Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Improving the solubility of pseudo-hydrophobic Alzheimer's Disease medicinal chemicals through co-crystal formulation

Natural products are ligands and potential inhibitors of Alzheimer's disease (AD) tau. Dihydromyricetin (DHM) is a CNS active natural product. Despite having signature polyphenolic character, DHM is ostensibly hydrophobic owing to intermolecular hydrogen bonds that shield hydrophilic phenols. Our research shows DHM becomes ionized at near-neutral pH allowing formulation of salts with transformed solubility. The MicroED co-crystal structure with trolamine reveals DHM salts as metastable solids with unlocked hydrogen bonding and a thermodynamic bent to solubilize in water. All salt formulations show better inhibitory activity against AD tau than the non-salt form, with efficacies correlating to enhanced solubilities. These results underscore the role of structural chemistry in guiding selection of solubilizing agents for chemical formulation. We propose DHM salts are appropriate formulations for research as dietary supplements to promote healthy aging by combating protein misfolding. Additionally, DHM is a suitable lead for medicinal chemistry and possible development of CNS pharmaceuticals.

Outer-coordination sphere in multi-H+/multi-e-molecular electrocatalysis

Electrocatalysis is an indispensable technique for small-molecule transformations, which are essential for the sustainability of society. Electrocatalysis utilizes electricity as an energy source for chemical reactions. Hydrogen is considered the “fuel for the future,” and designing electrocatalysts for hydrogen production has thus become critical. Furthermore, fuel cells are promising energy solutions that require robust electrocatalysts for key fuel cell reactions such as the interconversion of oxygen to water. Concerns regarding the rising concentration of atmospheric carbon dioxide have prompted the search for CO₂ conversion methods. One promising approach is the electrochemical conversion of CO₂ into commodity chemicals and/or liquid fuels, but such chemistry is highly energy demanding because of the thermodynamic stability of CO₂. All of the above-mentioned electrocatalytic processes rely on the selective input of multiple protons (H⁺) and electrons (e^–) to yield the desired products. Biological enzymes evolved in nature to perform such redox catalysis and have inspired the design of catalysts at the molecular and atomic levels. While it is synthetically challenging to mimic the exact biological environment, incorporating functional outer coordination spheres into molecular catalysts has shown promise for advancing multi-H⁺ and multi-e^– electrocatalysis. From this Perspective, herein, catalysts with outer coordination sphere(s) are selected as the inspiration for developing new catalysts, particularly for the reductive conversion of H⁺, O₂, and CO₂, which are highly relevant to sustainability. The recent progress in electrocatalysis and opportunities to explore beyond the second coordination sphere are also emphasized.

Hydrodechlorination of Dichloromethane by a Metal-Free Triazole-Porphyrin Electrocatalyst: Demonstration of Main-Group Element Electrocatalysis*

In this work, the electrocatalytic reduction of dichloromethane (CH₂ Cl₂ ) into hydrocarbons involving a main group element-based molecular triazole-porphyrin electrocatalyst H2PorT8 is reported. This catalyst converted CH₂ Cl₂ in acetonitrile to various hydrocarbons (methane, ethane, and ethylene) with a Faradaic efficiency of 70 % and current density of -13 mA cm^-2 at a potential of -2.2 V vs. Fc/Fc⁺ using water as a proton source. The findings of this study and its mechanistic interpretations demonstrated that H2PorT8 was an efficient and stable catalyst for the hydrodechlorination of CH₂ Cl₂ and that main group catalysts could be potentially used for exploring new catalytic reaction mechanisms.

Electrocatalytic Dechlorination of Dichloromethane in Water Using a Heterogenized Molecular Copper Complex

The remediation of organohalides from water is a challenging process in environment protection and water treatment. Herein, we report a molecular copper(I) complex with two triazole units, CuT2, in a heterogeneous aqueous system that is capable of dechlorinating dichloromethane (CH₂Cl₂) to afford hydrocarbons (methane, ethane, and ethylene). The catalytic performance is evaluated in water and presented high Faradaic efficiency (average 70% CH₄) across a range of potentials (-1.1 to -1.6 V vs Ag/AgCl) and high activity (maximum -25.1 mA/cm² at -1.6 V vs Ag/AgCl) with a turnover number of 2.0 × 10⁷. The CuT2 catalyst also showed excellent stability for 14 h of constant exposure to CH₂Cl₂ and 10 h of CH₂Cl₂ exposure cycling. The control compound, a copper-free triazole unit (T1), was also investigated under the same condition and showed inferior catalytic activity, indicating the importance of the copper center. Plausible catalytic mechanisms are proposed for the formation of C₁ and C₂ products via radical intermediates. Computational studies provided additional insight into the reaction mechanism and the selectivity toward the CH₄ formation. The findings in this study demonstrate that complex CuT2 is an efficient and stable catalyst for the dehalogenation of CH₂Cl₂ and could potentially be used for the exploration of the removal of halogenated species from aqueous systems.

Effects of Appended Poly(ethylene glycol) on Electrochemical CO2 Reduction by an Iron Porphyrin Complex

Electrochemical carbon dioxide (CO₂) reduction is a sustainable approach for transforming atmospheric CO₂ into chemical feedstocks and fuels. To overcome the kinetic barriers of electrocatalytic CO₂ reduction, catalysts with high selectivity, activity, and stability are needed. Here, we report an iron porphyrin complex, FePEGP, with a poly(ethylene glycol) unit in the second coordination sphere, as a highly selective and active electrocatalyst for the electrochemical reduction of CO₂ to carbon monoxide (CO). Controlled-potential electrolysis using FePEGP showed a Faradaic efficiency of 98% and a current density of -7.8 mA/cm² at -2.2 V versus Fc/Fc⁺ in acetonitrile using water as the proton source. The maximum turnover frequency was calculated to be 1.4 × 10⁵ s^-1 using foot-of-the-wave analysis. Distinct from most other catalysts, the kinetic isotope effect (KIE) study revealed that the protonation step of the Fe-CO₂ adduct is not involved in the rate-limiting step. This model shows that the PEG unit as the secondary coordination sphere enhances the catalytic kinetics and thus is an effective design for electrocatalytic CO₂ reduction.

