Detection of Chlamydia trachomatis in Papanicolaou-stained cervical smears by an indirect immunoperoxidase method

A two-step (indirect) immunoperoxidase method directed against Chlamydia trachomatis was developed. The method was then used to evaluate the specificity of cytologic changes suggestive of C. trachomatis in Papanicolaou smears of cervical specimens from women who were culture-negative for the organism. Positive immunoperoxidase staining was detected in 9 of 21 cases (43%) tested. Technical problems, especially background staining, precluded interpretation in the remainder of the cases. Cervical cytology, as demonstrated by immunoperoxidase staining, may, in some instances, be more sensitive than the culture. However, because the etiology of cytologic changes not specifically identified by immunoperoxidase staining may be due to other organisms or factors, immunoperoxidase procedures, as described, should not replace culture for confirmation of cytologic findings suggestive of C. trachomatis.     

Using the protein chip interface with quadrupole time‐of‐flight mass spectrometry to directly identify peaks in SELDI profiles – initial evaluation using low molecular weight serum peaks

Mass spectrometric profiling, particularly in the form of SELDI, has been used in many studies, particularly in attempts to generate diagnostic serum profiles. Several studies have generated promising results but one of the limitations is the inability to identify easily potential discriminatory peaks. This may enable specific assays to be developed and increased biological insight. We describe the first systematic technical evaluation of the ProteinChip interface coupled to a tandem mass spectrometer which allows direct sequencing of peptides <6000 Da, and describe the direct sequence identification of 21 peaks commonly observed in serum samples. Additionally we describe for the first time the use of on‐chip acetylation to assist in the validation of sequence identification.     

The effects of cross-fostering on the behaviour of two species of North American lemmings, Dicrostonyx groenlandicus and Lemmus trimucronatus: I. Olfactory preferences

To determine the role of the maternal environment in the development of adult olfactory preferences, the young of two species of North American lemmings (Dicrostonyx groenlandicus and Lemmus trimucronatus) were reciprocally cross-fostered shortly after birth. In-fostered (reared by foster conspecific females) and non-fostered animals served as controls. When adult, subjects were tested for olfactory preferences in a free-choice Y-maze olfactometer. When compared to controls, cross-fostered animals showed increased preference for heterospecific odour. This effect was stronger for males than for females. These results suggest that adult species-specific odour preferences are learned during the neonatal period.     

Natal origin and dispersal of problem saltwater crocodiles in the Darwin Harbor,Australia

Management programs that successfully recovered wild saltwater crocodile (Crocodylus porosus) populations in the Northern Territory of Australia did so with an expanding commitment to maintaining public safety. One aspect of the program is the ongoing removal of resident and immigrant crocodiles within Darwin Harbor (since 1979), the main urban center. We determined the likely sources of crocodiles caught as problem animals between 2015–2017 by comparing recently developed methods for population assignment. Depending on the assignment model used, we estimated that between 30% and 50% of crocodiles in Darwin Harbor originated from the Adelaide and Mary rivers, and the Kakadu region east of Darwin, and between 20% and 30% of crocodiles originated from the Finniss, Reynolds, and Daly rivers southwest of Darwin. Saltwater crocodiles occur at particularly high densities in these catchments. The remainder came from a mixture of different sources across the Northern Territory. The most common animals captured were immature (150–180 cm) males that have traveled 100–200 km. We did not identify any relationships between the distance from the inferred origin to Darwin Harbor and the size and sex of the crocodiles, or the year of capture. The targeted removal of crocodiles from specific sites such as Darwin Harbor, near where most people live, improves public safety in the highest risk areas, without compromising abundant source populations in most areas.     

Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation

The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation.     

Temporal and spatial responses of Chironomidae (Diptera) and other benthic invertebrates to urban stormwater runoff

In a longitudinal study of two streams whose lower reaches received unattenuated urban stormwater runoff, physical disturbance by stormflow was less important than the persistant unidentified chemical impacts of urban stormwater in limiting the distribution of Chironomidae, and Ephemeroptera, Trichoptera and Plecoptera (EPT). A hierarchical spatial analysis showed that chironomid density did not decrease from rural to urban stream reaches. Instead, the taxonomic composition of chironomid assemblages was significantly altered in urban versus rural reaches; chironomid assemblages in urban reaches exhibited higher average pollution tolerance scores. In contrast, the density of EPT was significantly lower in urban reaches. Despite higher values of stormflow tractive force in urban reaches, streambed stability tended to be greater in urban reaches. Modeling of temporal variation in chironomid density showed similar patterns in both rural and urban reaches: chironomid density had a unimodal relationship to rainfall index (RI), with highest densities at intermediate values of RI. Models of EPT density over time in rural reaches showed no significant relation to RI, and temporal variation in EPT density in urban reaches was not predictable. The abundance of fine particulate organic matter, including periphyton (FPOM), on cobbles was greater in urban reaches and showed a much greater degree of temporal variation than in rural reaches. In urban reaches, a negative relation between FPOM and RI indicated the importance of stormflow abrasion. Handling editor: K. Martens     

Antibody to beta-amyloid protein increases acetylcholine in the hippocampus of 12 month SAMP8 male mice

Amyloid beta protein (Abeta) is the primary constituent of plaque seen in Alzheimer's disease. Abeta is proposed to play an etiological role in Alzheimer's disease and to be a cause of the decrease in the level of acetylcholine in the hippocampus. The SAMP8 strain of mouse develops age-related increases in Abeta and deficits in learning and memory by 12 months of age. We examined in 12 month old SAMP8 mice the effects of giving antibody to Abeta by septal or intracerebroventricular (ICV) injection on acetylcholine levels in the hippocampus. Antibody to Abeta increased acetylcholine in the hippocampus over 100% after ICV injection and over 200% after septal injection. Injection of rabbit serum, antibody directed towards mouse IgG, or a blocking antibody directed towards human interleukin-1beta were without effect. These results suggest that antagonism of Abeta increases acetylcholine concentrations in the hippocampus, an area important for learning and memory.     

Proteomic analysis of primary cell lines identifies protein changes present in renal cell carcinoma

New markers/targets for renal cell carcinoma (RCC) are needed to enable earlier detection and monitoring of disease and therapeutic targeting. To identify such molecules, normal and RCC-derived primary cell lines have been used as a simplified model system for studying changes that accompany tumorigenesis. Short-term cultures allow enrichment of relevant cell types from tissue samples, which is balanced against the potential for in vitro changes. Examination of 3 proteins with altered expression in RCC tissue showed the maintenance of normal-tumour differences in culture, although some changes were apparent, including alteration in the isoform of aldolase. Comparative analysis of primary cell lines by 2-DE found 43 proteins up-regulated and 29 down-regulated in at least three out of five tumour cell lines. Many of the observed changes have been previously reported in RCC, including up-regulation of several glycolytic enzymes, vimentin and heat shock protein 27, validating the approach. Additionally, several novel changes in protein expression were found, including up-regulation of several proteins involved in actin cytoskeleton organisation such as radixin and moesin, two members of the septin family, and the actin bundling protein, fascin. Validation studies using Western blotting and immunohistochemistry indicate that several of these molecules may be useful as markers for RCC.