Mechanism of immunity to Corynebacterium pseudotuberculosis (Buchanan, 1911) in mice using inactivated vaccine

Mice can be passively protected against infection with Corynebacterium pseudotuberculosis with hyperimmune rabbit serum prepared against whole bacterial cells. The mechanism of immunity depends on the inhibition of secondary multiplication of the bacteria, not on antitoxic activity or enhanced phagocytosis and destruction. Passive transfer of macrophages obtained from mice immunized with inactivated vaccine to susceptible mice which were subsequently challenged showed that the macrophages have no specific immunizing properties.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The serological and immunological relationship of type strains A and D of Pasteurella multocida to field isolates from sheep

Investigations with antisera prepared in rabbits and sheep and active immunity experiments in mice showed that strains of Pasteurella multocida which, according to the haemagglutination test, are serologically related, do not necessarily give rise to cross immunity. Conversely, it was found that serologically unrelated strains may exhibit an appreciable degree of cross protection. The unreliability of the haemagglutination test as an indicator of immunological identity of strains was further confirmed in that peritoneal fluid from immunized mice showed passive protection properties despite the absence of haemagglutinating antibodies. There was no consistent agreement between the results obtained with antisera prepared in different species and active immunity experiments in mice, and this leads to the conclusion that different species probably vary quantitatively and qualitatively in their immune response to immunization with P. multocida. Attempts to determine whether combined bacterins afforded a better immunity than monovalent bacterins were inconclusive.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Relation between macrophage migration inhibition and immunity to Brucella abortus in guinea-pigs

A soluble protein antigen was prepared from Brucella melitensis Rev I with which macrophage migration inhibition (MMI) assays were successfully done using guinea-pig peritoneal exudate cells. By comparing the MMI, agglutinin response and immunity of groups and of individual guinea-pigs which had been immunized with either B. melitensis Rev I live vaccine or B. melitensis Rev I inactivated antigen, an association between the MMI and resistance to infection was demonstrated.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format

Immune response of Merino sheep to inactivated Corynebacterium pseudotuberculosis vaccine

The brand of yeast extract used for medium production is critical for the cultivation of large numbers of Corynebacterium pseudotuberculosis. The agglutination test was used to measure the antibody response which followed the inoculation of various inactivated C. pseudotubermlosis vaccines . The best results followed two subcutaneous injections of 5 ml vaccine prepared by inactivation with 0,5% formalin and standardized so that each dose contained a total of 0,025 ml packed cells. The addition of adjuvants to the vaccine had a negligible effect on the antibody response, but increasing the interval between the primary and secondary injections from 2 or 4 to 6 weeks resulted in a higher level of agglutinating antibodies. The antibody titres, however, returned to pre-immunization levels within 3 to 4 months. Freshly prepared vaccine was very toxic, apparently due to incomplete toxoiding of the exotoxin, but older vaccine was shown to be quite safe. A method was devised whereby chronic pulmonary abscesses could be established in experimental animals. Exposure of immunized sheep to artificial infection showed that they were well protected against subacute infection and death but that they were not able to restrict the development of abscesses effectively. The possible reasons for the disappointing results are discussed in terms of the mechanisms of immunity which may be involved.The articles have been scanned in colour with a HP Scanjet 5590;300dpi. adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

MicroRNA-224 is Readily Detectable in Urine of Individuals with Diabetes Mellitus and is a Potential Indicator of Beta-Cell Demise.

MicroRNA (miRNA) are a class of non-coding, 19-25 nucleotide RNA critical for network-level regulation of gene expression. miRNA serve as paracrine signaling molecules. Using an unbiased array approach, we previously identified elevated levels of miR-224 and miR-103 to be associated with a monogenic form of diabetes; HNF1A-MODY. miR-224 is a novel miRNA in the field of diabetes. We sought to explore the role of miR-224 as a potential biomarker in diabetes, and whether such diabetes-associated-miRNA can also be detected in the urine of patients. Absolute levels of miR-224 and miR-103 were determined in the urine of n = 144 individuals including carriers of a HNF1A mutation, participants with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM) and normal controls. Expression levels were correlated with clinical and biochemical parameters. miR-224 was significantly elevated in the urine of carriers of a HNF1A mutation and participants with T1DM. miR-103 was highly expressed in urine across all diabetes cohorts when compared to controls. For both miR-224 and-103, we found a significant correlation between serum and urine levels (p \u3c 0.01). We demonstrate that miRNA can be readily detected in the urine independent of clinical indices of renal dysfunction. We surmise that the differential expression levels of miR-224 in both HNF1A-MODY mutation carriers and T1DM may be an attempt to compensate for beta-cell demise

The use of point-of-care ultrasound in Tshwane public and private sector emergency units

