Rotavirus vaccines: an overview

Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. Vaccination is the only control measure likely to have a significant impact on the incidence of severe dehydrating rotavirus disease. In 1999, a highly efficacious rotavirus vaccine licensed in the United States, RotaShield, was withdrawn from the market after 14 months because of its association with intussusception. Two new live, oral, attenuated rotavirus vaccines were licensed in 2006: the pentavalent bovine-human reassortant vaccine (RotaTeq) and the monovalent human rotavirus vaccine (Rotarix). Both vaccines have demonstrated very good safety and efficacy profiles in large clinical trials in western industrialized countries and in Latin America. Careful surveillance has not revealed any increased risk of intussusception in the vaccinated groups with either vaccine. The new rotavirus vaccines are now introduced for routine use in a number of industrialized and developing countries. These new safe and effective rotavirus vaccines offer the best hope of reducing the toll of acute rotavirus gastroenteritis in both developed and developing countries.     

Rotavirus vaccines

Rotavirus, the most common cause of severe diarrhea and a leading cause of mortality in children, has been a priority target for vaccine development for the past several years. The first rotavirus vaccine licensed in the United States was withdrawn because of an association of the vaccine with intussusception. However, the need for a vaccine is greatest in the developing world, because the benefits of preventing deaths due to rotavirus disease are substantially greater than the risk of intussusception. Early vaccines were based on animal strains. More recently developed and licensed vaccines are either animal-human re-assortants or are based on human strains. In India, two candidate vaccines are in the development process, but have not yet reached efficacy trials. Many challenges regarding vaccine efficacy and safety remain. In addition to completing clinical evaluations of vaccines in development in settings with the highest disease burden and virus diversity, there is also a need to consider alternative vaccine development strategies.     

Neisseria meningitidis serogroup A vaccines: an overview

A recent report by the Weekly Epidemiological Record of an outbreak of Neisseria meningitidis serogroup A in the Great Lakes region shows that meningococcal epidemics are an unsolved problem in resource-poor countries, particularly in Africa [1]. During the last epidemic wave in the 1990s, about 350,000 people developed meningitis and 1000 people died [101]. An effective polysaccharide vaccine has been available since the early 1970s. Unfortunately, attempts to contain the epidemics by timely detection of cases through active surveillance and prompt mass vaccination campaigns have failed to prevent the deaths of thousands of people in several African countries in the 1980s and 1990s. This article describes the epidemiology of N. meningitidis serogroup A, the available polysaccharide vaccines, their advantages and limitations. The current vaccination policies and their economic implications are discussed, to clarify why the use of an effective vaccine has, to date, been disappointing. The recent exciting developments with respect to conjugate vaccines are described.     

Cytokines: an overview.

Cytokines are a broad, heterogeneous group of proteins and polypeptides that regulate intercellular communication. Examples of cytokines include interleukins, interferons, colony-stimulating factors, and a variety of growth factors. The preparation of large quantities of highly purified recombinant cytokines has provided a basis for their biological and physicochemical characterization. The pleiotropic biological effects of these factors are expressed through binding to specific, high-affinity cell-surface receptors. Although they are different in amino acid sequence, cytokines have a number of biological and physicochemical properties in common.     

Psychodermatology: an overview.

As the skin is an organ that has a primary function in tactile receptivity and reacts directly upon emotional stimuli, dermatological practice involves a psychosomatic dimension. It is, however, the high visibility of dermatoses and their easy accessibility which make the skin a direct target for behavioural problems. Furthermore, self-destructive tendencies and hypochondriacal features often express themselves through dermatological symptoms: dermatitis artefacta and skin hypochondriasis are among the specific psychocutaneous disorders discussed here. In view of the clinical interface between dermatology and psychiatry, general guidelines are formulated and specific aspects of psychotherapy, behavioural treatment and psychotropic drug treatment are discussed.     

CNS development: an overview.

The basic principles of the development of the central nervous system (CNS) are reviewed, and their implications for both normal and abnormal development of the brain are discussed. The goals of this review are (a) to provide a set of concepts to aid in understanding the variety of complex processes that occur during CNS development, (b) to illustrate how these concepts contribute to our knowledge of the normal anatomy of the adult brain, and (c) to provide a basis for understanding how modifications of normal developmental processes by traumatic injury, by environmental or experiential influences, or by genetic variations may lead to modifications in the resultant structure and function of the adult CNS.     

Psychosomatic medicine today: an overview.

The current status of several areas of interest in psychosomatic medicine, including specificity theory, life changes, and peptic ulcers, is reviewed, and their relevance to the practice of psychosomatic medicine discussed. The importance of neuro-psychopharmacological research to psychosomatic medicine is stressed, and a perspective is given on the usefulness of drugs in conjunction with intensive psychotherapy.     

