Prevalence of Overweight and Obesity among Students in the Kumasi Metropolis.

The aim was to determine the prevalence of obesity and overweight among students in the Kumasi metropolis. In a descriptive cross-sectional study, 500 students aged 10 to 20 years were examined from two junior high schools selected by multistage sampling technique and three randomly selected senior high schools. Height and weight were measured in all participants and the body mass index (BMI) of each individual was calculated. Body mass index classes were calculated according to the International Obesity Task Force standards. Out of the 500 students, 290 (58.00%) were males and 210 (42.00%) were females. The prevalence of underweight, normal weight, overweight, and obesity was 7.40%, 79.60%, 12.20%, and 0.80%, respectively. Overweight was more prevalent among students than obesity. There is therefore the need to establish effective public health promotion campaigns among students in order to curtail future implications on health.

17-ß Estradiol reduces atherosclerosis without exacerbating lupus in ovariectomized systemic lupus erythematosus-susceptible LDLr(-/-) mice.

OBJECTIVE: To test the hypothesis that estrogen treatment in a radiation chimera mouse model of systemic lupus erythematosus (SLE) and atherosclerosis will increase SLE-associated atherosclerosis by increasing autoantibody production and inflammation. METHODS: We used a radiation chimera mouse model in which bone marrow from the polygenic B6.Sle1.2.3 model of SLE was transferred to the low density lipoprotein receptor knock out (LDLr(-/-)) model of atherosclerosis on a C57BL/6 background (Sle/LDLr(-/-)). Ovariectomized chimeric mice were treated for 10 weeks with either 5.6 µg/day of 17ß-estradiol or placebo; outcomes included atherosclerosis plaque size, anti-dsDNA autoantibody production and renal pathology. RESULTS: Mean atherosclerosis plaque size was 67.4 ± 7.6% smaller in the estrogen treated group (p < 0.0001). Estrogen treated Sle/LDLr(-/-) mice had no significant difference in serum cholesterol concentration, lipoprotein distribution, anti-dsDNA autoantibody concentration, antibody isotype concentration and renal histopathology score compared to placebo. However, they had significantly lower mean urine protein to urine creatinine ratio (UP:UC). There was no correlation between atherosclerosis lesion size and either the renal histology score or UP:UC ratio in Sle/LDLr(-/-) mice. CONCLUSION: These results indicate that 17ß-estradiol is atheroprotective within the context of murine SLE independent of changes in serum cholesterol concentration, autoantibody concentration, or renal pathology. The SLE phenotype in Sle/LDLr(-/-) mice is not exacerbated by exogenous 17ß-estradiol administration, and the reduced UP:UC ratio suggests a protective effect against lupus nephritis.

Comparative pathology of smallpox and monkeypox in man and macaques.

In the three decades since the eradication of smallpox and cessation of routine vaccination, the collective memory of the devastating epidemics caused by this orthopoxvirus has waned, and the human population has become increasingly susceptible to a disease that remains high on the list of possible bioterrorism agents. Research using surrogate orthopoxviruses in their natural hosts, as well as limited variola virus research in animal models, continues worldwide; however, interpretation of findings is often limited by our relative lack of knowledge about the naturally occurring disease. For modern comparative pathologists, many of whom have no first-hand knowledge of naturally occurring smallpox, this work provides a contemporary review of this historical disease, as well as discussion of how it compares with human monkeypox and the corresponding diseases in macaques.

Clinicopathologic characterization of naturally occurring diabetes mellitus in vervet monkeys.

Diabetes mellitus (DM) is a group of chronic metabolic diseases characterized by persistent fasting hyperglycemia, and it can be of either polygenic or monogenic origin. Animal models have played an important role in elucidating the pathophysiology of the polygenic Type 1 and type 2 DM forms; however, useful animal models of the monogenic forms do not exist. The authors describe 4 cases of naturally occurring DM in vervet monkeys (Chlorocebus aethiops sabaeus), 1 of which has clinicopathologic findings consistent with type 2 DM, including persistent hyperglycemia, hypertriglyceridemia, islet amyloidosis, and reduced islet insulin immunostaining. In contrast, the 3 remaining animals have clinicopathologic similarities to a monogenic form of the disease, including a lack of islet amyloidosis and hypertriglyceridemia, as well as normal islet insulin immunostaining. In addition, pedigree analysis conducted on one of these animals is consistent with either an autosomal dominant or mitochondrial inheritance pattern, which supports a monogenic form of DM. The authors thus hypothesize that a naturally occurring monogenic form of diabetes may occur in vervet monkeys, making them a potential animal model for future studies.

