Envisioning the development of a CRISPR-Cas mediated base editing strategy for a patient with a novel pathogenic CRB1 single nucleotide variant.

BACKGROUND: Inherited retinal degeneration (IRD) associated with mutations in the Crumbs homolog 1 (CRB1) gene is associated with a severe, early-onset retinal degeneration for which no therapy currently exists. Base editing, with its capability to precisely catalyse permanent nucleobase conversion in a programmable manner, represents a novel therapeutic approach to targeting this autosomal recessive IRD, for which a gene supplementation is challenging due to the need to target three different retinal CRB1 isoforms. PURPOSE: To report and classify a novel CRB1 variant and envision a possible therapeutic approach in form of base editing. METHODS: Case report. RESULTS: A 16-year-old male patient with a clinical diagnosis of early-onset retinitis pigmentosa (RP) and characteristic clinical findings of retinal thickening and coarse lamination was seen at the Oxford Eye Hospital. He was found to be compound heterozygous for two CRB1 variants: a novel pathogenic nonsense variant in exon 9, c.2885T>A (p.Leu962Ter), and a likely pathogenic missense change in exon 6, c.2056C>T (p.Arg686Cys). While a base editing strategy for c.2885T>A would encompass a CRISPR-pass mediated "read-through" of the premature stop codon, the resulting missense changes were predicted to be "possibly damaging" in in-silico analysis. On the other hand, the transversion missense change, c.2056C>T, is amenable to transition editing with an adenine base editor (ABE) fused to a SaCas9-KKH with a negligible chance of bystander edits due to an absence of additional Adenines (As) in the editing window. CONCLUSIONS: This case report records a novel pathogenic nonsense variant in CRB1 and gives an example of thinking about a base editing strategy for a patient compound heterozygous for CRB1 variants.

Innate Immune Response Following AAV Administration.

Recombinant adeno-associated virus (rAAV) is a widely used tool for gene delivery due to its high efficiency to transduce postmitotic cells. However, host immune reactions targeting AAV can limit its therapeutic benefit in clinical applications. While most studies focused on adaptive immunity, initial innate immune responses are the first line of defense against viral vectors and help modulate subsequent adaptive immune responses. The understanding of innate immune responses to AAV can potentially improve safety and therapeutic efficiency of AAV. This article provides an overview of innate immune responses to AAV vectors.

[Stem Cells for Retina Replacement]. / Künstliche Netzhaut aus Stammzellen.

In ophthalmology, regenerative medicine is rapidly becoming a reality. Cell based treatment strategies in end stage retinal degeneration may be of therapeutic value, whatever the mechanism of disease mechanism. However, while corneal transplantation is commonly performed with excellent results, many obstacles must be overcome before retinal transplants can become clinically useful. The major problems are the production of appropriate transplants and functional integration in situ. New technologies allow the production of autologous transplants by inducing pluripotency in adult somatic cells. Driven by this development, exciting new research has been conducted on the development of artificial retinal tissue for basic research and transplantation. This article reviews this progress and discusses its clinical utility.

[Stem cell therapy for retinal diseases]. / Stammzelltherapie für Netzhauterkrankungen.

BACKGROUND: Due to an ageing population the incidence and prevalence of retinal diseases and visual disabilities will continue to grow. A great number of patients would principally be able to benefit from a stem cell-based therapy. OBJECTIVES: To introduce readers to the terminology and current concepts associated with stem cell therapy in ocular research and to provide an overview of the current status of preclinical and clinical research. MATERIAL AND METHODS: We performed a systematic review of relevant entries on ocular stem cell therapy for retinal diseases in PubMed and ClinicalTrials.gov. Differences between various stem cell types are displayed systematically, followed by a discussion of preclinical studies. Translational aspects are highlighted leading to the first clinical trials, including surgical and ethical facets. RESULTS: In preclinical studies, photoreceptor cell precursors and retinal pigment epithelium (RPE) cells were differentiated and subretinally transplanted into animal models. Besides exclusion of a teratoma formation, some functional improvements were also observed. Intraocular transplantation of stem cell-derived RPE cells was the first successful clinical application of pluripotent stem cells in man. CONCLUSION: Promising results of preclinical and clinical studies have identified important challenges and confirmed the potential of stem cell therapy for ophthalmology.

