Meningitis after acute Borrelia burgdorferi infection in HIV infection

HISTORY AND CLINICAL FINDINGS: A 39-year-old HIV positive patient developed myalgia, headache and cough 4 weeks after a tick bite. His temperature was 37.4 degrees C and a circular pale erythema was noted over the left lower leg. INVESTIGATIONS: C-reactive protein was raised to 120 mg/l, white blood cell count was 5860/microliter, CD4-lymphocyte count 250/microliter. The chest radiogram showed pneumonitic infiltration in the left lower lobe. There were IgM antibodies against Borrelia burgdorferi. TREATMENT AND COURSE: Left lower lobe pneumonia and chronic erythema migrans were diagnosed and he was given oral azithromycin (500 mg on the first day and 250 mg for 4 days). The pneumonia cleared up, but 2 weeks later he developed symptoms of meningitis (496 cells per microliter, 87% lymphocytes, positive Borrelia burgdorferi antibody titer), which quickly and lastingly responded to ceftriaxon (2 g daily by brief infusion for 14 days). CONCLUSION: This immune-compromised HIV-infected patient developed disseminated borreliosis with CNS involvement 2 weeks after the occurrence of chronic erythema migrans. The initial treatment of the latter with azithromycin was unable to prevent the meningitis. It is unlikely that there was a causal connection between the borreliosis and the pneumonia.     

The Dübendorf Study: a population-based investigation on normal values of blood pressure self-measurement

In a retrospective study of 50 consecutive children with posterior fossa tumors treated at Texas Children's Hospital, Houston, Tex., in 1989-1992, we evaluated perioperative factors which might influence the development of postoperative cerebrospinal fluid leaks. Factors analyzed included the presence of preoperative hydrocephalus, the institution of cerebrospinal fluid diversion, and the method of dural closure. No statistically significant impact on subsequent cerebrospinal fluid leakage was demonstrated.     

Preparation of dehydroxylated and delaminated talc: Meta-talc

The roentgen-amorphous delaminated and dehydroxylated phase was prepared applying intensive milling procedure and subsequent thermal treatment of talc. Due to the similarity in properties and in thermal behavior of this material with roentgen-amorphous delaminated and dehydroxylated kaolinite phase, i.e. meta-kaolinite, the name meta-talc was suggested for this material. The properties and the behavior during thermal treatment were investigated using thermal analysis, x-ray diffraction analysis, infrared spectroscopy and scanning electron microscopy. The suggested procedure changes the activation energy of dehydroxylation, the behavior during thermal treatment and the phase composition of the product. The kinetics and thermodynamics of the thermal transition were evaluated using Kissinger equation and Eyering law.     

The influence of structure order on the kinetics of dehydroxylation of kaolinite

The structural order of kaolinite is an important factor that shows a substantial effect on the processes which take place during the thermal treatment of kaolin. The influence of structural order on the dehydroxylation process was investigated by simultaneous thermogravimetry and differential thermal analysis (TG-DTA). The thermal analysis was performed on the samples with gradually decreasing structural order prepared by milling procedure. The apparent activation energy of dehydroxylation process decreases with decreasing structural order according to the exponential function. The extrapolation of experimental data leads to the estimation of apparent activation energy of 76.6 kJ mol^?1 and of frequency factor of 0.12 × 10⁴ s^?1 related to completely disordered form of kaolinite, while the ordered form shows the apparent activation energy of 216.17 kJ mol^?1 and the frequency factor of 9.26 × 10⁴ s^?1. The relationships between features such as the infrared pattern of treated material, the degree of structural order and the apparent activation energy were established.     

Infectious complications in 100 consecutive heart transplant recipients

The molecular basis for X-linked agammaglobulinemia, hyper-IgM syndrome, and severe combined immunodeficiency was recently identified. In X-linked agammaglobulinemia the molecular defect was found to reside in the gene encoding a novel cytoplasmic tyrosine kinase (bpk, atk, or btk) expressed by B and myeloid cells. This kinase belongs to a new subfamily of tyrosine kinases that contains SH1, SH2, and SH3 domains. A defect in the murine homologue of this kinase has been shown to be responsible for X-linked immunodeficiency in mice. Currently, the role of btk in B- and myeloid cell signaling is unknown. The molecular defect in X-linked hyper-IgM syndrome has been shown to reside in the gene encoding the T-cell activation protein gp39 (CD40L, TRAP). This protein binds to its counter receptor, CD40, on B cells and has been shown to participate in T-cell-dependent B-cell help leading to B-cell proliferation and isotype switching. X-linked severe combined immunodeficiency patients were found to have defects in the gene encoding the gamma-chain of the interleukin-2 receptor. This chain of the interleukin-2 receptor is constitutively expressed by T cells and is involved in the formation of high and intermediate affinity interleukin-2 receptor complexes. These two interleukin-2 receptor complexes are responsible for mediating interleukin-2-dependent signals.     

