INDUCTION OF TUMORS IN DOMESTIC RABBITS WITH NUCLEIC ACID PREPARATIONS FROM PARTIALLY PURIFIED SHOPE PAPILLOMA VIRUS AND FROM EXTRACTS OF THE PAPILLOMAS OF DOMESTIC AND COTTONTAIL RABBITS

A deoxyribonucleic acid preparation which showed infectivity and tumorigenic activity in domestic rabbits was isolated from the papillomatous tissue of wild cottontail rabbits by phenolic deproteinization procedure. The activity of the preparation could be completely abolished by its exposure to a minute amount (0.02 microg/ml) of DNAase. Antisera against Shope papilloma virus did not block the tumorigenic activity of the preparation, and trypsin and chymotrypsin had no effect on it. The extraction with phenol of a partially purified virus preparation also yielded extracts with tumorigenic potency. Extracts obtained from the domestic rabbit papilloma and submitted to phenolic deproteinization also proved infective and tumorigenic in rabbits of this sort, although the level of "tumorigenicity" was much lower than that of the cottontail preparations. Tests for intact virus, carried out with half of the extracts yielded wholly negative findings.

STUDIES ON HERPETIC INFECTION IN MICE : IV. THE EFFECT OF SPECIFIC ANTIBODIES ON THE PROGRESSION OF THE VIRUS WITHIN THE NERVOUS SYSTEM OF YOUNG MICE

Two-week-old mice inoculated with herpes virus on the pad of a hind foot regularly developed paralysis of the infected limb followed by paraplegia and encephalitis terminating fatally 5 or 6 days after inoculation. Hyperimmune rabbit serum given intraperitoneally at the time virus was inoculated on the foot pad prevented the formation of an herpetic lesion of the foot pad. When the antiserum was given 12 hours after inoculation of the virus, a typical infection of the epithelium of the foot pad developed, but the virus was prevented from causing obvious signs of infection of the nervous system in many of the animals. Amputation of the foot 2 hours after the inoculation of the virus prevented the paralysis of the hind leg. Some of the mice died of a delayed encephalitis. Amputation of the foot at 24 hours neither prevented nor delayed the sequence of paralysis of the hind leg, encephalitis, and death. In order to study immune serum therapy of an infection of the nervous system uncomplicated by a peripheral focus of infection or by traumatic disturbance of the central nervous system, 2-week-old mice were inoculated on the foot pad, the infected feet were amputated 24 hours later, and the immune serum was administered at varying intervals thereafter. Using litter mate controls and statistically significant numbers of mice, it was shown that hyperimmune rabbit serum, administered during the first one-third of the incubation period, retards and, in some cases, arrests the progress of herpetic infection within the nervous system.

Detection of root resorption using dentin and bone markers

OBJECTIVES - To test the hypothesis that during root resorption, organic matrix proteins and cytokines from the surrounding bone and dentin are released into the gingival crevice. MATERIAL AND METHODS - Subjects with mild (<2 mm loss) and severe root resorption (>2 mm) were identified. Control group subjects with no loss of root structure or undergoing orthodontic treatment were also identified. Gingival crevicular fluid (GCF) was collected non-invasively from the mesial and distal sides of each of the four upper incisors by using filter paper strips. The eluted GCF was used for analysis using western blot and enzyme-linked immunosorbent assay (ELISA) techniques. Antibodies used were against osteopontin (OPN), (osteoprotegerin) OPG, and receptor activator of nuclear factor kappa B ligand (RANKL). RESULTS - Western blot analysis showed differential expression of OPN, OPG, and RANKL in the control and root resorbed subjects. However, processed forms of these proteins were only observed in the root resorbed subjects. Results from ELISA with OPG antibodies revealed a difference in OPG concentration between the control and root resorption groups. ELISA results with RANKL antibodies did show a statistically significant difference between the control group and the two study groups. The ratio RANKL/OPG was statistically higher in subjects with severe root resorption than in the control subjects. CONCLUSIONS - Preliminary results confirm the presence of matrix proteins and cytokines in the GCF of root resorbed subjects. Further, OPG was locally present in excess amounts over RANKL and an increased RANKL/OPG in the study groups could be correlated with an increased bone resorption activity during orthodontic tooth movement.

