A spontaneous 99-kb chromosomal deletion results in multi-antibiotic susceptibility and an attenuation of contact haemolysis in Shigella flexneri 2a

A Tn5-generated mutant (strain S2430) of Shigella flexneri 2a (strain YSH6000) exhibited attenuated virulence and, in addition to the Tn5 insertion in the SalI K fragment of its virulence plasmid, had a 99-kb deletion within its chromosome. Unlike its wild-type parent, strain S2430 was susceptible to ampicillin, streptomycin, tetracycline and chloramphenicol. An independent multi-antibiotic susceptible variant of strain YSH6000 had a similar deletion. Southern blot analysis of pulsed field electrophoresis gels enabled the sizing of this deletion and its mapping to a region of the chromosome on NotI fragment D bounded by the S. flexneri homologues of ompA and pyrC. Hybridisation experiments with a probe specific to the multi-antibiotic resistance region indicated that this large deletion was responsible for antibiotic susceptibility. Both strain S2430 and a derivative of the antibiotic-susceptible variant, with a Tn5 insertion in its SalI K fragment, exhibited an equal reduction in contact haemolysis compared with the Tn5-bearing derivative of strain YSH6000. However, strain S2430 alone clearly displayed delayed plaque forming ability in LLC-MK2 monolayers, suggesting that the two examples of this deletion may not be identical.

Time trends of child development in a Jerusalem community

The study of the Development Quotient (DQ-according to the Brunet-Lezine test) of two-year-olds living in a geographically defined area in Western Jerusalem was carried out for the birth cohorts of 1971 to 1989 (n = 4314). An 'Early Stimulation' programme was implemented from 1975 through the Mother and Child Health Clinic. The stimulation programme provided mothers with skills to enhance the development of their children through social interaction, play and verbal stimulation from birth to two years of age. The mean DQ at 2 years old increased significantly from 104.6 (SD = 9.8) for the 1972 cohort to 108.9 (SD = 9.1) for those born in 1989. Coordination and posture subscores followed the trends of the total DQ while the trends in language development were less marked. There is indication that children whose mothers had 9-11 years of schooling benefited more than other children. Better achievement on the developmental test as expressed in the mean DQ was probably related to changing socio-demographic characteristics of the population, and the implementation of the 'Early Stimulation' programme. The widening gap of the DQ after an initial decrease among children whose mothers had < or = 8 years of schooling and those in higher educational groups during the 80s may have been caused by the fact that the latter are a very disadvantaged group of families compared with the rest of the population.

Differential regulation of inducible nitric oxide synthase production in bovine and caprine macrophages

Inducible nitric oxide synthase (iNOS) regulation in human and murine macrophages in vitro differs considerably. In this study, expression of macrophage iNOS in ruminants was addressed. Nitric oxide (NO) output by cattle and goat macrophages was as different as that by human and mouse macrophages. Bovine macrophages activated by heated Salmonella dublin or lipopolysaccharide (LPS) expressed high levels of iNOS mRNA, protein, and enzyme activity. Analogously cultured caprine macrophages did not respond to these and other activators by NO generation and iNOS expression. The lack of response was not due to general unresponsiveness to stimuli. Caprine iNOS mRNA was induced by stimulation of caprine macrophages with LPS, as shown by reverse transcription polymerase chain reaction. The level of mRNA expression in activated goat macrophages was lower than in resting bovine macrophages. A caprine 372-bp iNOS mRNA fragment that was sequenced closely resembled the bovine counterpart. This points to species-specific iNOS gene regulation.

Bilateral vertebral artery tortuosity with concomitant vertebral erosion: CT and MRA findings

Focal vertebral artery tortuosity has been periodically reported as a rare cause of cervical vertebral body and foraminal erosion. Almost all reported cases are unilateral. A case of bilateral vertebral artery tortuosity is described with computed tomography and magnetic resonance angiography findings included.

