Primary stability of two uncementedacetabular components of different geometry: hemispherical or peripherallyenhanced?

OBJECTIVE: This study compared the primary stability of two commercially available acetabular components from the same manufacturer, which differ only in geometry; a hemispherical and a peripherally enhanced design (peripheral self-locking (PSL)). The objective was to determine whether altered geometry resulted in better primary stability. METHODS: Acetabular components were seated with 0.8 mm to 2 mm interference fits in reamed polyethylene bone substrate of two different densities (0.22 g/cm(3) and 0.45 g/cm(3)). The primary stability of each component design was investigated by measuring the peak failure load during uniaxial pull-out and tangential lever-out tests. RESULTS: There was no statistically significant difference in seating force (p = 0.104) or primary stability (pull-out p = 0.171, lever-out p = 0.087) of the two components in the low-density substrate. Similarly, in the high-density substrate, there was no statistically significant difference in the peak pull-out force (p = 0.154) or lever-out moment (p = 0.574) between the designs. However, the PSL component required a significantly higher seating force than the hemispherical cup in the high-density bone analogue (p = 0.006). CONCLUSIONS: Higher seating forces associated with the PSL design may result in inadequate seating and increased risk of component malpositioning or acetabular fracture in the intra-operative setting in high-density bone stock. Our results, if translated clinically, suggest that a purely hemispherical geometry may have an advantage over a peripherally enhanced geometry in high density bone stock. Cite this article: Bone Joint Res 2013;2:264-9.

Human and canine leishmaniasis in asymptomatic and symptomatic population in Northwestern Greece.

The occurrence of human and canine Mediterranean visceral leishmaniasis (MVL) in Northwestern Greece was investigated during an 8-year survey (1994-2001). A total of 1200 blood sera samples, collected from asymptomatic human population, and 1200 blood sera samples from asymptomatic dogs were screened for Leishmania infantum antibodies using the indirect immunofluorescence test (IFA). Also during the survey 111 human subjects and 350 canines were referred as clinically suspect cases for MVL. Significant differences (p = 0.001) were found between the prevalence of MVL in symptomatic and asymptomatic human populations (12.6 and 0.5%, respectively), but a more modest difference was observed between symptomatic and asymptomatic canines (45.4 and 24.4%, respectively). From the results, it appears that Greece has a high background of canine leishmaniasis, which is likely to be a risk factor for the emergence of human MVL.

Bacterial strains isolated from eggs and their resistance to currently used antibiotics: is there a health hazard for consumers?

In order to study the putative transfer of antibiotic resistance from poultry to humans, hens' eggs were examined for the presence of various pathogens. Staphylococcus, Enterobacter, Escherichia, Proteus and Pseudomonas spp. were the most frequently isolated genera. Sensitivity tests, performed with the Kirby-Bauer technique, showed the presence of resistant strains of Staphylococcus aureus (to penicillin-G, tetracycline, erythromycin, clindamycin, cefalosporins, oxacillin, gentamycin, chloramphenicol and tobramycin), Enterococcus faecalis (to ampicillin, ciprofloxacin, clindamycin, gentamycin and tetracyclin), Escherichia coli (to tetracycline, erythromycin, ampicillin and cefalosporins), Enterobacter cloacae (to ampicillin, amoxycillin plus clavunalic acid, erythromycin and tetracycline), Pseudomonas stutzeri (to erythromycin and chlorampenicol) and Citrobacter freundii (to ampicillin, amoxycillin plus clavunalic acid, cefalosporins and co-trimoxazole).

Survival of enterobacteria in liquid cultures during microwave radiation and conventional heating.

Bacteria in food have been reported to survive in larger numbers after processing by microwave radiation than after conventional processing. The bactericidal effect of a domestic microwave oven (SHARP R-7280) on certain pathogenic enterobacteria species was investigated in vitro, in comparison with conventional heating (boiling). The death rates of different nosocomial strains of Escherichia coli, Salmonella sofia, Salmonella enteritidis, Proteus mirabilis and Pseudomonas aeruginosa were tested. The microwave oven and the conventional heating system used were both calibrated in order to calculate temperatures from exposure times. For each strain duplicate samples of 25 ml of pure culture with concentrations at least 10(6) cfu/ml were exposed to microwave radiation. An equal number of samples of the same volume and concentration were exposed to conventional heating. Subsequently all samples were examined qualitatively and quantitatively following standard microbiological procedures. The results indicate that microwaves have an efficient bactericidal effect on the enterobacteria in liquid cultures.

Detection of chlamydia trachomatis antigen using the direct immunofluorescence technique: a four year survey in Northwestern Greece.

The prevalence of Chlamydia trachomatis antigen in patients visiting the University Hospital of Ioannina, North-western Greece during 1991-1993 is surveyed. Six hundred and twenty two (622) samples (scrapings from the cervix, uretra and conjunctiva) were examined for the detenction of C. trachomatis antigen using the direct immunofluorescence technique (DIF). From the 662 samples examined by DIF, 579 were found negative (93%) and 43 positive (7%).

[Primary observation of a congenital intracranial teratoma in a twin with a healthy brother]. / Erstbeobachtung eines kongenitalen intrakraniellen Teratoms bei einem Zwillingskind mit gesundem Bruder.

Primary intracranial teratomas are rare germ cell tumors arising from embryonic tissues, which contain cellular or tissue derivates from all three germ layers. Today the early intrauterine diagnosis by ultrasound is possible. We first describe a patient with such a tumor which was diagnosed by routine ultrasound in the 33rd week of gestational age in a twin-pregnancy, of which the 2nd twin developed normally. This must be considered in the obstetrical situation. In such a case the parents should be advised accordingly.