Intraventricular chemotherapy in neonatal meningitis

All of 16 infants with neonatal meningitis treated during a 30-month period were found to have accompanying ventriculitis at the time of the initial ventricular puncture. Fifteen of these infants were caused by gramm-negative organisms. All infants received antibiotics systemically and intraventricularly via an implanted ventriculostomy reservoir or by direct ventricular injection. Antibiotic concentrations within the ventricular fluid were monitored during chemotherapy; the complications encountered during treatment are discussed. Fifteen infants survived the infection; of these, seven infants were normal at follow-up examinations. In our experience intraventricular chemotherapy as an adjunct to systemic administration of antibiotics has greatly reduced the mortality rate in neonatal meningitis.     

A novel catalyst–sorbent system for an efficient H2 production with in-situ CO2 capture

This paper presents an experimental investigation for an improved process of sorption-enhanced steam reforming of methane in an admixture fixed bed reactor. A highly active Rh/Ce_αZr_1−αO₂ catalyst and K₂CO₃-promoted hydrotalcite are utilized as novel catalyst/sorbent materials for an efficient H₂ production with in situ CO₂ capture at low temperature (450–500 °C). The process performance is demonstrated in response to temperature (400–500 °C), pressure (1.5–6.0 bar), and steam/carbon ratio (3–6). Thus, direct production of high H₂ purity and fuel conversion >99% is achieved with low level of carbon oxides impurities (<100 ppm). A maximum enhancement of 162% in CH₄ conversion is obtained at a temperature of 450 °C and a pressure of 6 bar using a steam/carbon molar ratio of 4. The high catalyst activity of Rh yields an enhanced CH₄ conversion using much lower catalyst/sorbent bed composition and much smaller reactor size than Ni-based sorption enhanced processes at low temperature. The cyclic stability of the process is demonstrated over a series of 30 sorption/desorption cycles. The sorbent exhibited a stable performance in terms of the CO₂ working sorption capacity and the corresponding CH₄ conversion obtained in the sorption enhanced process. The process showed a good thermal stability in the temperature range of 400–500 °C. The effects of the sorbent regeneration time and the purge stream humidity on the achieved CH₄ conversion are also studied. Using steam purge is beneficial for high degree of CO₂ recovery from the sorbent.     

Emulsifier Composition of Solid Lipid Nanoparticles (SLN) Affects Mechanical and Barrier Properties of SLN‐Protein Composite Films

Protein films can be applied to improve food quality and to reduce packaging waste. To overcome their poor water barrier properties, lipids are often incorporated. The function of incorporated lipid depends on the interface between filler and matrix. This study aimed to tailor the properties of a protein–lipid film by designing the oil/water interface to see if the concept of inactive/active filler is valid. Therefore, we varied the emulsifier stabilizing solid lipid nanoparticles (SLN) to promote (via β‐lactoglobulin) or to minimize (via Tween 20) interactions between particle surface and protein. SLN were incorporated into protein films and film properties were determined. Addition of SLN led to significantly decreased water vapor permeability (WVP) of protein films. However, WVP was mainly affected by the emulsifiers and not by the lipid. Protein‐stabilized SLN (BS) replaced a lacking protein in the protein network and therefore did not influence the mechanical properties of the films at ambient temperature. BS‐composite films were temperature sensitive, as lipid and sucrose palmitate melted at temperatures above 40 °C. Tween 20‐stabilized SLN (TS) led to reduced tensile strengths, probably due to perturbative effects of TS and plasticizing effects of Tween 20. Dynamic mechanical analysis showed that TS and Tween 20 increased film mobility. Melting of lipid and emulsifiers, and temperature‐dependent behavior of Tween 20 led to a strong temperature dependence of the film stiffness. By designing the interface, particles can be used to tailor mechanical properties of protein films. Tuned edible films could be used to control mass transfers between foods.     

Influence of rf-power on the plasma carbonitriding of titanium

The present work reports on the effect of input plasma processing power in the range of 350–650 W on the microstructure and mechanical properties of plasma nitrided Ti. The plasma processing time was 20 min and a gas mixture of 15% C₂H₂ and 85% N₂ was used. The characteristics of the carbonitrided layer have been investigated by microhardness measurements, surface roughness measurements, optical microscopy, and X-ray diffraction. The measured surface hardness values of the compound layer shows a maximum of 2050 HV0.1 for the sample treated at a plasma power of 550 W. The thickness of the carbonitrided layer continuously increases as the plasma power increases. Moreover, the highest carbonitriding rate of 3.52 μm²/s was observed when the input plasma power was adjusted at 600 W. This high carbonitriding rate of treated titanium samples is ascribed to the high concentration of active carbon and nitrogen species in the plasma atmosphere and the formed microcracks in the near surface of the sample during the plasma processing.     

