The incidence of black-pigmented (BP) Bacteroides spp. in 62 human dental root canal infections (35 acute and 27 clinically asymptomatic cases of apical periodontitis) in 57 adults was studied. Altogether 37 strains of BP Bacteroides were found in 31 infections, always in mixed anaerobic infections. Two different BP Bacteroides species were present in six infections. B. intermedius was most frequently isolated (15 of 62 canals; 24%) followed by B. denticola which was present in 12 cases. Asaccharolytic BP Bacteroides species, B. gingivalis and B. endodontalis, were found in eight cases. BP Bacteroides species were found both from symptomatic and asymptomatic infections, but there were also several symptomatic cases from which BP Bacteroides species were not isolated. B. gingivalis and B. endodontalis were present only in acute infections, B. intermedius was found both in symptomatic and asymptomatic infections, and B. denticolk occurred mostly in asymptomatic infections. BP Bacteroides species were isolated initially from 9 of the 11 teeth with symptoms at 1 week, but only from 22 of the 51 teeth that were symptomless at 1 week. Two strains of B. denticola were resistant to penicillin G at a concentration of 2.4 ,ug/ml, but the MIC of penicillin G for all other strains was 0.6 ,ug/ml or lower. Forty-two randomly selected patients received penicillin V (oral administration, 650 mg, three times daily) during the first week of endodontic therapy. Penicillin had no effect on the occurrence of symptoms after 1 week compared with the control group (20 patients).

A new technique for purification of bacterial pili was developed and applied to Escherichia coli strains isolated from the urine of patients with symptomatic urinary tract infections. After mechanical detachment from the bacterial cells, the pili were concentrated by precipitation with ammonium sulfate, dialyzed, and solubilized in buffer containing deoxycholate. The fraction containing the pili was purified further by ultracentrifugation in a sucrose gradient and by elution through a Sepharose 4B column in 6 M urea buffer. The pilus filaments were not dissociated by concentrated urea and were eluted in the void volume of the column. The purified pili had a molecular weight of 17,000. The isoelectric point of the pili from one of the strains was 4.9, and about 43% of the amino acids were hydrophobic. Hyperimmunesera raised in rabbits against the purified pili did not contain detectable antibodies to the lipopolysaccharide 0 antigen or to the capsular polysaccharide K antigen of the homologous strain. The pili obtained by this purification procedure are free from other detectable bacterial surface antigens, and the purified pilus filaments are of relatively homogeneous size. This procedure enables purification of the pili also from flagellated strains.flasks. The medium volume was 'Ao of the volume of 569 on July 9, 2020 by guest http://iai.asm.org/ Downloaded from LITERATURE CITED 1. Blakesley, R. W., and J. A. Boezi. 1l77. A new staining on July 9, 2020 by guest http://iai.asm.org/ Downloaded from turforsch. 76:148-155.

Pathology in the craniocervical junction is a serious complication of osteogenesis imperfecta (OI). Our aim was to analyze the prevalence and natural course of craniocervical junction anomalies in patients with OI during growth. In a one-center retrospective study, we analyzed lateral skull radiographs and midsagittal magnetic resonance images of 76 patients with either type I, III, or IV OI. The material included longitudinal series of 31 patients. In total, 150 patient images taken at ages 0 to 39 years were analyzed and compared with agematched control data. Craniocervical anomalies were observed in 37% of patients and in all OI types studied. Of the three types of anomalies, basilar invagination was seen in 13%, basilar impression in 15%, and platybasia in 29% of the patients. From those with an abnormal finding, 44% displayed more than one type of anomaly. At a group level, we found no evidence of progression of craniocervical junction pathology with age. We provide longitudinal and cross-sectional data on craniocervical junction dimensions in growing patients with OI and, based on those, suggest a radiological management strategy for diagnosis of cranial base pathology. A higher risk of having any of the pathological conditions was associated with a lower height Z-score. Careful follow-up of cranial base anomalies particularly in subjects with OI and severe growth failure is warranted. ß

A bacteriological investigation has been made in two cases of persistent periapical infections. Neither of the two infections responded to root canal therapy including penicillin or penicillin and erythromycin. Samples were taken aseptically for bacteriological examination through and root canals. Chloroform-washed, sterile paper points were used for sampling. Cultivation was performed immediately at chairside on Kanamycin-Vancomycin laked blood agar (KVLB) and blood agar supplemented with menadione, cysteine and glucose for anaerobic incubation and chocolate agar for aerobic incubation. Enterobacter cloacae was only isolate in case 1; Klebsiella pneumoniae and enterococci were found in case 2. Obligately anaerobic bacteria were not found. The treatment was successful after antibiotic therapy based on susceptibility testing of the isolates. The route of infection by facultative enteric rods is discussed.

Heritable dentin defects have been divided into 2 main categories: dentinogenesis imperfecta (DI) and dentin dysplasia (DD). Recent studies have shown that they share many features in common. Of the connective tissue diseases, only osteogenesis imperfecta (OI) has been linked to these disorders. So far, no definitive relation between the type of OI and the dental involvement can be established. Familial occurrence of DI with OI cannot be comprehensively explained by mutations in type I collagen genes. No information about the gene defects in DD is available. At the ultrastructural level, the organization of the normally cross-striated collagen fibers in the dentin matrix varies markedly in patients affected by DI.