Enhanced Electrocatalytic Activity of a Zinc Porphyrin for CO2 Reduction: Cooperative Effects of Triazole Units in the Second Coordination Sphere

The control of the second coordination sphere in a coordination complex plays an important role in improving catalytic efficiency. Herein, we report a zinc porphyrin complex ZnPor8T with multiple flexible triazole units comprising the second coordination sphere, as an electrocatalyst for the highly selective electrochemical reduction of carbon dioxide (CO₂ ) to carbon monoxide (CO). This electrocatalyst converted CO₂ to CO with a Faradaic efficiency of 99 % and a current density of -6.2 mA cm^-2 at -2.4 V vs. Fc/Fc⁺ in N,N-dimethylformamide using water as the proton source. Structure-function relationship studies were carried out on ZnPor8T analogs containing different numbers of triazole units and distinct triazole geometries; these unveiled that the triazole units function cooperatively to stabilize the CO₂ -catalyst adduct in order to facilitate intramolecular proton transfer. Our findings demonstrate that incorporating triazole units that function in a cooperative manner is a versatile strategy to enhance the activity of electrocatalytic CO₂ conversion.

A pH-Neutral, Aqueous Redox Flow Battery with a 3600-Cycle Lifetime: Micellization-Enabled High Stability and Crossover Suppression

Redox-flow batteries (RFBs) are a highly promising large-scale energy storage technology for mitigating the intermittent nature of renewable energy sources. Here, the design and implementation of a micellization strategy in an anthraquinone-based, pH-neutral, nontoxic, and metal-free aqueous RFB is reported. The micellization strategy (1) improves stability by protecting the redox-active anthraquinone core with a hydrophilic poly(ethylene glycol) shell and (2) increases the overall size to mitigate the crossover issue through a physical blocking mechanism. Paired with a well-established potassium ferrocyanide catholyte, the micelle-based RFB displayed an excellent capacity retention of 90.7 % after 3600 charge/discharge cycles (28.3 days), corresponding to a capacity retention of 99.67 % per day and 99.998 % per cycle. The mechanistic studies of redox-active materials were also conducted and indicated the absence of side reactions commonly observed in other anthraquinone-based RFBs. The outstanding performance of the RFB demonstrates the effectiveness of the micellization strategy for enhancing the performance of organic material-based aqueous RFBs.

Enhanced Molecular CO2 Electroreduction Enabled by a Flexible Hydrophilic Channel for Relay Proton Shuttling

The effects of primary and second coordination spheres on molecular electrocatalysis have been extensively studied, yet investigations of third functional spheres are rarely reported. Here, an electrocatalyst (ZnPEG8T) was developed with a hydrophilic channel as a third functional sphere that facilitates relay proton shuttling to the primary and second coordination spheres for enhanced catalytic CO₂ reduction. Using foot-of-the-wave analysis, the ZnPEG8T catalyst displayed CO₂ -to-CO activity (TOF_max ) thirty times greater than that of the benchmark catalyst without a third functional sphere. A kinetic isotopic effect (KIE) study, in conjunction with voltammetry and UV/Vis spectroscopy, uncovered that the rate-limiting step was not the protonation step of the metallocarboxylate intermediate, as observed in many other molecular CO₂ reduction electrocatalysts, but rather the replenishment of protons in the proton-shuttling channel. Controlled-potential electrolysis using ZnPEG8T displayed a faradaic efficiency of 100 % for CO₂ -to-CO conversion at -2.4 V vs. Fc/Fc⁺ . A Tafel plot was also generated for a comparison to other reported molecular catalysts. This report validates a strategy for incorporating higher functional spheres for enhanced catalytic efficiency in proton-coupled electron-transfer reactions.

PEGylation-Enabled Extended Cyclability of a Non-aqueous Redox Flow Battery

Non-aqueous redox flow batteries (RFBs) are promising energy storage devices owing to the broad electrochemical window of organic solvents. Nonetheless, the wide application of these batteries has been limited by the low stability and limited solubility of organic materials, as well as the insufficient ion conductivity of the cell separators in non-aqueous electrolytes. In this study, two viologen analogues with poly(ethylene glycol) (PEG) tails are designed as anolytes for non-aqueous RFBs. The PEGylation of viologen not only enhances the solubility in acetonitrile but also increases the overall molecular size for alleviated crossover. In addition, a composite nanoporous aramid nanofiber separator, which allows the permeation of supporting ions while inhibiting the crossover of the designer viologens, is developed using a scalable doctor-blading method. Paired with ferrocene, the full organic material-based RFB presents excellent cyclability (500 cycles) with a retention capacity per cycle of 99.93% and an average Coulombic efficiency of 99.3% at a current density of 2.0 mA/cm². The high performance of the PEGylated viologen validates the potential of the PEGylation strategy for enhanced organic material-based non-aqueous RFBs.