Evolution of a new nonclassical MHC class I locus in two Old World primate species

HLA-G is a nonclassical major histocompatibility complex (MHC) class I molecule that is expressed only in the human placenta, suggesting that it plays an important role at the fetal-maternal interface. In rhesus monkeys, which have similar placentation to humans, the HLA-G orthologue is a pseudogene. However, rhesus monkeys express a novel placental MHC class I molecule, Mamu-AG, which has HLA-G-like characteristics. Phylogenetic analysis of AG alleles in two Old World primate species, the baboon and the rhesus macaque, revealed limited diversity characteristic of a nonclassical MHC class I locus. Gene trees constructed using classical and nonclassical primate MHC class I alleles demonstrated that the AG locus was most closely related to the classical A locus. Interestingly, gene tree analyses suggested that the AG alleles were most closely related to a subset of A alleles which are the products of an ancestral interlocus recombination event between the A and B loci. Calculation of the rates of synonymous and nonsynonymous substitution at the AG locus revealed that positive selection was not acting on the codons encoding the peptide binding region. In exon 4, however, the rate of nonsynonymous substitution was significantly lower than the rate of synonymous substitution, suggesting that negative selection was acting on these codons.     

Reconstitution of a functional interleukin (IL)-7 receptor demonstrates that the IL-2 receptor gamma chain is required for IL-7 signal transduction

The interleukin (IL)-2 receptor gamma chain has recently been shown to be a component of the IL-7 and IL-4 receptors. Using a transient transfection assay and the trans-activation of reporter gene constructs which are under the control of cytokine-responsive promoter elements, we have studied signal transduction through the IL-7 receptor (IL-7R). The reporter gene expression was not stimulated by receptors that contained the cytoplasmic domain of the IL-7R, either as intact IL-7R or as part of a chimeric receptor. However, co-expression of the IL-7R with the IL-2 receptor gamma chain was able to stimulate gene activation. For maximal stimulation the intact cytoplasmic domains of each chain was required.     

Urologic complications after simultaneous pancreas-kidney transplantation: hand-sewn versus stapled duodenocystostomy

Pancreas transplantation with bladder drainage of exocrine secretions may be associated with significant urologic complications. Stapled and hand-sewn duodenocystostomies were compared in 61 recipients of simultaneous pancreas-kidney transplants. Both methods resulted in similar urologic complication and allograft survival rates. Duodenal segment leaks were associated with significant morbidity and decreased patient and allograft survival.     

Chondrosarcoma of the jaw and facial bones

BACKGROUND: Osteosarcomas of the jaw frequently have chondroblastic differentiation, causing confusion with chondrosarcomas. METHOD: Clinicopathologic features and results of treatment were analyzed for a series of 56 patients (27 males and 29 females from 1.5 to 88 years of age) with chondrosarcoma of jaw and facial bones. Twelve patients (21.4%) were younger than 20 years. RESULTS: The major symptom was nasal obstruction or a painless mass; the median interval from the first symptom until initial treatment was 1 year. Of the 56 chondrosarcomas, 25(44.6%) involved the alveolar portion of the maxilla and maxillary sinus; 23 (41.1%) involved the nasal septum, ethmoid, and sphenoid; 6 (10.7%) involved the mandible; and 2 (3.6%) involved the nasal tip. Of the 19 patients with radiographic studies, 15 (78.9%) had an expanding soft tissue mass with varied matrix calcification and destruction of bone and 2 had a purely lytic lesion. The lesion was difficult to assess in the two others. Most tumors had a lobulated growth pattern of hyaline cartilage. Hypercellularity, nuclear pleomorphism, and binucleation were common features. Forty-three tumors were grade 1, 13 were grade 2, and none were grade 3. Modalities of treatment were known for 51 of the 56 patients. Forty-six patients (90.2%) had surgical treatment, 2 (3.9%) had combination radiation therapy and chemotherapy, 1 (2%) had radiation therapy alone, and 2 (3.9%) had biopsy only. Follow-up adequate for analysis was obtained for 42 patients. Of these, 14 (33.3%) had local recurrence; uncontrolled recurrence developed in 9 (21.4%) patients. No distant metastases were documented. Overall actuarial survival at 5, 10, and 15 years was 80.7%, 65.3%, and 56%, respectively. Survival was analyzed for location, size, and histologic grade of tumor. No statistically significant differences were found. CONCLUSIONS: Chondrosarcomas of the jaw and facial bones are extremely rare, locally aggressive tumors.     

Martingales without tears

This pedagogical paper presents a casual introduction to martingales, or fair gambling processes. Our objective is to describe the concept of a martingale and its application to common statistical tests used in the analysis of survival data, but without the mathematical rigor required for formal proofs. We use heuristic arguments to demonstrate that the logrank statistic evaluated over followup time is a fair gambling process, and introduce some mathematical notation and terminology along the way. We then employ the counting process approach to show that the logrank statistic computed over followup time can be expressed as the difference of two martingale transforms, and thus is a martingale. These ideas are first time introduced in the context of a discrete time process, and are then generalized to a continuous time process. With slight modifications, the same idea extends from the logrank to other weighted Mantel-Haenszel statistics computed over time.