Radiofrequency ablation for colorectal liver metastases

The management of hepatic metastases from colorectal cancer (HMCRC) is multimodal including chemotherapy, surgical resection, radiation therapy, and focused destruction technologies. Radiofrequency ablation (RFA) is the most commonly used focused destruction technology. It represents a therapeutic option that may be potentially curative in cases where surgical excision is contra-indicated. It also increases the number of candidates for surgical resection among patients whose liver metastases were initially deemed unresectable. This article explains the techniques, indications, and results of radiofrequency ablation in the treatment of hepatic colorectal metastases.

Excitatory action of vasopressin in the brain of the rat: role of cAMP signaling

Brain vasopressin plays a role in behavioral and cognitive functions and in pathological conditions. Relevant examples are pair bonding, social recognition, fear responses, stress disorders, anxiety and depression. At the neuronal level, vasopressin exerts its effects by binding to V1a receptors. In the brainstem, vasopressin can excite facial motoneurons by generating a sustained inward current which is sodium-dependent, tetrodotoxin-insensitive and voltage-gated. This effect is independent of intracellular calcium mobilization and is unaffected by phospholipase Cβ (PLCβ) or protein kinase C (PKC) inhibitors. There are two major unsolved problems. (i) What is the intracellular signaling pathway activated by vasopressin? (ii) What is the exact nature of the vasopressin-sensitive cation channels? We performed recordings in brainstem slices. Facial motoneurons were voltage-clamped in the whole-cell configuration. We show that a major fraction, if not the totality, of the peptide effect was mediated by cAMP signaling and that the vasopressin-sensitive cation channels were directly gated by cAMP. These channels appear to exclude lithium, are suppressed by 2-aminoethoxydiphenylborane (2-APB) and flufenamic acid (FFA) but not by ruthenium red or amiloride. They are distinct from transient receptor channels and from cyclic nucleotide-regulated channels involved in visual and olfactory transduction. They present striking similarities with cation channels present in a variety of molluscan neurons. To our knowledge, the presence in mammalian neurons of channels having these properties has not been previously reported. Our data should contribute to a better knowledge of the neural mechanism of the central actions of vasopressin, and may be potentially significant in view of clinical applications.

Deciphering the H-Ras pathway in Xenopus oocyte

Xenopus oocytes are arrested in prophase of the first meiotic division. In response to progesterone, they re-enter meiosis and arrest again in metaphase of the second meiotic division. This process, called meiotic maturation, is under the control of the Cyclin B-Cdc2 complex, M phase promoting factor (MPF). Injection of a constitutively active Xenopus H-Ras protein activates MPF, suggesting that Ras proteins could be implicated in the progesterone transduction pathway. The aim of this study was (1) to elucidate the pathway triggered by H-Ras leading to MPF activation in Xenopus oocytes and (2) to investigate whether endogenous H-Ras is involved in the physiological process of meiotic maturation. We generated three constitutively active double mutants, each of them recruiting a single effector in mammalian cells, mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K) or RalGDS. Our results show that the activation of a PI3K-related enzyme is crucial for H-Ras-induced MPF activation, whereas the recruitment of either MAPK or RalGDS is not. However, although the H-Ras/PI3K pathway is functional in Xenopus oocytes, it is not the physiological transducer of progesterone responsible for meiotic resumption.

From progesterone to active Cdc2 in Xenopus oocytes: a puzzling signalling pathway

Since almost two decades, it is known that progesterone is responsible of the release of the prophase I arrest of amphibian oocytes and leads to the activation of the universal MPF, through a puzzling transduction pathway. It involves negative regulation of the cAMP-dependent protein kinase (PKA) and synthesis of new proteins, among them the c-Mos protooncogene product. The implication of the Mos/mitogenic activated protein kinase (MAP kinase) pathway in Cdc2 activation has been extensively studied and is now at the centre of a controversial debate. In this paper, we discuss the current progress and our recent results on the molecular mechanisms allowing progesterone to activate MPF and propose a model to partly resolve the long-standing inconsistencies concerning the role of Mos/MAP kinase during this process.

