Mode of chemotherapy does not affect complications with an implantable venous access device

BACKGROUND: Few reports have been made regarding the long term safety of implantable venous access devices used for the delivery of chemotherapeutic agents. The authors' goals were to determine the frequency of complications in patients receiving chemotherapy with these devices; to determine whether complications were associated with the mode of chemotherapy delivery (push/bolus or infusional regimens); and to evaluate the influence of other risk factors, including home-based versus hospital-based administration. METHODS: A total of 152 oncology patients at the John L. McClellan Memorial Veterans Administration Medical Center in Little Rock, Arkansas (ages 26-81 years; mean age, 62 years), who underwent surgical placement of an Infus-a-Port (Strato, Inc., Beverly, MA) between May 1, 1992 and May 31, 1994, were evaluated retrospectively for postplacement device complications, such as infection, thrombosis, and mechanical failure. RESULTS: Twenty-seven patients experienced 1 complication each: 17 episodes of device-related sepsis, cellulitis, or fever of unknown origin; 8 episodes of thrombosis or catheter occlusion; 1 episode of drug extravasation; and 1 mechanical failure. Patient age, frequency of port accession, mode of chemotherapy delivery, tumor type, and neutropenia were evaluated as risk factors, but none was statistically significant. Complications were more frequent during the first 90 days after implantation, but they continued to occur throughout the observation period. CONCLUSIONS: Complications attributable to an implantable venous access device were infrequent in this patient population. No differences in complications for patients receiving home-based versus hospital-based chemotherapy administration were noted, opening the possibility of significant time and cost savings with home treatment.     

Ascorbic acid stimulates chloride transport in the amphibian cornea

The cornea of the toad, Bufo marinus, actively transports chloride from the endothelial to the epithelial surface. This transport process has been related to the maintenance of the normal transparency of the cornea. Ion transport, as evidenced by the short-circuit current (SCC), is markedly stimulated by physiologic concentrations of ascorbic acid. Measurement of the unidirectional fluxes of 36Cl and 22Na shows that the increase in SCC is due primarily to a stimulation of the active transport of chloride.     

Transcrystalline morphology of nylon 6 on the surface of aramid fibers

In this paper, the isothermal crystallization of nylon 6 in the presence of Kevlar 129 fiber was investigated by polarized optical microscopy (POM). The formation of a transcrystalline domain was found to be mainly controlled by crystallization conditions, such as the temperature of the isothermal crystallization, residual time at melting temperature and the cooling rate of the melt. The nucleation rate of nylon 6 on the fibers was mainly affected by the crystallization temperature. The interfacial transcrystallinity of nylon 6 occurred on the surface of Kevlar 129 fiber in the temperature range 130–190 °C. The reason for the formation of interfacial transcrystalline morphology is discussed from the molecular level, based on the understanding of the packing mode of nylon 6 chains around fibers and the interaction between matrix and fibers. It was found that the lattice matching and hydrogen‐bonding between nylon 6 and poly(p‐phenylene terephthalamide) (PPTA) crystals play an important role in the epitaxial crystallization. Copyright © 2004 Society of Chemical Industry     

Poisoning and overdose

The differential diagnosis of all patients with altered mental status must include drug toxicity. In particular, intentional or unintentional overdosing and/or poisoning are common emergency department presenting complaints. A comprehensive approach to managing these patients must incorporate aggressive information gathering, a careful physical examination looking for toxic syndromes, and diagnostic testing. Proper decontamination is the key to effective management, as is the use of specific antidotes when indicated.     

Partial splenic embolization for treatment of disseminated intravascular coagulation in lymphangiomatosis

A 1-year-old boy presented with pericardial effusion, pulmonary infiltrates, and disseminated intravascular coagulation; lung biopsy indicated pulmonary lymphangiomatosis. He did not respond to medical therapy and was a poor surgical candidate; therefore, he underwent partial splenic embolization. The procedure resulted in a complete disappearance of the DIC and marked improvement in his cardiorespiratory status. He continues to thrive and is transfusion-independent 2 years after the procedure.     

A combined COMPACT and HazardExpert study of 40 chemicals for which information on mutagenicity and carcinogenicity is known, including the results of human epidemiological studies

The COMPACT approach for defining structural criteria for substrates and inducers of cytochrome P450 (CYP) enzymes which mediate the formation of reactive intermediates is discussed in the context of prediction of potential carcinogenicity. This is broadened to encompass structural studies on mammalian P450s, including those relevant to genetic polymorphism in man. The use of the COMPACT system, in parallel with the structure alert program HazardExpert (now incorporated into the Pallas system), for evaluating human carcinogenicity data is reported, as an example of the possible employment of a battery of short-term test procedures for safety evaluation. In particular, the importance of using the log P value (as a measure of compound lipophilicity) to assess the likelihood of a potentially toxic compound reaching the site of activation, is emphasized by the finding that most procarcinogens requiring metabolic activation by P450s are lipophilic in nature.