Factors influencing time to return to sport following clavicular fractures in adolescent athletes.

BACKGROUND: There is a trend toward increased surgical treatment of displaced clavicle fractures in the adolescent population presumably because of extrapolation of adult-derived best practice guidelines. The purpose of this study was to compare return to sport between nonoperative and operative treatment of clavicle fractures in high school athletes. METHODS: A retrospective review of clavicle fractures sustained in scholastic athletes participating in school-sponsored athletics in the upstate South Carolina was performed from 2015 to 2019. Injury circumstances, demographics, radiographs, treatment, and return to sport data were documented for all patients. Radiographs were evaluated for fracture location, comminution, displacement, shortening, and angulation. Patients were followed until complete return to sport, and results were compared based on sport participation, injury mechanism, fracture morphology, treatment type, and time to return to sport. RESULTS: Forty-seven patients (44 were male; average age 15.6 years) were included who all returned to sport within the original or subsequent season. Thirty-six patients (73%) were managed conservatively (30 middle third fractures, 4 medial third fractures, 2 distal third fractures), whereas 11 were managed surgically (11 middle third fractures). Eighty-one percent of fractures occured in collision athletes (55% in football). There was no difference in time loss based on participating in collision vs. noncontact sports (P = .4). Conservatively managed fractures returned to sport faster (61 ± 38 days vs. 100 ± 49 days; P = .008) compared with surgically managed patients. Fracture displacement ≥100% (100 ± 51 days vs. 54 ± 27 days; P = .001), greater comminution (128 ± 50 days vs. 59 ± 31 days; P = .001), and angulation (86 ± 52 days vs. 54 ± 22 days; P = .001) all were statistically significant for slower return to sport. Athletes presenting with clavicular shortening <2 cm returned to sport within a similar time frame as athletes with ≥2 cm (P = 0.1). CONCLUSION: Our results show that adolescent athletes with clavicular fractures predictably return to athletics, including collision sports. Athletes conservatively managed returned 40% faster than those with surgery. However, this appears to be associated with the severity and complexity of fractures treated surgically. This study provides evidence to counsel adolescent athletes following clavicular fractures on return to sport expectations.

Gamma-Ray and Radio-Frequency Radiation from Thunderstorms Observed from Space and Ground.

Terrestrial gamma ray flashes (TGFs) are a class of enigmatic electrical discharges in the Earth's atmosphere. In this study, we analyze an unprecedentedly large dataset comprised of 2188 TGFs whose signatures were simultaneously measured using space- and ground-based detectors over a five-year period. The Gamma-ray Burst Monitor (GBM) on board the Fermi spacecraft provided the energetic radiation measurements. Radio frequency (RF) measurements were obtained from the Global Lightning Dataset (GLD360). Here we show the existence of two categories of TGFs - those that were accompanied by quasi-simultaneous electromagnetic pulses (EMPs) detected by the GLD360 and those without such simultaneous EMPs. We examined, for the first time, the dependence of the TGF-associated EMP-peak-amplitude on the horizontal offset distance between the Fermi spacecraft and the TGF source. TGFs detected by the GBM with sources at farther horizontal distances are expected to be intrinsically brighter and were found to be associated with EMPs having larger median peak-amplitudes. This provides independent evidence that the EMPs and TGFs are produced by the same phenomenon, rather than the EMPs being from "regular" lightning in TGF-producing thunderstorms.

Peri-operative management of ophthalmic patients on anti-thrombotic agents: a literature review.

There is variability in the management of ophthalmic patients on anti-thrombotic agents (antiplatelets and anticoagulants) during the peri-operative period. A survey carried out in a UK teaching hospital on a cohort of ophthalmologists showed majority were comfortable with antiplatelet management but there was variability in managing patients on warfarin and direct oral anticoagulants (DOACs); 40% were unaware of existing guidelines. We aim to review the recommendations in the literature with regards to managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery. We reviewed incidences of complications, specifically, the haemorrhagic complications associated. Pubmed search was carried out on relevant keywords from January 2007 to August 2017. All relevant UK guidelines including the Royal College of Ophthalmologists and British Society of Haematology were reviewed. Literature recommendations for routine cataract surgery under topical or sub-Tenon's anaesthesia would be to continue all anti-thrombotic agents. For sharp needle anaesthesia, avoidance of dual antiplatelet therapy was recommended and warfarin could be continued if INR within therapeutic range. Recommendations for surgeries in glaucoma, vitreo-retinal, oculoplastic and lacrimal; and strabismus are presented. No evidence was found for corneal surgery. Haemorrhagic complications are reported in all groups. Limitations of this review include the retrospective nature, lack of randomized control trials and the limited evidence regarding DOACs. It is important for ophthalmologists to be aware of and balance the risk of thromboembolic events and risks of haemorrhagic complications for ophthalmic surgery. A multi-disciplinary approach is recommended for complex cases.

