A growth QTL ( Pbwg1 ) region of mouse chromosome 2 contains closely linked loci affecting growth and body composition

Abstract  Previous QTL studies have identified 24 QTLs for body weight and growth from 3 to 10 weeks after birth in an intersubspecific backcross mouse population between C57BL/6J and wild Mus musculus castaneus that has 60% of the body size of C57BL/6J. The castaneus allele at the most potent QTL (Pbwg1) on proximal chromosome 2 retards growth. In this study we have developed a congenic strain with a 44.1-Mb interval containing the castaneus allele at Pbwg1 by recurrent backcrossing to C57BL/6J. The congenic mouse developed was characterized by significantly higher body weight gain between 1 and 3 weeks of age and lower weight of white fat pads at 10 weeks of age than C57BL/6J. However, no clear difference in body weight at 1–10 weeks of age was observed between congenic and C57BL/6J strains. QTL analysis with 269 F2 mice between the two strains did not identify any QTLs for body weight at 1, 3, 6, and 10 weeks of age, but it discovered eight closely linked QTLs affecting body weight gain from 1 to 3 weeks of age, lean body weight, weight of white fat pads, and body length within the Pbwg1 region. The castaneus alleles at all fat pad QTLs reduced the phenotypes, whereas at the remaining growth and body composition QTLs, they increased the trait values. These results illustrate that Pbwg1, which initially appeared to be a single locus, was resolved into several loci with opposite effects on the composition traits of overall body weight. This gives a reason for the loss of the Pbwg1 effect found in the original backcross population.

A girl with spina bifida, an extra leg, and ectopic intestinal loops – a “foetus in foetu” or a whim of the neural crest?

Summary  This article describes a girl with an extra leg attached to her lower back, combined with a spina bifida and a myelomeningocele. Despite lacking sensory or motor functions, the leg grew proportionately with the rest of the body. The bony structures were almost normal. A cross section showed fat tissue with some centrally situated blood vessels, nerve bundles, and muscular fragments. Proximally, an isolated colon loop was found. The extra leg and intestine respected the dorsal fascia, without connection with the peritoneal or retroperitoneal compartments. The finding is discussed with reference to existing hypotheses for limb formation.

A giant extrasynovial osteochondroma in the infrapatellar fat pad: end stage Hoffa’s disease

Abstract  The infrapatellar fat pad of Hoffa is commonly injured but rarely discussed in the orthopaedic literature. Hoffa’s disease is the extension of various traumatic events due to impingement and inflammation of the infrapatellar fat pad and known as a vague reason for anterior knee pain. Inflammation is foreground during acute phase of the disease while impingement due to fibrosis and scar tissue of infrapatellar fat pad plays a major role in the chronic phase. The osteochondroma of the infrapatellar fat pad secondary to the Hoffa’s disease can be more problematic. Although, the fibrocartilaginous transformation and osteochondral metaplasia of infrapatellar fat pad was pointed out frequently in the literature, the published papers seem far from clarifying the relation between chronic impingement and formation of osteochondroma. We present a case of a giant ossifying chondroma in the infrapatellar fat pad that resulted from chronic Hoffa’s disease. Complete open resection was performed successfully after arthroscopic examination. The infrapatellar fat pad contains the entire progenitor cells for the development of an osteochondroma and chronic impingement may have promoter affect on this issue, thus, an osteochondroma may occur at the end-stage Hoffa’s disease.

A genome-wide linkage scan for quantitative trait loci underlying obesity related phenotypes in 434 Caucasian families

Abstract  To identify quantitative trait loci (QTLs) that contribute to obesity, we performed a large-scale whole genome linkage scan (WGS) involving 4,102 individuals from 434 Caucasian families. The most pronounced linkage evidence was found at the genomic region 20p11-12 for fat mass (LOD = 3.31) and percentage fat mass (PFM) (LOD = 2.92). We also identified several regions showing suggestive linkage signals (threshold LOD = 1.9) for obesity phenotypes, including 5q35, 8q13, 10p12, and 17q11.

A genetic component in the determination of worker polymorphism in the Florida harvester ant Pogonomyrmex badius

Summary.  The interplay of genetic and environmental factors in the determination of social insect castes has long intrigued biologists. Though an overwhelming majority of studies establish that factors such as nutrition, pheromones and temperature determine the developmental fate of worker larvae, genetic components have recently been shown to play a role in the determination of morphological worker castes in leaf-cutting ants. Here we demonstrate that the determination of worker castes in the strongly polyandrous Florida harvester ant, Pogonomyrmex badius, has a genetic component. The overall distribution of caste members among patrilines in our study colonies is significantly different from the intracolonial caste ratio. Though this effect was not apparent in all colonies, our results suggest that workers of different patrilines in P. badius differ significantly in their propensities to develop into a certain worker caste. This genetic basis of worker polymorphism may go unnoticed in many social hymenopterans because of their low intracolonial genetic diversity due to monogamous colony structure. The worker polymorphism of P. badius is a taxonomic isolate and presumably a young trait in the genus. Therefore, a common genetic component of the determination of morphological and behavioral worker castes in social insects might be farranging taxonomically and may even be based on a genetic machinery inherent to all hymenopterans, but dormant in most.

A Fuzzy-Set Approach for Addressing Uncertainties in Risk Assessment of Hydrocarbon-Contaminated Site

Abstract  This study presented an integrated approach for evaluating environmental risks associated with hydrocarbon-contaminated sites through incorporation of a multiphase multi-component modeling system within a general risk assessment framework. The uncertainties associated with risk evaluation criteria were emphasized and effectively addressed through the development of a fuzzy-set approach. This development was based on (a) simulation of the fate of the contaminant in the subsurface to calculate contaminant concentrations in groundwater; (b) examination of the excess lifetime cancer risk (ELCR) distributions; (c) quantification of uncertainties in ELCR evaluation criteria using fuzzy membership functions; (d) categorization of the related risk levels into low, low-to-medium, medium, medium-to-high, and high, and (e) assessment of risk levels based on ELCR distribution and fuzzy evaluation criteria. The developed fuzzy risk assessment approach (FRA) was applied to a hydrocarbon-contaminated site in western Canada. Three remediation scenarios with different efficiencies (0, 60, and 90%) and planning periods (10, 20, 40, and 60 years later) were considered, and the spatial and temporal variations of risk values were examined. The temporal variation of membership values for different risk levels at locations of interest was also identified. The FRA is useful for the decision maker to gain insight into the environmental risks by considering uncertainties and to make more realistic remediation decisions.

A follow-up study of the variations in the body composition of karate athletes

Abstract.   We monitored body composition variations in nine elitekarateists during a 3-year period (T1,T2, T3). Armcircumference (AC) and six skinfolds were measured. Arm musclecircumference (AMC) and area (AMA) were then calculated. Fatmass (FM) was calculated using the Durnin-Womersley, Sloan-Weir(S-W), Katch-McArdle and Lohman equations. The only significantincrease regarded the AC, AMC and AMA measurements betweenT1 and T2. Thetime course of the predicted FM amount using the differentequations was the same. In particular, the S-W equation did notseem to reflect the modifications in the amount of FM asevidenced by the total sum of the six skinfolds. Our subjectswere characterized by a substantial uniformity in bodycomposition parameters measured in this 3-year follow-upstudy.