[Gene therapy as a treatment concept for inherited retinal diseases]. / Gentherapie als Behandlungskonzept für erbliche Netzhauterkrankungen.

BACKGROUND: Gene therapy for inherited retinal diseases (IRDs) is currently being validated in several clinical trials and is becoming a promising therapeutic option for these previously incurable diseases. OBJECTIVES: The aim of this review is to give an overview of the concept, the application and the challenges associated with gene therapy. In particular, the pertinence of gene therapy for IRDs will be highlighted along with ongoing clinical trials in the field. MATERIAL AND METHODS: A systematic review of relevant entries on gene therapy and on gene therapy for IRDs, in particular in PubMed and ClinicalTrials.gov. RESULTS: Gene therapy is emerging not only as a therapy for monogenetic retinal diseases but also for complex genetic diseases, such as neovascular age-related macular degeneration. The discovery of adeno-associated viral vectors (AAVs) has marked a great improvement for IRD gene therapy. All clinical studies since 2006 demonstrated the safety and initial efficacy; however, not all expectations based on very successful preclinical studies were met. CONCLUSION: In future we can expect gene therapy to continue to become more clinically relevant. More than ever, it is now essential to generate precise characterizations of the natural disease progression of IRDs through observational or retrospective studies in order to guarantee a most effective study design.

In vivo biocompatibility of a new cyanine dye for ILM peeling.

PURPOSE: To investigate the biocompatibility of the new cyanine dye: 3,3'-Di-(4-sulfobutyl)-1,1,1',1'-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. METHODS: DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). RESULTS: No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. CONCLUSIONS: DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application.

[Spectral domain optical coherence tomography in the treatment of myopic choroidal neovascularization]. / Spectral-Domain-optische-Kohärenztomographie in der Behandlung der myopen choroidalen Neovaskularisationsmembran.

Spectral domain optical coherence tomography (SD-OCT) investigations provide additional information about the morphological characteristics of myopic choroidal neovascularization (mCNV). Reproducible measurements of intraretinal and subretinal fluid are of growing importance for an evaluation of progression. The non-invasive technique reduces the need for frequent fluorescence angiography after individual assessment. Appropriate correction of the reference arm is mandatory. Automatic adjustment of transversal measured values due to alterations in the paraxial field (depending on the axial length) has been implemented in a new device. Mirror artefacts and excess curvature can be avoided by reducing the length of the OCT cross-section (15°). New possibilities to record the choriocapillaris and choroid have expanded the knowledge of potential pathomechanisms and risk factors.

Induction of STAT3-related genes in fast degenerating cone photoreceptors of cpfl1 mice.

Cone dystrophies are genetic diseases characterized by loss of cone photoreceptor function and severe impairment of daylight vision. Loss of function is accompanied by a progressive degeneration of cones limiting potential therapeutic interventions. In this study we combined microarray-based gene-expression analysis with electroretinography and immunohistochemistry to characterize the pathological processes in the cone photoreceptor function loss 1 (cpfl1) mouse model. The cpfl1-mouse is a naturally arising mouse mutant with a loss-of-function mutation in the cone-specific Pde6c gene. Cpfl1-mice displayed normal rod-specific light responses while cone-specific responses were strongly diminished. Despite the lack of a general retinal degeneration, the cone-specific functional defect resulted in a marked activation of GFAP, a hallmark of Müller-cell gliosis. Microarray-based network-analysis confirmed activation of Müller-glia-specific transcripts. Unexpectedly, we found up-regulation of the cytokine LIF and the anti-apoptotic transcription factor STAT3 in cpfl1 cone photoreceptors. We postulate that STAT3-related pathways are induced in cpfl1 cone photoreceptors to counteract degeneration.

Bone spicule pigment formation in retinitis pigmentosa: insights from a mouse model.

