Staged lengthening and reconstruction for children with a leg-length discrepancy after excision of an osteosarcoma around the knee

AIMS

Children treated for osteosarcoma around the knee often have a substantial leg-length discrepancy at skeletal maturity. The aim of this study was to investigate the results of staged skeletal reconstruction after a leg lengthening procedure using an external fixator in these patients.

PATIENTS AND METHODS

We reviewed 11 patients who underwent staged reconstruction with either an arthroplasty (n = 6) or an arthrodesis (n = 5). A control group of 11 patients who had undergone wide excision and concurrent reconstruction with an arthroplasty were matched for gender, location, and size of tumour. We investigated the change in leg-length discrepancy, function as assessed by the Musculoskeletal Tumor Society Scale (MSTS) score and complications.

RESULTS

A mean 5.2 cm (1.7 to 8.9) of lengthening was achieved. The mean MSTS scores significantly improved after staged reconstruction (p = 0.003) but were still worse than those of the control group (p = 0.049). However, the MSTS scores of the arthroplasty subgroup were comparable with those of the controls, although the extensor lag was greater and the range of movement was less. The patient group experienced more complications, but all of these resolved.

CONCLUSION

Approximately 5 cm of lengthening and significant functional improvement can be achieved by staged reconstruction and lengthening, without major complications. Although it has limitations, this method of treatment seems to be a satisfactory surgical option for growing children with a significant leg-length discrepancy after excision of an osteosarcoma around the knee. Cite this article: Bone Joint J 2017;99-B:401-8.

Prediction of rebound phenomenon after removal of hemiepiphyseal staples in patients with idiopathic genu valgum deformity

AIMS

Our aim was to investigate the predictive factors for the development of a rebound phenomenon after temporary hemiepiphysiodesis in children with genu valgum.

PATIENTS AND METHODS

We studied 37 limbs with idiopathic genu valgum who were treated with hemiepiphyseal stapling, and with more than six months remaining growth at removal of the staples. All children were followed until skeletal maturity or for more than two years after removal of the staples.

RESULTS

On multivariate logistic regression analysis, the rate of correction, body mass index (BMI), age, and initial valgus angle were significantly associated with a rebound phenomenon. With those characteristics, a predictive model for rebound was generated using recursive partitioning analysis. Children with a rapid rate of correction had the most frequent and severe rebound phenomenon (incidence 79%, mean 4°), whereas those with a slow rate of correction had less rebound when they had low BMI (43%, 2°) and none when the BMI was ≥ 21 kg/m(2).

CONCLUSION

This is the first study to evaluate a predictive model for a rebound phenomenon after temporary hemiepiphysiodesis in children with idiopathic genu valgum. Cite this article: Bone Joint J 2016;98-B:1270-5.

Pre-harvest foliar application of ethephon strengthens gibberellins-induced fruit expansion in Pyrus pyrifolia

To identify the roles of ethylene in fruit development in Japanese pear Pyrus pyrifolia 'Niitaka', one of the non-climacteric genotypes, source-sink strength and fruit development during fruit expansion were investigated when ethephon was applied after a conventional gibberellic acid (GA) lanolin paste treatment on the pedicel. The results demonstrate that the conventional GA treatment during the early stage of fruit expansion resulted in larger fruit size and advanced fruit maturation, but pre-harvest foliar application of ethephon only advanced fruit maturation. However, pre-harvest foliar application of ethephon with a preceding conventional GA treatment during the early stage of fruit expansion dramatically improved fruit size and advanced fruit maturation over GA or ethephon alone. Moreover, the early foliar application of ethephon showed a better efficacy in increasing fruit size than the late spraying. A further study revealed that when ethephon was applied after the conventional GA treatment, it improved source-sink strength associated with leaf photosynthesis and the specific rate of [¹³C] accumulation in fruit, and also strengthened cell expansion more than did GA or ethephon alone.

Refractive outcome of combined phacoemulsification and endoscopic cyclophotocoagulation

PURPOSE

To compare the refractive outcome of eyes that underwent phacoemulsification combined with endoscopic cyclophotocoagulation (phaco-ECP) with the eyes that underwent phacoemulsification alone.

METHODS

A retrospective case series review of 103 consecutive eyes that underwent phaco-ECP and 62 eyes that underwent phacoemulsification between January 2006 and August 2012 was conducted. Post-operative refractive outcomes were obtained by subjective refraction or autorefraction. Demographic data, best corrected visual acuity, intraocular pressure, number of glaucoma agents and mean deviation of the Humphrey visual field test (MD) were also analysed.

RESULTS

The total number of eyes included in the study was 62 eyes for the phaco-ECP group and 62 eyes for the control group who underwent phacoemulsification alone. More than 90% of eyes (n = 56) in phaco-ECP group achieved post-operative refraction within ±1 dioptre (D) of the target refraction. In the control group, 100% of eyes achieved post-operative refraction within ±1D of the target refraction. When comparing the difference between the target and the actual refractive outcome between the phaco-ECP and the control group, there was no statistically significant difference.

