[Daptomycin-induced eosinophilic pneumonia associated with an early endoprosthesis infection]. / Daptomycin-induzierte eosinophile Pneumonitis im Rahmen eines Endoprothesenfrühinfektes.

Acute eosinophilic pneumonia (AEP) is a rare disease characteristically involving eosinophilic infiltration of lung parenchyma as well as fever, dyspnea, and coughing. A differentiation is made between primary and secondary AEP depending on the underlying etiology. Substances that most frequently cause secondary AEP are antibiotics, such as the lipopeptide daptomycin. This is a case report about a 69-year-old female patient who underwent antibiotic treatment with daptomycin for an infection of a knee prosthesis. During the treatment, signs of pneumonia developed and included the increased dependence on mechanical ventilation of the previously intubated patient, infiltrates on a chest X­ray, fever, and an increase in serum inflammation markers. Proof of bacteria as an underlying pathogen was not possible. A thoracic computed tomography (CT) scan showed opacities that are commonly seen in interstitial lung disease. Termination of daptomycin treatment due to renal failure led to an improvement of pulmonary symptoms. Re-exposure to daptomycin resulted in a recurrence of the symptoms. The diagnostic criteria for AEP according to Uppal et al. include 1) current exposure to daptomycin, 2) dyspnea with increased oxygen requirements or necessity for mechanical ventilation, 3) new infiltrates on chest X­ray or CT scan, 4) bronchoalveolar lavage with eosinophilia >25%, 5) improvement of clinical symptoms following daptomycin withdrawal, and 6) fever. With 5 out of the 6 criteria by Uppal et al. positive-an eosinophilia >25% being the only unmet criteria-an AEP induced by daptomycin was diagnosed. Withdrawal of daptomycin as well as high-dose cortisol bolus treatment led to a rapid recovery.

CheC is related to the family of flagellar switch proteins and acts independently from CheD to control chemotaxis in Bacillus subtilis.

Chemotaxis by Bacillus subtilis requires the inter-acting chemotaxis proteins CheC and CheD. In this study, we show that CheD is absolutely required for a behavioural response to proline mediated by McpC but is not required for the response to asparagine mediated by McpB. We also show that CheC is not required for the excitation response to asparagine stimulation but is required for adaptation while asparagine remains complexed with the McpB chemoreceptor. CheC displayed an interaction with the histidine kinase CheA as well as with McpB in the yeast two-hybrid assay, suggesting that the mechanism by which CheC affects adaptation may result from an interaction with the receptor-CheA complex. Furthermore, CheC was found to be related to the family of flagellar switch proteins comprising FliM and FliY but is not present in many proteobacterial genomes in which CheD homologues exist. The distinct physiological roles for CheC and CheD during B. subtilis chemotaxis and the observation that CheD is present in bacterial genomes that lack CheC indicate that these proteins can function independently and may define unique pathways during chemotactic signal transduction. We speculate that CheC interacts with flagellar switch components and dissociates upon CheY-P binding and subsequently interacts with the receptor complex to facilitate adaptation.

Selective methylation changes on the Bacillus subtilis chemotaxis receptor McpB promote adaptation.

The Bacillus subtilis McpB is a class III chemotaxis receptor, from which methanol is released in response to all stimuli. McpB has four putative methylation sites based upon the Escherichia coli consensus sequence. To explore the nature of methanol release from a class III receptor, all combinations of putative methylation sites Gln(371), Gln(595), Glu(630), and Glu(637) were substituted with aspartate, a conservative substitution that effectively eliminates methylation. McpB((Q371D,E630D,E637D)) in a Delta(mcpA mcpB tlpA tlpB)101::cat mcpC4::erm background failed to release methanol in response to either the addition or removal of the McpB-mediated attractant asparagine. In the same background, McpB((E630D,E637D)) produced methanol only upon asparagine addition, whereas McpB((Q371D,E630D)) produced methanol only upon asparagine removal. Thus methanol release from McpB was selective. Mutants unable to methylate site 637 but able to methylate site 630 had high prestimulus biases and were incapable of adapting to asparagine addition. Mutants unable to methylate site 630 but able to methylate site 637 had low prestimulus biases and were impaired in adaptation to asparagine removal. We propose that selective methylation of these two sites represents a method of adaptation novel from E. coli and present a model in which a charged residue rests between them. The placement of this charge would allow for opposing electrostatic effects (and hence opposing receptor conformational changes). We propose that CheC, a protein not found in enteric systems, has a role in regulating this selective methylation.