Immunity and vaccine development in Pasteurella multocida infections

The role of LPS in immunity was studied using monoclonal antibodies (MAbs) and active immunisation experiments. A panel of six MAbs produced against Pasteurella multocida serotype B:2 reacted with the LPS of serotypes B:2 and B:5, but not with other serotypes. The MAbs could opsonise P. multocida for phagocytosis by mouse macrophages, but were not bactericidal in the presence of complement. They conferred only partial passive protection in mice. Similar results showing only partial protection were obtained when purified LPS was used to actively immunise mice prior to challenge, suggesting that LPS plays a partial role in immunity to infection. The aroA gene from P. multocida serotypes A:1 and A:3 was cloned and inactivated by insertion of a kanamycin resistance gene. The mutated gene was re-introduced onto the chromosome by allelic exchange. The resultant aroA mutants were highly attenuated in a mouse model system, with a 6-log decrease in ID50. Virulence could be restored by complementation with a functional aroA gene. Mice immunised with two doses of the live mutants were protected against lethal challenge with the homologous parental strain, but not against the heterologous strain. P. multocida A:1 and A:3 expressed unique proteins when grown in iron-restricted medium. Moreover, the outer membrane (OM) fractions of these cells contained novel proteins of 75 kDa, 85 kDa and 94 kDa molecular mass. Mice were immunised with OM fractions prepared from serotype A:3 grown in iron-restricted (OM Fe-) or iron-replete (OM Fe+) media. When low challenge doses were used, both immunogens protected mice against serotype A:3, but only the OM Fe- fraction protected mice against heterologous challenge with serotype A:1. When higher challenge doses were used, only partial protection was observed.

Preparation of antisera to recombinant, soluble N-acetylglucosaminyltransferase V and its visualization in situ

N-Acetylglucosaminyltransferase V (GlcNAc-T V) is a glycosyltransferase which transfers N-acetylglucosamine in beta(1,6) linkage to the alpha(1,6)-linked mannose residue of Asn-linked oligosaccharides. This enzyme is characterized by several unusual properties: GlcNAc-T V is the largest lumenal Golgi glycosyltransferase described thus far, and its multiple mRNA transcripts range from 4.5 to about 9.5 kb; GlcNAc-T V mRNA and activity are regulated by the src tyrosine kinase signalling pathway; in brain tissue, large levels of GlcNAc-T V mRNA are present, but only relatively low levels of catalytic activity can be detected; a lectin-resistant cell line, Lec4A, expresses active GlcNAc-T V which is mislocalized intracellularly. In addition, the cell surface oligosaccharide products of this enzyme have been hypothesized to regulate intercellular adhesion. In order to devise specific inhibitors of this enzyme it is necessary to understand its physical structure and how structural changes can influence its activity and localization. We have expressed milligram amounts of a soluble form of recombinant rat GlcNAc-T V, purified it from CHO cell-conditioned media, and used it to prepare specific antisera. This antisera binds selectively to GlcNAc-T V and has been used to visualize B-16 mouse melanoma cell GlcNAc-T V on immunoblots after SDS-PAGE. When the antisera was used in immunofluorescence microscopy experiments on permeabilized B-16 and baby hamster kidney cells, intense, specific staining was observed in intracellular structures which appear to correspond to the Golgi apparatus.

Interferon-alpha primes macrophages for lipopolysaccharide-induced apoptosis

Apoptosis plays an important role in generating and maintaining an effective immune system. Many pathogens can perturb the homeostasis of the immune system by either inducing or suppressing cell death of immune cells. Using bovine macrophages as a model, we found that interferon-alpha, one of the host's responses to viral infection, can prime macrophages for activation-induced apoptosis. Exposure of bovine bone-marrow-derived macrophages to interferon-alpha and subsequent activation with lipopolysaccharide led to a strong downregulation of the macrophages' nitric oxide production when compared to lipopolysaccharide stimulation alone. We could show that this was due to induction of apoptosis after activation of the cells. Herpesvirus-induced type I interferon also primed bovine macrophages for lipopolysaccharide-induced apoptosis. Our studies describe how in a novel pathway an antiviral immune response could contribute to pathological sequelae of viral diseases.

