Mucin-bacterial interactions in the human oral cavity and digestive tract

Mucins are a family of heavily glycosylated proteins that are the major organic components of the mucus layer, the protective layer covering the epithelial cells in many human and animal organs, including the entire gastro-intestinal tract. Microbes that can associate with mucins benefit from this interaction since they can get available nutrients, experience physico-chemical protection and adhere, resulting in increased residence time. Mucin-degrading microorganisms, which often are found in consortia, have not been extensively characterized as mucins are high molecular weight glycoproteins that are hard to study because of their size, complexity and heterogeneity. The purpose of this review is to discuss how advances in mucus and mucin research, and insight in the microbial ecology promoted our understanding of mucin degradation. Recent insight is presented in mucin structure and organization, the microorganisms known to use mucin as growth substrate, with a specific attention on Akkermansia muciniphila, and the molecular basis of microbial mucin degradation owing to availability of genome sequences.     

Hypofractionation in radiotherapy

Major changes in cancer radiotherapy have followed a greater understanding of the biological effects of radiation on tumours and normal tissues. Clinical radiotherapy is today a solid body of knowledge with well defined scientific foundations. Key concepts in current radiobiology include lethal and sublethal injuries, dose-effect coefficients, α/β ratios, acute and late response, biologically equivalent dose, fraction dose, irradiation time and tumour regeneration between others. Effects of irradiation time and dose per fraction on tumours versus normal tissues are of special importance. Dose per fraction must be considered for analysis of effects in normal late-responding tissues. In contrast, both dose per fraction and irradiation time influence the response to radiation of malignant tumours and acute-responding tissues. Finally, the ability to quantify relationships between radiation dose and biological effect has been of particular value in the development of radiotherapy. This is illustrated by the growing use of high doses per fraction for the treatment of some cancers. *Supported by an unrestricted educational grant from Roche Farma S.A.     

Walking behaviours from the 1965–2003 American Heritage Time Use Study (AHTUS)

Background  

The American Heritage Time Use Study (AHTUS) represents a harmonised historical data file of time use by adults, amalgamating surveys collected in 1965–66, 1975–76, 1985, 1992–94, and 2003. The objectives of time-use studies have ranged from evaluating household and other unpaid production of goods and services, to monitoring of media use, to comparing lifestyles of more and less privileged social groups, or to tracking broad shifts in social behaviour. The purpose of this paper is to describe the process and utility of identifying and compiling data from the AHTUS to describe a range of walking behaviours collected using time-use survey methods over almost 40 years in the USA.     

Menkes' syndrome: ophthalmic findings

PURPOSE: To report the prevalence and clinical significance of ocular findings in 20 patients with Menkes' syndrome recruited for a clinical trial at the National Institute of Child Health and Human Development (NICHHD). DESIGN: Retrospective observational case series. PARTICIPANTS: Twenty patients with Menkes' syndrome enrolled in a clinical trial at the NICHHD, who underwent ophthalmic evaluation at the National Eye Institute from 1990 through 1997. METHODS: Review of clinical ophthalmic examination records, photographs, and visual evoked potential recordings. MAIN OUTCOME MEASURES: Prevalence of ophthalmic signs of unusual frequency in patients with Menkes' syndrome. RESULTS: There was a high prevalence of very poor visual acuity (8 patients), myopia at 21 months old or younger (5 of 9 patients this age who underwent cycloplegic refraction), strabismus (11 of 18 patients whose motility was evaluated), blue irides (15 of 16 patients whose iris color was documented), iris stromal hypoplasia and bilateral peripheral transillumination (7 and 3 patients, respectively), peripheral retinal hypopigmentation (7 of 18 patients whose retinal periphery was noted at the initial examination), and aberrant eyelashes (5 patients). CONCLUSIONS: Patients with Menkes' syndrome exhibit a high prevalence of several ocular findings, including some (very poor visual acuity, myopia, strabismus) that may warrant special care. Early ocular examination is thus indicated for patients with Menkes' syndrome, particularly those with mild variants of the disease, whose neurologic status is better and lifespan is longer.     

