Body temperature patterns and rhythmicity in free-ranging subterranean Damaraland mole-rats, Fukomys damarensis

Body temperature (T(b)) is an important physiological component that affects endotherms from the cellular to whole organism level, but measurements of T(b) in the field have been noticeably skewed towards heterothermic species and seasonal comparisons are largely lacking. Thus, we investigated patterns of T(b) patterns in a homeothermic, free-ranging small mammal, the Damaraland mole-rat (Fukomys damarensis) during both the summer and winter. Variation in T(b) was significantly greater during winter than summer, and greater among males than females. Interestingly, body mass had only a small effect on variation in T(b) and there was no consistent pattern relating ambient temperature to variation in T(b). Generally speaking, it appears that variation in T(b) patterns varies between seasons in much the same way as in heterothermic species, just to a lesser degree. Both cosinor analysis and Fast Fourier Transform analysis revealed substantial individual variation in T(b) rhythms, even within a single colony. Some individuals had no T(b) rhythms, while others appeared to exhibit multiple rhythms. These data corroborate previous laboratory work showing multiplicity of rhythms in mole-rats and suggest the variation seen in the laboratory is a true indicator of the variation seen in the wild.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Species-specific cell-matrix interactions are essential for differentiation of alveoli like structures and milk gene expression in primary mammary cells of the Cape fur seal (Arctocephalus pusillus pusillus).

Few models are in place for analysis of extreme lactation patterns such as that of the fur seals which are capable of extended down regulation of milk production in the absence of involution. During a 10-12 month lactation period, female fur seals suckle pups on shore for 2-3 days, and then undertake long foraging trips at sea for up to 28 days, resulting in the longest intersuckling bouts recorded. During this time the mammary gland down regulates milk production. We have induced Cape fur seal (Arctocephalus pusillus pusillus) mammary cells in vitro to form mammospheres up to 900 microm in diameter, larger than any of their mammalian counterparts. Mammosphere lumens were shown to form via apoptosis and cells comprising the cellular boundary stained vimentin positive. The Cape fur seal GAPDH gene was cloned and used in RT-PCR as a normalization tool to examine comparative expression of milk protein genes (alphaS2-casein, beta-lactoglobulin and lysozyme C) which were prolactin responsive. Cape fur seal mammary cells were found to be unique; they did not require Matrigel for rapid mammosphere formation and instead deposited their own matrix within 2 days of culture. When grown on Matrigel, cells exhibited branching/stellate morphogenesis highlighting the species-specific nature of cell-matrix interactions during morphological differentiation. Matrix produced in vitro by cells did not support formation of human breast cancer cell line, PMC42 mammospheres. This novel model system will help define the molecular pathways controlling the regulation of milk protein expression and species specific requirements of the extracellular matrix in the cape fur seal.     

Oligomeric hepatoproliferin disaggregates into an active monomer that was purified and forcefully dissociated into two different ionic species

Hepatoproliferin (HPF), a liver regeneration factor, was isolated initially as an aggregated molecule (big-HPF) and was purified into two homogeneous, bioactive species of 14 kDa and 18.5 kDa. These two big-HPFs were disaggregated to completion into two monomeric forms (small-HPFs) when incubated for 10 days in 0.15 M ammonium bicarbonate at 25 degrees C. Both monomeric forms were purified to homogeneity as active entities, one with a molecular mass of 944 Da and one with a molecular mass of 1066 Da. Each of the two (35)S-labelled small-HPFs was found, by enzymic analysis, to contain a charged sulfonated saccharide, which was neutralized by a specific amine. Monomeric HPF is therefore a stable ionic complex formed between these two ionic species. So strong was the electrostatic association that small-HPF remained intact in solution and no amine was displaced by the ammonium ions of the buffer. Small-HPF remained unimpaired during purification, since all activity was retained despite alternating acidic and basic conditions. However, when small-HPF was brought into contact with either a cationic or an anionic resin, it was dissociated to completion when mixed continuously with the resin for 4 days. The ionic entity that was released had no bio-activity and was either a pure radioactively labeled saccharide or a non-labeled amine, depending on the kind of resin used. When incubated together, the separated counterions combine to regain full activity after 2 days of reassociation. However, with incubation for longer, this reassociated small-HPF formed different oligomeric HPFs by aggregation. Small-HPF is therefore a new kind of growth enhancer, consisting of an acidic sulfonated saccharide and a basic amine assembled into a stable active ionic complex that has a tendency to aggregate.     

Black rhinoceros (Diceros bicornis) populations in northwestern Namibia are apparently not infected with piroplasms

Babesiosis is a potentially fatal disease in black rhinoceroses. Blood specimens collected from black rhinoceroses from Etosha National Park (n = 29) and Damaraland (n = 22), Namibia, were subjected to polymerase chain reaction using Theileria and Babesia genus-specific primers and reverse line blot, with negative results. The animals were sparsely infested with ticks. In the absence of suitable prophylactic measures, na?ve rhinoceroses would be at risk if translocated to Babesia-endemic areas.     

Isolation and characterization of polymorphic tetranucleotide microsatellite loci in the pelagic perciform fish Pomatomus saltatrix (Linnaeus, 1766) from South Africa

Eight polymorphic microsatellite loci, containing simple tetranucleotide repeats, were isolated de novo from a Pomatomus saltatrix partial genomic library using the fast isolation by amplified fragment length polymorphism of sequences containing repeats protocol. These loci were further characterized in 100 individuals from two putative populations off the South African east coast. The loci are highly polymorphic with 18-37 alleles (on average 24 alleles/locus) and the observed heterozygosity in both populations was high (0.79). These loci will be used to assess population structuring in P. saltatrix along the southern African coast with consideration of implications for future management of this important linefish species.     

Induction of photosporogenesis in Macrophomina phaseoli by an octadecenoic acid from peanuts

A qualitative bioassay was developed with Macrophomina phaseoli (Maubl.) Ashby to assess photosporogenic activity of different fatty acid fractions