A systematic review to assess the management of patients with cerebral metastases secondary to colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) rarely metastasizes to the brain. The incidence of cerebral metastases (CM) is estimated between 1 and 3%. Given the improved survival from advanced CRC as a result of surgical and oncological advances, it is anticipated that the incidence of patients with CM from CRC will rise over the next few years. The aim of this article was to systematically review the treatment options and outcome of patients with CM from CRC. METHODS: PubMed and Medline databases were examined using the search words or MESH headings "colorectal" "cancer/carcinoma/adenocarcinoma", "cerebral"/"brain" and "metastases/metastasis". RESULTS: CM from CRC are diagnosed on average 28.3 months after the primary tumour. The median survival time following diagnosis is 5.3 months. Surgery (with or without associated radiotherapy), stereotactic radiosurgery, whole brain radiotherapy and best supportive care result in median survival of 10.3, 6.4, 4.4 and 1.8 months, respectively. On average, the 1-year overall survival rate for patients with CM from CRC regardless of the treatment modality is estimated to be around 24%. CONCLUSIONS: The prognosis of patients with CM from CRC is dismal. Surgery may increase survival, but the additional benefit of perioperative radiotherapy cannot be ascertained due to paucity of data. Further studies are required to identify the role of the different oncological and surgical therapies and identify those patients likely to benefit most. Identification of patients who are at higher risk of developing brain metastases may be another important area for future research.

ASExpert: an integrated knowledge-based system for activated sludge plants.

The activated sludge process is commonly used for secondary wastewater treatment worldwide. This process is capable of achieving high quality effluent. However it has the reputation of being difficult to operate because of its poorly understood biological behaviour, variability of input flows and the need to incorporate qualitative data. To augment this incomplete knowledge with experience, knowledge-based systems were introduced in the 1980s however they didn't receive much popularity. This paper presents the Activated Sludge Expert system (ASExpert), which is a rule-based expert system plus a complete database tool proposed for use in activated sludge plants. The paper focuses on presenting the system's main features and capabilities to revive the interest in knowledge-based systems as a reliable means for monitoring plants. Then it presents the methodology adopted for ASExpert validation along with an assessment of testing results. Finally it concludes that expert systems technology has proved its importance for enhancing performance, especially if in the future it is integrated to a modern control system.

Halothane hepatitis without halothane: role of inapparent circuit contamination and its prevention.

Halothane and other halogenated anesthetic agents are liquids which are highly soluble in rubber and plastic materials widely used as components of anesthesia machines. These agents must be administered using machines equipped with vaporizers. We report a patient with a past history of halothane hepatitis in whom recurrence was suspected despite the fact that halothane had been avoided purposely during the subsequent operation. Circumstances led us to believe that inapparent circuit contamination of vaporizer-equipped anesthesia machine with halothane may be responsible for the inadvertant rechallenge and recurrence of halothane hepatitis. Vaporizer-equipped machines were tested for inapparent contamination with halothane and enflurane using Perkin-Elmer mass spectrometer. Oxygen alone was passed through the anesthesia circuits, and gas in the efferent limbs of the machines was tested for halothane (in eight machines) and enflurane (in two machines) which were found in various concentrations in all machines so tested. Our findings suggest that inapparent contamination may be widely prevalent in vaporizer-equipped anesthesia machines. The validity of this conclusion was confirmed in five patients with previous diagnosis of halothane hepatitis who subsequently underwent operations under general anesthesia during which machines never equipped with vaporizers were successful in preventing recurrence of hepatitis. We conclude that patients with a prior history of halothane hepatitis are at risk of inapparent circuit contamination-induced recurrent hepatitis. Unless such contamination can be confidently excluded, vaporizer-equipped machines should not be used to administer general anesthesia in these susceptible patients.

Mirizzi syndrome.

A 56-year-old woman was admitted to the hospital because of icterus and pruritus of 1 month duration. During her evaluation, endoscopic retrograde cholangiography revealed large cystic duct stones causing partial obstruction of the common hepatic duct. Successful management was accomplished with choledochojejunostomy and T-tube decompression. The case herein reported illustrates the typical clinical presentation and radiographic features of the Mirizzi syndrome.

Bilateral nipple necrosis after intravenous vasopressin therapy.

Bilateral nipple necrosis developed in two patients after intravenous vasopressin therapy for bleeding esophageal varices. When vasopressin therapy was promptly tapered and discontinued, recovery of skin changes occurred gradually. The role and some of the reported complications of vasopressin therapy in bleeding esophageal varices are discussed herein.

Focal nodular hyperplasia associated with the use of a synthetic anabolic androgen.

An adolescent with stunted growth was treated for 6 months with a synthetic anabolic androgen. During his evaluation for right upper quadrant pain an abnormal liver scan demonstrated what proved to be a hypervascular hepatic lesion. At surgery, the diagnosis of focal nodular hyperplasia was established. Herein we document the unusual association of focal nodular hyperplasia with use of a synthetic anabolic androgen.

Successful medical management of a Yersinia enterocolitica liver abscess.

An insulin-dependent diabetic patient with liver abscess secondary to Yersinia enterocolitica without septicemia is described. He had the diagnosis established by transhepatic needle aspiration of the abscess cavity. Successful management was accomplished with antibiotic therapy alone.

Kinetics of calcium transport in the hamster duodenum and ileum.

Dietary calcium is absorbed chiefly from the small intestine, and characteristics of the transport process differ depending on site. Because transport behavior is crucial to calcium homeostasis, we characterized kinetics of duodenal and ileal calcium transport in vivo in the hamster. We measured net calcium transport with 40Ca and flux into the animal (influx) with 45Ca over the concentration range of 0- 25 mM. Nonmediated transport was twice as great in duodenum as in ileum. Mediated transport showed Michaelis-Menten kinetics. Kt for mediated transport (4.3 mM) was the same in duodenum and ileum, whereas Vmax (mumol/h per g) was twice as great in ileum (290) as in duodenum (137). Thus, Kt defines similar carrier function at both sites, but Vmax suggests calcium transport capacity is doubled in ileum. The lower nonmediated transport in ileum limits secretion and the higher Vmax absorbs calcium at a greater rate, permitting the ileum to move luminal calcium against a concentration gradient more effectively than the duodenum. Thus, ileal calcium transport, by its site and functional characteristics, makes a crucial contribution to calcium homeostasis in the hamster.