'Switch' catalysis: from monomer mixtures to sequence-controlled block copolymers

A 'Switch' catalysis method is reviewed whereby a single catalyst is switched between ring-opening polymerization and ring-opening copolymerization cycles. It allows the efficient synthesis of block copolymers from mixtures of lactones, epoxides, anhydrides and carbon dioxide. In order to use and further develop such 'Switch' catalysis, it is important to understand how to monitor the catalysis and characterize the product block copolymers. Here, a step-by-step guide to both the catalysis and the identification of block copolymers is presented.This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

Catalysts for CO2/epoxide ring-opening copolymerization

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to control the composition, properties and applications of the resultant polymers. This review highlights and exemplifies some key recent findings and hypotheses, in particular using examples drawn from our own research.

The African Organization for Research and Training in Cancer: historical perspective

The African Organization for Research and Training in Cancer (aortic) is a bilingual (English and French) nonprofit organization dedicated to the promotion of cancer control and palliation in Africa. Its mission in respect to cancer control in Africa includes support of research and training;provision of relevant and accurate information on the prevention, early diagnosis, treatment, and palliation of cancer;promotion of public awareness about cancer and reduction of the stigma associated with it.In seeking to achieve its goal of cancer control in Africa, aortic strives to unite the continent and to make a positive impact throughout the region by collaboration with health ministries and global cancer organizations. The organization's key objectives are to further research relating to cancers prevalent in Africa, to support training programs in oncology for health care workers, to deal with the challenges of creating cancer control and prevention programs, and to raise public awareness of cancer in Africa. It also plans to organize symposia, workshops, meetings, and conferences that support its mission.Founded in September 1982, aortic was active only between 1983 (when its inaugural conference was held in the City of Lome, Togo, West Africa) and the late 1980s. The organization subsequently became inactive and moribund. In 2000, a group of expatriate African physicians and scientists joined in an effort with their non-African friends and colleagues to reactivate the dormant organization. Since its reactivation, aortic has succeeded in putting cancer on the public health agenda in many African countries by highlighting Africa's urgent need for cancer control and by holding meetings every two years in various African cities. National and international cancer control organizations worldwide have recognized the challenges facing Africa and have joined in aortic's mission.

Molecular and serological analysis of the epidemiology of myxoma virus in rabbits

The epidemiology of myxoma virus was studied by serology and molecular analysis of restriction fragment length polymorphisms (RFLPs) in genomic DNA. 159 isolates of myxoma virus were made over a period of 5 spring/summer epidemics from 12 field sites in south-eastern Australia. Virus isolates were classified into 10 genetic types using RFLPs detected with a panel of nine restriction endonucleases. Between 3 and 6 different genetic types were found during spring/summer periods across all sites and up to 3 different genetic types were isolated during an epidemic on a single site. The predominant type tended to change each year. A widespread mutation was identified in two genetic types with replacement of the 3' two-thirds of the M009L gene at the left hand inverted terminal repeat junction with a duplication of the region containing the M156R, M154L and M153R genes from the right hand end of the genome. This demonstrated how myxoma virus can potentially evolve by expansion of the inverted terminal repeat boundaries.

Identifying hazards in complex ecological systems. Part 3: Hierarchical Holographic Model for herbicide tolerant oilseed rape

This paper is the third in a series designed to demonstrate the application of rigorous, systematic hazard identification techniques to ecological systems. Here we use Hierarchical Holographic Modelling to identify the potential ecological hazards associated with the commercial release of herbicide tolerant oilseed rape. Hierarchical Holographic Models decompose complex systems into a series of sub-systems and consider interactions between the components and processes of these sub-systems in order to identify hazards. In this example we considered 1356 potential interactions between the biological, chemical and physical components and processes of the herbicide tolerant oilseed rape environment, and identified 152 potential hazards, grouped into 14 categories. The hazards were subsequently scored for degree of concern and plausibility, and then compared with an equivalent list of hazards generated independently by a checklist approach. The incidence of herbicide tolerant volunteers (and weeds) both on and off the farm had the highest average score of all the ecological hazard categories. The checklist based approach identified or implied 44% of the hazards identified in the Hierarchical Holographic Model, including nine of the ten hazards ranked most important. The checklist approach focussed almost exclusively on the phenotypic and genotypic hazards associated with herbicide tolerant oilseed rape and largely ignored the hazards associated with the circumstances surrounding its use. As a result the checklist identified only 6 out of the 79 potential hazards associated with changes to farming practice. The commercial release of herbicide tolerant oilseed rape will be associated with changes in tillage and the application of post-emergent herbicides. It may also lead to changes in spray schedules of insecticide and fungicide. Many of the environmental hazards identified with these changes are plausible and may warrant further investigation or targeted monitoring.

Risk assessment for release of genetically modified organisms: a virus to reduce the fertility of introduced wild mice, Mus domesticus

Risk assessment is a key task in developing genetically modified organisms (GMOs) intended for release into the environment. A risk assessment protocol is described, focusing on genetically modified biological control agents intended to reduce fertility in mammalian pests. The protocol is being applied to development of an immunocontraceptive murine cytomegalovirus vaccine intended to reduce the frequency and extent of costly troublesome plagues of introduced house mice, Mus domesticus, in southern Australia. Success of the agent, including regulatory approval for release to target populations, will depend on demonstrated biosafety, on the biophysical consequences of releasing the agent, and on public perceptions of the consequences and ongoing risks. The proposed risk assessment protocol addresses biosafety and the biophysical and social risks. It elicits perceptions of interaction and risk from the project scientists and from representatives of interested or affected sectors of society. The perceptions are documented for examination interactively in subsequent socially inclusive formal risk assessments. Representatives of the relevant social sectors participate with the scientists, iteratively if needed, in a workshop to assess the risks of releasing the particular GMO into the environment, using a formal inductive procedure, GENHAZ, designed specifically for assessment and management of the risks of GMOs. Use of this protocol is intended to precede and complement risk assessment and risk management procedures specified by gene technology legislation and regulations.