Functional muscle analysis of the Tcap knockout mouse.

Autosomal recessive limb-girdle muscular dystrophy type 2G (LGMD2G) is an adult-onset myopathy characterized by distal lower limb weakness, calf hypertrophy and progressive decline in ambulation. The disease is caused by mutations in Tcap, a z-disc protein of skeletal muscle, although the precise mechanisms resulting in clinical symptoms are unknown. To provide a model for preclinical trials and for mechanistic studies, we generated knockout (KO) mice carrying a null mutation in the Tcap gene. Here we present the first report of a Tcap KO mouse model for LGMD2G and the results of an investigation into the effects of Tcap deficiency on skeletal muscle function in 4- and 12-month-old mice. Muscle histology of Tcap-null mice revealed abnormal myofiber size variation with central nucleation, similar to findings in the muscles of LGMD2G patients. An analysis of a Tcap binding protein, myostatin, showed that deletion of Tcap was accompanied by increased protein levels of myostatin. Our Tcap-null mice exhibited a decline in the ability to maintain balance on a rotating rod, relative to wild-type controls. No differences were detected in force or fatigue assays of isolated extensor digitorum longus (EDL) and soleus (SOL) muscles. Finally, a mechanical investigation of EDL and SOL indicated an increase in muscle stiffness in KO animals. We are the first to establish a viable KO mouse model of Tcap deficiency and our model mice demonstrate a dystrophic phenotype comparable to humans with LGMD2G.

Central role of detachment faults in accretion of slow-spreading oceanic lithosphere.

The formation of oceanic detachment faults is well established from inactive, corrugated fault planes exposed on sea floor formed along ridges spreading at less than 80 km Myr(-1) (refs 1-4). These faults can accommodate extension for up to 1-3 Myr (ref. 5), and are associated with one of the two contrasting modes of accretion operating along the northern Mid-Atlantic Ridge. The first mode is asymmetrical accretion involving an active detachment fault along one ridge flank. The second mode is the well-known symmetrical accretion, dominated by magmatic processes with subsidiary high-angle faulting and the formation of abyssal hills on both flanks. Here we present an examination of approximately 2,500 km of the Mid-Atlantic Ridge between 12.5 and 35 degrees N, which reveals asymmetrical accretion along almost half of the ridge. Hydrothermal activity identified so far in the study region is closely associated with asymmetrical accretion, which also shows high levels of near-continuous hydroacoustically and teleseismically recorded seismicity. Increased seismicity is probably generated along detachment faults that accommodate a sizeable proportion of the total plate separation. In contrast, symmetrical segments have lower levels of seismicity, which occurs primarily at segment ends. Basalts erupted along asymmetrical segments have compositions that are consistent with crystallization at higher pressures than basalts from symmetrical segments, and with lower extents of partial melting of the mantle. Both seismic evidence and geochemical evidence indicate that the axial lithosphere is thicker and colder at asymmetrical sections of the ridge, either because associated hydrothermal circulation efficiently penetrates to greater depths or because the rising mantle is cooler. We suggest that much of the variability in sea-floor morphology, seismicity and basalt chemistry found along slow-spreading ridges can be thus attributed to the frequent involvement of detachment faults in oceanic lithospheric accretion.

Histologic and immunohistochemical characterization of spontaneous pituitary adenomas in fourteen cynomolgus macaques (Macaca fascicularis).

