Analysis of molecular variance (AMOVA) of Y-chromosome-specific microsatellites in two closely related human populations [published erratum appears in Hum Mol Genet 1997 May;6(5):828]

The analysis of seven Y-chromosome-specific microsatellite loci revealed a high level of polymorphism in two closely related human populations (Dutch, n = 89, and German, n = 70). Four of these loci were found to generate at least 77 different haplotypes, only 15 of which were shared by the two populations. These results demonstrate that highly informative PCR-based DNA typing of the Y chromosome is now feasible. Assuming a stepwise mutation model, a network comprising all minimum spanning evolutionary trees connecting the haplotypes was constructed. Analysis of molecular variance based upon this network indicated that the within-population heterogeneity with respect to haplotype descent was significantly smaller than the between-population heterogeneity, suggesting that males were more closely related to males from their own population as opposed to males from the other population. These findings suggest that Y-chromosomal microsatellites might be very useful not only for forensic purposes but also in association studies of multifactorial traits, allowing the characterization of the level of genetic distinctiveness of supposedly inbred or isolated populations and discrimination even between closely related populations.      

IL-2, IL-5, TNF-α and IFN-γ mRNA expression in epidermal keratinocytes of systemic lupus erythematosus skin lesions

OBJECTIVE:

To analyze cytokine gene expression in keratinocytes from patients with systemic lupus erythematosus (SLE).

INTRODUCTION:

Keratinocytes represent 95% of epidermal cells and can secrete several cytokines.

METHODS:

Keratinocytes were obtained by laser microdissection from 21 patients with SLE (10 discoid and 11 acute lesions) at involved and uninvolved sites. All patients were receiving a low/moderate prednisone dose and 18 were receiving chloroquine diphosphate. IL-2, IL-5, TNF-α and IFN-γ gene expression was evaluated by real-time PCR and expressed as the ratio (R) to a pool of skin samples from 12 healthy volunteers.

RESULTS:

Heterogeneity in cytokine gene expression was found among patients with SLE. Eighteen of 38 valid SLE samples (47%) presented overexpression (R>1) of at least one cytokine. Lesional skin samples tended to show higher cytokine expression than samples from uninvolved skin (p = 0.06). IL-5 and IFN-γ were the most commonly overexpressed cytokines. Samples with cytokine overexpression corresponded to more extensive and severe lesions. Prednisone dose did not differ between samples without cytokine overexpression (15.71±3.45 mg/day) and those with overexpressed cytokines (12.68±5.41 mg/day) (p = 0.216). Samples from all patients not receiving diphosphate chloroquine had at least one overexpressed cytokine.

CONCLUSIONS:

The heterogeneous keratinocyte cytokine gene expression reflects the complex immunological and inflammatory background in SLE. Patients with severe/extensive skin lesions showed a higher frequency of cytokine gene overexpression. Increased IFN-γ and IL-5 expression suggests that Th1 and Th2 cells are involved in SLE skin inflammation. The possibility that prednisone and antimalarial drugs may have contributed to low cytokine gene expression in some samples cannot be ruled out.     

A light and electron microscopic study of osteogenesis imperfecta bone samples, with reference to collagen chemistry and clinical phenotype

A detailed morphological study was carried out using light and electron microscopy on 36 bone specimens from patients suffering from osteogenesis imperfecta (OI) and 20 age- and site-matched control bone specimens. The findings were grouped into the clinical types of OI according to the Sillence classification. The morphological and ultrastructural alterations observed in OI bone correlate well with clinical severity. Thus, OI type I, the mildest type, showed the least abnormalities in bone ultrastructure. OI type IV closely resembled type I, with only minor abnormalities in the bone cells and osteoid. OI type III showed abnormalities in the structure and distribution of osteoid collagen fibrils, whilst OI type II, the lethal form, revealed many varied abnormalities such as thin cortical bone, sparse trabecular bone, increased numbers of osteoclasts and osteocytes, thin osteoid with thin collagen fibrils, and patchy mineralization.     