Phenotypical features of a Moroccan family with autosomal recessive Charcot-Marie-Tooth disease associated with the S194X mutation in the GDAP1 gene

BACKGROUND: The first locus for demyelinating autosomal recessive Charcot-Marie-Tooth (ARCMT) disease was identified in 8q13, where mutations in GDAP1 have been found. Mutations in the same gene have been detected in families with axonal ARCMT disease. OBJECTIVE: To determine the clinical, electrophysiologic, and morphologic characteristics of a consanguineous Moroccan family with ARCMT disease associated with the S194X mutation in the GDAP1 gene. METHODS: Four patients from a consanguineous Moroccan family were examined clinically and electrophysiologically. In one patient, a morphometric and ultrastructural study of a peroneal nerve biopsy sample was performed. Mutation in the coding region of the GDAP1 gene was identified by direct sequencing. RESULTS: Neuropathy was evident early in childhood, walking was delayed in one patient, and onset of symptoms occurred before 18 months in the others. The phenotype was severe: foot deformities and disabilities involving the hands and feet developed toward the end of the first decade, followed by involvement of proximal muscles in the lower limbs, leading to loss of autonomy. Electrophysiologic findings were consistent with an axonal form of CMT disease: motor nerve conduction velocities, recordable in one patient only, were greater than 40 m/sec. Sensory nerve action potentials were either abolished or substantially reduced in amplitude. The morphologic data supported the diagnosis of axonal neuropathy, showing a marked reduction in myelinated fibers and signs of axonal regeneration, including frequent pseudo-onion bulb formations. The 4 patients in this family were homozygous for the S194X mutation in the GDAP1 gene. CONCLUSION: Electrophysiologic and pathological findings support the hypothesis of an axonal disorder in this ARCMT family with the S194X mutation in the GDAP1 gene.     

An fMRI study of music sight-reading

The brain areas involved in music reading were investigated using fMRI. In order to evaluate the specificity of these areas we compared reading music notation to reading verbal and number notations in a task that required professional pianists to play the notes (in musical and verbal notations) and the numbers displayed on a 5-key keyboard. Overall, the three tasks revealed a similar pattern of activated brain areas. However, direct contrasts between the music notation and the verbal or the numerical notation tasks also revealed specific major foci of activation in the right occipito-temporal junction, superior parietal lobule and the intraparietal sulcus. We interpret the right occipito-temporal difference as due to differences at the encoding level between notes, words and numbers. This area might be analogous to one described for words, called the visual word form area. The parietal activations are discussed in terms of visuo-motor transcoding pathways that differ for the three types of notations used. Finally, we present a model of music reading that can possibly explain our findings.     

Economic costs of the foot and mouth disease outbreak in the United Kingdom in 2001

The authors present estimates of the economic costs to agriculture and industries affected by tourism of the outbreak of foot and mouth disease (FMD) in the United Kingdom (UK) in 2001. The losses to agriculture and the food chain amount to about Pound Sterling3.1 billion. The majority of the costs to agriculture have been met by the Government through compensation for slaughter and disposal as well as clean-up costs. Nonetheless, agricultural producers will have suffered losses, estimated at Pound Sterling355 million, which represents about 20% of the estimated total income from farming in 2001. Based on data from surveys of tourism, businesses directly affected by tourist expenditure are estimated to have lost a similar total amount (between Pound Sterling2.7 and Pound Sterling3.2 billion) as a result of reduced numbers of people visiting the countryside. The industries which supply agriculture, the food industries and tourist-related businesses will also have suffered losses. However, the overall costs to the UK economy are substantially less than the sum of these components, as much of the expenditure by tourists was not lost, but merely displaced to other sectors of the economy. Overall, the net effect of FMD is estimated to have reduced the gross domestic product in the UK by less than 0.2% in 2001.