Two levels of alliance formation among male bottlenose dolphins (Tursiops sp.)

In Shark Bay, Western Australia, male bottlenose dolphins (Tursiops sp.) cooperate in pairs and triplets to sequester and control the movements of females. We refer to this behavior as "herding" and to the male pairs and triplets as alliances. During a 25-month study (1987-1989) on the social relationships of males, we documented herding in 10 alliances. Males preferentially herded nonpregnant females likely to be in estrus. Alliance members associated with one another consistently when not herding females. Each alliance associated preferentially with one or two other alliances. Occasionally, two alliances combined and took females from another alliance or defended females against such efforts. This study documents multiple-level male alliances within a social group outside of humans.     

Scrub typhus vaccine candidate Kp r56 induces humoral and cellular immune responses in cynomolgus monkeys

A truncated recombinant 56-kDa outer membrane protein of the Karp strain of Orientia tsutsugamushi (Kp r56) was evaluated in cynomolgus monkeys (Macaca fascicularis) for immunogenicity and safety as a vaccine candidate for the prevention of scrub typhus. This recombinant antigen induced strong humoral and cellular immune responses in two monkeys and was found to be well tolerated. Antigen-specific immunoglobulin M (IgM) and IgG were produced to almost maximal levels within 1 week of a single immunization. Peripheral blood mononuclear cells from vaccinated animals showed an induction of antigen-specific proliferation and gamma interferon production. The Kp r56 was not as efficient as infection with live organisms in preventing reinfection but was able to reduce the inflammation produced at the site of challenge. This report describes the results of the first systematic study of the immunogenicity of a recombinant scrub typhus vaccine candidate in a nonhuman primate model.     

Chloride fluxes in crab muscle fibres

1. Isotopic techniques were used to study the efflux of Cl(-) from single cannulated muscle fibres of the crab Maia squinado.2. The efflux of (36)Cl(-) was found to be exponential with steady rate constants ranging from 0.01 to 0.07 min(-1). The steady efflux was ca. 1000-2000 pM cm(-2) sec(-1). The efflux was slightly depressed by K(+)-free saline and was unaffected by 40 mM-K(+) saline and NO(3) (-) saline. The influx and efflux of Cl(-) were presumed independent.3. The membrane conductance calculated from (36)Cl(-) flux data was consistent with that determined by the method of electrotonic spread for other marine crustacean muscle fibres. Cl(-) accounted for most of the membrane conductance.     

ETV6/RUNX1 fusion at diagnosis and relapse: some prognostic indications

This study was undertaken in order to compare the interphase and metaphase cytogenetics of 28 patients with ETV6/RUNX1 positive acute lymphoblastic leukemia, at diagnosis and relapse. The median time to relapse was 26 months. The significant fusion positive population heterogeneity revealed at interphase by a commercial probe for ETV6/RUNX1 fusion has not been described before. Six diagnostic samples had a single abnormal population; others had up to five each, which differed in the numbers of RUNX1 signals, and in the retention or loss of the second ETV6 signal. In contrast, the number of fusion signals was more constant. At relapse, there were fewer populations; the largest or unique clone was sometimes a re-emergence of a minor, diagnostic one, with a retained copy of ETV6 and the most RUNX1 signals. Abnormal, fusion negative clones were identified in bone marrow samples at extra-medullary relapse. Variant three or four-way translocations, which involved chromosomes 12 and 21, were prominent among the complex rearrangements revealed by metaphase FISH. The frequency of their occurrence at diagnosis and reappearance at relapse, sometimes accompanied by minor clonal evolution, was another new observation. Other recurrent cytogenetic features included a second copy of the fusion signal in six cases, partial duplication of the long arm of the X chromosome in two cases, and trisomy 10 in three cases. In comparing our data with previously reported cases, a picture is beginning to emerge of certain diagnostic features, which may provide circumstantial evidence of an increased risk of relapse.     

Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk

Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer.     

Evaluation procedures for membership of the Royal New Zealand College of General Practitioners

Membership of the Royal New Zealand College of General Practitioners is by examination. The criteria for membership and form of the examination have changed over the years. The latest examination includes two parts, part one including a multiple choice questionnaire and a simulated patient interview. Experienced practitioners can be excused this part. Part two includes a clinical diary and a visit to the practice during which the examiner watches consultations for half a day.     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.      

Laboratory infection of primates with Ascaris suum to provide a model of allergic bronchoconstriction

Wild-caught non-human primates are naturally sensitive to Ascaris antigen and provide a useful model for studying atopic asthma. The present study was carried out to determine the effect of experimentally infecting home-bred macaques with the nematode Ascaris suum and hence provide an alternative for the naturally occurring model. Following oral infection with the parasite the animals developed a blood eosinophilia and specific antibodies to purified Ascaris antigen. These antibodies appeared to be of the IgE class as they could be detected by a radiometric assay using a radiolabelled antibody to human IgE. However, on further investigation, using the passive cutaneous anaphylaxis test, two classes of antibody were found, a heat labile (56 degrees C) and a heat stable antibody. Lung lavage cells taken from monkeys infected with Ascaris suum were shown to include cells morphologically characteristic of mast cells and released histamine when challenged in vitro with Ascaris antigen. Hence this model of immediate hypersensitivity provides a simple alternative to the less accessible natural model.