CONCLUSIONS

Refractive outcome after phaco-ECP is comparable to phacoemulsification alone. This study suggests that the intraocular lens power can be selected for cataract surgery alone and that ECP does not change the effective lens position significantly; therefore, no modification of biometry formulae is required. Phaco-ECP should be considered as an effective, safe and predictable surgical treatment option for glaucoma patients with co-existing cataract.

Misinformation is prevalent in psoriasis-related YouTube videos

Background Psoriasis patients seek information online, but little is known about their interaction with YouTube. We examined the quality of content in psoriasis-related YouTube videos and investigated their interactions with viewers.Methods YouTube was searched using the term "psoriasis." Relevant videos in English were independently categorized by two reviewers as useful, misleading, or patient view (regarding experience with psoriasis). Disagreements were settled by a third reviewer. Videos were rated on a Global Quality Scale (GQS) (1=poor, 5=excellent).Results According to our reviewers, 17% of the 47 videos were useful, 21% were misleading, and 62% represented patient views. Mean GQS scores were 4.2 ± 1.3 for useful videos, 1.7 ± 0.7 for misleading videos, and 2.2 ± 1.1 for patient view videos (p<0.001). Video views per day did not differ among the categories (p=0.65), whereas useful videos had fewest "Likes" (useful: 31 ± 55, 33 misleading: 151 ± 218, patient views: 165 ± 325, p=0.06) and comments (useful: 9.8 ± 18.3, misleading: 64.1 ± 89.7, 124.9 ± 34 199.4, p=0.009).Conclusions Useful videos were highest in quality but had similar viewership as misleading and patient view videos, with lower popularity and  engagement of users compared to other categories. Physicians and psoriasis patients should be aware of this pattern when pproaching YouTube as a resource.

Impaired development and dysfunction of endothelial progenitor cells in type 2 diabetic mice

AIM

Dysfunction of circulating endothelial progenitor cells (EPCs) has been shown to affect the development of microvascular diseases in diabetes patients. The aim of this study was to elucidate the development and mechanical dysfunction of EPCs in type 2 diabetes (T2D).

METHODS

The colony-forming capacity of EPCs and differentiation potential of bone marrow (BM) c-Kit(+)/Sca-I(+) lineage-negative mononuclear cells (KSL) were examined in T2D mice, db/db mice and KKA^y mice, using EPC colony-forming assay (EPC-CFA).

RESULTS

T2D mice had fewer BM stem/progenitor cells, and proliferation of KSL was lowest in the BM of db/db mice. In T2D mice, the frequency of large colony-forming units (CFUs) derived from BM-KSL was highly reduced, indicating dysfunction of differentiation into mature EPCs. Only a small number of BM-derived progenitors [CD34(+) KSL cells], which contribute to the supply of EPCs for postnatal neovascularization, was also found. Furthermore, in terms of their plasticity to transdifferentiate into various cell types, BM-KSL exhibited a greater potential to differentiate into granulocyte macrophages (GMs) than into other cell types.

CONCLUSION

T2D affected EPC colony formation and differentiation of stem cells to mature EPCs or haematopoietic cells. These data suggest opposing regulatory mechanisms for differentiation into mature EPCs and GMs in T2D mice.

Determination of the rate of cerebral oxygen consumption and regional cerebral blood flow by non-invasive17Oin vivoNMR spectroscopy and magnetic resonance imaging: Part 1. Theory and data analysis methods Daniel Fiat and Seho Kang

Theory and novel data analysis methods of 17O inhalation measurements are presented for the calculation of CMRO2, regional cerebral blood flow (rCBF), the reflow (R), the arterial venous difference (AVD) and the partition coefficient (lambda). Several of the methods proposed for the determination of CMRO2 do not require measurements of regional cerebral blood flow and H2(17)O arterial concentration. All methods of analysis are based on the Kety-Schmidt approach.

RSK2 signals through stathmin to promote microtubule dynamics and tumor metastasis

Metastasis is responsible for >90% of cancer-related deaths. Complex signaling in cancer cells orchestrates the progression from a primary to a metastatic cancer. However, the mechanisms of these cellular changes remain elusive. We previously demonstrated that p90 ribosomal S6 kinase 2 (RSK2) promotes tumor metastasis. Here we investigated the role of RSK2 in the regulation of microtubule dynamics and its potential implication in cancer cell invasion and tumor metastasis. Stable knockdown of RSK2 disrupted microtubule stability and decreased phosphorylation of stathmin, a microtubule-destabilizing protein, at serine 16 in metastatic human cancer cells. We found that RSK2 directly binds and phosphorylates stathmin at the leading edge of cancer cells. Phosphorylation of stathmin by RSK2 reduced stathmin-mediated microtubule depolymerization. Moreover, overexpression of phospho-mimetic mutant stathmin S16D significantly rescued the decreased invasive and metastatic potential mediated by RSK2 knockdown in vitro and in vivo. Furthermore, stathmin phosphorylation positively correlated with RSK2 expression and metastatic cancer progression in primary patient tumor samples. Our finding demonstrates that RSK2 directly phosphorylates stathmin and regulates microtubule polymerization to provide a pro-invasive and pro-metastatic advantage to cancer cells. Therefore, the RSK2-stathmin pathway represents a promising therapeutic target and a prognostic marker for metastatic human cancers.