The development of disability scales for childhood and adolescent injuries

Scales for the study of injury-induced disabilities among 0-17 year olds were developed. Telephone interviews were conducted among parents of injured children (n = 432) 6 months after hospitalization in the three main hospitals of Jerusalem, about disabilities immediately following and 6 months after the injury. The scale for 4-17 year olds included 25 items derived from the International Classification of Disabilities, Impairments and Handicaps. Factor analysis revealed three dimensions of disability: personal care and daily activities; motor activities; and communication and sensory activities. The scale and the derived subscales on personal care and daily activities, and on motor activities showed high Cronbach's alpha, especially for disabilities immediately after the injury. The scale or subscales are easy to use, related to everyday activities performed by children in all cultures, are not related to the characteristics of the respondents, and have high consistency-reliability and construct validity. They may be used to assess the prevalence of disabilities in population studies.

Concerns and risk behaviors and the association between them among high-school students in Jerusalem

PURPOSE

To study the distribution, prevalence, determinants, and association between the health, social, and environmental concerns and risk behaviors of high school students in Jerusalem in order to provide a better basis for preventive and health promotion services.

METHODS

1078 tenth grade high school students, 15-16 years old answered an anonymous questionnaire including, perceived concerns and risk behaviors, (e.g., smoking, alcohol, drugs, and sexual activity). Concerns were grouped into six domains.

RESULTS

The most frequently reported concerns related to school, weight, coping with aggression, fatigue, war, enlistment into army, and relationships with peers. Girls had more concerns in the domains of self-image, anxiety, and relationships with peers (p < .05). Adolescents with mothers who had less education had significantly more concerns in the domains of anxiety and relationships with peers and adults (p < .05). Forty-seven percent engaged in at least one risk behavior (boys 63% and girls 34%). The Guttman scalogram indicated the following sequence of risk behaviors: alcohol, cigarettes, sex, and drugs. There were statistically significant associations between concerns and risk behaviors in the domains of anxiety, sex, and relationships with adults and peers.

CONCLUSION

Many adolescent concerns are universal, although the ranking and prevalence may vary based on different regional and population characteristics (e.g., in this population a high rate of concerns relating to aggression and war were identified). The results support the need to develop prevention and health promotion programs relating to the concerns and risk behaviors in the school and community, and individual counseling programs in primary care settings.

Hb Bibba or alpha 2 136(H19)Leu-->Pro beta 2 in a Caucasian family from Alabama

Several members of a large Caucasian family who presented with a congenital Heinz body hemolytic anemia were found to be carriers of the unstable Hb Bibba or alpha 2 136(H19)Leu-->Pro beta 2. Identification by protein analysis was hampered by the instability of the variant which complicated its isolation from shipped blood samples. Moreover, the detection of the CTG-->CCG mutation at codon 136 of the alpha 2 gene required the substitution of dGTP by dITP during the DNA sequencing process to prevent the occurrence of secondary structures and compressions in the sequencing gel. The first Hb Bibba heterozygote, characterized in 1968 (1), is believed to be a member of this family. The clinical expression of the disease is surprisingly variable.

Characterization of an antigenic oligosaccharide from Leptospira interrogans serovar pomona and its role in immunity

An antigenic oligosaccharide fraction derived from the lipopolysaccharide of Leptospira interrogans serovar pomona was isolated by endo-glycosidase H digestion and column chromatography. The oligosaccharide contained rhamnose, ribose, glucose, and glucosamine and inhibited the binding of opsonic, protective monoclonal antibodies directed against the lipopolysaccharide. When conjugated to diphtheria toxoid, the oligosaccharide elicited the production of agglutinating, opsonic antibodies.

Construction and vaccine potential of an aroA mutant of Pasteurella haemolytica

The aroA gene, encoding 5-enolpyruvylshikimate 3-phosphate synthase, from Pasteurella haemolytica biotype A, serotype 1 was cloned by complementation of the aroA mutation in Escherichia coli strain AB2829 after electroporation with a DNA library constructed in pUC18. The cloned P. haemolytica aroA gene was inactivated by insertion of a kanamycin resistance gene and reintroduced by allelic exchange into the chromosome of the parental P. haemolytica using PbluescriptII SK+. The P. haemolytica aroA mutant was highly attenuated in a mouse septicaemic model. Mice immunized intraperitoneally with two doses of live P. haemolytica aroA mutant were protected against a lethal parental strain challenge.

