear stress resistant and the antithrombotic as well as the antiaggregatory capacity of the transplanted cells were retained. Lining with autologous endothelial cells could improve the durability and clinical outcome of biological valve prostheses.

Animals↗
PubMed1997

[Prognostic factors in gallbladder carcinoma as a decision aid for reoperation].

In a retrospective study of patients with gallbladder carcinoma, predictive factors for survival were evaluated. TNM stage, according to the UICC and complete tumor resection, turned out to be the strongest values in multivariate analysis. So it is important to make an early correct diagnosis and to reach complete tumor resection during surgical procedure. In case of an incidental tumor after simple cholecystectomy, hepatic wedge resection and lymph node dissection should be performed in T2 stage and above.

Adult↗
PubMed1996

bcl-2 expression, p53 accumulation, and apoptosis in ovarian carcinomas.

Because little is known about the importance of apoptosis and its regulation in epithelial ovarian cancer, the authors looked for bcl-2 expression and p53 accumulation by immunohistochemistry in 148 ovarian carcinomas of different histologic types and stages. The number of apoptotic cells was assessed in situ by enzymatic detection of DNA fragmentation. Strong bcl-2 expression correlated with low histologic grade (P = .004) and was most often seen in endometrioid carcinomas (P = .001), whereas p53 accumulation was predominantly found in serous and undifferentiated carcinomas (P <.001) and high grade tumors (P <.001). p53 accumulation was associated with advanced tumor stage (P <.001) and the presence of residual disease after surgery (P <.001). Apoptosis increased with histologic grade (P = .012); apoptotic cells were sparse or absent in tumors of low malignant potential and mucinous carcinomas, but found in all other carcinoma types (P = .001). Apoptosis, bcl-2 expression, and p53 protein accumulation were not correlated with each other. The analysis of the postoperative course of 110 patients showed that survival depended on histologic tumor type (P = .0037), histologic grade (P = .0143), FIGO (International Federal of Gynecology and Obstetrics) stage (P = .0001), and absence or presence of postoperative residual tumor mass (P = .0001). p53 accumulation was also associated with adverse prognosis (P = .0001). However, bcl-2 positive carcinomas who had a statistically significantly better outcome than patients with p53 positive and bcl-2 negative tumors (P = .0443). Regarding FIGO stage and p53 alone in a Cox model, p53 proved to contribute additional prognostic information both in FIGO stages I/II as well as in FIGO stages III/IV. Thus, our observations point to different molecular alterations possibly underlying phenotypic diversity of ovarian carcinomas and provide clues for a better understanding of tumor progression in these neoplasms. Apoptosis plays a role in ovarian carcinomas, but seemingly is regulated in a different way than in nonneoplastic tissues.

Adenocarcinoma↗
PubMed1995

Prognostic significance of DNA ploidy in oral squamous cell carcinomas. A retrospective flow and image cytometric study with comparison of DNA ploidy in excisional biopsy specimens and resection specimens, primary, tumors, and lymph node metastases.

Deoxyribonucleic acid ploidy was determined in paraffin-embedded tumor tissue from 116 patients with primary oral squamous cell carcinomas (including 5 carcinomas of the lip and 14 of the tongue) by means of flow cytometry. One hundred six cases were suitable for evaluation (91%). Sixty-eight percent of the cases (n = 72) showed a nondiploid nuclear DNA content. Nondiploidy correlated significantly with presence of lymph node metastases (p < 0.02) but not with tumor stage, grading (World Health Organization), or relapse-free and overall survival. Carcinomas of the lip and tongue turned out to be diploid more frequently than other oral squamous cell carcinomas (p = 0.002). In the 21 cases in which a comparison of DNA content of excisional biopsy specimens and subsequent resection specimens was possible a difference in DNA ploidy was found in one case only. The comparison of primary tumors and their lymph node metastases in 30 cases revealed a discrepancy of DNA content in five cases (17%), which was connected with a shift from nondiploidy to diploidy in four out of five cases. Fifty cases studied in parallel by means of image cytometry with Feulgen-stained tissue sections exhibited a concordance of the ploidy status in 87% and a significant correlation of the DNA index values obtained with both methods (p < 0.01). These results demonstrate that DNA ploidy in oral squamous cell carcinomas is distributed rather homogeneously within the tumors and remains rather stable in the lymph node metastases. Despite a significant correlation between nondiploidy and presence of lymph node metastases, ploidy failed to be a statistically significant parameter for prognosis in oral squamous cell carcinomas in our investigation.

