Immunomodulatory Metabolites Released by the Frog-Killing Fungus Batrachochytrium dendrobatidis

Batrachochytrium dendrobatidis is a fungal pathogen in the phylum Chytridiomycota that causes the skin disease chytridiomycosis. Chytridiomycosis is considered an emerging infectious disease linked to worldwide amphibian declines and extinctions. Although amphibians have well-developed immune defenses, clearance of this pathogen from the skin is often impaired. Previously, we showed that the adaptive immune system is involved in the control of the pathogen, but B. dendrobatidis releases factors that inhibit in vitro and in vivo lymphocyte responses and induce lymphocyte apoptosis. Little is known about the nature of the inhibitory factors released by this fungus. Here, we describe the isolation and characterization of three fungal metabolites produced by B. dendrobatidis but not by the closely related nonpathogenic chytrid Homolaphlyctis polyrhiza. These metabolites are methylthioadenosine (MTA), tryptophan, and an oxidized product of tryptophan, kynurenine (Kyn). Independently, both MTA and Kyn inhibit the survival and proliferation of amphibian lymphocytes and the Jurkat human T cell leukemia cell line. However, working together, they become effective at much lower concentrations. We hypothesize that B. dendrobatidis can adapt its metabolism to release products that alter the local environment in the skin to inhibit immunity and enhance the survival of the pathogen.     

Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

Inflammation-induced increase in the density of neuropeptide-immunoreactive nerve endings in rat skeletal muscle

The density of substance P (SP)-, calcitonin gene-related peptide (CGRP)- and vasoactive intestinal polypeptide (VIP)-immunoreactive (ir) nerve endings was quantitatively evaluated in intact and inflamed gastrocnemius-soleus muscle of the rat. In persistently inflamed muscle (12 days after a single injection of Freund’s adjuvant into the muscle), the density of SP-ir fibres was significantly increased. CGRP- and VIP-ir fibres displayed an insignificant increase in density. The density of fibres ir for nerve growth factor (NGF) and for growth-associated protein 43 (GAP-43/B-50), a marker for axonal sprouting, regeneration and synaptic reorganisation, increased significantly in persistently inflamed muscle. The data are consistent with the established contribution of NGF on the expression of SP and GAP-43 in afferent neurones under the influence of a persistent inflammation. Received: 8 September 1997 / Accepted: 12 February 1998     

Polyanetholsulfosaures Natrium,ein neues synthetisches Mittel zur Hemmung der Blutgerinnung

Zusammenfassung Von der Vermutung ausgehend, daß die gerinnungshemmende Wirkung verschiedener Substanzen weniger von der chemischen Struktur als von der Molekulargröße abhängig sei, wurden wasserlösliche Derivate polymerisierter aromatischer Substanzen synthetisiert. Alle diese Körper zeigen gerinnungshemmende Wirkungen; als wirksamster erwies sich das polyanetholsulfosaure Natrium. In der Wirkungsdauer in vivo übertrifft es alle bekannten Mittel, in vitro erreicht es die Wirkung der durschnittlichen Hirudinpräparate.Mit 4 Abbildungen.     

Treatment of febrile episodes in neutropenic children by ceftazidime combined with netilmicin. Results of a multicenter study apropos of 88 cases

Infection is the most important cause of mortality in leucopenic patients. A broad spectrum antibiotic therapy is imperative in febrile and neutropenic patients. In a multicentric study we have used ceftazidime (100 mg/kg/d) and netilmicin (6 mg/kg/d) in 88 children (fever greater than or equal to 38.5 degrees C, neutropenia less than 500/mm3) treated for acute leukemias (59), non Hodgkin lymphomas (13) or solid tumors (16). Median age was 7 years (2 months-16 years). In patients who continued to remain febrile, vancomycin (40 mg/kg/d) was added after 48 hours. The effective treatment was continued until a neutrophil count greater than 1,000/mm3. The first combination (ceftazidime + netilmicin) was effective in 64 children (73%) and the second combination (ceftazidime + netilmicin + vancomycin) in 11 patients. Bacteria were isolated in 39 children: Escherichia coli: 9, Staphylococcus epidermidis: 9, Staphylococcus aureus: 8, Streptococcus: 6, Pseudomonas aeruginosa: 3, Streptococcus pneumoniae: 1, Haemophilus: 1, Klebsiella pneumoniae: 1, Proteus: 1, Serratia: 1, Flavobacterium: 1. In these 39 patients, 30 became apyretic with ceftazidime and netilmicin and 6 after vancomycin. All blood culture were negative after the first combination. The median duration of antibiotic therapy was 14 days (5-9 days: 28, 10-20 days: 43, greater than 20 days: 17). There were no death, no superinfection. Tolerance was good without kidney or liver or biological perturbation. We conclude that the combination ceftazidime and netilmicin is effective in neutropenic children.     

Macrophage activation syndrome linked to Epstein-Barr virus

Epstein-Barr virus infection is one of the etiologies that should be discussed in patients with macrophage activation syndrome. We report a case that is consistent with this diagnosis. The role of the Epstein-Barr virus in the etiologic diagnosis of VAHS (virus-associated hemophagocytic syndrome) is specified. In pediatric patients with VAHS, the other causes of macrophage activation should also be discussed.     

Antimicrobial resistance of Streptococcus pneumoniae recovered from outpatients with respiratory tract infections in Germany from 1998 to 1999: results of a national surveillance study

Clinically significant pneumococcal isolates were prospectively collected from outpatients with respiratory tract infections by 19 different clinical microbiology laboratories in Germany. Resistance rates in a total of 961 isolates were as follows: penicillin, 6.6%; clarithromycin, 10.6%; tetracycline, 13.9%; and levofloxacin, 0.1%. Among 324 isolates from children, pneumococcal serotypes 19F (17.0%), 23F (13.0%), and 6B (11.7%) were the predominant types.