BRAF mutation in papillary thyroid cancer-Prevalence and clinical correlation in a South-East Asian cohort

OBJECTIVE

BRAF mutation is the commonest mutation seen in papillary thyroid cancer (PTC), but its prevalence and clinical significance vary across countries. We aim to evaluate the prevalence and clinico-pathological correlation of BRAF mutation in PTC patients at our centre.

STUDY DESIGN

Retrospective cohort study of 75 consecutive archival thyroid specimens, whereby BRAF mutation was detected using a polymerase chain reaction (PCR) technique and correlated with clinical and pathological features and outcomes.

SETTING

Tertiary university hospital in Singapore.

PARTICIPANTS

A total of 75 consecutive histologically proven archival thyroid specimens from patients who underwent thyroidectomy for PTC were accrued for this study.

MAIN OUTCOME MEASURES

Main outcome is to determine the prevalence of the BRAF mutation in our South-East Asian population. Secondary aim is to correlate the mutational status with adverse pathological features like histological variants, multi-focality, lymphovascular invasion and extra-thyroidal extension, clinical features like demographics, TNM stage, recurrence and survival, as well as treatment details like type of surgery performed and radioiodine doses.

RESULTS

BRAF mutation was detected in 56% (42/75) of PTC. All but one BRAF-mutated PTC had the BRAFV600E mutation. BRAF-mutated tumours were associated with an advanced T-stage (P = 0.049) and were more likely to have a central neck dissection (P = 0.036). There was no significant correlation between BRAF mutation status and clinical outcomes.

CONCLUSION

The prevalence of BRAF mutation is 56%. BRAF mutation-positive tumours were associated with locally advanced disease, but not poorer survival.

Changes in verbal and visuospatial working memory from Grade 1 to Grade 3 of primary school: Population longitudinal study

BACKGROUND

Adaptive working memory training is being implemented without an adequate understanding of developmental trajectories of working memory. We aimed to quantify from Grade 1 to Grade 3 of primary school (1) changes in verbal and visuospatial working memory and (2) whether low verbal and visuospatial working memory in Grade 1 predicts low working memory in Grade 3.

METHOD

The study design includes a population-based longitudinal study of 1,802 children (66% uptake from all 2,747 Grade 1 students) at 44 randomly selected primary schools in Melbourne, Australia. Backwards Digit Recall (verbal working memory) and Mister X (visuospatial working memory) screening measures from the Automated Working Memory Assessment (M = 100; SD = 15) were used to assess Grades 1 and 3 (ages 6-7 and 8-9 years) students. Low working memory was defined as ≥1 standard deviation below the standard score mean. Descriptive statistics addressed Aim 1, and predictive parameters addressed Aim 2.

RESULTS

One thousand seventy (59%) of 1802 Grade 1 participants were reassessed in Grade 3. As expected for typically developing children, group mean standard scores were similar in Grades 1 and 3 for verbal, visuospatial, and overall working memory, but group mean raw scores increased markedly. Compared to "not low" children, those classified as having low working memory in Grade 1 showed much larger increases in both standard and raw scores across verbal, visuospatial, and overall working memory. Sensitivity was very low for Grade 1 low working memory predicting Grade 3 low classifications.

CONCLUSION

Although mean changes in working memory standard scores between Grades 1 and 3 were minimal, we found that individual development varied widely, with marked natural resolution by Grade 3 in children who initially had low working memory. This may render brain-training interventions ineffective in the early school year ages, particularly if (as population-based programmes usually mandate) selection occurs within a screening paradigm.

Profiles of language development in pre-school children: a longitudinal latent class analysis of data from the Early Language in Victoria Study

BACKGROUND

Pre-school language impairment is common and greatly reduces educational performance. Population attempts to identify children who would benefit from appropriately timed intervention might be improved by greater knowledge about the typical profiles of language development. Specifically, this could be used to help with the early identification of children who will be impaired on school entry.