Terahertz ambipolar dual-wavelength quantum cascade laser

Terahertz frequency quantum cascade lasers (THz QCLs) are compact solid-state sources of terahertz radiation that were first demonstrated in 2002. They have a broad range of potential applications ranging from gas sensing and non-destructive testing, through to security and medical imaging, with many polycrystalline compounds having distinct fingerprint spectra in the terahertz frequency range. In this article, we demonstrate an electrically-switchable dual-wavelength THz QCL which will enable spectroscopic information to be obtained within a THz QCL-based imaging system. The device uses the same active region for both emission wavelengths: in forward bias, the laser emits at 2.3 THz; in reverse bias, it emits at 4 THz. The corresponding threshold current densities are 490 A/cm(2) and 330 A/cm(2), respectively, with maximum operating temperatures of 98K and 120 K.

Apparent absolute oral bioavailability in excess of 100% for a vitronectin receptor antagonist (SB-265123) in rat. I. Investigation of potential experimental and mechanistic explanations

1. SB-265123 is a novel alphavbeta3 (the vitronectin receptor) antagonist. Previous rat studies with it revealed an apparent absolute oral bioavailability (Fapp) of greater than 100%. The present studies were conducted to investigate the potential causes for this observation. 2. Of 49 SB-265123 analogues evaluated in rat using an identical experimental design, Fapp > 100% was observed for 22 of them, suggesting that the observed Fapp >100% with SB-265123 was not anomalous. All 22 compounds had clearances < 15 ml min(-1) kg(-1). However, Fapp>100% were not recorded for all low-clearance analogues. 3. Using SB-265123 as a model to investigate potential artefacts, it was demonstrated that using a chiral assay did not decrease Fapp. Additionally, qualitative sample analysis demonstrated that no metabolites were present in the plasma that could interfere with the liquid chromatography coupled with tandem mass spectrometry detection assay. The high Fapp was also dose-order-, delivery system- and vehicle-independent, and was not affected by the feeding status of the animals. Furthermore, a linearity experiment and an absorption study indicated that oral administration of SB-265123 does not result in hepatic portal vein concentrations that exceed the pharmacokinetic linearity of SB-265123. 4. These observations suggest that the observed Fapp > 100% for SB-265123 is not due to an experimental artefact or an obvious pharmacokinetic non-linearity. The mechanism(s) for this phenomenon is explored further in the second part of the present paper.

Identifying the major influences on the microbial composition of roof harvested rainwater and the implications for water quality

Perceptions of the quality of roof harvested rainwater remain an impediment to widespread implementation of rainwater tanks on urban allotments. Previous literature reports on roof water quality have given little consideration to the relative significance of airborne environmental micro-organisms to roof catchment contamination and the issue of tank water quality. This paper outlines the findings of a recent study into the influence of weather on roof water contamination conducted at an urban housing development in Newcastle, on the east coast of Australia. Samples of direct roof run-off were collected during a number of separate rainfall events, and microbial counts were matched to climatic data corresponding to each of the monitored events. Roof run-off contamination was found to be under the strong influence of both wind speed and direction. The preliminary findings of an investigation currently under way into the microbial diversity of rainwater harvesting systems have also been presented. The results indicate that the composition of organisms present varied considerably from source to source and throughout the collection system. In all cases, evidence of faecal contamination was found to be negligible. The implications of these findings to the issues of tank water quality, health risk analysis and monitoring protocols have been discussed.

Analysis of nucleotide diversity of NAT2 coding region reveals homogeneity across Native American populations and high intra-population diversity

N-acetyltransferase 2 (NAT2), an important enzyme in clinical pharmacology, metabolizes antibiotics such as isoniazid and sulfamethoxazole, and catalyzes the transformation of aromatic and heterocyclic amines from the environment and diet into carcinogenic intermediates. Polymorphisms in NAT2 account for variability in the acetylator phenotype and the pharmacokinetics of metabolized drugs. Native Americans, settled in rural areas and large cities of Latin America, are under-represented in pharmacogenetics studies; therefore, we sequenced the coding region of NAT2 in 456 chromosomes from 13 populations from the Americas, and two from Siberia, detecting nine substitutions and 11 haplotypes. Variants *4 (37%), *5B (23%) and *7B (24%) showed high frequencies. Average frequencies of fast, intermediate and slow acetylators across Native Americans were 18, 56 and 25%, respectively. NAT2 intra-population genetic diversity for Native Americans is higher than East Asians and similar to the rest of the world, and NAT2 variants are homogeneously distributed across native populations of the continent.