Mechanism of imipenem resistance acquired by threePseudomonas aeruginosa strains during imipenem therapy

Imipenem sensitive pretherapy isolates (MICs 1–2 mg/l) and the corresponding resistant posttherapy isolates (MICs 16 mg/l) ofPseudomonas aeruginosa from three patients undergoing imipenem treatment were analyzed to establish the resistance mechanism. The identity of pyocin types, serotypes, DNA restriction endonuclease profiles and plasmid profiles strongly suggested isogenicity of pre- and posttherapy isolates. The imipenem resistant posttherapy isolates showed cross-resistance only to another carbapenem, meropenem. There were neither qualitative nor quantitative differences between pre- and posttherapy isolates in -lactamase production. Affinity of the penicillin-binding proteins 1A, 1B, 2, 3, 4, 4 and 5 for [¹⁴C]imipenem was the same in pre- and posttherapy isolates. One-dimensional and two-dimensional gel electrophoresis of outer membrane protein preparations showed diminished expression of an outer membrane protein of about 46.5 and 47.5 kilodaltons, respectively, in the posttherapy isolates. This protein had an apparent isoelectric point of about pH 5.2 in two-dimensional gel electrophoresis. Growth in proteose peptone no. 2 broth did not reduce expression of this outer membrane protein, which spoke against its identity with the outer membrane protein D1. The permeability of the outer membrane for imipenem was reduced in the posttherapy isolates, since addition of 0.5 or 0.25 of the MIC of the permeabilizing agent ethylenediaminetetraacetate reduced the MICs of imipenem for all isolates from each patient to the same (susceptible) level. The diminished expression of one of the outer membrane proteins might be the reason for this reduced permeability.     

Short course single daily ceftriaxone monotherapy for acute bacterial meningitis in children: Results of a Swiss multicenter study. Part II: Bacteriological results

Summary Thein vitro activity of ceftriaxone, ampicillin and chloramphenicol was studied at a reference laboratory against the isolates of the first 33 patients enrolled in a pediatric Swiss Multicenter Meningitis Study. The predictive value of the MIC data of 31 of the strains was further corroborated by two sets of bacterial killing curves in broth supplemented with 2 g/l of albumin. Ceftriaxone had the lowest geometric mean MIC values against all groups of isolates except for ampicillin againstStreptococcus agalactiae. The bactericidal activity of ceftriaxone and that of ampicillin, alone and in combination with chloramphenicol, was compared at six times the respective MICs and at pharmacologically readily achievable concentrations in cerebrospinal fluid. The bactericidal power of ceftriaxone at six times the MIC was as good or better than that of ampicillin alone or in combination againstNeisseria meningitidis andStreptococcus pneumoniae despite the very low drug concentrations of ceftriaxone compared to that of the competitors; and it was barely lower at six times the MIC and at 1 mg/l (a level that is readily surpassed in CSF at the 24 h trough level after a single daily dose of ceftriaxone of 100 mg/kg (neonates 50 mg/kg) than that of ampicillin and chloramphenicol at much higher concentrations againstHaemophilus influenzae type b.

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Einmal tägliche Ceftriaxon-Kurzzeittherapie der akuten bakteriellen Meningitis bei Kindern: Resultate einer Schweizerischen Multizenterstudie. Teil II: Bakteriologische Resultate

Zusammenfassung DieIn vitro-Aktivität von Ceftriaxon, Ampicillin und Chloramphenicol wurde im Rahmen einer pädiatrischen Schweizerischen Multizenter-Meningitis-Studie gegen die Erreger der ersten 33 Patienten mit akuter bakterieller Meningitis geprüft. Bei 31 Stämmen wurden die MHK-Werte — in mit 2 g/l Albumin-angereichertem Medium — zusätzlich durch je zwei Sätze Abtötungskurven ergänzt. Ceftriaxon zeigte gemessen am geometrischen Mittel die niedrigsten Hemmkonzentrationen für alle Bakterienspezies ausgenommen der von Ampicillin gegenStreptococcus agalactiae. Die bakterizide Aktivität von Ceftriaxon und Ampicilin — alleine und in Kombination mit Chloramphenicol — wurden bei je sechsfacher MHK der Isolate sowie bei im Liquorraum gut erreichbaren antibakteriellen Konzentrationen getestet. Die bakterizide Aktivität von Ceftriaxon entsprach derjenigen, von Ampicillin alleine oder in Kombination gegenNeisseria meningitidis undStreptococcus pneumoniae, oder übertraf sie, obschon die Konzentration von Ceftriaxon bei sechsfacher MHK sehr viel kleiner als die der Vergleichspräparate war. Selbst gegen die auf die Ampicillin-Chloramphenicol-Kombination äußerst empfindlichenHaemophilus influenzae Typ b erwies sich Ceftriaxon als nur geringfügig weniger aktiv als höhere Konzentrationen von besagter Kombination.