Aneuploidy↗
PubMed1995

[Recurrent multiple leiomyomatous hamartomas of the lung].

A 40 year old female was operated because of pulmonary leiomyomatous hamartoma. Despite repeated surgical resection therapy during the following years she developed recurrent multiple hamartoma. The indication for multiple surgery only included compression of central vessels or rapid growth of the hamartomas. The history of hysterectomy--as in our patient--is common for patients with multiple leiomyomatous pulmonary hamartoma. However, revision of the histological slides revealed no hint of uterine leiomyosarcoma. Therefore, a primary pulmonal (and recurrent) multiple hamartosis seems obvious.

Adult↗
PubMed1994

Morphological detection of X- and Y-chromosomes in smears and paraffin-embedded tissues using a non-isotopic in situ hybridization technique (NISH).

Pharyngeal smears and paraffin-embedded tissue specimens (skeletal muscle, kidney) obtained from 10 male and 10 female individuals were evaluated using non-isotopic in situ hybridization (NISH) with commercial X- and Y-specific biotinylated probes which recognize the pericentromeric regions DXZ1 and DYZ1/DYZ3 of the X- and Y-chromosome, respectively. The results provide evidence that the morphological sex determination of a single cell can be performed by critical application of this staining method leading to one nuclear signal in "male" cells using the Y-specific probe whereas "female" cells are negative. In situ hybridization of "female" tissues with an X-specific probe results regularly in 2 signals whereas "male" cells show only one spot in the nucleus.

Adult↗
PubMed1994

Deoxyribonucleic acid ploidy in seminomas with and without syncytiotrophoblastic cells.

Seminomas with human chorionic gonadotropin-producing syncytiotrophoblastic cells have been discussed as a distinctive subgroup with a worse prognosis. In a series of 50 seminomas (30 with immunohistochemically detectable syncytiotrophoblastic cells and 20 without syncytiotrophoblastic cells) deoxyribonucleic acid (DNA) ploidy was determined by flow cytometry in paraffin-embedded histopathological material. Comparatively, in 28 cases the DNA content was assessed by image cytometry on Feulgen-stained slides. DNA aneuploidy was detected in 49 seminomas (98%). No differences in the distribution of DNA index were observed between cases positive and negative for syncytiotrophoblastic cells (average DNA index 1.68 +/- 0.44 for positive cases and 1.71 +/- 0.52 for negative cases). Flow cytometry and image cytometry DNA index values showed a statistically significant correlation (p < 0.01). Intra-tumoral heterogeneity of DNA content was found in 2 seminomas negative for syncytiotrophoblastic cells. Multiploidy and hypertetraploidy were noted more often in negative cases also. DNA ploidy or distinct aneuploid stemlines did not correlate with histopathological tumor stage or clinical course. The results favor the notion that the occurrence of syncytiotrophoblastic cells in seminomas represents only an example of intra-tumoral variability of tumor cell differentiation and does not justify the definition as a separate subgroup with distinct biological behavior.

Adult↗
PubMed1994

DNA ploidy in carcinoma of the gallbladder. Prognostic significance and comparison of flow and image cytometry on archival tumor material.

