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Biomedical subjects

S Métairie

Publications and source records attributed to S Métairie.

7 recordsLinked to original sources

Controlled release of proteins from degradable poly(ether-ester) multiblock copolymers.

A new series of multiblock poly(ether-ester)s based on poly(ethylene glycol) (PEG), butylene terephthalate (BT) and butylene succinate (BS) segments were introduced as matrices for controlled release applications. The release of two model proteins, lysozyme and bovine serum albumin (BSA), from poly(ether-ester) films were evaluated and correlated to the swelling and degradation characteristics of the polymer matrices. First- and zero-order profiles were found for the release of lysozyme, depending on the composition of the polymer matrix. The initial diffusion coefficient was correlated to the swelling of the matrix, which increased with longer PEG segments and lower BT/BS ratios of the polymer. High swelling matrices released the lysozyme according to diffusion-controlled first-order release profiles. Zero-order release profiles were obtained from less swollen matrices due to a combination of diffusion and degradation of the matrix. In contrast to the release of lysozyme, BSA was released from the poly(ether-ester) matrices via delayed release profiles. Both the delay time and the release rate could be tailored by varying the matrix composition. The BSA release rate was mainly determined by the degradation, whereas the delay time was determined by a combination of the swelling and the degradation rate of the polymer matrix.

Diffusion↗

[Intra-hepatic cholangiocarcinoma].

Intra-hepatic cholangiocarcinoma (IHCC) is a rare tumor which arises from the epithelial cells of the intra-hepatic bile ducts; it may develop in a healthy liver and bile ducts or in bile ducts with malignant predisposition (Caroli's syndrome, primary sclerosing cholangitis). It has the worst prognosis of any tumor arising in the liver. Unlike hepatocellular carcinoma, no predisposing factors or high-risk populations have been demonstrated for cholangiocarcinoma other than intraphepatic choledocholithiasis such as is seen in east Asian populations. The most common clinical sign is a palpable tumor mass emphasizing that the tumor is usually detected at an advanced stage. CT scanning yields much clinical information but ultrasound-guided needle biopsy is necessary for diagnosis. Aggressive surgical resection is the only treatment modality which has afforded even slight prolongation of survival; hepatic resection must be large with uninvolved resection margins. When an IHCC is deemed resectable (localized tumor without hepatic metastases or intrahepatic or extrahepatic lymph node spread), pre-operative tumor embolization may be useful; when jaundice is present, percutaneous drainage of the dilated biliary system of the liver to be spared may also be necessary. Neither adjuvant nor neo-adjuvant chemotherapy or radiotherapy have shown proof of efficacity. Cholangiocarcinoma complicates sclerosing cholangitis in 10-15% of cases and is very difficult to diagnose. IHCC may also develop in Caroli's syndrome, where it is commonly found incidentally on pathologic examination of a resection specimen after surgery for a complication of the disease.

Bile Duct Neoplasms↗

Biodegradable poly(ether-ester) multiblock copolymers for controlled release applications.

Multiblock poly(ether-ester)s based on poly(ethylene glycol), butylene terephthalate, and butylene succinate units were synthesized by a two-step melt polycondensation reaction, with the aim of developing a new series of degradable polymers for controlled release applications. The copolymers were characterized with respect to their composition (NMR), thermal properties (DSC), and swelling. The main focus was on the degradation kinetics and release properties of the copolymers. The crystallinity and swelling could be tailored by the PEG segment length and the ratio of the building units. With increasing mol fraction succinate in the hard segment, the swelling increased. The in vitro degradation was found to occur by molecular weight decrease and mass loss. Substitution of the aromatic terephthalate units by aliphatic succinate units increased the degradation rate of the copolymers. Polymers with PEG segments of 1000 kg/mol showed a more pronounced degradation than copolymers containing shorter and longer PEG segments. Model proteins were successfully incorporated and released from the poly(ether-ester) films. Depending on the size of the protein, the release mechanism was based on diffusion of the protein and degradation of the matrix.

Animals↗

Rupture of internal iliac artery aneurysm into the bladder following aortic aneurysm repair.

This report describes a case of ruptured internal iliac artery aneurysm into the bladder after repair of an infrarenal abdominal aortic aneurysm. Aortic repair consisted of resection of the aneurysm followed by prosthetic interposition to reestablish arterial continuity. During the postoperative period, the patient had ischemia of left colon, which was successfully treated by the Hartmann procedure. A right internal iliac artery aneurysm measuring 50 mm in diameter was demonstrated by an abdominal CT scan during the initial hospitalization but was considered stable, since ultrasonography showed no change in diameter at 3 months and 1 year. The patient was lost from follow-up until 3 years later when he was hospitalized after rupture of the right iliac artery aneurysm, then measuring 120 mm in diameter, into the bladder. Surgical repair was undertaken. The procedure involved aortobifemoral bypass with suture of the bladder defect and branches of the internal iliac artery by the endoaneurysmal route. Postoperative recovery was uneventful. Upon reexamination 1 month after discharge from the hospital, the patient was asymptomatic. This rare case confirms the gravity of internal iliac artery aneurysm and the importance of therapeutic management to prevent rupture.

Aged↗

[Colorectal endometriosis. Diagnosis and management].

Endometriosis occurs in 5 to 10% of the female population. Bowel involvement present in 6 to 30% of cases is predominantly localized in the pelvic parts of the colon and rectum, close to the uterus. The goal of this work was to describe the present diagnostic and therapeutic management of deep colorectal endometriosis defined as infiltrating the digestive wall and usually requiring surgery. Colorectal endometriosis is a disabling disease. Anatomic lesions mimic those of a cancer. Modern investigations include endorectal endosonography, recognized as the best mean to assess the depth of invasion into the intestinal wall, and magnetic resonance imaging. Associated to exploratory laparoscopy, these investigations allow to select the optimal operative strategy for multifocal and complex lesions. Surgical objective is a total resection of endometriomas, to guarantee symptom relief and avoid recurrence. Difficulties in these procedures are usually due to fibrotic and vascularised lesions and associated gynaecological disorders. In elective cases, preoperative GH-RH analog hormonal treatment makes easier the surgical procedure. Colonic and/or rectal restorative resections, performed through laparoscopic approach or more frequently through laparotomy, have to be done according to the usual standards of colorectal surgery. Conservative surgery of the ovaries is mandatory in premenopausal patients.

Colorectal Neoplasms↗

[Femoral hernia].

A femoral hernia descends through the femoral canal beneath the inguinal ligament. Rare in man, it occurs in women over 50. It can be difficult to recognize and any symptoms of the groin may rise the diagnosis. Strangulation is a frequent (often first) manifestation of femoral hernia. Early diagnosis is important to avoid intestinal resection, a source of morbidity and mortality. Surgical treatment is mandatory for all diagnosed femoral hernia.

Aged↗