Mesencephalic astrocyte-derived neurotropic factor is an important factor in chondrocyte ER homeostasis.

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) resident protein that can be secreted due to an imperfect KDEL motif. MANF plays a cytoprotective role in several soft tissues and is upregulated in conditions resulting from intracellular retention of mutant protein, including two skeletal diseases, metaphyseal chondrodysplasia, Schmid type (MCDS) and multiple epiphyseal dysplasia (MED). The role of MANF in skeletal tissue homeostasis is currently unknown. Interestingly, cartilage-specific deletion of Manf in a mouse model of MED resulted in increased disease severity, suggesting its upregulation may be chondroprotective. Treatment of MED chondrocytes with exogenous MANF led to a decrease in the cellular levels of BiP (GRP78), confirming MANF's potential to modulate ER stress responses. However, it did not alleviate the intracellular retention of mutant matrilin-3, suggesting that it is the intracellular MANF that is of importance in the pathobiology of skeletal dysplasias. The Col2Cre-driven deletion of Manf from mouse cartilage resulted in a chondrodysplasia-like phenotype. Interestingly, ablation of MANF in cartilage did not have extracellular consequences but led to an upregulation of several ER-resident chaperones including BiP. This apparent induction of ER stress in turn led to dysregulated chondrocyte apoptosis and decreased proliferation, resulting in reduced long bone growth. We have previously shown that ER stress is an underlying disease mechanism for several skeletal dysplasias. The cartilage-specific deletion of Manf described in this study phenocopies our previously published chondrodysplasia models, further confirming that ER stress itself is sufficient to disrupt skeletal growth and thus represents a potential therapeutic target.

Unusual presentation of failed metal-on-metal total hip arthroplasty with features of neoplastic process.

Metal-on-metal (MoM) total hip arthroplasty (THA) is associated with increased incidence of failure from metallosis, adverse tissue reactions, and the formation of pseudotumors. This case highlights a 53-year-old female with an enlarging painful thigh mass 12 years status post MoM THA. Radiographs and advanced imaging revealed an atypical mass with cortical bone destruction and spiculation, concerning for periprosthetic malignancy. Open frozen section biopsy was performed before undergoing revision THA in a single episode of care. This case illustrates that massive pseudotumors can be locally aggressive causing significant femoral bone destruction and may mimic malignancy. It is important that orthopaedic surgeons, radiologists and pathologists understand the relative infrequency of periprosthetic malignancy in MoM THA to mitigate patient concerns, misdiagnosis, and allow for an evidence based discussion when treating massive pseudotumors.

Applications of Mass Spectrometry Imaging to Cancer.

Pathologists play an essential role in the diagnosis and prognosis of benign and cancerous tumors. Clinicians provide tissue samples, for example, from a biopsy, which are then processed and thin sections are placed onto glass slides, followed by staining of the tissue with visible dyes. Upon processing and microscopic examination, a pathology report is provided, which relies on the pathologist's interpretation of the phenotypical presentation of the tissue. Targeted analysis of single proteins provide further insight and together with clinical data these results influence clinical decision making. Recent developments in mass spectrometry facilitate the collection of molecular information about such tissue specimens. These relatively new techniques generate label-free mass spectra across tissue sections providing nonbiased, nontargeted molecular information. At each pixel with spatial coordinates (x/y) a mass spectrum is acquired. The acquired mass spectrums can be visualized as intensity maps displaying the distribution of single m/z values of interest. Based on the sample preparation, proteins, peptides, lipids, small molecules, or glycans can be analyzed. The generated intensity maps/images allow new insights into tumor tissues. The technique has the ability to detect and characterize tumor cells and their environment in a spatial context and combined with histological staining, can be used to aid pathologists and clinicians in the diagnosis and management of cancer. Moreover, such data may help classify patients to aid therapy decisions and predict outcomes. The novel complementary mass spectrometry-based methods described in this chapter will contribute to the transformation of pathology services around the world.