Background: The use of point-of-care ultrasound (POCUS) is an essential skill in the practice of emergency medicine (EM), with benefit to patient care by improving diagnostic accuracy. Despite this, there exists little data evaluating the use of POCUS in South African emergency units (EUs.). Methods: One hundred and seventeen doctors working in 12 public and private sector EUs in Tshwane were included. A questionnaire was used comprising of descriptive data regarding doctor demographics, levels of experience, and outcome data including POCUS frequency use, training level, indications for, and barriers to its use. Results: Many participants were general practitioners working in EUs (58.1%) followed by EM specialists and EM registrars. Of these participants, 88% used POCUS. Seventy one percent received informal POCUS training only. The indications for POCUS use were similar for both public and private sector, with no significant differences in overall use. The only significant association to POCUS use was age ( 33.3 years) and number of years since qualification ( 6.9 years.) Lack of and/or access to training were the main reasons for not using POCUS (18.8%.) There were no significant differences in the barriers to the use of POCUS between the sectors. Conclusion: Point-of-care ultrasound is used similarly in both public and private sector EUs in Tshwane. Lack of and/or access to POCUS training are the main barrier to its use. Contribution: This study underlines the state of POCUS use in Tshwane and highlights the barriers to its use, thus allowing academic heads and hospital managers to address them

The role of the PCA3 assay in predicting prostate biopsy outcome in a South African setting

OBJECTIVES • To evaluate the investigational role, ideal threshold and indications of the Prostate CAncer gene 3 (PCA3) assay in a South African context. • To better define the universality of the above marker since this is the pioneer study on the continent of Africa. PATIENTS AND METHODS • We prospectively evaluated 105 consecutive South African men referred for a prostate biopsy at two tertiary centres in the capital city, Pretoria. • Sequentially, PSA levels and post DRE urine samples were taken within 24 h before prostate biopsy. • The urine specimen was tested using the PROGENSA TM PCA3 assay and a score was generated as (PCA3 mRNA/PSA mRNA)× 1000. • The performance of this assay in predicting biopsy outcome was assessed, and compared with that of serum PSA. RESULTS • Median patient age was 67 years with a positive biopsy incidence of 42.9%. • The higher the PCA3 score the greater the probability of a positive biopsy ( P = 0.003). • This score performed independently of prostatic volume ( P = 0.3889) or the presence of a concurrent primary malignancy ( P = 0.804). • A threshold of 60 revealed a positive predictive value of 60% with an odds ratio of 4, whereas setting a limit of 35 revealed a positive predictive value of 54% and odds ratio of 3.5. • Using receiver operating characteristics for overall performance comparison, the PSA level (area under the curve 0.844) performed better than the PCA3 score (area under the curve 0.705). CONCLUSION • PCA3 assay has shown consistency and performed in line with previous studies but it did not surpass serum PSA in this population. • A PCA3 assay threshold of 60 performed better than the conventional limit of 35. • This assay may have a potential niche in a certain subset of South African men that includes patients with larger glands, previous negative biopsies and altered baseline PSA levels.IlexSA Medical and Lancet Laboratories (South Africa)

On the Origin and Spread of the Scab Disease of Apple: Out of Central Asia

Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion.Contexte Venturia inaequalis est un champignon ascomycete responsable de la tavelure du pommier, une maladie qui a envahi presque toutes les régions du monde où le pommier est cultivé posant ainsi de graves problèmes en production. Prévenir et enrayer efficacement la réussite d’un tel succès invasif nécessite des connaissances approfondies sur l’origine, les voies d’introduction, la biologie et la génétique de ces populations invasives. En utilisant le potentiel d’inférence de la génétique des populations, l’analyse de la variation de marqueurs génétiques offre la possibilité d’accéder à ces informations. Méthodologie et Principaux résultats Ici nous présentons l’analyse de données microsatellites obtenues pour 1273 souches de V. inaequalis provenant de 28 vergers prélevées dans 7 régions sur les 5 continents. L’analyse de la variance moléculaire révèle que 88% de la variation se retrouve dans les vergers échantillonnés, ce qui est compatible avec d’importantes migrations historiques du champignon entre et à l’intérieur même des régions. Malgré cette très faible structuration des populations, les différentes analyses de clustering mettent en évidence un partage des populations en groupes séparés correspondant à leur origine géographique, montrant ainsi que chaque région héberge une population distincte du champignon. Ensemble, les résultats obtenus sur la comparaison du niveau de variabilité entre populations, les analyses de coalescence et les modèles de migration testés plaident en faveur d’un scénario dans lequel le champignon aurait émergé d’Asie Centrale, où le pommier a été domestiqué, avant d’être introduit en Europe puis plus récemment dans les autres continents suite à l’expansion de la culture du pommier. Les niveaux de variabilité indiquent que ces territoires ont subi des introductions multiples et que les populations portent toutes des signatures révélant de fortes expansions démographiques après leur introduction. Enfin, la forte diversité génotypique des populations et l’association aléatoire des allèles entre loci suggèrent que le champignon présente une reproduction sexuée régulière à la fois dans les régions où il a été introduit et dans sa région native. Conclusion et Portée. Venturia inaequalis est un modèle de champignons phytopathogène invasif qui a maintenant atteint le stade ultime du processus invasif, c’est à dire une très large distribution géographique par des populations bien établies montrant une grande diversité génétique, une reproduction sexuée régulière et une histoire d’expansion démographique