[Surgical treatment of acute cholecystitis. A retrospective study of a series of 192 patients operated on over a period of 3 years]

Emergency conditions make laparoscopic treatment of acute cholecystitis challenging. The aim of this study is to retrospectively analyse our experience of cholecystectomy for acute cholecystitis performed between January 1995 and December 1997. In order to be included, patients had to present (i) symptoms of acute cholecystitis correlated with laboratory blood tests and ultrasonographic studies (ii) evidence of acute inflammation during the operation and (iii) histological confirmation of acute or subacute inflammation of the excised gallbladder. 192 patients were treated: 62 were totally managed laparoscopically (group CCN), 33 managed laparoscopically but required conversion to open cholecystectomy (group CCC) and 97 were managed conventionally by laparotomy (group CL). Mean age was significantly different between the three groups, (CCN: 55.6 +/- 15 years, CCC: 64.2 +/- 13 years, CL: 66.5 +/- 17 years), as was ASA score (CCN: ASA 3 and ASA 4: 16%, CCC: ASA 3 and ASA 4: 48%, CL: ASA 3 and ASA 4: 46%), and initial infectious signs (temp. > or = 38 degrees C: CCN: 35%, CCC: 39%, CL: 63%). Mean operative delay was significantly higher in the converted group [8.7 +/- 13 days (CCC) vs 4.5 +/- 8 days (CCN) and 5.4 +/- 8 days (CL)]. There were two (1%) bile duct injuries, one in the CCC group, the other in the CL group. Operative mortality was 2% (CCC: 0%, CCN: 0%, CL: 4%) and operative morbidity was 40% (CCN: 21%, CCC: 24%, CL: 57%). The mean postoperative hospital stay was shorter in the CCN group (6.5 +/- 3.5 days) and CCC group (9.6 +/- 4.4 days) vs the mean stay in the CL group (14.7 +/- 11.6 days). Appears to be beneficial for selected patients with low surgical risk to conclude laparoscopic cholecystectomy. It has yet to be shown whether this benefit can be extended to patients with a high surgical risk.

[Mucinous ductal ectasia of the pancreas]

We report a new case of mucinous ductal extasia of the pancreas observed in a 64-year-old man with a history of chronic exocrine failure. Diagnosis was obtained by CT, duodenal endoscopy and retrograde cholangio-pancreatography. Risk of malignant degeneration and increased CA 19-9 led to duodenopancreatectomy. Histology confirmed the diagnosis but revealed no malignant lesion. After a 3-year follow-up, the patient is in excellent health. Based on this observation and a review of the literature, we present the characteristic features of mucinous ductal ectasia of the pancreas.

Necrobiotic xanthogranuloma: a case without paraproteinemia but with transepithelial elimination

We report a female patient, now aged 60, followed for 20 years for lesions originally diagnosed as necrobiosis lipoidica diabeticorum. In fact, the anatomical and clinical features of her disorder correspond to the new entity described as necrobiotic xanthogranuloma. Two elements distinguish this from earlier cases: 1) two examinations failed to reveal paraproteinemia; 2) there was transepithelial elimination of cholesterol crystals and degenerated xanthomatous cell debris via hair follicles. This demonstrates the characteristic histology of the disorder and indicates that the diagnosis of necrobiotic xanthogranuloma should be considered even in the absence of paraproteinemia.

Eosinophilic fasciitis (Shulman syndrome) in association with morphea, immunological disturbance and profuse achromia

A case of localized eosinophilic fasciitis (EF) is reported. Profuse hypopigmentation, guttate morphea and immunological disturbances accompanied the subcutaneous changes. The case links Shulman's syndrome with classical localized cutaneous scleroderma.

Chloroquine-induced hypopigmentation of hair and freckles. Association with congenital renal failure

Hypopigmentation of hair and freckles occurred in a patient receiving chloroquine sulfate therapy. This patient had a severe congenital renal failure that presumably increased plasma and tissue levels of the drug substantially, accounting for the hypopigmentation.

[Mammary lymphatic scintiscans by intratumoral injection in the assessment of breast cancer. 105 examination in 100 patients (author's transl)]

One hundred and five scintiscans of the mammary lymphatic system were performed in 100 patients with breast cancer by intratumoral injection of 99 m Tc-labelled colloidal rhenium. The progression of the radioactive colloidal agent was followed on a series of films taken 1, 2 and 4 hours after the injection, and the images obtained were compared with post-operative findings of lymph node involvement. Patients with more than 3 carcinomatous lymph nodes had less than 2 foci of activity, while those with less than 3 carcinomatous lymph nodes had more than 2 foci of activity, owing to more rapid progression of the compound. The difference was highly significant (p less than 0,001).