Molecular tuning of an EF-hand-like calcium binding loop. Contributions of the coordinating side chain at loop position 3.

Calcium binding and signaling orchestrate a wide variety of essential cellular functions, many of which employ the EF-hand Ca2+ binding motif. The ion binding parameters of this motif are controlled, in part, by the structure of its Ca2+ binding loop, termed the EF-loop. The EF-loops of different proteins are carefully specialized, or fine-tuned, to yield optimized Ca2+ binding parameters for their unique cellular roles. The present study uses a structurally homologous Ca2+ binding loop, that of the Escherichia coli galactose binding protein, as a model for the EF-loop in studies examining the contribution of the third loop position to intramolecular tuning. 10 different side chains are compared at the third position of the model EF-loop with respect to their effects on protein stability, sugar binding, and metal binding equilibria and kinetics. Substitution of an acidic Asp side chain for the native Asn is found to generate a 6,000-fold increase in the ion selectivity for trivalent over divalent cations, providing strong support for the electrostatic repulsion model of divalent cation charge selectivity. Replacement of Asn by neutral side chains differing in size and shape each alter the ionic size selectivity in a similar manner, supporting a model in which large-ion size selectivity is controlled by complex interactions between multiple side chains rather than by the dimensions of a single coordinating side chain. Finally, the pattern of perturbations generated by side chain substitutions helps to explain the prevalence of Asn and Asp at the third position of natural EF-loops and provides further evidence supporting the unique kinetic tuning role of the gateway side chain at the ninth EF-loop position.

Optimizing the metal binding parameters of an EF-hand-like calcium chelation loop: coordinating side chains play a more important tuning role than chelation loop flexibility.

In calcium signaling pathways regulated by the EF-hand Ca2+ binding motif, proper regulation requires that the equilibrium and kinetics of Ca2+ binding to the EF-hand chelation loop be precisely optimized for each physiological application. Studies of small-molecule organic chelators have shown that metal binding parameters can be tuned both by the nature of the coordinating ligands and by the structural framework to which these ligands are attached. By analogy, the present study tests the relative importance of (i) coordinating side chains and (ii) backbone torsion angle constraints to the tuning of an EF-hand-like Ca2+ chelation loop. A series of engineered chelation loops are generated by modifying Ca2+ binding site of the Escherichia coli galactose binding protein. The resulting loops, each containing an altered coordinating side chain or a Gly substitution, are compared with respect to their metal binding affinities, specificities, and dissociation kinetics. The Gly variants examined include substitutions which eliminate or introduce a Gly at each of the nine chelation loop positions. The results reveal that Gly is not tolerated at loop positions 1, 3, 5, or 8 or at the external coordinating position, where the removal of a key coordinating or hydrophobic side chain destabilizes the protein. In contrast, Gly residues at loop positions 2, 4, 6, and 7, none of which is required for side chain coordination, have little effect on Ca2+ affinity and the ability to discriminate between cations of different size and charge. Kinetic measurements show that some of these Gly residues measurably alter the rates of metal ion association and dissociation, but in each case the two rates are changed by approximately the same factor so that the effects on equilibrium are minor. Overall, Gly residues yield surprisingly small effects at loop positions 2, 4, 6, and 7, especially when compared to the larger equilibrium and kinetic effects observed for coordinating side chain substitutions. It follows that the conserved Gly at position 6 is not required for Ca2+ binding and that constraints on the backbone torsion angles at the non-coordinating side chain positions 2, 4, 6, and 7 play a relatively minor role in tuning metal binding parameters. Instead, specific coordinating side chains optimize the metal binding parameters of the GBP chelation loop for its protein context and biological application.

Phase I/II trial of combined 131I anti-CEA monoclonal antibody and hyperthermia in patients with advanced colorectal adenocarcinoma.