METHODS

  This study applied longitudinal latent class analysis to assessments at 8, 12, 24, 36 and 48 months on 1113 children from a population-based study, in order to identify classes exhibiting distinct communicative developmental profiles.

RESULTS

Five substantive classes were identified: Typical, i.e. development in the typical range at each age; Precocious (late), i.e. typical development in infancy followed by high probabilities of precocity from 24 months onwards; Impaired (early), i.e. high probabilities of impairment up to 12 months followed by typical language development thereafter; Impaired (late), i.e. typical development in infancy but impairment from 24 months onwards; Precocious (early), i.e. high probabilities of precocity in early life followed by typical language by 48 months. The entropy statistic (0.84) suggested classes were fairly well defined, although there was a non-trivial degree of uncertainty in classification of children. That half of the Impaired (late) class was expected to have typical language at 4 years and 6% of the numerically large Typical class was expected to be impaired at 4 years illustrates this. Characteristics indicative of social advantage were more commonly found in the classes with improving profiles.

CONCLUSIONS

Developmental profiles show that some pre-schoolers' language is characterized by periods of accelerated development, slow development and catch-up growth. Given the uncertainty in classifying children into these profiles, use of this knowledge for identifying children who will be impaired on school entry is not straightforward. The findings do, however, indicate greater need for language enrichment programmes among disadvantaged children.

Internal representation of movement in children with developmental coordination disorder: a mental rotation task

Recent studies show that children with developmental coordination disorder (DCD) have difficulties in generating an accurate visuospatial representation of an intended action, which are shown by deficits in motor imagery. This study sought to test this hypothesis further using a mental rotation paradigm. It was predicted that children with DCD would not conform to the typical pattern of responding when required to imagine movement of their limbs. Participants included 16 children with DCD and 18 control children; mean age for the DCD group was 10 years 4 months, and for controls 10 years. The task required children to judge the handedness of single-hand images that were presented at angles between 0 degrees and 180 degrees at 45 degrees intervals in either direction. Results were broadly consistent with the hypothesis above. Responses of the control children conformed to the typical pattern of mental rotation: a moderate trade-off between response time and angle of rotation. The response pattern for the DCD group was less typical, with a small trade-off function. Response accuracy did not differ between groups. It was suggested that children with DCD, unlike controls, do not automatically enlist motor imagery when performing mental rotation, but rely on an alternative object-based strategy that preserves speed and accuracy. This occurs because these children manifest a reduced ability to make imagined transformations from an egocentric or first-person perspective.

Effect of Tamoxifen on Transforming Growth Factor β1Production by Keloid and Fetal Fibroblasts

BACKGROUND

Evidence suggests that keloid scar formation may be mediated, in part, by deranged growth factor activity, including that of transforming growth factor (TGF) beta1. Tamoxifen citrate has shown promise in the treatment of keloids.

OBJECTIVE

To evaluate the effect of tamoxifen on autocrine growth factor expression in keloid and fetal dermal fibroblasts, which exhibit scar-free healing.

DESIGN

Serum-free cell lines of keloid and fetal dermal fibroblasts were established. Cell cultures were exposed to different concentrations of tamoxifen solution (8 and 12 or 16 micromol/L). Cell counts were performed and supernatants collected at 24, 48, and 96 hours. Cell-free supernatants were quantitatively assayed for TGF-beta1 expression.

RESULTS

Keloid fibroblasts show increased per-cell TGF-beta1 production compared with fetal fibroblasts. Tamoxifen appeared to decrease per-cell TGF-beta1 production at each of the time points evaluated.

CONCLUSIONS

Keloids likely arise due to locally insufficient or excessive concentrations of specific growth factors. The higher level of TGF-beta1 produced by keloid cells compared with fetal fibroblasts could be related to the aberrant wound healing seen with keloids. The addition of tamoxifen may lead to improved wound healing in keloids by decreasing the expression of TGF-beta1.