Pituitary adenomas were identified in 14 of 491 (2.9%) cynomolgus macaques evaluated from 1994 to 2004. Cases included male (8) and female (6) cynomolgus macaques ranging from 18 to 32 years of age. Seven of the pituitary adenomas caused gross enlargement of the pituitary gland that was visible on postmortem examination, whereas the remaining 7 were multifocal microadenomas identified on histologic examination. A total of 35 adenomas were identified in the 14 macaques, 6 of which were being treated for diabetes mellitus. Mean (+/- SD) pituitary weight was 0.31 +/- 0.42 g, compared with 0.07 +/- 0.02 g for 430 historical control animals (P < 0.0001). Immunohistochemical staining for follicle-stimulating hormone, luteinizing hormone, prolactin, human growth hormone, thyroid-stimulating hormone, and adrenocorticotropic hormone was applied to pituitary tissue from all cases. Immunostaining revealed 22 of 35 (62.9%) lactotroph adenomas, 5 of 35 (14.3%) plurihormonal cell adenomas, 3 of 35 (8.6%) corticotroph adenomas, 2 of 35 (5.7%) null cell adenomas, 1 of 35 (2.9%) somatotroph adenomas, 1 of 35 (2.9%) mixed corticotroph-somatotroph adenomas, 1 of 35 (2.9%) mixed lactotroph-corticotroph adenomas, 0 of 35 gonadotroph adenomas, and 0 of 35 thyrotroph adenomas. This study represents the first extensive retrospective case series performed to evaluate the histologic and immunohistochemical characteristics of pituitary adenomas in cynomolgus macaques. Our findings indicated that macaque pituitary adenomas frequently had mixed histologic appearance and hormone expression, and that, similar to human pituitary adenomas, prolactin-secreting neoplasms were the most prevalent type.

Outbreak of Norwalk virus in a Caribbean island resort: application of molecular diagnostics to ascertain the vehicle of infection.

In 1998, an outbreak of gastroenteritis affected at least 448 persons including 122 staff at a resort hotel in Bermuda. A survey among staff indicated that gastroenteritis was associated with eating or drinking at the hotel (OR = 60, 95% CI = 2.4-15.1). Multiple specimens of drinking water had elevated faecal coliform levels and Escherichia coli present, suggestive of faecal contamination. Stools from 18 of the 19 persons with gastroenteritis that were tested were positive for genogroup-II Norwalk-like viruses (NLVs). RT-PCR analysis of a 31 specimen of water produced a genogroup-II NLV genome with a sequence identical to that of NLVs in the stools of three ill persons. This outbreak shows the value of new molecular diagnostics to link illness with a contaminated source through the use of sequence analysis. The risk of outbreaks such as these could be reduced in tourism dependent regions like Bermuda and the Caribbean by regular evaluation of data from the inspection and monitoring of drinking water supplies and waste water systems, by ensuring the chlorination of supplemental drinking water supplies and by establishing food-safety initiatives.

Incorporation of dispersion into the theory of electrophoresis of DNA and its complexes.

Incorporation of the dispersion coefficient into the theory of the mobility-shift assay for DNA-protein complexes was highly successful largely due to increased mathematical rigor. A model simulating electrophoretic migration of DNA across the phase boundary between the initial zone of macromolecule and the gel lane predicts the peak asymmetry observed experimentally. It also predicts that, under the agency of the dispersion coefficient, the peak will become progressively more symmetrical during migration along the gel lane.

Theory and practice of isoelectric focusing of interacting systems.

The theory of mass transport coupled to reversible protein interactions forms the basis for computer simulation of the isoelectric focusing behavior of several model systems. These include pH-dependent conformational transition, carrier ampholyte-induced interactions and protein-ligand interactions. The computational results compare favorably with experimental observations. In addition, a method is formulated for an isoelectric focusing procedure which enables determination of intrinsic ligand-binding constants for statistical binding of a charged ligand, binding to heterogeneous sites, and cooperative binding.

Theoretical studies on the mobility-shift assay of protein-DNA complexes.