Optimal Cultivation Time for Yeast and Lactic Acid Bacteria in Fermented Milk and Effects of Fermented Soybean Meal on Rumen Degradability Using Nylon Bag Technique

The objectives of this study were to determine an optimal cultivation time for populations of yeast and lactic acid bacteria (LAB) co-cultured in fermented milk and effects of soybean meal fermented milk (SBMFM) supplementation on rumen degradability in beef cattle using nylon bag technique. The study on an optimal cultivation time for yeast and LAB growth in fermented milk was determined at 0, 4, 8, 24, 48, 72, and 96 h post-cultivation. After fermenting for 4 days, an optimal cultivation time of yeast and LAB in fermented milk was selected and used for making the SBMFM product to study nylon bag technique. Two ruminal fistulated beef cattle (410±10 kg) were used to study on the effect of SBMFM supplementation (0%, 3%, and 5% of total concentrate substrate) on rumen degradability using in situ method at incubation times of 0, 2, 4, 6, 12, 24, 48, and 72 h according to a Completely randomized design. The results revealed that the highest yeast and LAB population culture in fermented milk was found at 72 h-post cultivation. From in situ study, the soluble fractions at time zero (a), potential degradability (a+b) and effective degradability of dry matter (EDDM) linearly (p<0.01) increased with the increasing supplemental levels and the highest was in the 5% SBMFM supplemented group. However, there was no effect of SBMFM supplement on insoluble degradability fractions (b) and rate of degradation (c). In conclusion, the optimal fermented time for fermented milk with yeast and LAB was at 72 h-post cultivation and supplementation of SBMFM at 5% of total concentrate substrate could improve rumen degradability of beef cattle. However, further research on effect of SBMFM on rumen ecology and production performance in meat and milk should be conducted using in vivo both digestion and feeding trials.

D1 receptor-mediated inhibition of medial prefrontal cortex neurons is disrupted in adult rats exposed to amphetamine in adolescence

Amphetamine (AMPH) exposure leads to changes in behavior and dopamine receptor function in the prefrontal cortex (PFC). Since dopamine plays an important role in regulating GABAergic transmission in the PFC, we investigated if AMPH exposure induces long-lasting changes in dopamine's ability to modulate inhibitory transmission in the PFC as well as whether the effects of AMPH differed depending on the age of exposure. Male Sprague-Dawley rats were given saline or 3 mg/kg AMPH (i.p.) repeatedly during adolescence or adulthood and following a withdrawal period of up to 5 weeks (Experiment 1) or up to 14 weeks (Experiment 2), they were sacrificed for in vitro whole-cell recordings in layer V/VI of the medial PFC. We found that in brain slices from either adolescent- or adult-exposed rats, there was an attenuation of dopamine-induced increases in inhibitory synaptic currents in pyramidal cells. These effects did not depend on age of exposure, were mediated at least partially by a reduced sensitivity of D1 receptors in AMPH-treated rats, and were associated with an enhanced behavioral response to the drug in a separate group of rats given an AMPH challenge following the longest withdrawal period. Together, these data reveal a prolonged effect of AMPH exposure on medial PFC function that persisted for up to 14 weeks in adolescent-exposed animals. These long-lasting neurophysiological changes may be a contributing mechanism to the behavioral consequences that have been observed in those with a history of amphetamine abuse.

DNA damage is a feature of feline injection-site sarcoma

Feline injection-site sarcoma (FISS) is commonly treated with surgery and radiation therapy. Despite aggressive therapy, FISS has a high recurrence rate. The true benefit of adjuvant chemotherapy is not known. DNA damage response mechanisms help protect against genomic instability but can also promote chemoresistance. In order to determine whether DNA damage is a feature of FISS, we evaluated tumour tissues with γH2AX immunohistochemistry. H2AX is phosphorylated to form γH2AX following DNA double strand breaks. Seventeen FISS specimens were evaluated prospectively. DNA damage ranged from 2.18 to33.7%, with a median of 16.2%. Significant differences were noted between cats (P < 0.0001). Mitotic index ranged from 0 to 57 with a median of 13 and did not correlate with γH2AX positivity (P = 0.2). Further studies are needed to determine if γH2AX expression may predict chemosensitivity and have independent value as a prognostic factor.

Glutaminolysis as a target for cancer therapy

Cancer cells display an altered metabolic circuitry that is directly regulated by oncogenic mutations and loss of tumor suppressors. Mounting evidence indicates that altered glutamine metabolism in cancer cells has critical roles in supporting macromolecule biosynthesis, regulating signaling pathways, and maintaining redox homeostasis, all of which contribute to cancer cell proliferation and survival. Thus, intervention in these metabolic processes could provide novel approaches to improve cancer treatment. This review summarizes current findings on the role of glutaminolytic enzymes in human cancers and provides an update on the development of small molecule inhibitors to target glutaminolysis for cancer therapy.