Expression of receptor activator of nuclear factor kappabeta ligand (RANKL) and tumour necrosis factor related, apoptosis inducing ligand (TRAIL) in breast cancer, and their relations with osteoprotegerin, oestrogen receptor, and clinicopathological variables

BACKGROUND

Receptor activator of nuclear factor kappabeta ligand (RANKL) has an important role in bone remodelling, and tumour necrosis factor related, apoptosis inducing ligand (TRAIL) can induce apoptosis in cancer cells. Their functions are linked by their interactions with osteoprotegerin (OPG).

OBJECTIVE

To investigate the expression of RANKL and TRAIL in a large series of unselected breast cancers and to analyse the relations between these expressions and the expression of OPG, oestrogen receptor, and clinicopathological variables.

METHODS

395 breast cancers were sampled into tissue microarrays and immunohistochemistry undertaken for RANKL and TRAIL.

RESULTS

There was strong expression of RANKL in 14% of the cancers and strong expression of TRAIL in 30%. Expression of RANKL had a negative association with expression of oestrogen receptor (p = 0.036). Expression of TRAIL had a negative association with the Nottingham Prognostic Index (p = 0.021). There was a significant negative relation between expression of RANKL and TRAIL (p<0.005). Unsupervised cluster analysis produced a dendrogram that showed a clear division into two groups, and the expression of oestrogen receptor was significantly higher in one of those groups (p = 0.012).

CONCLUSIONS

There is apparent loss of expression of RANKL in 86% of breast cancers; those tumours that retain expression tend to be oestrogen receptor negative and of a high histological grade. There is strong expression of TRAIL in 30% of breast cancers and these tend to be of better prognostic type. These results may be important in the processes of metastasis to bone and the apoptotic cell death pathway in cancer.

Wind, rain and bacteria: The effect of weather on the microbial composition of roof-harvested rainwater

The microbiological and chemical quality of tank-stored rainwater is impacted directly by roof catchment and subsequent run-off contamination, via direct depositions by birds and small mammals, decay of accumulated organic debris, and atmospheric deposition of airborne micro-organisms and chemical pollutants. Previous literature reports on roof water quality have given little consideration to the relative significance of airborne micro-organisms. This study involved analyses of direct roof run-off at an urban housing development in Newcastle, on the east coast of Australia. A total of 77 samples were collected during 11 separate rainfall events, and microbial counts and mean concentrations of several ionic contaminants were matched to climatic data corresponding to each of the monitored events. Conditions both antecedent to, and those prevailing during each event, were examined to investigate the influence of certain meteorological parameters on the bacterial composition of the roof water and indirectly assess the relative contribution of airborne micro-organisms to the total bacterial load. Results indicated that airborne micro-organisms represented a significant contribution to the bacterial load of roof water at this site, and that the overall contaminant load was influenced by wind velocities, while the profile (composition) of the load varied with wind direction. The implications of these findings to the issues of tank water quality and health risk analysis, appropriate usage and system design are discussed.

Mechanisms of the Synergistic Interaction between the Bisphosphonate Zoledronic Acid and the Chemotherapy Agent Paclitaxel in Breast Cancer Cells in vitro

Breast cancer patients often receive both paclitaxel and zoledronic acid as part of their treatment, and these drugs are reported to have synergistic effects on the induction of apoptosis of breast cancer cells in vitro. We have found that the synergistic interaction is drug sequence dependent, with maximal levels of apoptosis achieved when cells are treated with paclitaxel followed by zoledronic acid, as opposed to the reverse sequence or simultaneous treatment. The synergistic interaction persists at clinically relevant concentrations and incubation periods. We report that the sequential treatment is associated with cell cycle changes and depends on breast cancer cell characteristics, with hormone independence, mutated p53 status and presence of BRCA1 gene being associated with higher levels of apoptosis. Finally, we have found that the synergistic induction of apoptosis is via zoledronic acid-mediated inhibition of the mevalonate pathway.

Tuberculosis skin testing, anergy and protein malnutrition in Peru

SETTING

Malnutrition and intestinal parasites cause immunosuppression. This may cause false-negative tuberculin skin tests (TST) and failure to identify tuberculosis (TB) infection.

OBJECTIVE

To assess factors associated with TST positivity and anergy in disadvantaged communities in Peru.

DESIGN

A study of 212 randomly selected adults: 102 in a rural Amazonian village and 110 shanty town residents in urban Lima.

