[Placental site trophoblastic tumor].
A clinical case of placental site trophoblastic tumor, is presented in a patient of 27 years old. Diagnosis, clinical behavior and treatment are emphasized in this very infrequent pathology.
Adult↗
Biomedical subjects
R Rosati
Publications and source records attributed to R Rosati.
The exon structure of the mouse alpha 2(IX) collagen gene shows unexpected divergence from the chick gene.
One cosmid and two overlapping phage clones covering the entire mouse alpha 2(IX) collagen gene including 12 kilobase pairs (kb) of 5'- and 8 kb of 3'-flanking sequences were isolated from two genomic libraries. The overall gene structure was determined by restriction mapping and nucleotide sequencing. The gene spans 16 kb from the start of transcription to the polyadenylation site and contains 32 exons. It codes for a mRNA of 3 kb that translates into a polypeptide of 688 amino acids. The intron-exon junctions and mRNA structure were confirmed by amplification of cDNA made for mouse cartilage RNA. The coding sequence of the mouse alpha 2(IX) collagen gene shows marked similarities to those for other type IX collagen chains. Although the overall exon-intron organization of the mouse gene is very similar to the chick alpha 2(IX) gene, some unexpected differences were observed at the splice junctions. Split codons characteristic for the central triple helical domain of the chick were not found in the mouse gene that thus exhibited a long stretch of exons with sizes that are multiples of 9 base pairs in this domain. The promoter of the mouse alpha 2(IX) collagen gene contains some G + C-rich elements including three Sp1 consensus recognition sites and a far upstream CCAAT box but no TATAA box. Both primer extension and RNase protection assays revealed several transcription start sites within 418 base pairs of the promoter. The present study reports the first complete nucleotide sequence of any type IX collagen gene and forms the basis for comparative structural studies on this collagen type and for experiments involving transgenic mice.
Amino Acid Sequence↗
Normal long bone growth and development in type X collagen-null mice.
To investigate the role of type X collagen in skeletal development, we have generated type X collagen-null mice. Surprisingly, mice without type X collagen were viable and fertile and had no gross abnormalities in long bone growth or development. No differences were detected between the type X collagen-null mice and controls when growth plates of both newborn and 3-week old mice were examined by histology and by immunostaining for extracellular matrix components of bone including osteopontin, osteocalcin and type II collagen. Our results suggest that type X collagen is not required for long bone development. However, mice and humans with dominant acting type X collagen mutations have bone abnormalities, suggesting that only the presence of abnormal type X collagen can modify bone growth and development.
Animals↗
[Right adrenal adenoma: laparoscopic exeresis].
The authors report the case of a non functioning adrenal adenoma, incidentally diagnosed and excised through a laparoscopic approach. Indications to adrenalectomy for such a pathological condition and surgical technique are reviewed and discussed. In consideration of the relatively rare disease and of the scant literature on minimally-invasive approach to right adrenalectomy, it seemed worth reporting this case and the technical skills performed to ease this operation through laparoscopy.
Adenoma↗
[Thoracoscopic techniques in treatment of esophageal diseases].
Some malignant and benign diseases of the esophagus are generally treated through a thoracotomic approach. While this may be justified in the curative treatment of cancer, thoracotomy may be avoided for benign diseases if good functional results can be obtained through a minimally invasive approach. Long-term results with careful clinical and manometric monitoring of patients operated on for epiphrenic diverticula have to be considered to define the possible role of thoracoscopic approach to this disease since a laparoscopic approach, which includes transhiatal diverticulectomy, myotomy, and fundoplication, seems to have excellent results. As for leiomyomas thoracoscopy represents the first choice approach since it allows a complete removal of the benign tumor with a limited access. In case of malignant diseases, thoracoscopic esophagectomy has in our opinion few indications. Extent of lymphnodal dissection appears to be the major limiting factor of the technique. Moreover, high-risk patients need anyway a double-lumen intubation and a prolonged single-lung ventilation. Modifications of respiratory function after thoracoscopy have to be compared with those occurring after thoracotomy and after transhiatal esophagectomy. Studies on lymphadenectomy and on respiratory physiopathology will help in define a possible role of this approach.
