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The article discusses the safety, efficacy and cost for rotavirus vaccine improvement and its adoption in low- and middle-income countries. It mentions that concerns from the experts regarding vaccine-related risks led to the demise of the rotavirus vaccine in the market. It informs that the vaccine is helpful in preventing diarrheal disease but only a few countries have adopted this vaccine in their national immunization programs in spite of World Health Organization (WHO) recommendations.

Presents a letter to the editor commenting on the article "Ethics: A Weapon to Counter Bioterrorism," published in the March 25, 2005 issue of the journal "Science."

Presents a letter to the editor about bioterrorism countermeasures.

The threat of bioterrorism has prompted the U.S. to undertake a vast biodefense initiative, including funding biodefense-related scientific research at unprecedented levels. Unfortunately, the many ethical, economic, environmental, legal, and social implications (E(3)LSI) of biodefense research and activities are not yet receiving the attention they warrant. Previously, in laudable demonstrations of foresight and responsibility, the federal government has funded research into the E(3)LSI of other recent scientific endeavors--namely, the Human Genome Project and the nanotechnology research program--through directed appropriations from their respective research budgets. This article advocates and proposes a model for a portion of biodefense funding to be similarly set aside for an E(3)LSI research program to complement biodefense research, to ensure that bioterror preparedness does not give rise to harmful or otherwise undesirable unintended consequences.

Resistance to antibody-based anticancer approaches has become of considerable interest because of the rapidly growing clinical use of several different monoclonal antibodies as therapeutic agents, coupled with the recent finding that their efficacy may be attributable in part to their participation in host antibody-dependent cellular cytotoxicity. In this proof-of-concept study, we demonstrate the novel ability of an antiadhesive antibody (SHE78-7), targeted at the potent homophilic cell adhesion molecule E-cadherin, to play a dual role as participant in, and sensitizing agent for, host immune-mediated antitumor activity. SHE78-7 disrupted preformed multicellular aggregates (spheroids) of HT29 colon carcinoma cells both in vitro and in vivo in an ascites tumor xenograft model, but had no direct antitumor effect in vitro. In vivo, however, i.p. injection of SHE78-7 significantly prolonged the survival of nude mice carrying established i.p. HT29 xenografts, most notably when injections were given biweekly. This antitumor effect was dependent on the antiadhesive effect of SHE78-7 and could be effectively recapitulated via treatment with a combination of nondisruptive anti-hMHC-I antibodies, capable of recruiting an F(c)-mediated immune response but ineffective as a monotherapy and antiadhesive F(ab')(2) fragments of SHE78-7. Furthermore, additional therapy experiments using such F(ab')(2) fragments, or mice lacking activating F(c)gammaRIII receptors or inhibitory F(c)gammaRIIB, unequivocally indicated a role for host antibody-dependent cellular cytotoxicity, mediated by F(c)gammaRIII and negatively regulated by F(c)gammaRIIB. Taken together, the results suggest a possible means of improving antibody-based therapies of cancer, namely targeting antigens, selectively expressed or up-regulated by target cancer cells, which mediate cell-cell adhesive functions.

A number of recent preclinical studies have sparked interest in the concept of exploiting conventional chemotherapeutic drugs as antiangiogenics. Such antiangiogenic activity is achieved or optimized by metronomic-dosing protocols in which the drug is given at comparatively low doses using a frequent schedule of administration (e.g., once to three times per week) with no breaks, particularly when combined with an endothelial cell-specific antiangiogenic drug. The use of p.o. chemotherapeutic drugs is particularly suitable for this type of treatment strategy. We tested one such drug, cyclophosphamide (CTX), in a protocol wherein the drug was administered to mice at low doses, of approximately 10-40 mg/kg on a daily basis through the drinking water. CTX is typically given p.o. to patients, but it has almost always been injected when treating preclinical mouse tumor models. We found p.o. CTX to be a safe and convenient treatment with significant antitumor efficacy. Growth delays were observed for human orthotopic breast or ectopic colon cancer xenografts in nude or SCID mice. Established PC3 human prostate tumor xenografts could be induced to almost fully regress, remaining virtually nonpalpable for > or =2 months of continuous therapy, after which tumors began to grow progressively. These re-emergent tumors were not found to be drug resistant when tested in new hosts, using the same treatment protocol. Regression of spontaneously arising, late-stage pancreatic islet cell carcinomas in Rip Tag transgenic mice was also observed. The effects of continuous p.o. CTX treatment were enhanced significantly in an orthotopic, metastatic breast cancer xenograft model when used in combination with an antivascular endothelial growth factor receptor-2 blocking antibody. Maximum tolerated dose levels established for other mouse strains proved highly toxic to SCID mice, whereas daily p.o. low-dose regimens of CTX were well tolerated. Taken together, the results demonstrate the feasibility of delivering CTX in a p.o. metronomic chemotherapy regimen, which proved safe, reasonably efficacious, and potentially applicable to chronic treatment. Such a regimen may be particularly well suited for integration with antiangiogenic drugs.

One of the greatest barriers to the treatment of cancer with chemotherapeutic drugs is acquisition of drug resistance. This includes multidrug resistance mediated by P-glycoprotein (Pgp) to multiple lipophilic natural compounds such as taxanes, doxorubicin (Adriamycin), and vinblastine. The considerable efforts made thus far to reverse this and other types of drug resistance have had very limited success. We report here that a variety of orthotopic human breast cancer xenografts selected for high levels of Pgp and multidrug resistance respond in a significant and durable manner to different continuous low-dose (e.g., one-tenth the maximum tolerated dose of chemotherapy) chemotherapy regimens, when used in combination with an antivascular endothelial cell growth factor (anti-VEGF) receptor-2 (flk-1)-neutralizing antibody (DC101). The Pgp substrates paclitaxel (Taxol), Adriamycin, and vinblastine were all effective using this type of combination treatment, although the chemotherapy protocols showed little or no effect as monotherapies. Similar results were also obtained using cisplatinum (a non-Pgp substrate drug) against cisplatinum-resistant tumors. Evidence of significant tumor cell death by the combination treatment was detected within 3 weeks of initiation of therapy by histopathological analysis, in the absence of shrinkage of tumor mass. There were, however, marked differences in the cumulative toxicity of long-term regimens of Adriamycin and cisplatinum, where toxicity was observed, when compared with the tubulin inhibitors, vinblastine and Taxol, where it was not. We conclude that vascular-targeting protocols involving frequent administration of very low doses of certain chemotherapeutic drugs can provide a stable and safe way to circumvent multidrug resistance in established orthotopically growing tumors, as long as these are used in combination with a second antiangiogenic drug, in this case, anti-VEGFR-2 blocking antibodies.