Comparing Bayesian neural network algorithms for classifying segmented outdoor images

In this paper we investigate the Bayesian training of neural networks for region labelling of segmented outdoor scenes; the data are drawn from the Sowerby Image Database of British Aerospace. Neural networks are trained with two Bayesian methods, (i) the evidence framework of MacKay (1992a,b) and (ii) a Markov Chain Monte Carlo method due to Neal (1996). The performance of the two methods is compared to evaluating the empirical learning curves of neural networks trained with the two methods. We also investigate the use of the Automatic Relevance Determination method for input feature selection.

Health status of northern bobwhite quail (Colinus virginianus) in eastern Kansas

The health status of wild northern bobwhite quail (Colinus virginianus) from Lyon County, Kansas, was evaluated by conducting comprehensive health assessments on 25 birds. Gross lesions indicative of avian pox, ulcerative enteritis, and quail bronchitis were not present. Serologic tests for antibodies to Salmonella pullorum, Salmonella gallinarum, Pasteurella multocida, Mycoplasma gallisepticum, Mycoplasma synoviae, and avian adenoviruses were all negative. Intestinal coccidia (Eimeria spp.) were found in 36% of the birds. Only three species of helminth parasites were found: Dispharynx nasuta in two birds, Cyrnea colini in one bird, and larval Physaloptera sp. in four birds. Arthropod parasites (ticks, lice, mites, and/or chiggers) were present on 96% of the birds examined. Compared with wild bobwhite populations in the southeastern United States, the diversity, prevalence, and intensities of microbial and parasitic agents were low.

Functional consensus for mammalian osmotic response elements

The molecular mechanisms underlying adaptation to hyperosmotic stress through the accumulation of organic osmolytes are largely unknown. Yet, among organisms, this is an almost universal phenomenon. In mammals, the cells of the renal medulla are uniquely exposed to high and variable salt concentrations; in response, renal cells accumulate the osmolyte sorbitol through increased transcription of the aldose reductase (AR) gene. In cloning the rabbit AR gene, we found the first evidence of an osmotic response region in a eukaryotic gene. More recently, we functionally defined a minimal essential osmotic response element (ORE) having the sequence CGGAAAATCAC(C) (bp -1105 to -1094). In the present study, we systematically replaced each base with every other possible nucleotide and tested the resulting sequences individually in reporter gene constructs. Additionally, we categorized hyperosmotic response by electrophoretic mobility shift assays of a 17-bp sequence (-1108 to -1092) containing the native ORE as a probe against which the test constructs would compete for binding. In this manner, binding activity was assessed for the full range of osmotic responses obtained. Thus we have arrived at a functional consensus for the mammalian ORE, NGGAAAWDHMC(N). This finding should accelerate the discovery of genes previously unrecognized as being osmotically regulated.

Randomized trial of intensive cyclophosphamide, epirubicin, and fluorouracil chemotherapy compared with cyclophosphamide, methotrexate, and fluorouracil in premenopausal women with node-positive breast cancer. National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine the relative efficacy of an intensive cyclophosphamide, epirubicin, and fluorouracil (CEF) adjuvant chemotherapy regimen compared with cyclophosphamide, methotrexate, and fluorouracil (CMF) in node-positive breast cancer.

PATIENTS AND METHODS

Premenopausal women with node-positive breast cancer were randomly allocated to receive either cyclophosphamide 100 mg/m2 orally days 1 through 14; methotrexate 40 mg/m2 intravenously (i.v.) days 1 and 8; and fluorouracil 600 mg/m2 i.v. days 1 and 8 or cyclophosphomide 75 mg/m2 orally days 1 through 14; epirubicin 60 mg/m2 i.v. days 1 and 8; and fluorouracil 500 mg/m2 i.v. days 1 and 8. Each cycle was administered monthly for 6 months. Patients administered CEF received antibiotic prophylaxis with cotrimoxazole two tablets twice a day for the duration of chemotherapy.

RESULTS

The median follow-up was 59 months. One hundred sixty-nine of the 359 CMF patients developed recurrence compared with 132 of the 351 CEF patients. The corresponding 5-year relapse-free survival rates were 53% and 63%, respectively (P = .009). One hundred seven CMF patients died compared with 85 CEF patients. The corresponding 5-year actuarial survival rates were 70% and 77%, respectively (P = .03). The rate of hospitalization for febrile neutropenia was 1.1% in the CMF group compared with 8.5% in the CEF group. There was one case of congestive heart failure in a patient who received CMF compared with none in the CEF group. Acute leukemia occurred in five patients in the CEF group.

CONCLUSION

The results of this trial show the superiority of CEF over CMF in terms of both disease-free and overall survival in premenopausal women with axillary node-positive breast cancer.

Baylisascaris sp. found in a wild northern bobwhite (Colinus virginianus)

During a telemetry study conducted between 1993 and 1995 in east-central Kansas (USA) on northern bobwhite (Colinus virginianus) populations, a wild adult male quail was found with signs of disorientation and torticollis in August 1994 in Lyon County, Kansas. Based on histological and parasitological examination, it was determined that the bird was infected with larval nematodes of the genus Baylisascaris spp. This is the first known recorded case of Baylisascaris sp. in a wild game bird species.