BACKGROUND: This pilot project was undertaken to evaluate the toxicity of and tumor response to combined 131I anti-carcinoembryonic antigen monoclonal antibody (131I anti-CEA RMoAb) and hyperthermia in patients with metastatic colorectal adenocarcinoma. METHODS: Nine patients who had colorectal carcinoma with liver metastases were enrolled in this study. Intact 131I anti-CEA RMoAb was used (the specific antibody was IMMU-4, provided by Immunomedics, Inc., Morris Plains, NJ). During the diagnostic phase, dosimetry revealed that the tumor site received a higher radiation dose than the surrounding normal tissues in only six patients. These six, who were treated with radioimmunotherapy and hyperthermia, were the basis of this study. The first three patients were treated with 30 mCi/m2 of 131I anti-CEA RMoAb, and the next three received 60 mCi/m2. Pharmacokinetic clearance data were reported for all nine patients. RESULTS: Thermometry data revealed an average T90 of 40.3 (+/- 1.4 degrees C) and T50 of 41.1 (+/- 1.2 degrees C). The average thermal dose equivalent at 42.5 degrees C was 34.5 (+/- 21.5) minutes. The average Tmin, Tmax, and Tmeam were 40 (+/- 1.2 degrees C), 42.4 (+/- 0.7 degrees C), and 41.1 (+/- 1.1 degrees C), respectively. The pharmacokinetic clearance data of antibody showed monoexponential plasma clearances in all patients except one, in whom a biexponential plasma clearance was observed. In general, similar plasma and whole-body clearances as well as similar urinary excretions were observed when diagnostic and therapeutic phases for each patient were compared. Two of the six patients showed a marked improvement in their symptoms; five patients showed a drop in carcinoembryonic antigen levels. A follow-up computed tomography scan one month after treatment showed no change in tumor volume in five patients; one patient showed a partial response. Three patients developed toxicity, two developed moderate thrombocytopenia (39,000 and 58,000), and the other patient developed hematoma resulting from the insertion of a catheter for thermometry. CONCLUSIONS: It is feasible to combine hyperthermia and radiolabeled monoclonal antibodies, and the combination was well tolerated by these patients. The interaction between hyperthermia and low dose rate radioimmunotherapy is complex. Further studies are necessary to explore the use of this combined modality in the management of maligancies.

Evoked potential changes from 13 weeks of simulated toluene abuse in rats.

Fischer 344 rats were exposed to 8000 ppm toluene vapor in an 'abuse' paradigm for 13 weeks to develop an animal model for 'solvent neurotoxicity.' Exposures to toluene were multiple and short (15 to 35 min), adjusted according to tolerance. Although body weight was reduced 23% from controls, the toluene-exposed rats appeared healthy. Evoked potentials taken postexposure were, however, mildly to severely affected. Flash-evoked potentials were slow and topographically disorganized; 10 kHz tone-pip auditory brainstem responses (ABRs) had severe loss of power and loss of detail. Click and 30 kHz ABRs, somatosensory-evoked potentials, and caudal nerve action potentials were less affected. No neuropathologic changes were detected by light microscopy (perfusion fixation, special stains). Thus, postexposure multimodal functional effects were readily detected after subchronic, severe episodic exposures to toluene.

Teratogenic evaluation of a polybromodiphenyl oxide mixture in New Zealand white rabbits following oral exposure.

Polybromodiphenyl oxide (PBDPO), a potential flame retardant additive in thermoplastics and thermosets, was tested for its embryo/fetal toxicity and teratogenicity in pregnant rabbits. PBDPO was orally administered to groups of 26 New Zealand White rabbits at dose levels of 0 (corn oil, vehicle control), 2, 5, or 15 mg/kg/day in a dose volume of 1 ml/kg body weight on Days 7 through 19 of gestation. The offspring were then examined on Day 28 of gestation. No evidence of teratogenicity was observed at any dose level tested. Pregnant rabbits in the 15 mg/kg/day dose group showed evidence of maternal toxicity as exhibited by significant increases in absolute and relative liver weights and decreased body weight gain during gestation Days 7 through 20 and Days 7 through 28. Slight fetal toxicity accompanied the maternal toxicity at the high dose level, as demonstrated by an increase in the incidence of delayed ossification of the sternebrae.

Teratologic evaluation of orally administered nitrapyrin in rats and rabbits.

Pregnant Fischer 344 rats and New Zealand White rabbits were orally administered 0, 5, 15, or 50 mg nitrapyrin/kg/day on Gestation Days 6 through 15 (rats) or 0, 3, 10, or 30 mg/kg/day on Gestation Days 6 through 18 (rabbits). In rats, 50 mg/kg/day produced slight histopathologic changes in the livers of pregnant females. Fetal examination revealed no evidence of fetotoxicity or teratogenicity among rats at dose levels up to 50 mg/kg/day. Among rabbits, a significant depression in maternal weight gain and increased absolute and relative liver weights were observed at 30 mg/kg/day. An increased incidence of crooked hyoid bone among fetal rabbits in the 30 mg/kg/day dose group was considered indicative of fetotoxicity but not teratogenicity. Thus, administration of nitrapyrin was not teratogenic at dose levels up to 50 mg/kg/day in rats and 30 mg/kg/day in rabbits.

Clinical evaluation and prerelease management of American river otters in the second year of a reintroduction study.