BACKGROUND: Bone spicule pigments (BSP) are a hallmark of retinitis pigmentosa (RP). In this study, we examined the process of BSP formation in the rhodopsin knockout (rho (-/-)) mouse, a murine model for human RP. METHODS: In rho (-/-) mice from 2 to 16 months of age, representing the range from early to late stages of degeneration, retinal sections and whole mounts were examined morphologically by light and electron microscopy. The results were compared to scanning laser ophthalmoscopy of BSP degeneration in human RP. RESULTS: After the loss of all photoreceptor cells in rho-/- mice, the outer retina successively degenerated, leading to approximation and finally a direct contact of inner retinal vessels and the retinal pigment epithelium (RPE). We could show that it was the event of proximity of retinal vessel and RPE that triggered migration of RPE cells along the contacting vessels towards the inner retina. Ultrastructurally, these mislocalized RPE cells partially sealed the vessels by tight junction linkage and deposited extracellular matrix perivascularly. Also, the vascular endothelium developed fenestrations similar to the RPE-choroid interface. In whole mounts, the pigmented cell clusters outlining retinal capillaries correlated well with BSPs in human RP. The structure of the inner retina remained well preserved, even in late stages. CONCLUSIONS: The Rho (-/-) mouse is the first animal model that depicts all major pathological changes, even in the late stages of RP. Using the rho (-/-) mouse model we were able to analyze the complete dynamic process of BSP formation. Therefore we conclude that: (1) In rho (-/-) retinas, BSPs only form in areas devoid of photoreceptors; (2) Direct contact between inner retinal vessels and RPE appears to be a major trigger for migration of RPE cells; (3) The distribution of the RPE cells in BSPs reflects the vascular network at the time of formation. The similarity of the disease process between mouse and human and the possibility to study all consecutive steps of the course of the disease makes the rho (-/-) mouse valuable for further insights in the dynamics of BSP formation in human RP.

[Usher syndrome: clinical features, diagnostic options, and therapeutic prospects]. / Klinik, Diagnostik und Behandlungsoptionen des Usher-Syndroms.

Usher syndrome denotes a clinically and genetically heterogeneous combination of retinitis pigmentosa and sensorineural deafness. The division into subtypes I, II, and III is based on the degree of hearing loss: Type I is characterized by deafness from birth together with ataxia and retarded motor development, type II by a stationary deafness of a moderate degree, and type III by a progressive deafness with adult onset. In Germany, Usher syndrome currently bears particular relevance because in January 2009 a new compulsory screening of auditory function in newborn infants was introduced. Consequently, it can be expected that a higher number of patients with Usher syndrome will be identified in early childhood and referred to ophthalmologists. The focus of this work is to introduce the typical clinical picture of Usher syndrome, summarize diagnostic options, and give an overview of therapeutic strategies.

Topical imiquimod and intralesional interleukin-2 increase activated lymphocytes and restore the Th1/Th2 balance in patients with metastatic melanoma.

BACKGROUND: Patients with metastatic skin disease in malignant melanoma are difficult to treat, with unresectable lesions proving the biggest challenge. We have recently published data showing a significant clinical response in patients with multiple in-transit melanoma metastases treated with a combination of topical imiquimod and intralesional interleukin (IL)-2. Here we report the results of immunological analysis with the aim of highlighting correlations with our clinical findings. OBJECTIVES: To investigate the systemic effects of our localized combination treatment in patients with accessible metastases of melanoma, and to correlate this with their clinical responses. METHODS: The peripheral blood mononuclear cells of patients were collected at various time points throughout the treatment. Using antibodies to T-cell subsets we measured the changes in cell populations, and along with polyclonal stimulation, changes in cytokine production from these cells over a treatment course. RESULTS: We report an increase in the mean CD4/CD8 ratio from 2.78 to 3.54 with treatment (P < 0.01), and a rise in the percentage of CD25+ cells in the CD4+ population from 14.52% to 38.56%. Furthermore, staining with activation and T-regulatory markers showed that the majority of this population is activated T cells. Cytokine analysis on polyclonally stimulated peripheral blood mononuclear cells showed an increase in the ability of cells to produce interferon (IFN)-gamma over the treatment course, with an initial rise in the IFN-gamma/IL-5 ratio in five of six patients. CONCLUSIONS: The results of this study provide evidence that, in the majority of patients with in-transit metastases of melanoma, therapy with a combination of topical imiquimod and intralesional IL-2 induces a systemic immunological effect by reversing some of changes noted in patients with malignant disease.

Phase I/II study of topical imiquimod and intralesional interleukin-2 in the treatment of accessible metastases in malignant melanoma.