Ankle fractures in the elderly: risks and management challenges.

Ankle fractures are the third most common osseous injury in the elderly, behind hip and distal radius fractures. While there is a rich history of clinical advancement in the timing, technique, perioperative management, and associated risks of hip fractures, similar evaluations are only more recently being undertaken for ankle fractures. Traditionally, elderly patients were treated more conservatively; however, nonoperative management has been found to be associated with increased mortality. As such, older and less healthy patients have become operative candidates. The benefits of geriatric/orthopedic inpatient comanagement that have been well elucidated in the hip fracture literature also seem to improve outcomes in elderly patients with ankle fractures. One of the orthopedist's roles is to recognize the complexities of osteoporotic bone fixation and optimize wound healing potential. Though the immediate cost of this surgical approach is inevitably higher, the ultimate cost of long-term care has been found to be substantially reduced. It is important to consider the mortality and morbidity benefits and cost reductions of operative intervention and proper inpatient care of geriatric ankle fractures when they present to the emergency department or the office.

Cartilage-specific ablation of XBP1 signaling in mouse results in a chondrodysplasia characterized by reduced chondrocyte proliferation and delayed cartilage maturation and mineralization.

OBJECTIVE: To investigate the in vivo role of the IRE1/XBP1 unfolded protein response (UPR) signaling pathway in cartilage. DESIGN: Xbp1(flox/flox).Col2a1-Cre mice (Xbp1(CartΔEx2)), in which XBP1 activity is ablated specifically from cartilage, were analyzed histomorphometrically by Alizarin red/Alcian blue skeletal preparations and X-rays to examine overall bone growth, histological stains to measure growth plate zone length, chondrocyte organization, and mineralization, and immunofluorescence for collagen II, collagen X, and IHH. Bromodeoxyuridine (BrdU) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses were used to measure chondrocyte proliferation and cell death, respectively. Chondrocyte cultures and microdissected growth plate zones were analyzed for expression profiling of chondrocyte proliferation or endoplasmic reticulum (ER) stress markers by Quantitative PCR (qPCR), and of Xbp1 mRNA splicing by RT-PCR to monitor IRE1 activation. RESULTS: Xbp1(CartΔEx2) displayed a chondrodysplasia involving dysregulated chondrocyte proliferation, growth plate hypertrophic zone shortening, and IRE1 hyperactivation in chondrocytes. Deposition of collagens II and X in the Xbp1(CartΔEx2) growth plate cartilage indicated that XBP1 is not required for matrix protein deposition or chondrocyte hypertrophy. Analyses of mid-gestation long bones revealed delayed ossification in Xbp1(CartΔEx2) embryos. The rate of chondrocyte cell death was not significantly altered, and only minimal alterations in the expression of key markers of chondrocyte proliferation were observed in the Xbp1(CartΔEx2) growth plate. IRE1 hyperactivation occurred in Xbp1(CartΔEx2) chondrocytes but was not sufficient to induce regulated IRE1-dependent decay (RIDD) or a classical UPR. CONCLUSION: Our work suggests roles for XBP1 in regulating chondrocyte proliferation and the timing of mineralization during endochondral ossification, findings which have implications for both skeletal development and disease.

Evaluation of the NovaSure endometrial ablation procedure in women with uterine cavity length over 10 cm.

