Peracute streptococcal pyomyositis: report of two cases and review of the literature

Pyomyositis occurs infrequently in temperate climates. The fulminating peracute form caused by group A Streptococcus is exceedingly rare. We present two children with streptococcal pyomyositis. One child was admitted in septic shock and required intensive supportive care during the acute stage of his illness. Persistent swelling and tenderness of his left thigh presented a diagnostic problem, which was eventually resolved with the aid of computerized tomography. Despite appropriate antibiotic therapy from the onset of illness, surgical debridement of the affected muscle was necessary. The second child presented with pyomyositis of the left paravertebral muscles and signs of incipient shock but did well on antibiotic therapy alone.     

Concomitant and discriminatory validity of the Adolescents' Fear of Dental Treatment Cognitive Inventory

The revised edition of the Inventaire cognitif de la peur des traitements dentaire pour adolescent(e)s [Adolescents' Fear of Dental Treatment Cognitive Inventory] (ICPTD-A) was administered to 38 subjects chosen at random and to nine subjects chosen with an obvious dental phobia problem. Its concomitant validity was established by relating the ICPTD-A scores to those of a behavioral test. The Pearson correlation coefficients that were thus obtained were -0.66 for the general population and -0.87 for the population suffering from dental phobia. The discriminatory validity was then established with a repeated measurement variance analysis based on the scores of the dental phobics after the administration of a recognized psychological treatment program intended to reduce their phobia. The results have shown a statistically significant difference between the experimental and control groups as well as a significant difference between pre- and posttreatments. The authors have therefore concluded that the ICPTD-A is a valid tool for the assessment of dental phobia in 12-15-year-old adolescents.     

Bactericidal activity of human lactoferrin: influence of physical conditions and metabolic state of the target microorganism.

Lactoferrin is an iron-binding protein that is bactericidal against Streptococcus mutans and several other microorganisms. In this study, the influence of several physical conditions as well as the metabolic state of S. mutans on lactoferrin susceptibility were investigated. After exposure to lactoferrin, a 15-min lag period occurred before the initiation of killing, indicating that a two-step process is involved in lactoferrin killing. Cultures harvested during the early exponential phase were very sensitive to lactoferrin, whereas cultures harvested in the early stationary phase were markedly more resistant. The rate of killing was dependent on temperature; there was no loss of viability at 2 degrees C. Killing occurred at pH 5.0 to 6.0 in water and 20 mM glycine, but did not occur at any pH in 50 mM sodium phosphate or N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffer. Addition of exogenous ferrous or ferric ions did not reverse or prevent lactoferrin killing, nor did addition of 1 mM magnesium chloride.     

Rapid antimicrobial susceptibility testing of urinary tract isolates and samples by flow cytometry

A multiparametric flow cytometry antimicrobial susceptibility test was developed and its performance was evaluated on clinical urine isolates and samples in comparison with standard methods. Alterations in cytoplasmic membrane integrity were monitored by propidium iodide, and the anionic probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)) was used to measure changes in membrane potential. Microbial size and cellular content were analysed by light scattering. Twelve antibiotics were tested on 6 ATCC control strains, 22 urine isolates and 19 clinical urine samples, variously containing Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, Staphylococcus aureus, S. saprophyticus and S. epidermidis. Agreement between the flow cytometry results, broth microdilution and disk diffusion tests was 93.9% (n = 328 tests). Of the 20 discrepancies observed, 18 were for species other than E. coli. Perfect correlation was obtained with five antibiotics, whereas norfloxacin, nitrofurantoin and tetracycline were responsible for 13(65%) of the 20 discrepancies.     

Phylogenomics of the dog and fox family (Canidae,Carnivora) revealed by chromosome painting

Canid species (dogs and foxes) have highly rearranged karyotypes and thus represent a challenge for conventional comparative cytogenetic studies. Among them, the domestic dog is one of the best-mapped species in mammals, constituting an ideal reference genome for comparative genomic study. Here we report the results of genome-wide comparative mapping of dog chromosome-specific probes onto chromosomes of the dhole, fennec fox, and gray fox, as well as the mapping of red fox chromosome-specific probes onto chromosomes of the corsac fox. We also present an integrated comparative chromosome map between the species studied here and all canids studied previously. The integrated map demonstrates an extensive conservation of whole chromosome arms across different canid species. In addition, we have generated a comprehensive genome phylogeny for the Canidae on the basis of the chromosome rearrangements revealed by comparative painting. This genome phylogeny has provided new insights into the karyotypic relationships among the canids. Our results, together with published data, allow the formulation of a likely Canidae ancestral karyotype (CAK, 2n = 82), and reveal that at least 6–24 chromosomal fission/fusion events are needed to convert the CAK karyotype to that of the modern canids. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Substance P given intrathecally at the spinal T9 level increases adrenal output of adrenaline and noradrenaline in the rat