Comparative genomic hybridization: an overview.

Comparative genomic hybridization (CGH) is a newly described molecular-cytogenetic assay that globally assays for chromosomal gains and losses in a genomic complement. In this assay, normal human metaphase chromosomes are competitively hybridized with two differentially labeled genomic DNAs (test and reference), which upon fluorescence microscopy, reveal the chromosomal locations of copy number changes in DNA sequences between the two complements. Application of CGH to DNAs extracted from fresh frozen specimens and cell lines of various tumor types has revealed a number of recurring chromosomal gains and losses that were undetected by traditional cytogenetic analysis. Few previously known sites were found to be in higher copy number, or lost by CGH, while many novel amplified regions were identified. These regions warrant further molecular genetic studies aimed at isolating the perturbed genes. Since CGH can also be performed on DNA extracted from formalin-fixed paraffin-embedded archived tumor specimens with few modifications, gains and losses of genetic material can be determined for specimens that would otherwise be unanalyzable. Prospective and retrospective application of CGH to tumor specimens would permit correlative studies to be performed, possibly identifying diagnostic and prognostic indicators of disease. CGH may also have a future role in detection and identification of chromosomal abnormalities in prenatal diagnosis and in dysmorphic anomalies.     

Reptilian thymus gland: an ultrastructural overview.

Like in higher vertebrates, the thymus gland of reptiles consists of lymphoid cells within epithelial framework and characteristic myoid cells. Mammalian-like Hassall's corpuscles are absent. Secretory cells, secretory and degenerative cysts as well as phagocytic cells, and plasma cells can be observed. Interdigitating cells and some characteristic features of thymic innervation and vascular system are also described in the reptilian thymus gland.     

Biofeedback and behavioral medicine: an overview.

Biofeedback is a behavioral method of achieving or enhancing voluntary control of physiological processes. Basic studies indicate that a variety of autonomic nervous system and other internal bodily changes can be modified with the method. It has been shown that specific responses and patterns of responses can be controlled. Biofeedback appears to be a promising method of altering symptoms of psychophysiological and medical disorders, e.g., high blood pressure, vascular changes in migraine, neuromuscular abnormalities, and cardiac arrhythmias. This research has stimulated a renewed interest in the role of behavior and the usefulness of behavioral principles in the etiology, treatment, and prevention of medical disorders. The term 'behavioral medicine' calls attention to this new perspective in medicine.     

Pregnancy and rheumatoid arthritis: an overview.

The literature concerning the relationship of rheumatoid arthritis (RA) to pregnancy is reviewed. The amelioration of RA during pregnancy is a complex process. No specific factor that causes amelioration and is amenable to therapeutic intervention has been identified. Either RA is associated with lower fertility/fecundity, or pregnancy induces a protective effect against the development of the disease. The biological mechanism of these findings is not established.     

Immunotoxicology: an overview

It is now known that chemicals and drugs may induce selective toxicity which may alter the interactions between immunocompetent cells, especially if the toxicity occurs during proliferation and differentiation. Hence, a flexible panel of sensitive in vivo and in vitro assays has been developed and validated to assess the immunotoxicity or immunopharmacology of suspect agents in rodents. The combined use of such sequential analysis methods with host resistance assays can effectively define immunomodulation following exposure to xenobiotics. Methods development, refinement and validation will be an ongoing requirement because of our rapidly expanding knowledge of the cell biology of the immune system. Classic studies of the comparative preclinical toxicology of several immunosuppressive drugs have substantiated species similarities and have contributed significantly to the development of predictive rodent models for extrapolation to humans. Studies of immunopharmacology and immunotoxicity of cyclosporin A, for example, produced both the desired pharmacology and the undesired toxicity at similar doses in both rodents and humans. When species differences are observed during toxicology studies they are most probably due to differences in absorption, disposition, metabolism, excretion, or delivered dose at the target tissue, rather than major species differences in cellular targets or cell physiology. This assumption is the basis for using rodent species to predict the toxicity of chemicals and drugs under development.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biomineralization: an overview

Biomineralization describes the deposition of mineral within or outside the cells of living organisms. Examples include iron and gold deposits in bacteria and other unicellular organisms, silicates in algae and diatoms, carbonates in diatoms and nonvertebrates, and calcium phosphates and carbonates in vertebrates. The formation of these deposits involves similar mechanisms, but there are distinctions in each case, and those similarities and distinctions are the subject of this overview. A comparison of the apatitic mineral in bones and teeth is presented as a model for understanding these factors.