OBJECTIVE: To evaluate procedure-related adverse events, post-procedure menstrual bleeding status, and surgical re-intervention in women with a sounded uterine length > 10 cm compared to women with a sounded uterine length ≤ 10 cm who underwent the NovaSure endometrial ablation procedure. METHODS: We conducted a retrospective cohort study of 188 women from a Canadian community-based gynaecology practice. Eighty-seven women had a sounded uterine length > 10 cm, and 101 patients had a sounded length ≤ 10 cm. Procedure-related adverse events, post-procedure menstrual bleeding status, and surgical re-interventions were compared between groups. RESULTS: Mean uterine sounding lengths were 11.0 ± 0.6 cm and 8.9 ± 0.8 cm in the > 10 cm and ≤ 10 cm groups, respectively. There were no differences between the groups in demographic characteristics or gynaecologic history, with the exception of higher BMI in the > 10 cm group and a greater prevalence of dysmenorrhea in the ≤ 10 cm group. Overall, 44.1% of all participants had been unsuccessfully treated with hormonal therapy, and 20.7% had failed non-hormonal treatment before the ablation procedure. The remaining 35.2% of participants had declined alternative therapy and proceeded directly to endometrial ablation. No serious procedure-related adverse events occurred in either group. Menstrual bleeding status at follow-up at 30.4 ± 15.3 months (> 10 cm group) and 30.5 ± 15.5 months (≤ 10 cm group) was not different between the groups (P = 0.85). In women who did not undergo surgical re-intervention after the initial ablation, amenorrhea was reported by 51.9% in the > 10 cm group and 65.9% in the ≤ 10 cm group. CONCLUSION: The NovaSure endometrial ablation procedure was associated with successful menstrual bleeding outcomes in women with sounded uterine length > 10 cm. No serious procedure-related adverse events occurred, and the need for surgical re-intervention was low. There was no significant difference in bleeding rates between the > 10 cm and ≤ 10 cm uterine length cohorts.

Objectif : Comparer, chez des femmes ayant subi une ablation de l'endomètre au moyen de la technique NovaSure et présentant une longueur utérine déterminée par hystérométrie de plus de 10 cm ou de 10 cm ou moins, les événements indésirables associés à l'intervention, l'état des saignements menstruels à la suite de l'intervention et la nécessité de procéder à une nouvelle intervention chirurgicale. Méthodes : Nous avons mené une étude de cohorte rétrospective qui portait sur 188 femmes ayant fréquenté une pratique gynécologique communautaire au Canada. Quatre-vingt-sept de ces femmes présentaient une longueur utérine déterminée par hystérométrie de plus de 10 cm, tandis que les 101 autres présentaient une longueur utérine déterminée par hystérométrie de 10 cm ou moins. Les événements indésirables associés à l'intervention, l'état des saignements menstruels à la suite de l'intervention et la nécessité de procéder à une nouvelle intervention chirurgicale sont les paramètres qui ont été comparés chez ces deux groupes de femmes. Résultats : Les longueurs utérines moyennes déterminées par hystérométrie ont été de 11,0 ± 0,6 cm et de 8,9 ± 0,8 cm au sein des groupes « > 10 cm ¼ et « ≤ 10 cm ¼, respectivement. Aucune différence n'a été constatée entre les groupes en matière de caractéristiques démographiques ou d'antécédents gynécologiques, exception faite d'un IMC accru au sein du groupe « > 10 cm ¼ et d'une prévalence accrue de dysménorrhée au sein du groupe « ≤ 10 cm ¼. De façon globale, 44,1 % de toutes les participantes avaient connu l'échec de l'hormonothérapie et 20,7 % avaient connu l'échec d'un traitement non hormonal avant la tenue de l'ablation. Les participantes composant les autres 35,2 % avaient refusé d'avoir recours à un traitement de rechange et décidé de subir directement une ablation de l'endomètre. Aucun événement indésirable grave associé à l'intervention ne s'est manifesté dans l'un ou l'autre des groupes. Aucune différence n'a été constatée entre les groupes (P = 0,85) pour ce qui est de l'état des saignements menstruels au moment du suivi à 30,4 ± 15,3 mois (groupe « > 10 cm ¼) et à 30,5 ± 15,5 mois (groupe « ≤ 10 cm ¼). Chez les femmes qui n'ont pas eu à subir une nouvelle intervention chirurgicale à la suite de l'ablation initiale, une aménorrhée a été signalée par 51,9 % des participantes du groupe « > 10 cm ¼ et par 65,9 % des participantes du groupe « ≤ 10 cm ¼. Conclusion : La technique NovaSure d'ablation de l'endomètre a été associée à des issues réussies en matière de saignements menstruels chez les femmes présentant une longueur utérine déterminée par hystérométrie de plus de 10 cm. Aucun événement indésirable grave associé à l'intervention ne s'est manifesté et la nécessité de procéder à une nouvelle intervention chirurgicale était faible. Aucune différence significative n'a été constatée en matière de taux de saignement entre les groupes « > 10 cm ¼ et « ≤ 10 cm ¼.