In the first year (1984) of a reintroduction study, 10 American river otters (Lutra canadensis) from Louisiana were transported to Oklahoma, held for 5 days for clinical evaluation, surgical implantation with intra-abdominal radiotelemetry devices, and then released in Oklahoma. Four of 10 otters released died within 32 days. Clinical evaluation indicated that respiratory tract disease, bacterial and parasitic infections, and inanition may have contributed to the death of these otters. In the second year (1985) of the study, an exotic feline diet was fed, and the holding period for 10 otters was increased to provide time for evaluation and treatment before surgery, postsurgical acclimation to Oklahoma, and reevaluation before release. Although the initial clinical findings on otters in the second year were similar to those found in the first year, otter body weights increased, and the prevalence and severity of clinical abnormalities decreased with treatment during the second-year holding period. Three of 10 second-year otters died during the holding period, and contributing causes of death were determined to be: trauma (hepatic hematoma), inanition, renal disease, pneumonia, salmonellosis (Salmonella anatum), and a retropharyngeal abscess (Klebsiella pneumoniae). Seven healthy otters were reintroduced into Oklahoma in 1985, and postrelease deaths were not experienced.

Clinical evaluation of American river otters in a reintroduction study.

Ten American river otters (Lutra canadensis) were evaluated clinically before release into Oklahoma waterways. Otters were immobilized for physical, radiographic, and electrocardiographic examinations and for collection of blood samples. Hematologic and serum biochemical analyses, urinalyses, parasitologic examinations, surgical omental biopsies, and necropsy findings were included. Respiratory tract disease, bacterial and parasitic infections, and starvation apparently were contributing causes of postrelease mortality in 4 of the otters.

Idiopathic skeletal muscle necrosis in bluegills.

Skeletal muscle degeneration and necrosis in a wild population of bluegills (Lepomis macrochirus) were investigated. Hemorrhage and large areas of muscle necrosis were evident at necropsy. Histologically, muscle fibers were granular, vacuolated, and fragmented. Ultrastructural alterations included mitochondrial swelling, clumping and loss of actin and myosin fibrils, swelling of T tubules, and loss of continuity of the sarcolemma. An etiologic agent was not identified.

The effects on earnings of interregional and interindustry migration.

"The purpose of this study is to examine a model of the decision to migrate between regions and/or industries and its effect on earnings. The study is based on a large set of individual microdata taken from the [U.S.] Social Security Administration's One Percent Continuous Work History Sample." The data are for 1971 and 1973. "Results of estimation provide strong support for the hypothesis of self-selection among region and industry migrants. Additional empirical evidence supports the notion of comparative advantage in migrant earnings, implying that earnings distributions of individuals who made a particular combination of migration decisions may differ from those of the population as a whole."

Malignant catarrhal fever in an Indian gaur and greater kudu: experimental transmission, isolation, and identification of a herpesvirus.

Herpesviruses were isolated in bovine cell cultures from buffy coat cells obtained from an Indian gaur (Bos gaurus) and a greater kudu (Tragelaphus strepsiceros) with clinical signs of the head and eye form of malignant catarrhal fever (MCF). Both animals were from herds housed in a zoologic park in Oklahoma. Serial transmission of the head and eye form of MCF was accomplished by using whole blood from the gaur into a Hereford-Angus heifer, then whole blood from the heifer into a Holstein calf, and finally, whole blood from the calf into a white-tailed deer (Odocoileus virginianus). A herpesvirus was isolated in bovine cell cultures inoculated with buffy coat cells from the heifer, and 2 deer inoculated with this herpesvirus developed the head and eye form of MCF. A deer inoculated with whole blood from the greater kudu also developed clinical signs of MCF, and a herpesvirus was subsequently recovered from the deer. Clinical signs of MCF included a mucopurulent catarrh, pyrexia (38.8 to 42.1 C), anorexia, and corneal opacity, and death occurred between postinoculation days 15 and 21.

Comparative pathology of the African form of malignant catarrhal fever in captive Indian gaur and domestic cattle.

The African strain of malignant catarrhal fever virus was isolated and identified in a herd of captive Indian gaur (Bos gaurus). Gross lesions included oral ulcerations, corneal opacity, and multifocal myocarditis. Microscopic lesions were characterized by lymphocytic vasculitis/perivasculitis in all tissues examined. Blood was serially passed from a gaur to a domestic heifer (Bos taurus), and then to a domestic calf. Clinical signs and gross and microscopic lesions similar to those of the gaur were seen in both inoculated animals.