Prevalence of dental fluorosis in children taking part in an oral health programme including fluoride tablet supplements from the age of 2 years

International Journal of Paediatric Dentistry 2010; 20: 347–352 Aim. To investigate the prevalence of dental fluorosis in children who had participated in an oral health programme between the ages 2–5 years, including fluoride tablets from the age of 2 years. Design. The study group consisted of 135 10‐ to 11‐year‐old children who had participated in the programme, including parent education, tooth‐brushing instruction and prescribed fluoride tablets (0.25 mg NaF) (2–3 years: 1 tablet/day; 3–5 years: 2 tablets/day). The prevalence of dental fluorosis in the study group was compared with that in a nonintervention reference group consisting of 129 children of the same ages. The analysis was based on photos of the permanent maxillary front teeth using the Thylstrup & Fejerskov (TF) Index. Results. No statistically significant difference in prevalence of dental fluorosis was seen between the two groups. Forty‐three percent of the children in the study group and 38% in the reference group had fluorosis, the majority of a mild nature (TF‐score 1). None had a TF score above 2. The pattern was the same after correction for parent reported intake of tablets at 3 and 5 years of age. Conclusion. Introduction of fluoride tablets at the age of 2 years did not result in increased prevalence of dental fluorosis.     

Quantitative analysis of the anatomy of the epineurium of the canine recurrent laryngeal nerve

The purpose of this investigation was to determine the amount of epineurium surrounding the recurrent laryngeal nerve (RLN) compared with a limb nerve, that to flexor hallicus longus (NFHL). Nerve samples were obtained from 10 adult dogs and studied using scanning electron microscopy and light microscopy to measure the relative proportion of epineurium and the relative proportions of adipose and collagenous tissue comprising the epineurium in both nerves. Significantly greater relative epineurial cross-sectional areas and adipose content were found in the RLN than in the NFHL. Based on observations on noncranial peripheral nerves, the findings indicate that the RLN is better protected against deformational forces associated with compression than stretching forces. The RLN may not be structured well for successful reinnervation after injury. The patterns observed for adipose tissue in RLN epineurial tissue appeared unique compared with those previously reported in peripheral nerves. The primary role associated with adipose tissue is to 'package' the nerve for protection. The RLN is considered to be a vital nerve in the body, as are other cranial nerves. The large proportions of adipose tissue in the epineurium may relate to the importance of protecting this nerve from injury.     

Chemical synthesis of o-thiophosphotyrosyl peptides

The synthon for O-thiophosphotyrosine, Fmoc-Tyr[PS(OBzl)₂]-OH ( 1c ), was prepared in 63%;, yield from Fmoc-Tyr-OH by first transient protection as the ^tBuMe₂Si-ester and phosphinylation with (BzlO)₂PNⁱPr₂/ tetrazole followed by oxidation of P(III) to P(V) vith S₈x in CS₂. Building block 1c was incorporated in the Fmoc solid-phase synthesis of two O-thiophosphotyrosine-containing peptides H-Thr-Glu-Pro-Gln-Tyr(PS)-Gln-Pro-Gly-Glu-OH ( 2 ) and H-Thr-Arg-Asp-Ile-Tyr(PS)-Glu-Thr-Asp-Phe-Phe-Arg-Lys-OH ( 3 ), corresponding to sequences of the p60^src (523–531) protein and an insulin receptor ( IR ) (1142–1153) analogue, respectively. An alternative approach of synthesis, the global phosphorylation of a resin-bound peptide, also proved useful. Thus, the free tyrosyl side-chain containing-peptide IR (1142–1153) on support was phosphinylated with the above phosphoramidite reagent followed by oxidation with either S₈/CS₂ or tetraethylthiuram disulfide/CH₃CN solutions. Deprotection and peptide-resin cleavage was performed with a TFA/thiophenol (H₂O) mixture. Crude peptides 2 and 3 were stable to the acidolytic deprotection. Preparative RP(C₁₈)HPLC was initially performed using 0.1% TFA(aq) EtOH solvents. However, analyses of fractions resulting from the purification step indicated significant decomposition of thiophosphopeptide in solution. Stability measurements both as a function of time and pH. further confirmed this initial finding. Purifications performed at intermediate pH using a triethylammonium acetatc (pH 7.5) CH₃CN solvent system overcame this problem.     

An event-related potential study of sensory representations of unfamiliar tonal patterns

Tonal patterns were delivered to 17 subjects instructed to read a self-selected book and to ignore the auditory stimuli. The standard pattern contained eight 50-ms segments differing in frequency. Infrequent changes of single segments within the pattern elicited negative modulations of the event-related brain potentials (ERPs) as compared with the ERPs elicited by the standard pattern. The change consisted of either a duplication of a single segment or an interchange of two segments within the pattern. Because of the nature of the change, the ERP modulation cannot be explained by a simple refractoriness mechanism or by assuming that the mechanism generating the negative modulation relies on representations of only the spectral but not the temporal information of the pattern. Therefore, the spectral and the temporal information of the tonal patterns were represented by the information processing system on a grain of single segments.