Development and use of virus-vectored immunocontraception

Virus-vectored immunocontraception (VVIC) is perceived to present biological risks, real or baseless, which create social and political constraints to deploying VVIC for managing vertebrate pests. Developing and deploying VVIC must be justified and address biological, social and political risks. Future needs for pest management will influence deployment of VVIC. Projections of human society and pest impact on agriculture and conservation suggest increasing need for cost-beneficial strategies. Best strategies are likely to integrate various methods, possibly including forms of VVIC. Processes identifying future pest impacts and roles for VVIC are shown using the rabbit in Australia. Present research developing VVIC aims to test physiological feasibility, to develop it for specific pests, and address aspects of ecological feasibility. Minimizing biological risks through choosing species-specific antigens and, if possible, viral vectors, is central and overseen by regulatory authorities. International collaborators study related valued species to develop protective strategies. Excellent science can withstand legal or public challenge to safe and cost-beneficial VVIC if aided by information needed by the public exposed to media distortion of scientific debate, complex argument and concepts of probability and risk. Sound science needs support from strategies for public processes to enable cost-beneficial management of vertebrate pests.

ORE, a eukaryotic minimal essential osmotic response element. The aldose reductase gene in hyperosmotic stress

Organisms, almost universally, adapt to hyperosmotic stress through increased accumulation of organic osmolytes but the molecular mechanisms have only begun to be addressed. Among mammalian tissues, renal medullary cells are uniquely exposed to extreme hyperosmotic stress. Sorbitol, synthesized through aldose reductase, is a predominant osmolyte induced under hyperosmotic conditions in renal cells. Using a rabbit renal cell line, we originally demonstrated that hyperosmotic stress induces transcription of the aldose reductase gene. Recently, we cloned the rabbit aldose reductase gene, characterized its structure, and found the first evidence of an osmotic response region in a eukaryotic gene. Now, we have progressively subdivided this 3221-base pair (bp) region into discrete fragments in reporter gene constructs. Thereby, we have functionally defined the smallest sequence able to confer hyperosmotic response on a downstream gene independent of other putative cis-elements, that is, a minimal essential osmotic response element (ORE). The sequence of the ORE is CGGAAAATCAC(C) (bp -1105/-1094). A 17-bp fragment (-1108/-1092) containing the ORE used as a probe in electrophoretic mobility shift assays suggests hyperosmotic induction of a slowly migrating band. Isolation of trans-acting factor(s) and characterization of their interaction with the ORE should elucidate the basic mechanisms for regulation of gene expression by hyperosmotic stress.

Betaine transporter cDNA cloning and effect of osmolytes on its mRNA induction

Cells generally adapt to long-term hyperosmolality by accumulating compatible organic osmolytes, thereby helping to normalize both volume and intracellular inorganic ion concentration. When organic osmolytes are accumulated, as in renal inner medullary cells, it is the sum of their concentrations that is theoretically important. In effect, when one organic osmolyte rises, the others generally fall to maintain their sum approximately constant. The present study addresses the mechanism controlling betaine accumulation. Hypertonicity induces accumulation of betaine, sorbitol, inositol, and other organic osmolytes in PAP-HT25 cells, a line derived from rabbit renal papilla. Hypertonicity increases the betaine transporter expression in these cells. To obtain a specific probe for betaine transporter mRNA, we cloned from PAP-HT25 cells a cDNA that encodes the full protein. We then examined the effect of betaine, sorbitol, and inositol on betaine transporter mRNA abundance. Increased accumulation of any of these three organic osmolytes reduces betaine transporter mRNA. We previously observed similar results for aldose reductase, the enzyme responsible for osmotically regulated sorbitol accumulation. We conclude that the accumulation of organic osmolytes regulates betaine transporter gene expression. Because the aldose reductase gene is controlled in a similar fashion, we surmise that the two genes share a common signal for induction.

Effectiveness and Cost-Efficiency of Control of the Wild Rabbit, Oryctolagus Cuniculus (L.), By Combinations of Poisoning, Ripping, Fumigation and Maintenance Fumigation

An experiment compared effectiveness, cost and cost-efficiency of factorial combinations of the four commonly used methods of rabbit control on grazing properties in the Southern Tablelands of eastern Australia. Sixteen different treatment combinations were applied to 32 sites. The treatments comprised initial control, applied over four months, followed by repeated maintenance control on half the replicates, applied after intervals of 2,6 and 12 months. Initial control comprised no treatment, or poisoning (P) with sodium monofluoroacetate (1080), or warren-ripping (R), or chloropicrin pressure fumigation (F), or combinations of these (P+R, P+F, R+F, P+R+F). Maintenance control consisted of phosphine-diffusion fumigation (M). Indices of rabbit abundance were compared one month before treatments were implemented. Treatment effects were assessed one month after completion of the initial control, and one and 5-6 months after the three maintenance controls, and additionally nine months after the second maintenance control. Control combinations that were highly effective and cost-efficient included both warren-ripping and maintenance treatment. Poisoning prior to warren-ripping, or fumigating subsequently, or both, improved effectiveness and cost-efficiency. Warren-ripping interacted positively with one or more subsequent fumigations, improving effectiveness and cost-efficiency non-additively. Control combinations that excluded warren-ripping were ineffective and cost-inefficient, and one combination interacted negatively. Single treatments of poisoning or fumigation were cost-inefficient, allowing rabbits to recolonise rapidly to densities higher than original. Only multiple combination treatments or repeated applications were highly effective and cost-efficient; single applications of any method were inefficient and costly. The most effective and cost-efficient combination comprised the maximum six applications including ripping and maintenance treatment, namely P+R+F+M. The high effort and expenditure on the initial control resulted in high effectiveness and cost-efficiency, which maintenance control sustained at low cost. Maintenance treatments sustained or achieved effective control of rabbits; the cost of maintenance treatments halved on each repetition.