Administration of 10 micrograms of substance P intrathecally to the spinal T9 level of the adult rat, anaesthetized with urethane, provoked an increase in free catecholamines in plasma taken from the inferior vena cava. Adrenaline levels at 1 min after administration were 154.8 +/- 10.8% (mean +/- SE; n = 11) of preadministration levels and noradrenaline levels were 153.5 +/- 11.8% of preadministration levels. Differences between the values of free catecholamines in animals given substance P vs those given vehicle only were statistically significant at 1 and 10 min postinjection, but not at 30 min. Administration of a substance P analogue with central antagonistic properties 15 min before substance P was given prevented expression of the effects of substance P. These results suggest that substance P may be an excitatory chemical mediator of synaptic transmission in spinal pathways controlling adrenal medullary output. Thus dysfunction of substance P mechanisms may underlie some animal models of hypertension and may be involved in some cases of essential hypertension in man as well as in autonomic dysfunction associated with some neurological entities.     

Na/P(i) cotransporter ( Npt2) gene disruption increases duodenal calcium absorption and expression of epithelial calcium channels 1 and 2

Mice homozygous for the disrupted type-II Na/P(i) cotransporter gene ( Npt2(-/-)) exhibit hypophosphataemia, increased serum concentration of 1,25-dihydroxyvitamin D (1,25-(OH)(2)D) and calcium (Ca) and elevated urinary Ca excretion. To determine whether the hypercalcaemia and hypercalciuria are secondary to 1,25-(OH)(2)D-stimulated intestinal Ca absorption, we examined the effect of Npt2 gene disruption on serum Ca and urinary Ca excretion after an overnight fast, and on duodenal Ca absorption. We also compared the duodenal expression of the epithelial Ca channels, ECaC1 and ECaC2, and calbindinD(9K) mRNAs, relative to that of beta-actin mRNA, in Npt2(+/+) and Npt2(-/-) mice. Both serum Ca and urine Ca/creatinine were significantly decreased in Npt2(-/-) mice after an overnight fast and were no longer different from that in wild-type mice. Absorption of (45)Ca from isolated duodenal segments in vivo and (45)Ca appearing in the plasma were significantly increased in Npt2(-/-) compared with Npt2(+/+) mice. In addition, the duodenal abundance of ECaC1, ECaC2 and calbindinD(9K) mRNAs was significantly elevated in mutant mice relative to that in wild-type mice. In contrast, both duodenal Ca absorption and ECaC1 and ECaC2 mRNA abundance were lower in mice with X-linked hypophosphataemia ( Hyp) than in normal littermates. In summary, we provide evidence for increased duodenal Ca absorption in Npt2(-/-) mice and suggest a role for ECaC1, ECaC2 and calbindinD(9K) in mediating this response.     

Autosome and Sex Chromosome Diversity Among the African Pygmy Mice, Subgenus Nannomys (Murinae; Mus)

The African pygmy mice, subgenus Nannomys, constitute the most speciose lineage of the genus Mus with 19 recognized species. Although morphologically very similar, they exhibit considerable chromosomal diversity which is here confirmed and extended by the G-banding analysis of 65 mice from West and South Africa. On the basis of their karyotype and distribution area, the specimens were assigned to at least five species. Extensive differentiation both within and between species was observed that involved almost exclusively Robertsonian translocations, 23 of which are newly described. Two of the rearrangements were sex chromosome-autosome translocations, associated in some cases with partial deletions of the X or Y chromosomes. Several authors have predicted that the highly deleterious effect of this rearrangement would be reduced if the sex and autosomal segments were insulated by a block of centromeric heterochromatin. The C-banding analyses performed showed that among the species carrying X-autosome translocations, one followed the expected pattern, while the other did not. In this case, functional isolation of the sex and autosome compartments must involve other repetitive sequences or genomic traits that require further molecular characterization. Such studies will provide insight into the causes and consequences of the high diversity of sex chromosome rearrangements in this subgenus.