Side-chain control of porosity closure in single- and multiple-peptide-based porous materials by cooperative folding.

Porous materials are attractive for separation and catalysis-these applications rely on selective interactions between host materials and guests. In metal-organic frameworks (MOFs), these interactions can be controlled through a flexible structural response to the presence of guests. Here we report a MOF that consists of glycyl-serine dipeptides coordinated to metal centres, and has a structure that evolves from a solvated porous state to a desolvated non-porous state as a result of ordered cooperative, displacive and conformational changes of the peptide. This behaviour is driven by hydrogen bonding that involves the side-chain hydroxyl groups of the serine. A similar cooperative closure (reminiscent of the folding of proteins) is also displayed with multipeptide solid solutions. For these, the combination of different sequences of amino acids controls the framework's response to the presence of guests in a nonlinear way. This functional control can be compared to the effect of single-point mutations in proteins, in which exchange of single amino acids can radically alter structure and function.

Incidence of neovascularization in the fellow eye of patients with unilateral retinal angiomatous proliferation.

AIMS: The aim of this study is to describe the incidence and characteristics of neovascularization in the fellow eye of patients with retinal angiomatous proliferation (RAP). METHODS: This is a retrospective study conducted on all patients with a diagnosis of unilateral RAP commencing treatment in a single centre between November 2002 and January 2010. Clinical biomicroscopic examination, fluorescein angiography, and if required, indocyanine green angiography, and optical coherence tomography were used to evaluate all patients. RESULTS: In all, 37 patients had a follow-up of ≥1 year, 28 ≥2 years, and 11 ≥3. Patients who developed RAP in the fellow eye were: 2 of 37 (5.4%) within 1 year of follow-up, 4 of 28 (14.2%) within 2 years, and 4 of 11 (36.3%) within 3 years. CONCLUSION: In our case series, the risk of neovascularization in the fellow eye of patients with unilateral RAP increased with time. Approximately one-third of patients with a 3-year follow-up developed a bilateral disease. Our findings warrant further large-scale investigation.

Double-blind, placebo-controlled evaluation of extended-release bupropion in elderly patients with major depressive disorder.

Major depressive disorder in the elderly is associated with increased morbidity and reduced quality of life. This 10 week, placebo-controlled study investigated the efficacy and tolerability of extended-release bupropion (150-300 mg once daily) in depressed patients aged 65 years or older. The statistical assumptions necessary for the validity of the protocol-specified analysis of covariance were not met for the analysis of the primary outcome variable (Montgomery-Asberg Depression Rating Scale total score at Week 10, last observation carried forward). Alternative statistical methods used for the analysis of this variable demonstrated statistical significance. Statistically significant improvements were observed on the majority of secondary end points when compared with placebo, including the health outcome measures for motivation and energy, and life satisfaction and contentment. Adverse events were generally mild to moderate and similar between treatment groups. This study demonstrated that the extended-release bupropion is an effective, well-tolerated treatment for major depression in the elderly.

Comparing pregnancy in adolescents and adults: obstetric outcomes and prevalence of anemia.

OBJECTIVE: To characterize the obstetric outcome and prevalence of anemia in primiparous adolescents and compare them with those in older primiparas. METHODS: We conducted a retrospective chart review of 207 adolescents (or20 years old) whose prenatal care was provided by a single obstetrician in Kingston, Ontario, and who had a live singleton birth at >or24 weeks gestation between 1996 and 2004. RESULTS: The mean age of the adolescents (T) was 17.5 years and of the adults (A) 27.3 years. More than 95% of the women were Caucasian. Mean gestational age at delivery was similar in the two groups (T 39.4 weeks, A 39.6 weeks, P = 0.25). Adolescents were more likely to have a preterm delivery (T 12.6%, A 7.5%, P = 0.038), although smoking rather than young maternal age was an independent risk factor for preterm delivery (odds ratio [OR] 3.2; 95% confidence intervals [CI] 1.47.5). A significantly lower proportion of adolescents delivered by Caesarean section (CS) (T 12.1%, A 27.7%, P < 0.001). Older maternal age, higher pre-pregnancy BMI, increased weight gain during pregnancy, and pre-delivery anemia were all independent risk factors for CS. Smoking was the most influential factor in predicting infant birth weight. Adolescents had significantly more low birth weight infants (< 2500 g) than adults (T 10.1% vs. A 4.3%, P = 0.008). Gestational age rather than young maternal age was the most significant risk factor for low birth weight (OR 3.3; 95% CI 1.95.7). After controlling for smoking status, adolescents were 2.5 times more likely than adults to be anemic at 26 to 35 weeks gestation and pre-delivery. CONCLUSION: Our results suggest that primiparous adolescents have significantly different obstetric outcomes from primiparous adults. Smoking and anemia are significant risk factors for poor obstetric outcomes and are potentially modifiable.