Brain-derived neurotrophic factor-enriched collagen tubule as a substitute for autologous nerve grafts

BACKGROUND

Autologous nerve interposition grafts are frequently harvested by head and neck surgeons. The sacrifice of these donor nerves guarantees some degree of morbidity, including sensory loss, additional incision sites with associated potential complications, and prolonged operative time. An alternative to autologous nerve grafting is, therefore, desirable.

OBJECTIVE

To determine if a collagen tubule (CT) filled with either a plain collagen gel or a brain-derived neurotrophic factor (BDNF)-enriched collagen gel could be used to achieve functional and histologic outcomes equivalent to an autologous nerve graft in bridging a 15-mm nerve gap in the rabbit facial nerve.

DESIGN

A prospective, randomized, blinded animal study with a control group.

METHODS

Thirty rabbit facial nerves were resected (15-mm segments) to create nerve gaps. The gaps were bridged using 1 of 3 methods, assigned randomly: a reversed facial nerve (control), a collagen gel-filled CT, or a BDNF-enriched collagen gel-filled CT. The animals were evaluated after 6 weeks in a blinded fashion for functional nerve recovery, axon count, and axonal diameter.

RESULTS

There were no significant differences between the autologous nerve graft group, the collagen gel-filled CT group, or the BDNF-enriched collagen gel-filled CT group (n = 10 for each group) for functional nerve recovery (P =.94). The mean axon count and the mean axonal diameter were highest in the BDNF-enriched collagen gel-filled CT group, but these differences failed to reach statistical significance (P =.18 and.96, respectively).

CONCLUSIONS

Collagen tubules filled with BDNF-enriched collagen gel appear to be at least as good as autologous nerve grafts for bridging short facial nerve gaps. Larger experimental studies are warranted to determine if clinical trials are justified.

Delayed repair of transected nerves: effect of brain-derived neurotrophic factor

OBJECTIVE

To determine if administration of brain-derived neurotrophic factor (BDNF) after peripheral nerve transection can improve the functional outcome in situations where epineurial repair must be delayed.

DESIGN

Randomized, blinded, controlled trial.

SUBJECTS

Thirty-four Sprague-Dawley rats.

INTERVENTION

Sciatic nerves were transected and, after a 2-week delay, repaired with epineurial sutures. Animals were assigned to receive daily administration of lactated Ringer solution (LR [control] group); BDNF delivered at the time of nerve transection through 2 weeks after nerve repair, for a total of 4 weeks (BDNF-early group); or BDNF delivered at the time of nerve repair through 2 weeks after repair (BDNF-late group). Outcome was assessed using sciatic functional indices (SFIs) and histomorphometric analysis.

RESULTS

The SFI maximal recovery was superior in the BDNF groups, but this difference did not reach statistical significance (SFI, -90.1+/-9.6 [LR group], -85.7+/-7.6 [BDNF-early group], and -84.6+/-4.8 [BDNF-late group], where normal function is 0 and complete loss of function is -100; P = .27). The mean axon diameter tended to be greater in the BDNF groups compared with the LR group, i.e., 2.43+/-0.23 microm (LR group), 2.80+/-0.44 microm (BDNF-early group), and 2.83+/-0.38 microm (BDNF-late group) (P = .05).

CONCLUSIONS

The local administration of BDNF to nerves that underwent transection and then repair after a delay resulted in an increase in axonal diameters and maximal SFIs, a difference that did not reach statistical significance. The timing of BDNF administration after nerve transection did not affect neuronal regeneration.

