Effects of tibolone on bone quality in ovariectomized monkeys

OBJECTIVE: The purpose of this report is to examine the effects of two doses of tibolone on bone quality (bone biomarkers, bone density, and bone strength) in ovariectomized cynomolgus monkeys fed high-fat diets. DESIGN: Ovariectomized cynomolgus monkeys were randomized into one of five treatment groups: placebo-treated control, tibolone (0.2 mg/kg/day), tibolone (0.05 mg/kg/day), conjugated equine estrogens (Premarin, 0.042 mg/kg/day), and conjugated equine estrogens plus medroxyprogesterone acetate (0.042 and 0.167 mg/kg/day, respectively). Bone quality was assessed by determining bone strength and density in vertebrae and femora collected after 24 months of treatment. RESULTS: Monkeys treated for 24 months with tibolone had increased bone mineral density in the distal femur and improved biomechanical properties in the midshaft femur compared with placebo-treated ovariectomized monkeys, as did monkeys treated with conjugated equine estrogens with or without medroxyprogesterone acetate. No treatment effects were seen in lumbar vertebra bone density or strength. There was no significant difference between tibolone and estrogen on biomechanical properties of the femur. CONCLUSION: These data show that tibolone is comparable to conjugated equine estrogens with or without medroxyprogesterone acetate in decreasing bone turnover and increasing bone strength in ovariectomized monkeys.     

Genomic structure and evolution of the ancestral chromosome fusion site in 2q13-2q14.1 and paralogous regions on other human chromosomes

Human chromosome 2 was formed by the head-to-head fusion of two ancestral chromosomes that remained separate in other primates. Sequences that once resided near the ends of the ancestral chromosomes are now interstitially located in 2q13-2q14.1. Portions of these sequences had duplicated to other locations prior to the fusion. Here we present analyses of the genomic structure and evolutionary history of >600 kb surrounding the fusion site and closely related sequences on other human chromosomes. Sequence blocks that closely flank the inverted arrays of degenerate telomere repeats marking the fusion site are duplicated at many, primarily subtelomeric, locations. In addition, large portions of a 168-kb centromere-proximal block are duplicated at 9pter, 9p11.2, and 9q13, with 98%-99% average sequence identity. A 67-kb block on the distal side of the fusion site is highly homologous to sequences at 22qter. A third ~100-kb segment is 96% identical to a region in 2q11.2. By integrating data on the extent and similarity of these paralogous blocks, including the presence of phylogenetically informative repetitive elements, with observations of their chromosomal distribution in nonhuman primates, we infer the order of the duplications that led to their current arrangement. Several of these duplicated blocks may be associated with breakpoints of inversions that occurred during primate evolution and of recurrent chromosome rearrangements in humans.     

The GAA triplet-repeat sequence in Friedreich ataxia shows a high level of somatic instability in vivo,with a significant predilection for large contractions

Friedreich ataxia is commonly caused by large expansions of a GAA triplet-repeat (GAA-TR) sequence in the first intron of the FRDA gene. We used small-pool PCR to analyze somatic variability among 7190 individual FRDA molecules from peripheral blood DNA of subjects carrying 12 different expanded alleles, ranging in size from 241 to 1105 triplets. Expanded alleles showed a length-dependent increase in somatic variability, with mutation loads ranging from 47% to 78%. We noted a strong contraction bias among long alleles (>500 triplets), which showed a 4-fold higher frequency of large contractions versus expansions. Some contractions were very large; of all somatic mutations scored, approximately 5% involved contractions of >50% of the original allele length, and 0.29% involved complete reversion to the normal/premutation length (< or =60 triplets). These observations contrast sharply with the strong expansion bias seen in expanded CTG triplet repeats in myotonic dystrophy. No somatic variability was detected in >6000 individual FRDA molecules analyzed from 15 normal alleles (8-25 triplets). A premutation allele with 44 uninterrupted GAA repeats was found to be unstable, ranging in size from 6 to 113 triplets, thus establishing the threshold for somatic instability between 26 and 44 GAA triplets. Analysis of an additional 7850 FRDA molecules from serially passaged lymphoblastoid cell lines carrying nine expanded alleles (132-933 triplets) showed very low mutation loads, ranging from 0% to 6.2%. Our data indicate that expanded GAA-TR alleles in Friedreich ataxia are highly mutable and have a natural tendency to contract in vivo, and that these properties depend on multiple factors, including DNA sequence, triplet-repeat length and unknown cell-type-specific factors.     

Waves earlier than P3 are more informative in putative subcortical Dementias: A study with mapping and neuropsychological techniques

Summary Thirty subjects (normal controls, patients with putative subcortical dementia and non-demented patient controls) were studied using advanced neurophysiological (16 scalp-electrode positions, computer-assisted brain electrical activity mapping, auditory oddball paradigm) and neuropsychological techniques. Our study suggests that waves earlier than P₃ (N₁, P₂ and N₂) are all correlated with global measures of cognitive functions. They are, however, differentially correlated with specific measures of cognitive functions, N₁ and P₂ with mental speed and N₂ with short-term memory. The abnormalities of these waves (earlier than P₃) may be an electrophysiologic marker of dementia in patients with putative subcortical states.     