The genetics of otosclerosis: pedigree studies and linkage analysis.

Otosclerosis is one of the commonest causes of hearing loss in adults. The hereditary nature of the disease has been acknowledged for over a century but the precise genetic basis of the disorder has as yet not been characterised. It is currently recognised that familial otosclerosis exhibits autosomal dominant inheritance with variable penetrance and expression. More recently, family linkage studies have identified three chromosomal regions that can be ascribed to this disorder: otosclerosis 1 on chromosome 15, otosclerosis 2 on chromosome 7 and a third locus on chromosome 6. The genes responsible for the disease within these regions remain to be defined. The work presented in this paper firstly examined the familial nature of the disease in a cohort of individuals that had undergone surgery for otosclerosis. Following detailed ascertainment, pedigrees were constructed for subsequent genetic analysis. The laboratory analysis included linkage analysis of the candidate region on the long arm of chromosome 15, linkage analysis of the aggrecan protein gene within the 15q region and linkage analysis to chromosome 7q. The pedigree studies confirmed the hereditary nature of otosclerosis and the recognised mode of inheritance. Linkage to the chromosome 15 locus, the candidate aggrecan gene and the chromosome 7 locus was excluded, confirming that otosclerosis exhibits locus heterogeneity.

A disorder resembling pseudoachondroplasia but without COMP mutation.

Pseudoachondroplasia (PA) is an autosomal dominant skeletal dysplasia characterized by disproportionate short stature, generalized ligamentous laxity, irregular epi-metaphyseal ossification, and vertebral anomalies that regress with age. It usually manifests in the second year of life or later. The clinically and radiographically variable disorder is caused by mutations in the COMP gene. Parental gonadal mosaicism may lead to recurrence of the disorder in children of unaffected parents. Here, we describe sibs with bone changes similar to those seen in very severe PA born to clinically and radiographically unaffected parents. Sequencing of all 19 exons of the COMP gene failed to disclose a mutation. The sibs appear to be affected by a disorder resembling PA but resulting from a defect of an extracellular matrix protein other than COMP. It may be suspected in patients with unusually severe dwarfism, severe epi-metaphyseal abnormalities, and persistent platyspondyly.

Case selection in macular relocation surgery for age related macular degeneration.

BACKGROUND: To date there has been no randomised controlled trial demonstrating the safety and efficacy of macular relocation surgery (MRS) for age related macular degeneration (AMD). Vision can be improved in some patients and made worse in others despite successful surgery or because of complications. PURPOSE: To determine which patients would benefit from MRS. METHODS: Twenty nine patients with exudative AMD took part in a prospective, non-comparative, interventional study. Macular relocation surgery involved phacoemulsification, vitrectomy, 360 degrees retinotomy, excision of choroidal neovascular membrane, and macular relocation using an infusion of 5-fluorouracil and low molecular weight heparin as adjuvant to prevent proliferative vitreoretinopathy. Patients underwent protocol refraction preoperatively and six-monthly postoperatively by designated optometrists. Preoperative fundus fluorescein angiograms were read by masked observers and the lesions were classified according to a set protocol. The main outcome measures were visual improvement, final vision of better than 20/400, reading speed, critical print size. Logistic and multiple stepwise linear regressions were used to identify independent factors which predicted the main outcomes. RESULTS: Preoperative visual acuity (20/120 or worse) and lesion type (predominantly classic or submacular haemorrhage) were significantly associated with visual improvement (coefficient of regression B = 26.8, p<0.001 and B = 14.9 with p = 0.045 respectively). There were no significant independent factors which predicted a final distance logMAR visual acuity of 1.3 (20/400) or any arbitrary definition of blindness. CONCLUSIONS: The study showed that it was possible to select cases that were more likely to experience an improvement in vision following MRS.