The aim of this investigation was to determine whether the cytometrically assessed DNA ploidy is a parameter of prognostic significance in gallbladder carcinomas. For this purpose the DNA content of tumor cells from archival tumor material from 80 patients with cholecystic cancer was analysed retrospectively by using comparatively different cytometrical methods, namely flow cytometry (FCM) and image cytometry, using tissue sections (ICM-S) and nuclear suspensions (ICM-N). Conventional tumor classifications (according to pTNM and Nevin) were able to predict the further clinical course. DNA ploidy showed a statistically significant correlation only to histological grade (P < 0.001), but not to tumor stage and survival. Only a trend towards a poorer outcome for patients harboring non-diploid tumors became evident especially when no residual tumor was present postoperatively (R 0-stage; P = 0.08). The different cytometrical methods discussed in detail, showed a highly significant concordance in the determination of DNA index values (DI) and in the classification of the tumors as either diploid or non-diploid. In conclusion, our results indicate that cytometrical determination of DNA ploidy provides no further prognostic informations in gallbladder carcinomas as compared to conventional tumor staging.

Aged↗
PubMed1994

[Epidermal proliferation rate after skin expansion in the dog model].

The aim of this study was to evaluate the time course of the epidermal proliferation under the influence of skin expansion. Therefore 99 expanders were implanted in 18 beagles. The expansion times were between 2 hours and 4 months. Cells in the S-phase were marked by in vivo application of bromodesoxyuridine (BrdU). The tissue specimens were immunohistochemically stained and positive nuclei counted. The proliferation index increased markedly about 32 hours after the onset of the expansion and decreased afterwards slowly during the first week. Because the dog is the most appropriate species for experimental expansion studies (4,5) it can be assumed that skin expansion leads to a stimulation of the epidermal proliferation during the first few days also under clinical conditions. Nevertheless, the amount of skin that can be surgically used depends not only on the characteristics of the epidermal layer, but also on the dermis with its strong fibre system. Own studies published elsewhere (8) have shown that the dermal fibres react much slower to the expansion stimulus, so that even though there is an early epidermal proliferation increase new surgically applicable skin can only be produced by long-term expansion.

Animals↗
PubMed1994

Bacteria: a major pathogenic factor for anastomotic insufficiency.

The aim of this study was to determine the influence of bacteria on the development of anastomotic insufficiency following gastrectomy in the rat. Fifty-seven male Wistar rats were randomly assigned to three groups and subjected to gastrectomy. Group I (n = 20) was orally inoculated with 10(9) Pseudomonas aeroginosa organisms on postoperative day 1. Group II (n = 20) served as the control group. Group III (n = 17) was decontaminated with 320 mg of tobramycin, 400 mg of polymyxin B, and 500 mg of vancomycin per liter of fluid administered from preoperative day 7 to postoperative day 10. Swabs from the oropharynx and rectum were cultured and analyzed daily for gram-positive and gram-negative bacteria. Surviving animals were sacrificed on postoperative day 10. All animals were autopsied immediately following death. Anastomotic insufficiency was defined as a histologically proven transmural defect at the suture line. Along with an effective reduction of pathogenic bacteria colonizing the oropharynx, the rate of anastomotic insufficiency could be reduced significantly, to 6% in decontaminated animals compared with 80% in controls (P < 0.001 by Fisher's exact test). Inoculation of group I animals with P. aeruginosa led to an increase of anastomotic insufficiency up to 95% and a significant increase in mortality (P < 0.05). We conclude that bacteria play a major role in the pathogenesis of anastomotic insufficiency following gastrectomy in the rat.

Anastomosis, Surgical↗
PubMed1994

[DNA cytometry using paraffin embedded tumor tissues. Comparison of flow cytometry (FCM) and image cytometry (ICM)].