Carcinoma, Squamous Cell↗
[The current role of microsurgery in the therapy of idiopathic varicocele].
The authors report a case of recidivant varicocele. After having considered the epidemiological and clinical features of varicocele, traditional and microsurgical technics are analyzed and discussed.
Adult↗
Production of transgenic mice expressing the Ki-ras oncogene under the control of a thyroglobulin promoter.
Transgenic mice have been generated bearing three fusion genes consisting of: (a) a 900-base pair rat thyroglobulin promoter followed by a gene coding for a chloramphenicol acetyl transferase activity; (b) the same promoter followed by the complementary DNA of the human activated Ki-ras oncogene; (c) a 2000-base pair rat thyroglobulin promoter followed by the complementary DNA of the human activated Ki-ras. We have shown that the 900-base pair rat thyroglobulin promoter is able to direct the expression of the reporter gene specifically in the thyroid gland of transgenic mice. The mice bearing the two Ki-ras constructs, which express the transgene in thyroid glands, show thyroid abnormalities, although at very low incidence. These lesions appear after a long latency and with a benign aspect, thus suggest that, in agreement with literature data on naturally occurring human thyroid tumors, the action of an activated ras gene is not sufficient to attain a complete malignant conversion of thyroid glands in vivo. However, ras expression in thyroid follicular cells represents a favorable ground for tumor development, as shown by the fact that goitrogen stimulation experiments increase the occurrence of tumors.
Adenoma↗
The mouse collagen X gene: complete nucleotide sequence, exon structure and expression pattern.
Overlapping genomic clones covering the 7.2 kb mouse alpha 1(X) collagen gene, 0.86 kb of promoter and 1.25 kb of 3'-flanking sequences were isolated from two genomic libraries and characterized by nucleotide sequencing. Typical features of the gene include a unique three-exon structure, similar to that in the chick gene, with the entire triple-helical domain of 463 amino acids coded by a single large exon. The highest degree of amino acid and nucleotide sequence conservation was seen in the coding region for the collagenous and C-terminal non-collagenous domains between the mouse and known chick, bovine and human collagen type X sequences. More divergence between the sequences occurred in the N-terminal non-collagenous domain. Similarity between the mammalian collagen X sequences extended into the 3'-untranslated sequence, particularly near the polyadenylation site. The promoter of the mouse collagen X gene was found to contain two TATAA boxes 159 bp apart; primer extension analyses of the transcription start site revealed that both were functional. The promoter has an unusual structure with a very low G + C content of 28% between positions -220 and -1 of the upstream transcription start site. Northern and in situ hybridization analyses confirmed that the expression of the alpha 1(X) collagen gene is restricted to hypertrophic chondrocytes in tissues undergoing endochondral calcification. The detailed sequence information of the gene is useful for studies on the promoter activity of the gene and for generation of transgenic mice.
Amino Acid Sequence↗
[Submucosal modified hemorrhoidectomy by the Parks' technique].
The authors report several modified techniques derived from Parks haemorrhoidectomy. They operated on 81 patients with II and III degree haemorrhoids with this technique and they present why they did it and the good results obtained.
Hemorrhoids↗
[Clinical use of a new compression surgical stapler in surgery of the large intestine].
The clinical experience with the use in colorectal surgery of a new compression anastomotic device developed by the Authors is reported. From May 1986 through June 1990, 95 patients underwent large bowel anastomosis using this device. Operations performed included 51 left hemicolectomies or anterior resections of the sigmoid and rectum, 23 left colon resections, 19 right hemicolectomies, and two total colectomies. Twenty-nine anastomoses were performed below the pelvic peritoneal reflection and 18.5% of them resulted less than 4 cms from the anal verge while 20% were located between 4.5 and 8 cms. Five (5.2%) intraoperative diverting colostomies were needed. The rings were evacuated postoperatively after a mean of 10.9 days with none or very little discomfort. Operative mortality was 1.0% (one patient died of myocardial infarction). Anastomotic complications included five (5.2%) clinical and four (4.2%) subclinical leakages. No haemorrhages or stenoses were observed. This initial clinical experience shows the anastomotic device is reliable and justifies further experimentation.