Serotype and genus specific protein antigens of Pasteurella multocida, revealed by monoclonal antibodies

Two monoclonal antibodies (mAbs) reacting with protein antigens of Pasteurella multocida strain M1404 were produced and designated DM-1 and DM-4. DM-1 reacted only with the homologous Heddleston serotype 2. On the other hand, DM-4 reacted with all the 16 Heddleston serotypes and with other Pasteurella spp., but not with any of the other genera tested. Both mAbs may thus be of significance for identification and classification. The antibodies could agglutinate P. multocida only if the cells were treated with 1N HCl. Neither of the mAbs could opsonise P. multocida for phagocytosis by mouse macrophages nor did they protect recipient mice against lethal infection. Active immunisation of mice gave rise to only partial protection against challenge infection, suggesting a minor role for these particular proteins in protection from infection.

Nucleotide sequence of the rhamnose biosynthetic operon of Shigella flexneri 2a and role of lipopolysaccharide in virulence

N1308, a chromosomal Tn5 mutant of Shigella flexneri 2a, was described previously as a lipopolysaccharide (LPS) mutant with a short O side chain. N1308 formed foci, but not plaques, in LLC-MK2 cell monolayers and was negative in the Serény test. In this study, the wild-type locus inactivated in N1308 was cloned and further defined by means of complementation analysis. A 4.3-kb BstEII-XhoI fragment of S. flexneri 2a YSH6200 DNA was sufficient to restore both normal LPS and virulence phenotype to the mutant. DNA sequencing of this region revealed four genes, rfbA, rfbB, rfbC, and rfbD, encoding the enzymes required for the biosynthesis of activated rhamnose. The four genes were expressed in Escherichia coli, and the expected protein products were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N1308 was shown to have normal levels of surface IpaC and IpaD, while a Western blot (immunoblot) of whole-cell lysates or outer membrane fractions indicated an elevated level of appropriately localized VirG. An in vitro invasion assay revealed that N1308 had normal primary invasive capacity and was able to multiply and move normally within the initial infected cell. However, it exhibited a significant reduction in its ability to spread from cell to cell in the monolayer. A double immunofluorescence assay revealed differences between LLC-MK2 cells infected with the wild-type YSH6000 and those infected with N1308. The wild-type bacteria elicited the formation of the characteristic F-actin tails, whereas N1308 failed to do so. However, N1308 was capable of inducing deposition of F-actin, which accumulated in a peribacterial fashion with only slight, if any, unipolar accumulation of the cytoskeletal protein.

Immunochemical studies of opsonic epitopes of the lipopolysaccharide of Leptospira interrogans serovar hardjo

Leptospiral lipopolysaccharides (LPS) are the main antigens responsible for immunity in leptospirosis. In this investigation we studied the nature of the antigenic determinants of LPS extracted from Leptospira interrogans serovar hardjo (reference strain Hardjoprajitno). The reactions of anti-LPS monoclonal antibodies (mAbs) MUM/F1-4/hardjo (IgM) and MUM/F1-6/hardjo (IgG) with whole cell lysates in Western immunoblotting analysis were unaffected by proteinase K treatment. Periodate treatment of the LPS destroyed the binding of MUM/F1-6/hardjo but preserved that of MUM/F1-4/hardjo. Alkaline phosphatase decreased significantly the binding of MUM/F1-4/hardjo to the LPS but only slightly that of MUM/F1-6/hardjo. On the other hand, phosphodiesterase totally destroyed the binding capacity of both monoclonal antibodies in enzyme immunoassays (EIA). A number of mono- and oligosaccharides was used in EIA inhibition studies. Mannose-6-phosphate and galactose-6-phosphate inhibited the binding of MUM/F1-4/hardjo (50% inhibition at a concentration of 5 mM) to the antigen, but glucose-6-phosphate did not. Galactosamine and mannosamine inhibited the binding of MUM/F1-6/hardjo (50% inhibition at a concentration of 3-4 mM), whereas only a weak inhibition was observed with glucosamine. In contrast, N-acetylated amino sugars did not show any inhibition. An O-acetyl group also appears to be involved in the antigen-antibody binding process.