The theory of mass transport coupled to reversible macromolecular interactions under chemical kinetic control forms the basis for computer simulation of the electrophoretic mobility-shift behavior of protein-DNA complexes. Model systems include (i) specific binding of a univalent protein molecule to a single site on the DNA molecule; (ii) the putative cage effect; (iii) cooperative binding to multiple sites; (iv) formation of looped complexes of 1:1 and 2:1 stoichiometry; (v) noncooperative and cooperative, nonspecific binding modes; and (vi) binding of dimerizing transcriptional factors to response elements of target genes. Favorable comparison of simulated with experimental mobility-shift behavior indicates that the phenomenological mechanisms, whereby observed mobility-shift patterns are generated during electrophoresis, are embodied in the theory. These studies have provided guidelines for definitive interpretation of mobility-shift assays and for the design of experiments to develop a detailed understanding of the particular system under investigation.

NMR and CD conformational studies of bradykinin and its agonists and antagonists: application to receptor binding.

Most physiological processes are regulated by peptides that perform their functions by interacting with specific receptors on cells. Specific conformations of the peptides are required for correct interactions to take place, and a knowledge of the biologically important conformation is vital for the understanding of biological function. Over the last few years extensive studies using nuclear magnetic resonance and circular dichroism have been carried out on bradykinin (Arg1-Pro2-Pro3-Gly4-Phe5-Ser6-Pro7-Phe8-Arg9) and its antagonists with the objective of developing new drugs to combat severe pathologies associated with its production. In the present review, these techniques for the determination of peptide conformation are reviewed and applied to the study of bradykinin and its antagonists. Modeling of these conformational data in the presence of the B2 receptor or an antibody allows the biologically active conformations to be deduced and these are presented in this review.

A comparative NMR and molecular dynamics study of the conformations of bradykinin B1 and B2, B2, and B1-specific receptor antagonists B-9430, B-9436, and B-9858.

Extensive proton magnetic resonance experiments were carried out on three bradykinin peptide antagonists B-9430, B-9436, and B-9858 in aqueous solutions as well as in sodium dodecylsulphate micelles (B-9430 and B-9436) and CD3OH/H2O (60%/40%) mixtures for B-9858. All three peptides showed no observable secondary structure in aqueous solution. However, in their respective structure-inducing solvents, B-9430 (B1 and B2 receptor antagonist) and B-9436 (a B2 receptor antagonist) exhibit a type II beta-turn involving residues 2-5, and B-9430 also exhibits a type II' beta-turn involving residues 6-9 (in sodium dodecylsulfate micellar solutions), whereas B-9858, a B1-specific receptor antagonist, exhibits only a type II beta-turn involving residues 2-5 (in CD3OH/H2O solutions). Simulated annealing calculations on B-9858 confirm the experimental conclusions based on the nmr data. In addition, simulated annealing of the (2S, 3aS, 7aS)-octahydroindole-2-carboxylic acid (Oic residue), which is present in two of the three decapeptides studied, show that the one-chair conformation of the six-membered ring predominates, in agreement with the experimental data. The activities of these peptides are compared with their secondary structures and the specific receptor activity appears to depend on the presence of specific amino acid residues, such as N-(2-indanyl) glycine (Nig) and D[alpha-(2-indanyl) glycine] (D-Igl) as well as on elements of secondary structure.

Models of mobility-shift assay of complexes between dimerizing protein and DNA.

The theory of mass transport coupled to macromolecular interactions under chemical kinetic control forms the basis of four different models of the electrophoretic mobility-shift assay of complexes formed between dimerizing proteins and DNA. The theory of mass action was applied to the set of simultaneous dimerization (either simple or ligand-induced) and DNA-binding reactions in order to fix the initial equilibrium composition of mixtures to be assayed. Theoretical mobility-shift patterns were obtained for a range of protein concentrations at constant DNA concentration by numerical solution of the set of simultaneous transport-reaction equations appropriate for each model. In those cases in which dimerization in solution is modeled (including heterodimerization), analysis of the peaks in the patterns provides apparent binding constants, which, when extrapolated to infinite dilution of protein, yield acceptable estimates of equilibrium constants. Those for binding of dimer are products of two or three equilibrium constants, from which the equilibrium binding constant can be extracted, provided that dimerization and, where required, ligand-binding constants are determined by independent physicochemical methods. Dimerization of protein when bound to DNA is distinctive in that extrapolation to infinite dilution of protein is not required.

