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Biomedical subjects

D Pezet

Publications and source records attributed to D Pezet.

At least 19 recordsLinked to original sources

[Complementary tests in acute appendicitis].

The incidence of appendicectomy is high in France and this operation is performed in 15 to 45% of the cases for a histologically normal appendix. White blood cell count has a very good sensitivity but a bad specificity. The same observation goes for plain abdominal X-rays, the use of while must be limited in children and young women. Barium enema, frequently performed in anglo-saxon countries, show in 90 to 100% of the cases an abnormal image of the caecum or a lack of visualisation of the appendix. Ultrasounds visualize the appendix with a good sensitivity, provided there is no perforation. Laparoscopy is a good diagnostic tool, but must not be considered as a routine procedure. Studies of diagnosis scores show that, except for the white blood cell count, biological and radiological investigations are particularly interesting to eliminate another pathology.

Acute Disease

Status of sex steroid hormone receptors in large bowel cancer.

To determine the potential role of sex steroid hormones in the development of colorectal tumors in humans, specific androgen (AR), estrogen (ER), and progesterone (PGR) receptors were investigated in normal mucosa (NM) and in tumor (T) paired biopsy specimens from 94 patients. Androgen receptors were detected in 98% and 96% of NM and T samples, ER in 91% and 83% of NM and T biopsy samples, whereas PGR were detected only in 14% and 10% of NM and T specimens, respectively. These incidences are independent of the sex and age of the patients. They are not related to tumor localization, histologic grade, or stages of Dukes' classification. Scatchard analysis of labeled ligand binding indicated the existence of one single class of high affinity binding sites; the calculated dissociation constant (Kd) was 1.7 +/- 0.6 10(-9) molar concentration (M) for 5 alpha-dihydrotestosterone (DHT) and 0.6 +/- 0.3 10(-9) M for estradiol (E2). These values were identical in NM and T tissue for both AR and ER. The binding capacity for DHT was 148 +/- 67 and 93 +/- 43 fmol/mg of cytosol protein in NM and T tissues, respectively (P less than 0.05). The ER content was lower and similar in NM and T biopsy specimens: 19 +/- 9 and 18 +/- 10 fmol/mg protein, respectively. The PGR content was 10 +/- 4 in NM versus 17.5 +/- 6 fmol/mg protein in T specimens. It is observed that the elevated AR in normal mucosa is not related to any known function for androgens in the digestive tract. The receptor pattern observed in tumors does not support the hypothesis previously raised in the case of chemically induced colonic tumors in rodents.

Adenocarcinoma

1,25-Dihydroxyvitamin D3 receptors and human colon adenocarcinoma.

Epidemiological evidence suggests that dietary calcium and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) might have a protective effect against colorectal cancers. Since the presence of receptors is required for steroid action, specific 1,25-(OH)2D3 receptors (RD3) were investigated in biopsies taken at different levels of the colon. The study involved 90 biopsies from patients operated on for colorectal adenocarcinoma. They were paired biopsies from adenocarcinoma tissue and adjacent normal mucosa. In addition, 26 normal intestinal mucosa biopsies from patients without cancer were examined. RD3 receptors were assayed in tissue extract by the dextran-coated charcoal technique and also characterized by sucrose density gradient sedimentation. Scatchard analysis showed a single class of specific high affinity-low capacity sites binding for 1,25-(OH)2D3. The incidence of RD3 was 86 per cent in normal mucosa (n = 77) and lower in carcinoma (n = 34), for which the incidence decreased significantly (P less than 0.001) from right colon (58 per cent) to left colon (37 per cent) and rectum (19 per cent). These data suggest that the normal colon is a potential target organ for 1,25-(OH)2D3 which might modulate calcium transport in the colon. Loss of receptivity to 1,25-(OH)2D3 is associated with malignant transformation.

Adenocarcinoma

[Diagnostic and therapeutic strategy in acute pancreatitis].

The diagnostic and therapeutic management of acute pancreatitis (AP) is directly related to the severity of the initial attack. Mild AP usually subsides spontaneously. On the other hand, severe AP requires admission to an intensive care unit and supportive care for multiple organ failure. During the second phase of the disease, repeated CT scans with the routine use of percutaneous fine needle aspiration and drainage allows both diagnosis and treatment of pancreatic abscesses. However, infected necrosis usually requires surgical drainage. The treatment of acute biliary pancreatitis must be performed during the same admission for mild AP. In contrast, it seems better to postpone any kind of surgical treatment in the severe forms of gallstone pancreatitis. The efficacy of endoscopic sphincterotomy has not yet been demonstrated.

Acute Disease

Evidence of 1,25-dihydroxyvitamin D3-receptors in human digestive mucosa and carcinoma tissue biopsies taken at different levels of the digestive tract, in 152 patients.

Epidemiological and experimental data suggest that dietary calcium and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) are protective against colorectal cancers, while their activity on colon mucosa still remains unknown. Since the presence of receptors is required for steroid action, specific 1,25-(OH)2D3 receptors were investigated in biopsies taken at different levels of the digestive tract from the oesophagus to the rectum and in pancreas. The total study involved biopsies from 152 patients. In 82% of the cases they were paired biopsies in adenocarcinoma tissue and in adjacent normal mucosa (NM). There were 120 operated on for colorectal adenocarcinoma (HCRA). 1,25-(OH)2D3 receptor was assayed in tissue extract by the dextran-coated charcoal (DCC) technique and also characterised by sucrose density gradient centrifugation. Scatchard analyses showed a single class of specific high affinity-low capacity sites binding for 1,25-(OH)2D3 with a Kd = 1.48 +/- 0.8 x 10(-10) M (n = 119). The sedimentation coefficient of the steroid receptor complex was approximately 3.2 S. The incidence of 1,25-(OH)2D3 receptors was significantly higher in NM (82.5%) than in HCRA (34.5%). In HCRA this incidence decreased from right colon (64.7%) to left colon (27.7%) and rectum (15%). All positive HCRA in left colon and rectum (16/76) were histologically well differentiated. The receptor content in NM and HCRA was in the same range: (median) 10-314 (58) and 13-175 (64) fmol/mg protein. These data suggest that 1,25-(OH)2D3 may modulate calcium transport in colon, as in the intestine. Also, loss of receptivity to 1,25-(OH)2D3 is observed as associated with malignant transformation of the human colorectal mucosa.