Cloning, genomic organization, and osmotic response of the aldose reductase gene

Diverse organisms accumulate organic osmolytes to adapt to hyperosmotic stress. The molecular basis of eukaryotic gene osmoregulation remains obscure. Aldose reductase [AR; alditol:NAD(P)+ 1-oxidoreductase, EC 1.1.1.21], which catalyzes the conversion of glucose to sorbitol (an organic osmolyte), is induced in renal medullary cells under hyperosmotic conditions. Elevated extracellular NaCl increases AR mRNA transcription in PAP-HT25 cells, a cell line derived from the rabbit renal papilla. We have cloned and characterized the rabbit AR gene to determine how it is regulated by hyperosmolality. The length of the gene, not including 5' or 3' flanking regions, is approximately 14.7 kilobases (kb) organized into 10 exons and 9 introns. The transcription start site is 36 base pairs upstream of the initiator methionine codon. A 5-kb fragment containing approximately 3.5 kb of 5' flanking region was isolated. The 3.5-kb sequence was examined for basal promoter activity and hyperosmotic response in luciferase reporter gene constructs. A 235-base-pair fragment (base pairs -208 to +27) was able to drive the downstream reporter gene in transfected PAP-HT25 cells under isoosmotic conditions (300 mosmol/kg of H2O). When this fragment plus the remaining upstream sequence (from approximately base pair -3429 to base pair +27) was used, cells in hyperosmotic medium (500 mosmol/kg of H2O) showed about 40-fold induction of luciferase expression compared with cells in isoosmotic medium. The upstream fragment (from approximately base pair -3429 to base pair -192) also conferred osmotic response to a heterologous promoter (B19). This finding evidences putative osmotic response element(s) (OREs) within a specific DNA fragment in a eukaryotic genome. Identification and characterization of OREs within this fragment and their associated trans-acting factors should reveal the molecular mechanisms of gene regulation in osmotic stress.

Water channel vesicles from toad urinary bladder contain a family of proteins present in other tissues

Antidiuretic hormone (ADH) stimulation causes the fusion and subsequent retrieval of cytoplasmic vesicles containing water channels (WCV) with the apical membrane of toad bladder granular cells. Previously, we showed that purified WCV contain 12 major protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. To identify various WCV proteins, we screened a panel of mouse monoclonal antibodies and characterized an immunoglobulin G1 monoclonal antibody, 5E5, that recognizes integral membrane WCV proteins of 38, 33, and 31 kDa. Immunocytochemistry and Western blot analyses show that 5E5 binds to multivesicular body endosomes shown previously to contain ADH water channels. In addition, 5E5 recognizes these proteins in selected cells of the skin, intestine, liver, kidney, spleen, and lung. However, 5E5 does not appear to recognize components of the water channel itself. We conclude that WCV contain several membrane proteins recognized by 5E5 that are present in certain cells of the other organs. Monoclonal 5E5 provides a probe to determine the structure and function of these endosomal proteins as well as their role in the ADH water permeability response.

Some epidemiological features of the human T-cell lymphotropic virus type I (HTLV-I) and ATL in Nigerians

With a seroprevalence rate (SPR) of 6%-10% among healthy adult blood donors (ABD), Nigeria and other African locales represent an endemic zone for HTLV-I. We studied SPR in patients with leukaemia, lymphomas, solid tumours, and chronic disorders, as well as in groups of men and women with varying sexual lifestyles. Serum specimens were screened with ELISA and then confirmed with Western blot (WB). Sexual practices were investigated among volunteers of different sexual backgrounds by means of a questionnaire. Female prostitutes (FP) (13.0%) and patients with sexually transmitted diseases (STDP) (16.7%) had the highest SPR while a low rate occurred in religious celibate males (RCM) but not in religious celibate females (RCF) (11.8%). Heterosexual activity as well as geographical location of the place of birth constituted the most important risk factors for HTLV-I. HIV antibodies were demonstrable in none of the study subjects. ATL was associated with 100% SPR (4/4) while SPR in other clinical states were not different from normal. Western blot profile was rarely of strong poly band but more frequently of weak oligo band pattern with absent or weak p19 compared to p24. Only 18% of non Hodgkin's lymphoma in Ibadan, Nigeria was seropositive compared to 50% and > 60% in Japanese and Caribbean endemic zones respectively. The high SPR and aberrant WB profiles indicate reactivity to HTLV-I and to an HTLV-II-like activity, probably a new virus in the region. Excluding the aberrant WB profile, SPR based on HTLV-I-related profile was 3.8%-4.8% in ABD, 13% in FP, 10% in STDP, 1.9% in RCM, 0% in RCF, and 25% in ATL patients. The HTLV-II-related profile showed no such heterosexual association, but occurred in 75% of ATL patients. HTLV-I and probably and an HTLV-II-like virus appear to play a role in STD and lymphoma epidemiology in Nigeria.

Frequency of adult T-cell leukaemia/lymphoma and HTLV-I in Ibadan, Nigeria

Sera from a small sample of adult blood donors, healthy school children and patients with lymphoma, leukaemia, non-haematologic cancer, congenital and inflammatory disorders from Ibadan, Nigeria were screened for HTLV-I antibody by an enzyme-linked immunoabsorbent assay and confirmed by investigational Western blot. Seventy-nine of 236 positively screened samples could not be tested for confirmation. Seropositive reactivity was observed in nine of 123 blood donors, and 3 of 46 healthy school children but banding patterns on Western blot were often sparse. Among non-Burkitt's non Hodgkin's lymphoma patients six of 30 were HTLV-I positive including four of four with clinical features of adult T-cell leukaemia (ATL). Other clinical conditions had a frequency of positivity indistinguishable from healthy donors. Western blot patterns ranged from strong with multiple bands, which were uncommon, to those with only p24 and p21 envelope positive which were frequent. Given the relative paucity of clinical ATL and the unusual Western blot patterns the true rate of HTLV-I infection may be lower than estimated. It is possible that a cross-reactive HTLV-I-like virus accounts for this pattern.