Adenocarcinoma↗
Reduced amounts of cartilage collagen fibrils and growth plate anomalies in transgenic mice harboring a glycine-to-cysteine mutation in the mouse type II procollagen alpha 1-chain gene.
We have generated transgenic mice harboring a glycine-to-cysteine mutation in residue 85 of the triple helical domain of mouse type II collagen. The offspring of different founders displayed a phenotype of severe chondrodysplasia characterized by short limbs and trunk, cranio-facial deformities, and cleft palate. The affected pups died of acute respiratory distress caused by an inability to inflate lungs at birth. Staining of the skeleton showed a severe retardation of growth for practically all bones. Light microscopic examination indicated a decrease in cartilage matrix density, a severe disorganization of growth plate architecture, and the presence of streaks of fibrillar material in the cartilage matrix. Electron microscopic analysis showed a pronounced decrease in the number of typical thin cartilage collagen fibrils, distension of the rough endoplasmic reticulum of chondrocytes, and the presence of abnormally large banded collagen fibril bundles. The level of expression of the mutant type II procollagen alpha 1 chain transgene in cartilage tissues was approximately equal to that of the endogenous gene in two of the strains. We propose that the principal consequence of the mutation is a considerable reduction in density of the typical thin cartilage collagen fibrils and that this phenomenon causes the severe disorganization of the growth plate. We also postulate that the abnormal thick collagen fibrils are probably related to a defect in crosslinking between the collagen molecules. The cartilage anomalies displayed by these transgenic mice are remarkably similar to those of certain human chondrodysplasias.
Animals↗
Preferential expression of the dbl protooncogene in some tumors of neuroectodermal origin.
We have investigated the expression of the dbl protooncogene in a wide variety of human tumors of different embryological derivation. We found that proto-dbl mRNA could be detected preferentially in a few neoplastic histiotypes of neuroectodermal origin. The common, normal 5-kilobase size of the proto-dbl transcript detected indicated that the proto-dbl in these tumors was not rearranged. These data, in agreement with our previous reports, suggest that the dbl protooncogene is expressed in a highly tissue-specific manner and indicate that this gene may be involved in the growth and differentiation of some cells of neuroectodermal origin.
Animals↗
Effects of intraperitoneal chemotherapy on anastomotic healing in the rat.
The effect of perioperative intraperitoneal (ip) (2 mg/kg) vs intravenous (iv) (1.5 mg/kg) mitomycin-C on healing of intestinal anastomoses was studied in rats after jejunal section and anastomosis. When the animals were killed 7 days after surgery 52.8% in the ip group had an anastomotic leak (41.2% causing death of the animals), compared to 20% in the iv group and none in the control group. Mean anastomotic bursting pressure was 156 mm Hg in the ip group, 178 mm Hg in the iv group, and 203 mm Hg in controls (P less than 0.01). Hydroxyproline content of the intestinal segment containing the anastomosis was 2.26 micrograms/mg in the ip group, 3.49 in the iv, and 4.91 in controls (ip vs controls, P less than 0.01). Histological examination of the anastomoses in rats given ip mitomycin showed significantly "slower" anastomotic healing than in iv rats and controls. Electron microscopy showed that the mean diameter of collagen fibers was significantly smaller (P less than 0.05) in ip rats (34 nm) than iv (51 nm) and controls (79 nm). An intraoperative bolus of mitomycin thus significantly impaired the healing of a jejunal anastomosis in the rat, more so after ip than iv injection. Thus in clinical practice ip adjuvant chemotherapy after surgery should perhaps be delayed until wound repair has reached an advanced stage.