Growth of keloid-producing fibroblasts in commercially available serum-free media

The purpose of this study was to update our in vitro serum-free keloid fibroblast (KF) model by use of commercially available media. Prior evaluations of fibroblast characteristics in vitro, especially that of growth factor measurement, have been confounded by the presence of serum-containing media. KFs were obtained from patients undergoing facial keloid removal. The 4 commercially available serum-free media evaluated were AIM-V (Gibco, Grand Island, NY), Fibroblast Growth Medium (FGM; Clonetics, San Diego, CA), HB GRO (Irvine Scientific, Santa Ana, CA), and UltraCULTURE (BioWhittaker Inc, Walkersville, MD). The main outcome measures were sustained KF growth and viability as compared with serum-based models. The KFs in UltraCULTURE had a higher viability but did not grow as well as in FGM. The KFs in HB GRO and AIM-V demonstrated significantly decreased viability. Because of FGM's satisfactory proliferative support and viability comparable with serum-based medium, it is recommended for the in vitro propagation of keloid-producing fibroblasts.

Iron, iron-binding proteins and immune system cells

In summary, the work reviewed in the present paper indicates that 1. Iron and the iron-binding proteins can act as regulators of immune function, and not only as a result of a nutritional dependence of lymphoid cells on transferrin and transferrin-iron. Subsets of cells of the immune system respond differently to increases in iron concentration in vitro and in vivo. 2. Macrophages and lymphocytes differ in the H and L subunit content of the ferritins synthesized in response to increases in iron concentration in vitro. 3. NK activity by adherent and nonadherent cells differ in their susceptibility to the enhancing effect of lactoferrin in vitro. 4. Responses to mitogen stimulation by PHA and Con A are diminished, while the PWM response remains unaffected by exposure to acidic ferritins or by increasing concentrations of iron in vitro and in vivo. 5. Pretreatment of effector but not target cells with iron results in diminished responses in the MLR, an effect that appears to be related to the HLA-A locus. 6. In situ hybridization studies indicate that transferrin is synthesized by a specific subset of the T lymphocytes. 7. Transient increases in serum iron concentration above the full saturation of transferrin, reproducing the clinical situation frequently seen in hereditary hemochromatosis, are followed by a series of cellular changes in the synovium that can be correlated to changes in the course of an experimental model of arthritis in the rat.

Ibuprofen and diflunisal in rheumatoid arthritis: a double-blind comparative trial

Both diflunisal (750 mg/day) and ibuprofen (1600 mg/day) were shown to be superior to placebo in the treatment of rheumatoid arthritis in a double-blind cross-over trial. Neither drug affected lymphocyte transformation to plant mitogens. Diflunisal scored better than ibuprofen at the dose levels chosen but the differences did not reach significance.

A single-blind crossover trial of the anti-inflammatory drug sodium meclofenamate and placebo, including an evaluation of hand grip and of lymphocyte responsiveness

A single-blind crossover trial was carried out in 21 patients with active rheumatoid arthritis to assess the effectiveness and tolerance of sodium meclofenamate (300 mg per day) compared with placebo. After a 1-week washout period patients had two periods of active medication, each of 2 weeks, separated by 1 week on placebo. Morning stiffness, walking speed, pain score, patient impression of response, joint tenderness and power, work and maximum grip strength achieved by hand grip were all improved by sodium meclofenamate and an anti-inflammatory effect of the drug was demonstrated, with some reduction in the swelling of PIP joints. There was no advantage in assessing pain on full movement of the small joints of the hands in addition to direct tenderness. Power, work and rate of grip release achieved during hand grip provided more information about hand function than maximum grip strength alone. Lymphocyte transformation to non-specific mitogens was enhanced by the drug. Twelve patients had some form of gastro intestinal complaint during the study and it is suggested that diarrhoea is likely to prove to be the major limiting factor of acceptance by some patients.

Mechanisms of shock blood induced tissue anoxia

An isolated limb perfusion system in pigs was used to assess and relate hemodynamic variables to oxygen consumption in shock. Perfusion with shock blood results in a significantly increased peripheral vascular resistance, which can be blocked by phentolamine. However, a significantly reduced oxygen consumption seen during perfuslion with shock blood is not eliminated with phentolamine despite normal peripheral vascular resistance. The cause of the reduced oxygen consumption is not known, but the results suggest that other factors apart from a decreased blood flow due to catecholamine release are important in contributing to end organ anoxia and failure in shock.