Paradoxical Reaction of Tuberculosis in a Heart Transplant Recipient During Antituberculosis Therapy: A Case Report

INTRODUCTION

Tuberculous paradoxical reactions (PRs) are excessive immune reactions occurring after antituberculosis (TB) treatment and are commonly observed in immunocompromised hosts such as patients infected with the human immunodeficiency virus.

CASE REPORT

We recently encountered a 63-year-old male heart transplant recipient who developed tuberculous PR after treatment for miliary TB. The patient had been receiving immunosuppressive therapy with cyclosporine and mycophenolate mofetil for over 15 years. The diagnosis of miliary TB was made based on the presence of intermittent fever and fatigue; thus, anti-TB treatments (isoniazid, levofloxacin, ethambutol, and pyrazinamide) were started, which led to rapid defervescence and regression of the granular shadow and pleural effusion. However, a new persistent fever and confused state developed 1 month after the anti-TB therapy was started. After excluding possible etiologies of the patient's symptom, a PR was suspected, and anti-TB drugs were continued; corticosteroids were added as anti-inflammatory agents. After that, he has shown a favorable course with long-term anti-TB chemotherapy.

CONCLUSION

A PR should always be considered when the patients' symptoms of tuberculosis re-exacerbate after an appropriate anti-TB therapy. A PR commonly occurs in patients with various immunologic conditions including heart transplant recipients.

NMR structure of Streptomyces killer toxin-like protein, SKLP: further evidence for the wide distribution of single-domain betagamma-crystallin superfamily proteins

A protein isolated from the culture supernatant of the soil bacterium, Streptomyces sp. F-287, exhibits cytocidal effects for both budding and fission yeasts, and causes morphological changes of yeasts and filamentous fungi. This protein, which was the first killer toxin-like protein for yeasts identified in the Streptomyces microorganism, was named SKLP (Streptomyces killer toxin-like protein). Since the amino acid sequence of the protein, as determined by sequential Edman degradations, seemed to be unique, we determined the structure by NMR spectroscopy. Although the actual target of SKLP in yeasts has not been determined yet, the structure might give us a clue to characterize the targets. The solution structure of SKLP determined by NMR, however, turned out to be a single-domain crystallin-like protein, with two Greek key motifs and a short extra beta-strand at the N terminus. The final ensemble of 20 NMR structures overlaid onto their mean coordinate with rmsd values of 0.32(+/-0.06) A for the backbone atoms involved in the secondary structure elements. As a yeast killer toxin, WmKT, isolated from the yeast strain Williopsis mrakii also has a Greek key beta-barrel fold, we have made a detailed comparison of the structural features of SKLP with the other crystallin superfamily proteins. It is very interesting that SKLP has a unique electrostatic potential distribution on the molecular surface. Namely, one surface of the beta-barrel fold in SKLP has a large negatively charged region, with an isolated positive charge of the Arg62 side-chain at the center. The edge of this surface is surrounded by positively charged residues, including Arg31, Arg65 and Arg74. The salient features of the charge distribution on this surface and the cluster of Arg residues might be related to the target binding of SKLP.

Profiling of Caenorhabditis elegans proteins using two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization-time of flight-mass spectrometry

The nematode Caenorhabditis elegans (C. elegans) is the first animal whose whole 97 Mb genome sequence, encoding ca. 19000 open reading frames (ORF's), has been essentially determined. We tried to establish a 2-DE map of the nematode proteome by means of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). A soluble protein fraction of mixed stages of the worm, wild-type strain N2, was applied to 2-D PAGE. After Coomassie Brilliant Blue (CBB) staining, 1200 spots were detected and 140 major spots were excised from the gel and subjected to in-gel digestion with Achromobacter protease I (lysyl endopeptidase). Resulting peptides were analyzed by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) followed by peptide mass fingerprinting for protein identification. With this approach we have obtained a two-dimensional electrophoresis (2-DE) protein map in which 69 spots were localized as landmarks for comparison of expression profiles to elucidate the basis of various biological events.