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Inheritance of Acquired-Immunity to Myxomatosis

Male domestic rabbits mating after recovering from myxomatosis may transmit immunity to progeny born to the female in the next seven months, including progeny sired by other males lacking immunity (Sobey and Conolly 1986). In wild rabbits, Oryctolgus cuniculus (L.), we observed similar enhanced immunity in progeny of immune sires. The inherited immunity relates to the prior time of infection of the sire, and appears to be non-genetic; it complements genetic resistance and may persist into the progeny's reproductive lifetime. Inherited acquired immunity may reduce the effectiveness of myxomatosis in some wild rabbit populations.

Continuous in-vitro cultivation of Plasmodium falciparum in Ibadan: solutions to scientific and logistical problems

The technique of continuous in-vitro cultivation of Plasmodium falciparum has not been widely applied in malaria-endemic areas, due to scientific as well as purely logistical problems. Methods for solving or coping with these problems are described. They have already proved effective for over 4 years. The parasites harvested have been satisfactory, as judged by reproducible logarithmic growth curves and normal morphology in Leishman-stained smears as well as phase-contrast microscopy of wet-preparations. They have also been successfully used as antigen sources in the malarial fluorescent-antibody test and to investigate enhanced platelet aggregation in experimental malaria.

Genetic-Resistance to Myxomatosis in Australian Wild Rabbits, Oryctolagus-Cuniculus (L)

We examined the role of genetics of rabbit populations in the development of resistance to myxomatosis. We compared the responses of progeny from rabbit populations of Australian arid, mediterranean and subalpine regions when challenged at two ambient temperatures by plaque-purified virus of two myxoma strains of contrasting virulence, Uriarra and Lausanne. Wild rabbit populations have diverged in genetic resistance to myxomatosis since the rabbit was introduced to Australia 125 years previously. Founder effects and natural selection are possible causes. Rabbits from the warm dry regions died of Lausanne strain infection more slowly than rabbits from the cool moist region. Genetic resistance to myxomatosis probably diverged regionally as epizootics selected rabbit populations during the 34 years since the myxoma virus was introduced. Adaptation of rabbit populations to different environments might also have contributed to diverging resistance. Mortality was similar among regional groups and did not correlate with survival time, suggesting either polymorphism within populations, a prerequisite of natural selection, or variation in non-genetic immunity. Warmer conditions did not affect mortality but extended survival times. Therefore myxoma strains predominating in warm regions may be more virulent than those in cooler regions. Mean temperature may cause levels of genetic resistance to vary among regions. Mortality rates were less than those observed previously. Uriarra strain killed < 5% of infected rabbits compared to 35% previously. Lausanne strain killed 88%, formerly 98%. Selection during storage or plaque-purification may have decreased viral virulence, and recent natural selection may have increased genetic resistance of rabbits to myxomatosis.

Environmental and Genetic Influences on Growth of the Wild Rabbit, Oryctolagus-Cuniculus (L) in Australia

Environmental variation caused more variation in the growth rates of wild rabbits than did genetic divergence among populations in three climatic regions in Australia. The growth of various parts of the body responded to different environmental influences. Growth of the body core of kittens varied with the number of littermates. Growth of the pes varied with ambient temperature and the number of littermates. Growth of the pinnae, organs with special thermoregulatory function, was affected markedly by ambient temperature. Growth rates in regional rabbit populations differed consistently in two generations, manifesting differences in physiology and possible genetic divergence. Sub-alpine rabbits grew faster in body length and head length than did rabbits of mediterranean and arid climates. The extremities of mediterranean rabbits grew slower than those of arid and sub-alpine rabbits. The regional variation in growth physiology was determined either by persisting influence of the field environments transmitted maternally through two generations, or by genetic divergence of populations since the few progenitors were introduced to Australia 125 years previously.

Haemolytic anaemia associated with Nigerian barbecued meat (red suya)

Five cases of haemolytic anaemia occurring in male Nigerians following the ingestion of spiced barbecued meat (suya) are described. Although suya is a popular food item in various parts of Nigeria, all five patients described in this report had consumed a special brand, called red suya, purchased from vendors at a popular road junction between the cities of Lagos and Ibadan. Ingestion of the culprit suya sample was followed within 24 h by malaise and fever, while passage of dark-coloured urine and jaundice followed 1-3 days thereafter. Glucose-6-phosphate dehydrogenase (G6PD) deficiency was demonstrated by a fluorescent screening test in all cases, while the enzyme phenotype was shown to be GdA- in all four cases studied by starch-gel electrophoresis, thus suggesting that G6PD deficiency was a predisposing factor in the cases reported in this series. The haemolytic disease was self-limiting and full recovery followed in all cases. In view of the markedly circumscribed range from where the patients originated, the culprit agent responsible for the haemolytic disease is believed to be a recently introduced food additive that is probably accessible only to a limited number of suya vendors.