In order to examine the correlation of cytometric DNA ploidy in paraffin-embedded tumour material, a comparison was made of flow (FCM) and image cytometry (ICM); in the case of ICM FEULGEN-stained tissue sections (8-10 microns) and in some cases nuclear suspensions were used. Tumour tissue from seminomas (FCM: n = 50; ICM/section: n = 28), oral squamous carcinomas (FCM: n = 110; ICM/section: n = 50) and adenocarcinomas of the gallbladder (FCM: n = 50; ICM/section: n = 46; ICM/nuclear susp.: n = 40) was studied. The concordance regarding diploid/non-diploid characteristics was 96.5% in the case of seminomas, 87% in oral carcinomas and 100% in gallbladder carcinomas. A statistically significant correlation of DNA indices of FCM with ICM histograms was found in all three organ tumours examined. 6% of oral and up to 18% gallbladder carcinomas, however, could not be evaluated by means of FCM due to poor quality of the histograms (coefficient of variation (CV) > 6%). In the determination of DNA indices and resolution of multiploid stemlines, FCM analysis proved to be superior. Regional intratumoural differences and rare tumour populations were best detected by ICM using sections. Without correction factors being used, these sections did not show any significant deviation of DNA indices from the other methods used. Our study has revealed that in paraffin-embedded tumour material FCM and ICM usually provide well-correlating results, when standardised and controlled preparation and measuring procedures are applied.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

[Comparative experimental studies of mechanical and holmium laser synovectomy].

The goal of this study was to evaluate tissue reactions in rabbit knees following laser synovectomy using a holmium:YAG laser (wavelength: 2.1 microns) and to compare these results with those found after conventional mechanical abrasion treatment. Chronic arthritis was immunologically induced in one knee joint each of 48 rabbits. Twelve served as controls, 12 were sham-operated, 12 were exposed to laser radiation, and 12 others were treated according to conventional methods. In the laser group, a pulse length of 1 ms at a repetition rate of 3 Hz resulted in a pulse energy of 600 mJ. After periods of 1 day, 1 week and 1 and 3 months, respectively, three animals from each group were sacrificed and the synovialis was examined macroscopically and histologically using light and electron microscopy. Edema, acute inflammation, and coagulation necrosis occurred immediately following laser therapy. After 1 week, the synovial layer showed slight fibrosis, which was comparable to that found in the controls. One month later the surface appeared to be smooth. The mechanical abrasion caused hemorrhage and necrosis. Fibrosis was pronounced in all capsular layers, and after 3 months the surface appeared coarse and villous in this group. Based on these preliminary findings, holmium-laser synovectomy may offer an alternative to existing therapeutic techniques in the treatment of rheumatoid arthritis. The arthroscopic approach could prevent additional capsular fibrosis associated with mechanical irritation.

Animals↗
PubMed1993

Sennosides and aloin do not promote dimethylhydrazine-induced colorectal tumors in mice.

In a model of dimethylhydrazine-induced colorectal tumors in male mice aloin- or sennoside-enriched diets (0.03%) did not promote incidence and growth of adenomas and carcinomas after 20 weeks. Furthermore, in anthranoid-fed mice no significant changes in serum electrolytes as well as parameters of hepato- and nephrotoxicity were observed.

1,2-Dimethylhydrazine↗
PubMed1993

[Prostate cancers and potential precancerous conditions: DNA cytometric investigations and interphase cytogenetics].

The topic of this investigation was to compare precancerous lesions of the prostate (prostatic intraepithelial neoplasia -PIN- and atypical hyperplasia -AH-) and invasive carcinomas concerning DNA ploidy (image cytometry/ICM) and morphologically feasible chromosomal aberrations (interphase cytogenetics/NISH). The aim was to find clues to formal pathogenesis of prostatic cancer. Prostatic tissue of 76 patients (76 areas with carcinoma, 71 with PIN, and 12 with AH) was examined by means of ICM. In 44 cases of coincidental PIN and carcinoma, the gradings of PIN and carcinoma correlated. C-values, 2,5c-exceeding-rate, and aneuploidy rate turned out to increase in PIN and carcinoma with increasing grading (P < 0.01). In some of these cases NISH was carried out in serial sections by applying centromer-(X,Y,1,7,8,10,17,18) and telomer-(1p) specific DNA probes. The result of this approach was an increase in the number of chromosomal aberrations and chromosomes involved correlating with the grading. Our conclusion is that PIN 1 could be regarded as the precancerous lesion mainly to higher differentiated carcinomas, whereas PIN 2 and 3 should be considered a preneoplastic condition mainly of moderately and low differentiated carcinomas.

Chromosome Aberrations↗