Monkeypox virus detection in rodents using real-time 3'-minor groove binder TaqMan assays on the Roche LightCycler

During the summer of 2003, an outbreak of human monkeypox occurred in the Midwest region of the United States. In all, 52 rodents suspected of being infected with monkeypox virus were collected from an exotic pet dealer and from private homes. The rodents were euthanized and submitted for testing to the United States Army Medical Research Institute of Infectious Diseases by the Galesburg Animal Disease Laboratory, Illinois Department of Agriculture. The rodent tissue samples were appropriately processed and then tested by using an integrated approach involving real-time polymerase chain reaction (PCR) assays, an antigen-detection immunoassay, and virus culture. We designed and extensively tested two specific real-time PCR assays for rapidly detecting monkeypox virus DNA using the Vaccinia virus F3L and N3R genes as targets. The assays were validated against panels of orthopox viral and miscellaneous bacterial DNAs. A pan-orthopox electrochemiluminescence (ECL) assay was used to further confirm the presence of Orthopoxvirus infection of the rodents. Seven of 12 (58%) animals (seven of 52 (15%) of all animals) tested positive in both monkeypox-specific PCR assays and two additional pan-orthopox PCR assays (in at least one tissue). The ECL results showed varying degrees of agreement with PCR. One hamster and three gerbils were positive by both PCR and ECL for all tissues tested. In addition, we attempted to verify the presence of monkeypox virus by culture on multiple cell lines, by immunohistology, and by electron microscopy, with negative results. Sequencing the PCR products from the samples indicated 100% identity with monkeypox virus strain Zaire-96-I-16 (a human isolate from the Congo). These real-time PCR and ECL assays represent a significant addition to the battery of tests for the detection of various orthopoxviruses. In light of the recent monkeypox virus transmissions, early detection of the virus is crucial for both natural outbreaks and potential acts of bioterrorism.     

Rapid diagnosis of smallpox infection and differentiation from its mimics.

The potential for a bioterrorism-induced smallpox outbreak has been much discussed of late. The literature of the late 1960s stressed that the distinction between smallpox and the other viral-induced vesicle-forming diseases, namely varicella zoster and disseminated herpes simplex, was difficult to make. Given that the cutaneous manifestations of smallpox would be among the initial symptoms, we reviewed 2 cases of smallpox diagnosed in South America in the 1970s in conjunction with 9 cases of multiple skin vesicles diagnosed as either disseminated herpes simplex or varicella-zoster. These were examined by routine hematoxylin and eosin stain (H&E) as well as by in situ hybridization. A blind review of the cases demonstrated that each showed striking intraepithelial vesicles containing multinucleated squamous cells exhibiting a ground glass appearance of the nuclear chromatin. Thus, as expected, routine H&E examination could not differentiate the 2 smallpox cases from the other 9 samples. In situ hybridization easily distinguished the 2 cases of smallpox from the other 9 samples, 5 of which contained varicella-zoster (two had been misdiagnosed as herpes) and the other 4 were disseminated herpes simplex. The in situ test, readily accomplished in any histology-based molecular laboratory in 4 hours, allows for the rapid and specific identification of smallpox infection and, importantly, its distinction from its mimics. Formalin fixation, which is optimal for in situ hybridization, guarantees the inactivation of the smallpox virus.     

Validation of an equation for predicting energy cost of arm ergometry in women

Few studies have examined the validity of metabolic equations for the prediction of energy cost (VO(2)) of arm ergometry in women. Therefore, the purpose of this study was (a) to compare directly measured and predicted VO(2) values using the American College of Sports Medicine (ACSM) equation and (b) to develop and validate a prediction equation for women. A sample of 60 female subjects with mean (+/-SD) age, weight and height 26.5 +/- 14.4 years, 61.5 +/- 7.6 kg, 163.3 +/- 6.0 cm, respectively, was randomly assigned to an equation group (N = 40) and a cross validation group (N = 20). All subjects performed an incremental arm ergometry test (10 W increases every 2 min), until termination criteria were met. Repeated measures ANOVA indicated significant differences between the measured VO(2) and ACSM predicted VO(2) during all the incremental test work rate. Multiple linear regression analysis was used to develop the following upper body exercise VO(2) prediction equation: VO(2)(ml . kg(-1) . min(-1) = 23.461 - (0.272 x Body Weight) + (0.403 x watts) [R(2) = 0.82, SEE = 2.79] Cross validation indicated lower variability using the current prediction equation. An additional independent sample of 13 subjects performed a 30-min steady-state test at 40% of their pre-determined maximal work rate. VO(2) measured during the 30 min steady-state test (was significantly different P < 0.05) from the ACSM prediction at all time intervals. There were no significant differences using the above equation following the 5 min time interval. Therefore, a new equation is proposed as a means of providing a gender-specific energy cost prediction equation.