Recent advances in chemotherapy of the lymphomas: a review

A review of some of the developments over the last two decades in the field of chemotherapy of the lymphomas is provided. The evolution of the current treatment regimens through clinical trials is emphasized, and the need to develop a similar approach to cancer chemotherapy in African treatment centres is advocated. In view of their different natural histories, non-Hodgkin's lymphoma (NHL) of 'favourable' and 'unfavourable' histologic variants need to be treated differently. While the former type of NHL need only a non-myelosuppressive chemotherapy, the latter would benefit from intensive chemotherapy involving the use of adriamycin and cytosine arabinoside, which appear to have salutary effects in this form of NHL. Burkitt's and Hodgkin's lymphomas are both highly curable forms of cancer and indications are given in support of further improvement in their current chemotherapeutic management. As over 50% of adequately treated lymphoma patients are likely to experience prolonged survival, more attention is now being directed to factors contributory to their quality of life. Thus, some complications of chemotherapy and their prevention are reviewed.

Osteopetrosis in a Nigerian woman--a case report

A case of osteopetrosis complicated by chronic osteomyelitis of the mandible, pathological fractures, pancytopenia and splenomegaly is presented. Family studies revealed a dominantly inherited pattern.

Iatrogenic and idiopathic acute myelogenous leukemia: a comparison of clinical features and treatment complications

We have compared the clinical and laboratory features as well as treatment complications observed in 6 patients with iatrogenic acute myelogenous leukemia (I-AML) with those of 26 patients with idiopathic acute myelogenous leukemia (AML). I-AML patients were significantly younger and their disease appeared less virulent on admission than in the AML patients. Following identical chemotherapy, hemorrhagic complications and the need for platelet support were found to be similar for both groups. Major infections, including systemic candidiasis and Gram-negative septicemias, occurred 3 times more frequently among I-AML than AML patients. More marked suppression and delayed regeneration of the bone marrow also occurred in I-AML patients. These observations and other factors, such as post-splenectomy state and inherent immune deficiency among surgically staged lymphoma patients as well as radiation induced immunologic impairment, may have contributed to the increased propensity to develop infection observed in this group of patients. Five of the 6 I-AML and 17 of the 26 AML patients achieved remission. We attribute the satisfactory outcome in our I-AML patients to treatment in a protective environment and availability of facilities for hematologic supportive care.

Water Physiology and Nutrition in Fluctuating Populations of Rattus-Colletti in Monsoonal Northern-Territory, Australia

During wet and dry seasons and transitions of the monsoonal cycle, rates of water turnover and nutritional variables were measured on a population of Rattus colletti which fluctuated between extremes of high and low abundance. Rate of water turnover (RWT in millilitres per day) and body weight ( W, in kilograms) were related allometrically: RWT = aW*O.742 � 0.061, where a varied between seasons and sexes. Seasonal rates of water turnover were consistent with physiological adaptation in R. colletti to seasonal aridity. Rate of water turnover correlated with seasonal hydric regime, varying by a factor of 3.5 between dry and wet seasons. During the wet season, low body weight and lack of breeding seemed to be caused by flooding and its physical and social consequences. During dry season aridity the rats were short of food and water, but not in a dry season when rain fell and breeding ensued. Reproduction increased requirements for food and water in both sexes. Juveniles had relatively high requirements, and shortages appeared to retard growth. Very large populations resulted from prolific breeding after dry season rain had sustained high consumption of food and water on the riverine plains, the dry season habitat. Population decline resulted from very high wet season rainfall followed by a rainless dry season when food and water intakes were depressed, probably because the previous rainfall pattern reduced the availability of sedge corms, the dry season source of food and water. This climatic pattern recurred in the next wet and dry seasons, reinforcing the effects on R, colletti, which became rare for several years on both riverine systems studied.

Prospective studies on Hodgkin's disease in Ibadan--a preliminary report

A preliminary report of a prospective study of Hodgkin's disease (HD) is provided, based on clinical and laboratory findings on 21 patients seen between July 1978 and December 1979 at the University College Hospital (UCH), Ibadan. Staging procedure was minimized to relatively simple surgical procedures like lymphangiography and percutaneous biopsy. Staging laparotomy was performed only in one case. Female patients were significantly older than males (P less than 0.05). Patients with lymphadenopathy were significantly older than those without (P less than 0.05), while those with systemic symptoms were significantly younger than those without. Eighteen (86%) of the patients presented with stage IV disease while 12 (57%) had the unfavourable histologic "mixed cellularity' or "lymphocyte depleted' variants. Systemic symptoms were present in 16 (76%) of patients. Fifty-three % of adequately treated patients showed poor response to chemotherapy. The prognosis of HD in Ibadan is on the whole unfavourable. A delineation of the prognostic factors is indicated.

Neoplastic diseases of the haemopoietic system in Ibadan: preliminary report of a prospective study

The clinical and epidemiological features of haemopoietic malignancies in Ibadan have been evaluated in this preliminary analysis on findings on 113 patients seen at the University College Hospital, Ibadan, Nigeria, from July 1978 to June 1981. Twenty-seven patients had acute myelogenous (AML), twenty-two acute lymphoblastic (ALL), thirty-one chronic myelocytic (AML), thirty-one chronic lymphocytic leukaemia (CLL), two had polycythaemia rubra vera (PRV) and one myelofibrosis (MF). Incidence rates (IR) of 0.9 X 10(-5) and 1.9 X 10(-5) were estimated for acute leukemia (AL) and all leukemia subtypes respectively. Chloroma occurred frequently in association with AML especially in childhood, and CLL in elderly patients (greater than 50 years) and ALL appeared to manifest unusually aggressive features in spite of apparently adequate chemotherapy. Some of these clinical and epidemiological features suggest deviant biology of some haemopoietic malignancies in Ibadan.