BACKGROUND: Patients with metastatic skin disease in malignant melanoma can be difficult to treat effectively, often requiring repeated treatments with different modalities in an attempt to control their disease. Treatment of nonsurgically resectable melanoma deposits is unsatisfactory, as they are often multiple and recurring. Anecdotal evidence from individual use of imiquimod in superficial metastases and intralesional interleukin (IL)-2 in subcutaneous deposits suggests that the combination may be more effective in bulky subcutaneous disease. OBJECTIVES: To investigate the combination of topical imiquimod and, for selected lesions, intralesional IL-2, to treat a small cohort of patients with accessible melanoma metastases resistant to other treatments. METHODS: Thirteen patients were recruited: all had evidence of multiple cutaneous and/or subcutaneous metastases. Imiquimod was applied to the metastases on a daily basis for 4 weeks, before the introduction of intralesional IL-2. This was injected up to three times a week, into selected lesions, with 0.1 mL injected per lesion at a concentration of 3.6 MIU mL(-1), a total of 1 mL being given at each session. The treated lesions were assessed individually at intervals of 3 months. RESULTS: Thirteen patients were treated, with 10 being eligible for assessment. In total, 182 lesions were treated: 137 purely cutaneous lesions and 41 subcutaneous lesions. Overall, a clinical response was seen in 92 lesions (50.5%) with 74 (40.7%) of these being a complete response (CR) with 91% of the CRs being in the cutaneous lesions. New lesions did appear during the treatment course; however, patients with cutaneous disease experienced a marked slowing of the appearance of new cutaneous lesions. No cutaneous lesions that responded reappeared on cessation of treatment. CONCLUSIONS: The combination of imiquimod and IL-2 is effective in controlling this mixed cutaneous and subcutaneous disease, and is well tolerated. Imiquimod alone is often enough to elicit a response in purely cutaneous lesions. The addition of intralesional IL-2 increases the response rates in subcutaneous lesions, and in otherwise refractory cutaneous lesions.

Rejuvenescimento do braço: sistematização de tratamento / Arm renewing: treatment systematization

Este estudo avaliou 10 pacientes operadas com o objetivo de rejuvenescimento do braço, no período de março a novembro de 2002, no Hospital de Clínicas da Universidade Federal do Paraná. Os pacientes foram divididos em quatro grupos conforme o grau de flacidez e o volume de tecido celular subcutâneo do braço, segundo a classificação de TEIMOURIAN (1998). O tratamento cirúrgico foi individualizado para cada grupo. O primeiro grupo (duas pacientes) apresentava adiposidade moderada e flacidez mínima e foi submetido a lipoaspiração com bons resultados. O segundo grupo, (duas pacientes) apresentava moderada adiposidade e moderada flacidez de pele e optou-se pela realização de lipoaspiração do braço seguido de sutura externa formando uma prega de pele na axila. As pregas axilares evoluíram com resultado estético insatisfatório, necessitando reoperação após 6 meses com ressecção do excesso de pele, além de serem mais dolorosos que os demais grupos. O terceiro grupo (3 pacientes) apresentava flacidez moderada e adiposidade intensa, onde se indicou lipoaspiração seguido de braquioplastia com ressecção pele e fechamento em forma de “T”, obtendo-se bons resultados. O quarto grupo (duas pacientes) apresentava mínima adiposidade e intensa flacidez de pele e foram submetidas a braquioplastia tradicional com ressecção do excesso de pele evoluindo com cicatrizes extensas, porém de boa qualidade.

This study has availed 10 operated patients looking for the arm rejuvenation, in the period from march to november of 2002 in Hosp. das Clínicas da Universidade Federal do Paraná. The patients were divided in four groups according to the flaccid level and to the arm loose tissue volume, due to the TEIMOURIAN classification (1998).The surgical approach was individualized for each group. The first group(two patients) presented moderate adiposity and a few flaccid and underwent to liposuction with good results. The second group(two patients) presented mild adiposity and skin limpness, and decided a arm liposuction followed by a extern suture forming a skin ridge in the axilla. The axillary rigde developed with unsatisfactory. The third group (two patients) consists of patients who have excess fat and a fair amount of loose skin, decided a liposuction followed by a resected skin defect with the T excision with good results. The fourth group (two patients) consist of patients who skin laxity and depletion of subcutaneous fat making brachioplasty the procedure of choice, with extensive scars and visible, but tolerate.