A pH-sensitive fluor, CypHer 5, used to monitor agonist-induced G protein-coupled receptor internalization in live cells.

G protein-coupled receptors (GPCRs) are the largest family of proteins involved in transmembrane signal transduction and are actively studied because of their suitability as therapeutic small-molecule drug targets. Agonist activation of GPCRs almost invariably results in the receptor being desensitized. One of the key events in receptor desensitization is the sequestration of the receptor from the cell surface into acidic intracellular endosomes. Therefore, a convenient, generic, and noninvasive monitor of this process is desirable. A novel, pH-sensitive, red-excited fluorescent dye, CypHer 5, was synthesized. This dye is non-fluorescent at neutral pH and is fluorescent at acidic pH. Anti-epitope antibodies labeled with this dye were internalized in an agonist concentration- and time-dependent manner, following binding on live cells to a range of GPCRs that had been modified to incorporate the epitope tags in their extracellular N-terminal domain. This resulted in a large signal increase over background. When protonated, the red fluorescence of CypHer 5 provides a generic reagent suitable for monitoring the internalization of GPCRs into acidic vesicles. This approach should be amenable to the study of many other classes of cell surface receptors that also internalize following stimulation.

Comparison of megakaryopoiesis in vitro of paired peripheral blood progenitor cells and bone marrow harvested during remission in patients with acute myeloid leukaemia.

We have studied paired peripheral blood progenitor cells (PBPC) and bone marrow (BM) samples from 12 acute myeloid leukaemia (AML) patients following intensive chemotherapy, and assessed direct granulocyte-macrophage colony-forming units (CFU-GM), erythroid burst-forming units (BFU-E), megakaryocyte CFU (CFU-Mk) numbers and the production of CD61+ (platelet glycoprotein IIIa) cells in suspension culture in response to various haemopoietic growth factor combinations. We found that CFU-GM and BFU-E numbers per 105 mononuclear cells were similar in both AML PBPC and BM harvests; CFU-Mk numbers, however, were significantly higher in PBPC than BM. In addition, the higher total white cell count of the PBPC harvests meant that PBPC have much higher numbers of total progenitors per collection. CD61+ cell numbers in suspension cultures of AML PBPC and BM were lower than those of harvested normal marrow. However, response to pegylated recombinant human megakaryocyte growth and development factor (PEGrHuMGDF) both alone and in combination with other growth factors was qualitatively similar to that of normal BM. As with normal BM, response to PEGrHuMGDF alone did not increase further with addition of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), interleukin 6 (IL-6) or erythropoietin (EPO) in the AML PBPC and BM. Further responses over PEGrHuMGDF alone were seen when added with stem cell factor (SCF) or with a combination of SCF + IL-3 + EPO in both AML PBPC and BM cultures; however, the magnitude of the response was greater in the PBPC cultures. Response to PEGrHuMGDF + IL-3 was seen in the PBPC cultures but not in the AML BM. These data suggest that, in AML patients, there are proportionally more megakaryocyte progenitor cells in the mobilized PBPC than in the BM harvests, which would explain the more rapid platelet recovery following PBPC autografts.

Clinical and radiographic features of multiple epiphyseal dysplasia not linked to the COMP or type IX collagen genes.

Multiple epiphyseal dysplasia (MED) is a mild chondrodysplasia affecting the structural integrity of cartilage and causing early-onset osteoarthrosis in adulthood. The condition is genetically heterogeneous. Mutations in the COMP gene and in two genes (COL9A2; COL9A3), coding respectively for the alpha2(IX) and alpha3(IX) chains of type IX collagen, can cause the autosomal dominant forms of MED. Mutations in the DTDST gene have recently been identified in a recessive form of MED. However, for the majority of MED cases, the genetic defect still remains undetermined. We report a three-generation family with an autosomal dominant form of MED, characterised by normal stature, joint pain in childhood and early-onset osteoarthrosis, affecting mainly the hips and knees. Based on discordant inheritance among affected individuals linkage of the phenotype to the COMP, COL9A1, COL9A2, COL9A3 genes was excluded. Our study provides evidence that at least another locus, distinct from COL9A1, is involved in autosomal dominant MED.