Comment on mobility-shift computations featuring cage effects.

Theoretical mobility-shift patterns are computed by solution of conservation equations for electrophoresis coupled with chemical reaction. The chemical reaction term is often formulated in terms of dissociation of the protein-DNA complex in a gel cage. This formulation assumes that once the dissociated protein escapes the cage, it goes down a sink and is totally lost. This implies that the concentration of the escaped protein is too low to affect significantly the rates of protein-DNA association along its migration pathway.

Demonstration of an upper limit to the range of association rate constants amenable to study by biosensor technology based on surface plasmon resonance.

Numerical simulation of BIAcore sensorgrams has highlighted the need for concern about an assumption, inherent in current determinations of rate constants for macromolecular interactions, that the concentration of solute in the flowing phase remains constant at its injected value. This assumption is shown to be valid for systems with effective association rate constants equal to or less than 10 M(-1) values characteristic of antibody interactions with protein antigens. However, the assumption loses validity when the effective association rate constant is raised to 10 M' . The basic correctness of the latter prediction is verified by an experimental study of the interaction between soybean trypsin inhibitor and immobilized -trypsin, a system with comparable reaction kinetics.

An NMR, CD, molecular dynamics, and fluorometric study of the conformation of the bradykinin antagonist B-9340 in water and in aqueous micellar solutions.

A detailed NMR, CD, fluorometry, and molecular modeling study of a novel bradykinin antagonist B-9340, containing a novel amino acid D-Igl (alpha-(2-indanyl)glycine) at position 7, was carried out. The sequence of B-9340 is D-Arg0-Arg1-Pro2-Hyp3-Gly4-Thi5-Ser6-D- Igl7-Oic8-Arg9, where Hyp is hydroxyproline, Thi is beta-(2-thienyl)alanine, and Oic is (3aS,7aS)-octahydroindole-2-carboxylic acid. The CD results exhibit a striking effect of SDS on the spectrum of the BK antagonist, indicating that interaction with the surfactant induces a folded peptide structure. The interaction of this antagonist with phosphatidylinositol was monitored by fluorometry, indicating that the interaction of the peptide with the lipid is cooperative, and gives a Hill coefficient of 2.3. The two-dimensional proton NMR measurements indicate that B-9340 has no stable secondary structure in water solution and contains about 10-15% cis peptide bonds arising from Pro2, Hyp3, and Oic8. In SDS micelles, NMR reveals the existence of two beta-turns based on a number of medium-range connectivities that were useful for molecular modeling. The actual molecular modeling and dynamic runs were performed on B-9340 in an environment consisting of a layer of octyl sulfate anions and water. Ther results indicate that the structure of B-9340 in a micellar environment is characterized by a nonideal betaII-turn comprising residues Pro2 to Thi5, a nonideal betaII'-turn comprising residues Ser6-Arg9, and broad folding in the middle part of the molecule. The structure is stabilized by several hydrogen bonds and by a salt bridge between the guanidine moiety of Arg1 and the carboxyl group of Arg9, whereas the middle part of the peptide is buried in the micelle. The structure is deposited as Brookhaven PDB file 1 BDK.

Extended theory of the electrophoretic mobility-shift analysis of nonspecific protein-DNA complexes, featuring cooperativity.

The simulated electrophoretic mobility-shift behavior of a model system, in which the nonspecific binding of a protein to a DNA fragment is cooperative, was compared with the experimental behavior of the DNA: histone-like bacterial protein (HU) system. It was concluded that the binding of HU to an 88 bp DNA fragment is, at least, not highly cooperative. The theory of mobility-shift analysis was extended even further to encompass high affinity sequence-specific binding of protein to a DNA fragment followed by weak nonspecific binding, the latter governed by conditional probabilities. In addition to featuring a ladder of incremental protein-DNA complexes, the computed mobility-shift patterns placed emphasis upon stabilization of weak, nonspecific complexes in gel cages.