Protein profiling of rat cerebella during development

Protein profiles of developing rat cerebella were analyzed by means of two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). The analysis of adult rat cerebellum gave rise to a protein map comprising approximately 3000 spots detectable by silver staining following high resolution 2-DE with a pH range of 3-10 and a mass range of 8-100 kDa. To obtain landmarks for comparison of developmental profiles of cerebellar proteins, 100 spots were subjected to peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and 67 spots were assigned on the map. Analysis of profiles of the developing cerebella revealed significant changes in the expression of proteins during development. In most cases the expression levels of proteins increased as the cerebellum matured, while the expression of 42 spots appeared specific or remarkably abundant in the immature cerebellum. Peptide mass fingerprinting of these spots allowed us to identify 29 proteins, which include, in addition to proteins of unknown function, many proteins known to have roles in the development of the central nervous system. These results suggest that the proteomic approach is valuable for mass identification of proteins involved in cerebellar morphogenesis.

Interaction of cyclomaltononaose (delta-CD) with several drugs

The effects of delta-cyclodextrin (delta-CD; cyclomaltononaose) on solubility of 14 drugs that are slightly soluble or insoluble in water were studied and compared with those of conventional cyclodextrins (CDs) such as alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), and gamma-cyclodextrin (gamma-CD). In general, delta-CD had a weak complex-forming ability with the drugs examined in comparison with beta-CD and gamma-CD. However, in the case of digitoxin, delta-CD enhanced solubility of the guest molecules. To determine the mechanism of inclusion complex formation of delta-CD with digitoxin, the interaction of both drugs was investigated by the solubility method and spectroscopic methods such as ultraviolet (UV) and 1H-NMR (nuclear magnetic resonance). The changes in chemical shift (1H) and hypsochromic shift of UV suggested that digitoxin was partially included in the cavity of delta-CD.

Correlation among secondary structure, amyloid precursor protein accumulation, and neurotoxicity of amyloid beta(25-35) peptide as analyzed by single alanine substitution

Structure-neurotoxicity relationships of amyloid beta (25-35) peptide were studied by replacing each amino acid with Ala. In contrast to the general tendency in hydrophobicity-toxicity relationships, replacement of Asn27 yielded a more hydrophobic but less toxic analog and that of Met35 gave a less hydrophobic but more toxic one. Sedimentation profiles and CD spectra indicated that peptide aggregation via intermolecular beta-sheet formation is essential for the neurotoxicity of amyloid beta (25-35) peptide. The correlation between neurotoxicity and amyloid precursor protein accumulation suggested that the latter is one of the pathways of the neuronal death caused by amyloid beta protein.

Tyr13 is essential for the activity of omega-conotoxin MVIIA and GVIA, specific N-type calcium channel blockers

Two analogs of omega-conotoxin MVIIA, a 25mer peptide neurotoxin, were synthesized by replacing Lys2 or Tyr13 with Ala. The activities of synthetic analogs were estimated from the inhibitory action on 125I-omega-conotoxin GVIA binding to chick brain synaptic plasma membranes. As in the case of omega-conotoxin GVIA, replacement of Tyr13 resulted in an enormous reduction in activity. In contrast, substitution of Ala for Lys2 gave only a small effect. These results indicate that Tyr13 is a critical amino acid of omega-conotoxin MVIIA and GVIA for blocking N-type calcium channel function.

Accumulated photon echoes by using a nonlaser light source

Accumulated photon echoes have been observed by use of a light-emitting diode. This is to our knowledge the first observation of photon echoes that are excited by a nonlaser light source. In the incoherent-light photon echo, the time resolution is equal to the inverse of the overall spectral width of the excitation light. Therefore we can easily get a high time resolution by using nonlaser light with a broad spectrum. Moreover the use of nonlaser light in the photon-echo experiment will extend the technique into wavelength regions where lasers are not currently available.