Thrombocytopenia: the good,the bad and the ugly

New thrombocytopenia may be associated with a variety of conditions and diagnosis can be challenging. Presentation can vary from life-threatening bleeding or thrombosis to an incidental finding in an asymptomatic patient. New thrombocytopenia requires urgent investigation. Investigations are mainly guided by findings from the clinical history, physical examination, full blood count and blood film analysis. Aside from the actively bleeding patient, rare but life-threatening causes of thrombocytopenia must be identified early as they require urgent treatment. These include thrombotic thrombocytopenic purpura, disseminated intravascular coagulation, suspicion of new acute promyelocytic leukaemia, and vaccine-induced prothrombotic immune thrombocytopenia. Here, we discuss how to approach a patient with new thrombocytopenia, along with key differentials not to be missed.KEYWORDS: thrombocytopenia, thrombosis, bleeding, platelets, haematology     

Smallpox vaccine: the good, the bad, and the ugly

Smallpox inarguably shaped the course of human history by killing countless millions in both the Old World and the New World. Dr. Edward Jenner's discovery of vaccination in the late 18th century, and the global eradication of smallpox in the 1970s, rank among the greatest achievements in human history. Amidst recent growing concerns about bioterrorism, smallpox vaccination has resurfaced from the history books to become a topic of major importance. Inoculation with vaccinia virus is highly effective for the prevention of smallpox infection, but it is associated with several known side effects that range from mild and self-limited to severe and life-threatening. As the United States moves forward with plans to vaccinate selected health care workers and the military, and perhaps offer the vaccination to all citizens in the future, it is important to fully understand and appreciate the history, risks, and benefits of smallpox vaccination.     

The good,the bad and the ugly: how altered peptide ligands modulate immunity

Background: The basis of T cell immune responses is the specific recognition of an immunogenic peptide epitope by a T cell receptor. Peptide alterations of such T cell epitopes with single or few amino acid variations can have drastic effects on the outcome of this recognition. These altered peptide ligands can act as modulators of immune responses as they are capable of downregulating or upregulating responses. Objective/methods: We review how altered peptide ligands can have ‘good’ ‘bad’ and ‘ugly’ outcomes in treating diseases. Results/conclusion: Altered peptide ligands have been used as immunotherapeutics in autoimmune (and allergic) diseases, infectious diseases and cancer. In the next five years we anticipate seeing a number of altered peptide ligands in clinical trials, progressing from contradictory classifications of good, bad or ugly, to the exciting outcome of ‘useful’.     

Pressure modes of mechanical ventilation: the good, the bad, and the ugly

Numerous pressure modes are currently available on ventilators. The application of microprocessor technology has resulted in sophisticated mode options that are very responsive to patient-initiated efforts, yet little is known about how to use the modes or their effect on patient outcomes. This article describes a wide variety of pressure modes including traditional modes such as pressure support and pressure-controlled ventilation in addition to less traditional new modes such as airway pressure release ventilation, biphasic positive airway pressure, Pressure Augmentation (Bear 1000, Viasys Healthcare, Yorba Linda, California), Volume Support (Maquet, Bridgewater, New Jersey), Pressure Regulated Volume Control (Maquet, Bridgewater, New Jersey), Volume Ventilation Plus (Puritan Bennett, Boulder, Colorado), Adaptive Support Ventilation (Hamilton Medical, Switzerland), and Proportional Assist Ventilation (Dr?ger Medical, Richmond Hill, Ontario, Canada). The "good, the bad, and the ugly" issues surrounding the application, evaluation, and outcomes of the modes are discussed.