Accommodation of females in the high-G environment: the USAF Female Acceleration Tolerance Enhancement (FATE) Project.

BACKGROUND: In 1993, the U.S. Secretary of Defense opened combat aircraft assignments to women. To verify the adequacy of acceleration (+Gz) protection for female high-G aircrew, USAF investigators conducted fit tests of standard and developmental G-protective equipment and determined the effectiveness of a unique laboratory modification (AL Mod) of the standard (CSU-13B/P) anti-G suit during gender-comparative centrifuge evaluations. METHODS: Investigators determined relaxed +Gz tolerance and straining endurance to +4.5 to +7 Gz and +5 to +9 Gz simulated aerial combat maneuver (SACM) centrifuge profiles (4.5-7 SACM: 8 females and 10 males; and 5-9 SACM: 6 females and 8 males, respectively). Additionally, in the 5-9 SACM study, between and within gender SACM endurance differences were assessed before and after female subjects' use of the AL Mod. Ten female subjects also were fit tested in extended coverage, developmental G-protective equipment. RESULTS: There was no gender difference in 4.5-7 SACM endurance. Male 5-9 SACM endurance exceeded that of females in the unmodified CSU-13B/P (p < 0.05), but gender parity was achieved when females wore the AL Mod. Fit modifications of developmental G-protective equipment were not required, but smaller sizes of the standard CSU-13B/P and a developmental anti-G suit were indicated and developed. CONCLUSION: In properly fitted anti-G suits, gender parity in SACM endurance is achievable; however, full accommodation of female aircrew in the high-G environment will require the AL Mod and/or smaller sized anti-G suits.

The effect of exposure to 35,000 ft on incidence of altitude decompression sickness.

INTRODUCTION: Exposure to 35,000 ft without preoxygenation (breathing 100% oxygen prior to decompression) can result in severe decompression sickness (DCS). Exercise while decompressed increases the incidence and severity of symptoms. Clarification of the level of activity vs. time to symptom onset is needed to refine recommendations for current operations requiring 35,000-ft exposures. Currently, the U.S. Air Force limits these operations to 30 min following 75 min of preoxygenation. The objective of this study was to determine the effect of exercise intensity on DCS incidence and severity at 35,000 ft. METHODS: Following 75 or 90 min of ground-level preoxygenation, 54 male and 38 female subjects were exposed to 35,000 ft for 3 h while performing strenuous exercise, mild exercise, or seated rest. The subjects were monitored for venous gas emboli (VGE) with an echo-imaging system and observed for signs and symptoms of DCS. RESULTS: Exposures involving strenuous and mild exercise resulted in higher incidence (p < 0.05) and earlier onset of symptoms (p < 0.05) of DCS than exposure at rest. Mild and strenuous exercise during exposure did not differ in incidence or rate of onset. Incidence at 30 min of exposure was 8% at rest and 23% while exercising. CONCLUSION: The results showed that current guidelines for 35,000-ft exposures keep DCS risk below 10% at rest. Exercise, even at mild levels, greatly increases the incidence and rate of onset of DCS.

Exercise-induced altitude decompression sickness.

BACKGROUND: It has been known since World War II that exercise at altitude increases incidence of decompression sickness (DCS). However, data on the effects of specific exercise types at altitude are lacking. This research focused on the relative hazards of exercise without motion (isometric, straining) vs. dynamic exercise involving motion. The study also compared arm vs. leg exercise. METHODS: There were 32 healthy male subjects exposed, while resting, to 29,500 ft (8992 m) for 4 h or until DCS occurred, at which time they were brought to ground level. If the subject developed DCS on this exposure, he was exposed in successive months to lower altitudes, using the same procedure, until the subject was free of symptoms for the 4-h exposure. At this symptom-free altitude, as low as 20,000 ft (6096 m), the subject performed isometric arm, isometric leg, dynamic arm and dynamic leg exercises at less than 10% of maximal oxygen consumption, each during separate exposure months. Precordial venous gas emboli (VGE) were monitored every 20 min during each exposure with a Hewlett-Packard SONOS 1000 Echo Imaging System. RESULTS: Dynamic arm, dynamic leg, isometric arm, and isometric leg exercise induced DCS in 50%, 38%, 41% and 31% of the subjects, respectively. VGE incidence varied from 47-66%. No significant differences in DCS or VGE were found. CONCLUSIONS: Under our test conditions, there was no difference between dynamic and isometric exercise in eliciting DCS. Exercise during exposure to the symptom-free altitude for 4 h produced a 40% incidence DCS.