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Members of the Swiss Multicenter Meningitis Study Group: Dr.E. Martin, Zürich; Dr.S. Rampini, Zürich; Dr.P. Sigg, Zürich; Dr.A. Fanconi, Winterthur; Dr.K. Baerlocher, St. Gallen; Dr.R. Haller, Münsterlingen; Dr.D. Vischer, Chur; Dr.O. Toenz, Luzern; Dr.H. Frei, Baden; Dr.E. Gugler, Aarau; Dr.G. Stalder, Basel; Dr.M. Vest, Bruderholz; Dr.H. Suter, Biel;Dr. M. Gianinazzi, Lugano; Dr.V. D'Appuazzo, Mendrisio; Dr.C. Godard, Monthey.     

Kyphoplastie in Kombination mit intraoperativer Radiotherapie

Background

Operative and radiotherapeutic procedures are available for the treatment of symptomatic vertebral metastases. The method for treatment of vertebral metastases presented in this article involves a combination of intraoperative radiotherapy (IORT) and kyphoplasty.

Methods and results

Kyphoplasty-IORT allows treatment of symptomatic vertebral metastases between vertebrae T3 and L5. With the patient under intubation narcosis an extrapedicular or bipedicular access to the vertebra is selected as for conventional kyphoplasty. This is followed by insertion of special sheaths of the radiation applicator and radiation therapy is intraoperatively administered via a radiation generator (Intrabeam®, Carl Zeiss Surgical, Oberkochen, Germany). The radiation dose is 8 Gy at a depth of 5–10 mm depending on the study protocol (50 kV X-radiation). Following radiation a conventional kyphoplasty procedure (Medtronic, USA) is carried out and the vertebra stabilized with cement.

Conclusions

The procedure presented demonstrates a new approach to treatment of vertebral metastases and represents a valuable alternative to previously established methods.     

Delivery of desflurane by a Tec 6 vaporizer at a concentration superior to that posted on the regulating valve]

We report the case of a defective Tec 6 vaporizer (Datex-Ohmeda) which delivered higher concentrations of desflurane (end-tidal concentration: 3.5 vol%) than indicated by the vaporizer dial setting (2 vol%), at a fresh gas flow of 1 L.min-1. This condition was caused by a defective rotary control valve. Therefore it is essential to administer desflurane only in presence of a vapour analyser.     

Generator localization by current source density (CSD): Implications of volume conduction and field closure at intracranial and scalp resolutions

The topographic ambiguity and reference-dependency that has plagued EEG/ERP research throughout its history are largely attributable to volume conduction, which may be concisely described by a vector form of Ohm’s Law. This biophysical relationship is common to popular algorithms that infer neuronal generators via inverse solutions. It may be further simplified as Poisson’s source equation, which identifies underlying current generators from estimates of the second spatial derivative of the field potential (Laplacian transformation). Intracranial current source density (CSD) studies have dissected the “cortical dipole” into intracortical sources and sinks, corresponding to physiologically-meaningful patterns of neuronal activity at a sublaminar resolution, much of which is locally cancelled (i.e., closed field). By virtue of the macroscopic scale of the scalp-recorded EEG, a surface Laplacian reflects the radial projections of these underlying currents, representing a unique, unambiguous measure of neuronal activity at scalp. Although the surface Laplacian requires minimal assumptions compared to complex, model-sensitive inverses, the resulting waveform topographies faithfully summarize and simplify essential constraints that must be placed on putative generators of a scalp potential topography, even if they arise from deep or partially-closed fields. CSD methods thereby provide a global empirical and biophysical context for generator localization, spanning scales from intracortical to scalp recordings.