New approaches in the treatment of bacterial infections

Recently, several new drugs for the treatment of bacterial infections have been developed. Quinupristin/dalfopristin, moxifloxacin and gatifloxacin have been approved throughout the world for clinical use. Levofloxacin has been approved for the treatment of community-acquired pneumonia caused by penicillin-resistant Streptococcus pnuemoniae. The Food and Drug Administration has approved linezolid for clinical use, and new drug applications for gemifloxacin and telithromycin were filed. Other new targets have surfaced in the quest for novel antibacterial agents.     

Proteomic approaches to bacterial differentiation

Mass spectrometry-based proteomics has been used extensively to explore the proteomes of various organisms, and this technology is now being applied to the characterization of bacterial species. Predominantly, two methods emerge as leaders in this application. Intact protein profiling creates fingerprints of bacterial species which can be used for differentiation and tracking over time. Peptide-centric approaches, analyzed after enzymatic digestion, enable high-throughput proteome characterization in addition to species determination from the identification of peptides distinctive to a species. Highlighted herein is an application of a peptide-centric approach to the identification and quantitation of species-specific peptide identifiers using an in silico exploration and an experimental mass spectrometry-based method. The application to microbial communities is addressed with an in silico analysis of an artificial complex community of 25 microorganisms.     

Practical approaches to plant volatile analysis

Plants emit volatile organic compounds (VOCs) that play important roles in their interaction with the environment and have a major impact on atmospheric chemistry. The development of static and dynamic techniques for headspace collection of volatiles in combination with gas chromatography-mass spectrometry analysis has significantly improved our understanding of the biosynthesis and ecology of plant VOCs. Advances in automated analysis of VOCs have allowed the monitoring of fast changes in VOC emissions and facilitated in vivo studies of VOC biosynthesis. This review presents an overview of methods for the analysis of plant VOCs, including their advantages and disadvantages, with a focus on the latest technical developments. It provides guidance on how to select appropriate instrumentation and protocols for biochemical, physiological and ecologically relevant applications. These include headspace analyses of plant VOCs emitted by the whole organism, organs or enzymes as well as advanced on-line analysis methods for simultaneous measurements of VOC emissions with other physiological parameters.     

Etiology of suppurative bacterial meningitis

The results of the laboratory examination of 2034 patients with meningococcal infection and purulent meningitides, hospitalized during the period of June 1980 to October 1983, revealed that three main etiological agents were responsible for these diseases: meningococci, pneumococci and Haemophilus influenzae. The susceptibility of the patients to different etiological agents was found to depend on their age. Children aged up to 3 years constituted 75% of the patients with meningitis caused by H. influenzae; 50% of the patients with meningococcal infection were children aged up to 5 years; pneumococcal meningitis occurred more frequently in adults. Serogroup A meningococci were found to prevail in patients with meningococcal infection. Besides, in children serogroup C meningococci could be isolated in 24% of cases. Since 1983 the cases of the isolation of strains belonging to serogroup B increased in number. Among the pneumococci responsible for the disease serotypes 1, 19, 6 and in children serotype 12 occurred most frequently.     

Transposon-based approaches to identify essential bacterial genes

Transposons are a powerful tool for identifying genes essential for bacterial viability. The availability of many bacterial genome sequences and the large number of genes of unknown function therein have inspired the generation of a variety of different approaches. These methods are described and their advantages and disadvantages are discussed.     

Surgical management of bacterial meningitis.

A variety of associated lesions may require the neurosurgeon''s assistance in the management of bacterial meningitis. As treatment of this infection of the central nervous system proceeds, the surgeon will have to decide about the concurrent or subsequent operative treatment of congenital dysraphic states, paraneural infections, compound fractures or penetrating wounds of thecranium or spine, or infected bypass shunts for cerebrospinal fluid (CSF). In patients with intractable meningitic infections the surgeon may have to insert a ventricular drainage-irrigation system to permit adequate perfusion of the CSF pathways with antibiotic. Hydrocephalus or subdural effusions complicating meningitis may bring the patient to the surgeon long after the infection has been cured. This paper examines these problems and outlines the current principles of management.     

New approaches to the treatment of osteoporosis

Under physiological conditions, maintenance of skeletal mass is the result of a tightly coupled process of bone formation and bone resorption. Disease states, osteoporosis included, arise when this delicate balance is disrupted such as in menopause, when estrogen levels decrease dramatically corresponding with the cessation of ovarian function. Current therapies for the treatment of osteoporosis, including estrogen replacement therapy, selective estrogen receptor modulators and bisphosphonates, are primarily based on blunting the resorption component of bone homeostasis. Although selective estrogen receptor modulators offer bone protection without the side effects of estrogen replacement therapy, there are some areas of improvement for the current generation of selective estrogen receptor modulators; particularly in reducing their antagonistic properties in the central nervous system that lead to vasomotor symptoms. There are few therapies that are focused on increasing bone formation, but they offer promising avenues in which to expand the repertoire of drugs to restore bone mass. Selective androgen receptor modulators, parathyroid hormone analogs, oxytocin analogs and statins, all with improved pharmacological properties in bone, are among the potential approaches to eliciting anabolic effects in the skeleton.