Anastomosis, Surgical↗
Clinical application of a new compression anastomotic device for colorectal surgery.
Fifty-six patients underwent large bowel anastomosis by the compression anastomotic device developed by the authors from May 1986 through December 1988. Operations performed were 40 left hemicolectomies or anterior resections of the sigmoid and rectum, 7 left colon resections, 7 right hemicolectomies, and 2 total colectomies. Twenty-one anastomoses were done on the extraperitoneal rectum, in 7 cases less than 4 cm from the anal verge and in 9 cases between 4.5 and 8 cm. Five intraoperative diverting colostomies were done (9%). The rings of the device were evacuated postoperatively after a mean of 11 days with little or no discomfort. Operative mortality was 1.8% (one patient died of myocardial infarction). Anastomotic complications were one (1.8%) clinical and one (1.8%) subclinical leak. Mean postoperative hospital stay was 14 days. This initial clinical experience shows that the anastomotic device is reliable.
Adult↗
The ret proto-oncogene is consistently expressed in human pheochromocytomas and thyroid medullary carcinomas.
We have recently reported the identification of a new oncogene, named PTC, frequently activated in human thyroid papillary carcinomas. This gene is a novel rearranged form of the ret proto-oncogene and we have shown that this rearrangement occurred in vivo as a tumor-specific somatic event. In an effort to further examine the role of this oncogene in human malignancies, we have investigated the expression of the ret oncogene in a number of human tumors. We consistently detected expression of normal-sized transcripts of the ret proto-oncogene in human pheochromocytomas and in human medullary thyroid carcinomas (MTC), both of familial and sporadic type. Moreover, we showed that ret mRNA levels were increased following (Bu)2cAMP-induced differentiation of a human MTC cell line (TT). Since the ret gene has been mapped on chromosome 10, close to the gene which predisposes patients to the MEN2A syndrome, we suggest that this region of chromosome 10 might be involved in the proliferative and differentiative patterns of these neuroectodermal tissues.
Adrenal Gland Neoplasms↗
[Cyclosporin (CyA) and H2 antagonists].
An experimental study on rats in order to discovery any possible interaction between Ciclosporin (CyA) and H2-receptor antagonists has been carried out. The results obtained demonstrated that the serum levels of CyA were higher in rats treated with CyA and Cimetidine or Ranitidine, but not Famotidine. It is probable that the increase of ciclosporinaemia is the consequence of an increased hepatotoxicity due to administration of Cya in association with Cimetidine or Ranitidine.
Animals↗
Drug interaction between cyclosporin A and nizatidine in Sprague-Dawley rats.
The H2-receptor antagonists seem to be effective in prevention and treatment of stress ulcer in transplant recipients. In a previous study on rats, an increase was observed in cyclosporinaemia and hepatotoxicity after administration of cimetidine or ranitidine in association with cyclosporin A (CyA). On the contrary, famotidine does not influence the blood CyA levels. The aim of the study was to detect the possible synergistic nephro- and hepatotoxicity of nizatidine administered in association with CyA, assaying the serum creatinine, the ALT and AST levels, and histological features of thirty young male Sprague-Dawley rats, divided into 6 groups of five animals each. After 10 days, all the rats were sacrificed, their blood was collected to assay serum creatinine, ALT, AST and serum CyA levels: kidneys and livers were processed for light microscopy. The results obtained demonstrated that, while the level of creatinine was normal in each group, the average level of transaminase and the serum levels of CyA were significantly higher in the animals receiving the association of CyA and nizatidine. Furthermore, this group demonstrated a mild infiltrate of the liver characterized in some cases with eosinophilic polymorphonuclear cells. In light of the results obtained, it is probable that the increase of cyclosporinaemia is the consequence of an enhanced hepatotoxicity due to administration of CyA in association with nizatidine.
Animals↗
[Hemorrhoids: current therapeutic directions].
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Cryosurgery↗