[High-resolution x-ray computed tomography of bronchiolo-alveolar carcinoma]

Bronchioloalveolar cell carcinoma may cause three main patterns on CT: solitary nodule, parenchymal consolidation, and multicentric disease. The nodules usually have spiculated margins and frequently contain bubble-like lucencies or pseudo-cavitation. When presenting as consolidation, this is due mainly to mucin secretion and results in areas of lower attenuation than soft tissue. Multicentric disease is characterized by the presence of multiple nodules which may mimic metastatic disease. Although bronchioloalveolar cell carcinoma may cause different patterns on high-resolution CT, certain CT findings are sufficiently characteristic to suggest the underlying diagnosis.

Construction of a shuttle vector for use between Pasteurella multocida and Escherichia coli

The isolation of a small plasmid from Pasteurella multocida has enabled the construction of a shuttle vector for use between P. multocida and Escherichia coli. The vector pBAC64 contains the origin of replication from P. multocida, an antibiotic resistance gene which functions in P. multocida, and the E. coli vector pUC18. The presence of the pUC18 multiple cloning site together with the lacZ' gene provides a screening method and allows cloning and manipulation in E. coli as well as cloning in P. multocida.

Isolation, characterization, and expression of a cDNA encoding N-acetylglucosaminyltransferase V

A cDNA clone for the complete coding sequence for alpha-1,3(6)-mannosylglycoprotein beta-1,6-N-acetylglucosaminyltransferase V (GlcNAc-T V, EC 2.4.1.155) was isolated and expressed in COS-7 cells. Degenerate oligonucleotide primers for polymerase chain reaction were synthesized based on the amino acid sequence of three tryptic peptides isolated from affinity-purified GlcNAc-T V. Polymerase chain reaction amplimers were isolated from rat and mouse mRNA. A cDNA-encoding full-length enzyme was isolated from a rat 1 cell (EJ-ras-transformed) library and sequenced. Transient expression of this clone in COS-7 cells, followed by enzymatic activity assays, demonstrated that this cDNA sequence encodes GlcNAc-T V. Northern analysis of rat kidney mRNA revealed a single band corresponding to a length of about 7 kilobases. Sequence analysis of the cDNA clone demonstrated an open reading frame that encoded a type II membrane protein of 740 amino acids.

Moyamoya disease: no need for anastomotic surgery?

This paper describes an Australian of Caucasian descent with severe Moyamoya disease. She presented at the age of 34 with a subarachnoid haemorrhage. Between the ages of 45 and 48 she had multiple episodes of cerebrovascular ischaemia. Anastomotic surgery was carefully considered but not undertaken. Ten year follow up showed her to be extremely well without any further episodes of cerebrovascular disease. Accordingly it is recommended that surgery is probably not necessary in some cases, particularly in adults.

Site of transcriptional activation of virB on the large plasmid of Shigella flexneri 2a by VirF, a member of the AraC family of transcriptional activators

VirB plays a central role in the regulation of virulence of Shigella flexneri. It acts as a transcriptional activator and is itself transcriptionally activated by another virulence protein, VirF. Experiments were performed in order to identify the site upstream of virB at which VirF binds in order to activate transcription. Progressive 5' deletions of the DNA upstream of the transcription start point of virB were constructed by subcloning and Bal31 deletion. These deletion derivatives were cloned into the chloramphenicol acetyltransferase (CAT) reporter gene plasmid pKK232-8 and the resulting plasmids were analysed using a CAT activity assay. This allowed identification of minimal regions required for VirB promoter activity and regions required for full enhancement of promoter activity by VirF. A region approximately 100 bp upstream from the transcription start point of virB was identified as being necessary for full activation of this promoter by VirF. This region encompasses at least one inverted repeat which may play a role in transcription repression in the absence of the activator protein, VirF.