Male/female SACM endurance comparison: support for the Armstrong Laboratory modifications to the CSU-13B/P anti-G suit.

BACKGROUND: The standard anti-G suit (CSU-13B/P) was designed based on male body structure. Females differ from males with respect to body proportionality. In Armstrong Laboratory (AL) studies, females have terminated centrifuge simulated air combat maneuvers (SACM) because of anti-G suit (CSU-13B/P modified according to original T.O. 14P3-6-121)(OTO) discomfort. AL modifications to the suit have since been adopted in the OTO in an attempt to provide females a best-fit suit (AL Mod). The study examined male/female SACM endurance with females wearing both the OTO and the AL Mod suits. METHODS: There were 6 females and 8 males who performed a +5.0 to +9.0 Gz SACM to fatigue using the anti-G straining maneuver with anti-G suit inflation. The females performed in both the OTO and AL Mod suits while the males performed in the OTO suit only (OTO was their best-fit suit). RESULTS: Wearing the OTO, males performed the SACM significantly longer than the females, three of whom reported severe suit discomfort. However, when the females wore the AL Mod suit, their SACM endurance almost doubled over their OTO performance and none reported suit discomfort. When wearing their best-fit suits, there was no significant gender difference in SACM endurance. CONCLUSIONS: These data support the efficacy of the AL modifications to the CSU-13B/P anti-G suit through greatly improved performance during the +5.0 to +9.0 SACM in females. These data also suggest that, in the small sample examined, when fitted with a best-fit anti-G suit, females can endure the +5.0 to +9.0 SACM to the same degree as males.

Female acceleration tolerance: effects of menstrual state and physical condition.

INTRODUCTION: The literature contains a paucity of information on female tolerance to high sustained acceleration. With women now flying high-performance aircraft, gender-specific factors that may affect female acceleration tolerance have become increasingly important. The purpose of this investigation was to determine how menstrual state and physical condition affect acceleration tolerance. We hypothesized the menstrual cycle would have no effect on acceleration tolerance and that a positive correlation would exist between physical fitness level and tolerance to high sustained acceleration. METHODS: Centrifuge exposures on 8 female subjects consisted of a relaxed gradual-onset run (0.1 G.s-1) to the visual endpoint, a rapid-onset run (6 G.s-1) to +5 GZ for 15 s, and a +4.5 to +7 GZ simulated aerial combat maneuver (SACM) to physical exhaustion. Acceleration tolerance data were collected at onset of menstruation and 1, 2 and 3 weeks following the onset for two complete menstrual cycles. On separate days, body composition, anaerobic power output and peak oxygen uptake were determined. Retrospective data from 10 male subjects who had performed the +4.5 to +7 GZ SACM were analyzed and compared to these data. RESULTS: Analysis of variance revealed no significant difference in relaxed tolerance or SACM duration between the four selected menstrual cycle time points. Time-to-fatigue on the +4.5 to +7 GZ SACM was positively (p < or = 0.05) correlated with absolute fat-free mass (r = 0.87) and anaerobic power production (r = 0.76) in female subjects. However, when these variables were adjusted for total body mass, the significant correlations no longer existed. No correlation was found between SACM duration and absolute (L min-1) nor relative (ml.kg-1.min-1) aerobic fitness. Time-to-fatigue during the SACM was not significantly different between male and female subjects (250 +/- 97 and 246 +/- 149 s, respectively).

Treatment of unstable distal radius fractures: methods and comparison of external distraction and ORIF versus external distraction-ORIF neutralization.

Twenty-six closed unstable distal radius fractures were treated using a combination of internal fixation, external distraction (intraoperative), and, in some cases, up to 4 weeks of postoperative external fixation (neutralization). Intraoperative stability check determined the need for external neutralization. This combined technique allowed a comprehensive approach to even the most unstable fracture by merging the advantages of internal and external fixation. Up to 4 weeks of external fixation (neutralization) was not associated with the complications of external fixation usually reported.