RESULTS

Respectively 52% and 53% of urban and rural jungle populations were TST-positive. Using simultaneous tetanus and candida skin tests, 99% had at least one positive skin test. Generalised anergy was therefore rare, despite frequent intestinal parasitic infection, including 34% helminth infection prevalence in the jungle. TST positivity was associated with age (P = 0.001), known TB contact (P = 0.02) and poor household ventilation (P = 0.007). TST positivity was not significantly associated with crowding, reported past TB, single/multiple BCG vaccination, income, intestinal parasites, dietary factors, body mass index or body fat. Individuals with lower anthropometric body protein, as measured by corrected arm muscle area, were less likely to be TST-positive (P = 0.02), implying that protein malnutrition caused tuberculin-specific anergy.

CONCLUSION

These results identify the importance of household ventilation for community TB transmission and add to the evidence that protein malnutrition suppresses TB immunity, causing false-negative TST results.

Tolerance of deviations in eye and mouth position

OBJECTIVE

To develop and refine a technique for measuring the tolerance for deviations in facial appearance.

DESIGN

A psychophysical method was administered using photocopies of altered facial photographs to measure tolerances for deviations in eye position and mouth angulation and judges' reaction time.

METHODS

Stimulus photos were displayed as Kodachrome slides to 76 individuals grouped by their familiarity with craniofacial anomalies, i.e. dental professionals, orthodontic and craniofacial patients, also a group of normal patients.

RESULTS

(1) Tolerance for deviation of facial appearance varies inversely with the magnitude of the physical deviations from normal; (2) tolerance varies directly as a function of assumed familiarity with deviation; (3) response and reaction time varied inversely with the tolerance for facial deviation.

CONCLUSION

Significant differences in tolerance and reaction time were found among the groups and depended on whether an isolated feature was judged or if the feature was judged in the context of the whole face.

Tuberculosis and nutrition: disease perceptions and health seeking behavior of household contacts in the Peruvian Amazon

SETTING

Households of TB patients in the Peruvian Amazon.

OBJECTIVE

To investigate how knowledge and beliefs of household contacts about TB affected health seeking behavior.

DESIGN

Interviews with 73 patients finishing treatment and 79 of their adult household contacts.

RESULTS

Contacts were knowledgeable about free screening and treatment, but contacts who noted weight loss, not cough, were more likely to be screened for TB (P = 0.03). Forty-two per cent reported that TB was prevented by nutrition, 28% by separating eating utensils, and only 19% by avoiding a coughing patient. Only one household contact reported being stigmatized. Stigma centered upon nutrition, and only 12% knew of the association between TB and HIV. Only 14% had a BMI < 20, yet 30% reported regularly going to sleep hungry. Free food packages were reported to be the most important reason for treatment adherence by 33% of patients.

CONCLUSION

Contacts misperceived TB as a nutritional disease and did not fear airborne transmission, which should be corrected by public health education. Weight loss, and not cough, led to screening. Stigma appeared to be minimized because risk was perceived as personal, through malnutrition, rather than exposure-based. Nutritional incentives that utilize these beliefs may reduce diagnostic delay and enhance treatment adherence.

Osteoprotegerin (OPG) Produced by Bone Marrow Stromal Cells Protects Breast Cancer Cells from TRAIL-Induced Apoptosis

Advanced breast cancer is often associated with metastatic bone disease, causing a number of serious complications for the patients such as hypercalceamia, pain, nerve compression and fractures. The formation of bone metastases depends on complex interactions between tumour cells and the cells of the bone microenvironment, but the precise molecular mechanisms involved in the development of tumour-induced bone disease have not been identified. We have investigated the ability of bone marrow stromal cells (BMSC) isolated from breast cancer patients to generate osteoprotegerin (OPG), a molecule involved both in bone turnover and cell survival. The potential survival effects of OPG are mediated through binding to a member of the TNF super family, TNF-related Apoptosis Inducing Ligand (TRAIL), preventing association between TRAIL and its death-inducing receptors present on a number of tumour cell types. In the present report we show that bone marrow stromal cells isolated from breast cancer patients produce OPG when grown in culture. The levels of OPG present in BMSC conditioned medium is sufficient to protect breast cancer cells from undergoing TRAIL induced apoptosis. Our data suggest that bone-derived OPG may increase survival of breast cancer cells that reach the bone microenvironment as part of the metastatic process.

