Prospective study of bacterial meningitis in North East Thames region, 1991-3, during introduction of Haemophilus influenzae vaccine.

OBJECTIVE--To describe the epidemiology of primary bacterial meningitis in the North East Thames region over a three year period before and during the introduction of the vaccine for Haemophilus influenzae type b. DESIGN--Analysis of information on cases of primary bacterial meningitis identified by microbiology laboratories in the region, with collection of case data by questionnaire. MAIN OUTCOME MEASURES--Annual incidence rates for types of meningitis according to age and ethnic group. RESULTS--The annual incidence rates for the three major causes of bacterial meningitis in the general population were 1.9/100,000 for Neisseria meningitidis, 1.6/100,000 for Haemophilus influenzae before vaccination, and 1.0/100,000 for Streptococcus pneumoniae. Higher rates of H influenzae meningitis were found in Asians compared with white people (3.6/100,000 v 1.5/100,000, P = 0.01). As a result of the vaccine programme introduced in October 1992 the number of cases of H influenzae meningitis in children under 5 years has fallen by 87%. CONCLUSIONS--Bacterial meningitis is a serious problem especially in preschool children. There are differences in the incidence of some causes of bacterial meningitis in different ethnic groups; with H influenzae type b being significantly more common among black and Asian people than among white people. The immunisation programme for H influenzae type b in the North East Thames region has been successful in reducing the incidence of this type of meningitis in Asian and white populations. The numbers were too small to evaluate in the black population.     

Inducible nuclear expression of NF-kappa B in primary B cells stimulated through the surface Ig receptor

Constitutive expression of NF-kappa B has been associated with developmental maturity in B cells on the basis of studies using continuously growing cell lines and plasmacytomas; however, little is known about the behavior of NF-kappa B in primary, mature B cells. In the present work, the regulation of NF-kappa B expression was studied by analyzing subcellular fractions of adult murine splenic B cells with the electrophoretic mobility shift assay using a kappa B-containing oligonucleotide. Although nuclear extracts from resting B cells contained kappa B-binding activity, additional kappa B-binding activity was present in cytosolic fractions in a form that became apparent after treatment with detergent. Competition analysis indicated that the DNA binding activity detected by electrophoretic gel mobility shift assay was specific for the kappa B motif, and UV photo-cross-linking showed the molecular size of kappa B-binding protein to be similar to that of the DNA binding subunit of NF-kappa B. Nuclear expression of kappa B-binding activity was markedly induced by treatment of B cells with phorbol ester or with LPS. Most notably, kappa B-binding activity was induced after surface IgR cross-linking, and the mechanism of this induction involved PKC. Further, anti-Ig-induced activity was superinduced in the presence of cycloheximide. These results indicate that nuclear NF-kappa B is rapidly induced as a result of B cell stimulation, and further suggest that NF-kappa B may play a specific role in mature B cells after ligand binding to surface Ig distinct from its postulated developmental role as a stage-specific factor involved in kappa-enhancer function.     

Quantitative structure-activity relationships of structurally similar odorless and odoriferous benzenoid musks

To reveal the difference of molecular property between structurallysimilar odorless and odoriferous musk compounds, 10 pairs ofbenzenoids (monocyclic-, dicyclic- and tricyclic-) were examined.Molecular structures of all compounds were optimized by MNDO(modified neglect of diatomic differential overlap) consideringconformation. Parameters effective in discriminating two groups,group A of 10 odorless compounds and group B of 10 musk odorcompounds, were searched from 34 candidate parameters by adaptiveleast squares. The best three parameters found were log P value(octanol/water partition coefficient), the longest side lengthof hexahedron circumscribing a molecule, and the parameter whichexpresses structural hindrance to the functional group whena molecule approaches the receptor site. The two groups of compoundswere completely discriminated using these three parameters.     

Streamer F mutants and chemotaxis of Dictyostelium.

Streamer F mutants have been found to be useful tools for studying the pathway of signal transduction leading to chemotactic cell movement. The primary defect in these mutants is in the structural gene for the cyclic GMP specific phosphodiesterase. This defect allows a larger and prolonged peak of cyclic GMP to be formed in response to the chemotactic stimulus, cyclic AMP. This characteristic aberrant pattern of cyclic GMP accumulation in the streamer F mutants has been correlated with similar patterns of changes in the influx of calcium from the medium, myosin II association with the cytoskeleton, myosin phosphorylation and a decrease in speed of movement of the amoebae. From these studies a sequence of events can be deduced that leads from cell surface cyclic AMP stimulation to cell polarization prior to movement of the amoebae in response to the chemotactic stimulus.     

Fine structure of frozen-etched lipid granules in the fat body of an insect

Lipid storage in fat-body cells of adult female black flies was examined using freeze-etching electron microscopy. Frozen-etched lipid granules exhibited a laminated structure. The molecular arrangement of the lipid granule may depend on the physiological condition of the insect and may be involved in the control of lipid metabolism in the fat-body cell.     

Conditional Maximum Likelihood Estimation Following a Group Sequential Test

We consider estimation after a group sequential test. An estimator that is unbiased or has small bias may have substantial conditional bias (Troendle and Yu, 1999, Coburger and Wassmer, 2001). In this paper we derive the conditional maximum likelihood estimators of both the primary parameter and a secondary parameter, and investigate their properties within a conditional inference framework. The method applies to both the usual and adaptive group sequential test designs. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Exploitation of Arabidopsis-tomato synteny to construct a high-resolution map of the ovatecontaining region in tomato chromosome 2.

High-resolution genetic and physical maps were constructed for the region of chromosome 2 containing the major fruit-shape locus ovate. A total of 3,000 NIL F2 and F3 NILs derived from Lycopersicon esculentum cv. Yellow Pear (TA503) x L. pennellii (a wild tomato) were used to position ovate adjacent to the marker TG645 and flanked by markers TX700 and BA10R (a 0.03-cM interval). BAC libraries and a BIBAC library were screened with the closest marker, TG645. Genetic mapping with the ends of isolated BAC clones revealed that two BAC clones (100 and 140 kb) both contained the ovate locus. Screening of sequences from these BAC clones revealed synteny between this segment of tomato chromosome 2 and the chromosome-4 region of Arabidopsis containing the BAC clone ATAP22. Microsynteny between the two genomes was exploited to find additional markers near the ovate locus. The placement of ovate on a BAC clone will now allow cloning of this locus and, hence, may open the door to understanding the molecular basis of fruit development and also facilitate the genetic engineering of fruit-shape characteristics. This also represents the first time that microsynteny with Arabidopsis has been exploited for positional cloning purposes in a different plant family.     

Active compounds in Populus nigra L. wilted leaves responsible for attracting Helicoverpa armigera (Hübner) (Lep., Noctuidae) and new agaropectin formulation

Abstract:  The leaf extracts of Populus nigra were collected and identified by steam distillation, air entrainment and gas chromatographic–mass spectrometric analysis. Electroantennograms were recorded from Helicoverpa armigera adults in response to the chemicals identified. Both aromatic compounds and green-leaf volatiles elicited strong responses. Field experiments revealed that the active compounds responsible for attracting H. armigera moths are mainly short-side-chain aromatic alcohols and aldehydes. We, for the first time, used agaropectin as the controlled-release matrix of insect attractants. A five-component lure containing all the aromatics without phenolics, mixed in the proportions as found in the steam distillate of the leaves collected in August, produced the best trap catch. The results showed that the volatiles of wilted leaves of P. nigra can attract H. armigera adults by feeding attraction.