Biopsy

[Comparative study of the content of 1,25-dihydroxyvitamin D3 receptors in digestive mucosa and adenocarcinoma].

We have studied and compared the 1,25-dihydroxyvitamin D3 receptor (RD3) content of 154 human digestive carcinoma with the normal mucosa one, removed at distance from the same surgical specimen. The distribution of biopsies is as follows: 5 oesophagus, 10 stomach, 6 small bowel, 35 right colon, 47 left colon, 40 rectum and 11 pancreas. RD3 were measured by the Dextran Coated Charcoal method and characterized by sucrose gradient ultracentrifugation. One single class of high affinity binding sites (kD = 1.5 +/- 0.7 x 10(-10) M) was defined, with a sedimentation coefficient of approximately 3.4 S. The RD3 was present in the 6 samples of small bowel and in 82% of whole normal mucosa, whatever their localization along the digestive tract and pancreas, while in the tumoral tissue, the RD3 was positive in only 32% of the cases. In these tumor specimens the incidence decreases from 64% in the right colon to 27% in the left colon and only 15% in the rectum (P less than 0.001). RD3 rates vary slightly with the localization and are of the same level in normal tissues and in tumors: 10-314 (median = 59) vs 13-175 (median = 64) (P greater than 0.005) respectively. No significative variations relating to age or sex of patients were found. However, all RD3 positive tumors from left colon and rectum were well differentiated histologically. These results show that the normal colonic mucosa is a potential target for 1,25-dihydroxyvitamin D3, which can play a role in the metabolism of calcium and other ions. They also suggest that vitamin D3 could be a modulator of colorectal cell growth and differentiation and its receptor is frequently lost during malignant transformation.

Adenocarcinoma

[Retroperitoneal perforation of duodenal ulcer responsible for abscess].

The authors report a case of retroperitoneal perforation of a duodenal ulcer. This is a rare condition which is exceptionally responsible for abscess formation. If often has a poor prognosis. In the present case, the abscess was infrahepatic. The diagnosis of the origin of the abscess was established by radiological opacification via percutaneous puncture. Surgical drainage and irrigation performed via an extraperitoneal approach centered over the cavity, combined with triple-agent antibiotic therapy (penicillin, gentamicin, metronidazole) ensured collapse followed by sterilisation of the abscess cavity. The ulcer was cured by medical treatment. This case differs from the published case in terms of the diagnostic procedures classically used (upper gastrointestinal endoscopy and small bowel series), the infrahepatic site of the abscess and the extraperitoneal surgical treatment which avoided dissemination to the peritoneal cavity.

Abscess

[Sarcomatous recurrence of leiomyoma of the inferior vena cava].

In a 63-year old woman, a surgically removed leiomyoma of the inferior vena cava recurred, 4 years later, as a leiomyosarcoma. These two smooth muscle tumours, one benign the other malignant, seldom involve the inferior vena cava. Both produce few clinical symptoms and therefore are belatedly diagnosed, except for suprarenal or retrohepatic lesions which rapidly exhibit signs of compression. Computerized tomography, angioscans and cavography are necessary to make a provisional diagnosis and determine the operative strategy. The differential diagnosis between leiomyoma and leiomyosarcoma rests on cellular or nuclear atypias, mitotic index and sometimes cytological and staining details showing the myofibril. These tumours develop slowly in the renal segment. Treatment is primarily surgical. The case reported here raises the problem of the leiomyoma-leiomyosarcoma sequence: are we confronted with degeneration, or is there such a thing as a smooth muscle fibre disease?

Diagnosis, Differential

[Spontaneous hepatic hematoma during pregnancy].

Spontaneous hepatic haemorrhage is a rare complication in pregnancy. It usually occurs in multiparous women who have toxaemia of pregnancy. We give a case history of a primigravid patient who was not toxemic. The hepatic haemorrhage presented as blood in the peritoneal cavity which in turn gave rise to abdominal pain with hypovolaemic shock. The surgical treatment consisted in removing the segment of the liver that had been bleeding. The physiopathology of hepatic haemorrhage as described in the literature shows that there was evidence of consumptive coagulopathy with coalescence of periportal areas of liver necrosis. Treatment therefore is that of hepatic trauma. Maternal mortality runs at 70%.

Adult

[Mediastinoscopy in the evaluation of the operability of bronchial cancer].

Mediastinoscopy is an invasive technique used to explore the anterior and upper mediastinum. The axial mediastinum and its lymph nodes are explored through the cervical approach, and the pulmonary vessels and anterior mediastinal lymph nodes through the parasternal approach. Bronchial carcinomas which extend to the mediastinum, either via the lymphatic system or by contiguity, are of extremely severe prognosis. The advent of mediastinoscopy has considerably reduced the number of exploratory thoracotomies and therefore the operative mortality rate, while increasing the resectability rate to 95%. It has also narrowed the indications for surgery without decreasing the number of curative resections. In the hands of experienced operators, the technique has a low morbidity rate. CT examination is not as accurate as mediastinoscopy to evaluate the mediastinal extension of bronchial carcinomas, but it can help to lay down the indications for the invasive technique, thereby limiting its use to selected cases.

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