The value of counting BCG scars for interpretation of tuberculin skin tests in a tuberculosis hyperendemic shantytown, Peru

SETTING

The tuberculin skin test (TST) is widely used as a diagnostic or screening test for Mycobacterium tuberculosis infection and disease. A peri-urban shantytown in the desert hills of south Lima, Peru, highly endemic for tuberculosis, and where bacille Calmette-Guérin (BCG) vaccine had been given in multiple doses until 1995.

OBJECTIVE

To analyze the effect of multiple BCG vaccines on TST in a community-based setting.

DESIGN

Point-prevalence survey of TST reactions of 572 people aged 6-26 years from 255 households. TST reactions were compared to the observed number of BCG scars and other potential risk factors (age, living with a TST-positive person, and contact with active tuberculosis).

RESULT

People with two or more scars had significantly larger reactions, even after adjusting for potential risk factors. The adjusted population attributable fraction of being TST-positive and having two or more BCG scars was 26%.

CONCLUSION

There is no demonstrated benefit of repeat BCG vaccination. We therefore recommend that physicians take into consideration the number of BCG scars when interpreting the TST and that programs give no more than one BCG vaccination.

Genome sequence of the Brown Norway rat yields insights into mammalian evolution

The laboratory rat (Rattus norvegicus) is an indispensable tool in experimental medicine and drug development, having made inestimable contributions to human health. We report here the genome sequence of the Brown Norway (BN) rat strain. The sequence represents a high-quality 'draft' covering over 90% of the genome. The BN rat sequence is the third complete mammalian genome to be deciphered, and three-way comparisons with the human and mouse genomes resolve details of mammalian evolution. This first comprehensive analysis includes genes and proteins and their relation to human disease, repeated sequences, comparative genome-wide studies of mammalian orthologous chromosomal regions and rearrangement breakpoints, reconstruction of ancestral karyotypes and the events leading to existing species, rates of variation, and lineage-specific and lineage-independent evolutionary events such as expansion of gene families, orthology relations and protein evolution.

The Vesosome - A Multicompartment Drug Delivery Vehicle

Assembling structures to divide space controllably and spontaneously into subunits at the nanometer scale is a significant challenge, although one that biology has solved in two distinct ways: prokaryotes and eukaryotes. Prokaryotes have a single compartment delimited by one or more lipid-protein membranes. Eukaryotes have nested-membrane structures that provide internal compartments--such as the cell nucleus and cell organelles in which specialized functions are carried out. We have developed a simple method of creating nested bilayer compartments in vitro via the "interdigitated" bilayer phase formed by adding ethanol to a variety of saturated phospholipids. At temperatures below the gel-liquid crystalline transition, T(m), the interdigitated lipid-ethanol sheets are rigid and flat; when the temperature is raised above T(m), the sheets become flexible and close on themselves and the surrounding solution to form closed compartments. During this closure, the sheets can entrap other vesicles, biological macromolecules, or colloidal particles. The result is efficient and spontaneous encapsulation without disruption of even fragile materials to form biomimetic nano-environments for possible use in drug delivery, colloidal stabilization, or as microreactors. The vesosome structure can take full advantage of the 40 years of progress in liposome development including steric stabilization, pH loading of drugs, and intrinsic biocompatibility. However, the multiple compartments of the vesosome give better protection to the interior contents in serum, leading to extended release of model compounds in comparison to unilamellar liposomes.

The genome sequence of the malaria mosquito Anopheles gambiae

Anopheles gambiae is the principal vector of malaria, a disease that afflicts more than 500 million people and causes more than 1 million deaths each year. Tenfold shotgun sequence coverage was obtained from the PEST strain of A. gambiae and assembled into scaffolds that span 278 million base pairs. A total of 91% of the genome was organized in 303 scaffolds; the largest scaffold was 23.1 million base pairs. There was substantial genetic variation within this strain, and the apparent existence of two haplotypes of approximately equal frequency ("dual haplotypes") in a substantial fraction of the genome likely reflects the outbred nature of the PEST strain. The sequence produced a conservative inference of more than 400,000 single-nucleotide polymorphisms that showed a markedly bimodal density distribution. Analysis of the genome sequence revealed strong evidence for about 14,000 protein-encoding transcripts. Prominent expansions in specific families of proteins likely involved in cell adhesion and immunity were noted. An expressed sequence tag analysis of genes regulated by blood feeding provided insights into the physiological adaptations of a hematophagous insect.