Verfahren zur selbsttätigen Chlorierung für die Ermittlung der oxydischen Einschlüsse in einem Chrom-Nickel-Stahl mit rd. 18% Cr und 8% Ni

Übersicht über das Schrifttum. Beschreibung und Arbeitsweise des Gerätes. Erprobung an Rückständen aus einem Stahl mit 0,10% C, 17,5% Cr, 1,6% Mo, 14,0% Ni, 0,7% Nb, 0,26% Ti und 0,3% W. Verhalten von Eisenoxyd und Manganoxyd bei längerer Chlorierungsdauer. Anwendung auf Stähle mit 18% Cr und 8% Ni sowie 18% Cr und 10% Ni, mit und ohne Molybdän, Niob und Titan, die zum Teil unter Argon, im Vakuum und im Elektronenstrahlofen umgeschmolzen waren.     

Melectin: a novel antimicrobial peptide from the venom of the cleptoparasitic bee Melecta albifrons

A novel antimicrobial peptide designated melectin was isolated from the venom of the cleptoparasitic bee Melecta albifrons. Its primary sequence was established as H-Gly-Phe-Leu-Ser-Ile-Leu-Lys-Lys-Val-Leu-Pro-Lys-Val-Met-Ala-His-Met-Lys-NH(2) by Edman degradation and ESI-QTOF mass spectrometry. Synthetic melectin exhibited antimicrobial activity against both gram-positive and -negative bacteria and it degranulated rat peritoneal mast cells, but its hemolytic activity was low. The CD spectra of melectin measured in the presence of trifluoroethanol and sodium dodecyl sulfate showed a high content alpha-helices, which indicates that melectin can adopt an amphipathic alpha-helical secondary structure in an anisotropic environment such as the bacterial cell membrane. To envisage the role of the proline residue located in the middle of the peptide chain on biological activity and secondary structure, we prepared several melectin analogues in which the Pro11 residue was either replaced by other amino acid residues or was omitted. The results of biological testing suggest that a Pro kink in the alpha-helical structure of melectin plays an important role in selectivity for bacterial cells. In addition, a series of N- and C-terminal-shortened analogues was synthesized to examine which region of the peptide is related to antimicrobial activity.     

Mechanism and kinetics of wollastonite fibre dissolution in the aqueous solution of acetic acid

The dissolution of fibrous wollastonite (CaSiO₃) in the aqueous solution of acetic acid (3 mol dm^− 3) was investigated in the temperature interval from 25 to 50 °C using mixed batch-type reactor. An incongruent dissolution of wollastonite proceeds under applied acidic condition. The pH of solvent was increasing during leaching of calcium and its actual value depended on the concentration of Ca²⁺ ions in the solution according to the Henderson buffer equation. That enabled the monitoring of dissolution kinetics via concentration of Ca in the dispersion medium of suspension of wollastonite measurement. The kinetic parameter of the process was evaluated from measured dissolution rates of wollastonite at constant temperature using the empirical Arrhenius equation. The apparent activation energy and pre-exponential factor estimated from the Arrhenius plot are 47 ± 1 kJ mol^− 1 and (1.8 ± 0.9) × 10³ s^− 1. The kinetics analysis of the process indicates that the process is driven by the stationary two-dimensional diffusion (D₂).     

The kinetic analysis of the thermal decomposition of kaolinite by DTG technique

The thermal decomposition of kaolinite was studied by differential thermogravimetry (DTG) technique under non-isothermal conditions. Samples of industrially treated (washed) kaolin with high content of the medium ordered kaolinite were calcined using a heating rate from 1 to 40 K min^− 1. The apparent activation energy and frequency factor for the dehydroxylation of kaolinite was evaluated by Kissinger method as 195 ± 2 kJ × mol^− 1 and (8.58 ± 0.33) × 10¹⁴ s^− 1, respectively. Avrami exponent of the process was estimated using Kissinger empirical kinetic models and Carne equation.     

Surface and Grain Boundary Segregation in Fe‐3%Si Alloy

The surface segregation on the Fe‐3wt.%Si alloy was studied using X‐ray Photoelectron Spectroscopy (XPS) with synchrotron radiation at 150 eV photon beam energy (Si 2p). A silicon oxide layer and also segregation of Si atoms in three clearly resolved phases occurred during heat treatment. A formation of silicides mainly with the Fe₃Si superstructure was observed. A silicon nitride layer was created by nitrogen ion implantation. The structure and atomic ordering in a surface layer of the samples (approx. 300 nm thick) was checked by Conversion Electron Mössbauer Spectroscopy (CEMS). Simultaneously emission Mössbauer spectroscopy was used for the investigation of the Si concentration and atomic ordering at grain boundaries.