The treatment of femoral head deformity and coxa magna by the Ganz femoral head reduction osteotomy

The aspherical coxa magna femoral head can be made more spherical by intra-articular osteotomy. The Ganz technique of femoral head reduction osteotomy to reduce the size and restore the spherical shape of the femoral head has been performed in 20 patients over the past 5 years. A good or excellent functional and radiographic result was obtained in 14 of the 20. A fair result (decreased pain but no improvement in range of motion) occurred in 3, and a poor result (stiffness and pain) occurred in 3. The preliminary results of this technique are therefore very promising.     

Gelfoam first metatarsophalangeal replacement/interposition arthroplasty—A case series with functional outcomes

Reported below are the functional results of a case-series of Gelfoam^®-based first metatarsophalangeal total joint replacements using an interposition arthroplasty technique carried out between April 1997 and December 2007. All patients who underwent Gelfoam-based arthroplasty under the care of a single surgeon were included; outcome scores and complications were recorded. A total of 31 joints in 31 consecutive patients were followed for a mean duration of 64 (range 24–150) months, and the mean patient age at the time of operation was 48 ± 9 (range 35–80) years. Hallux rigidus was the primary diagnosis in all of the cases except one in which a failed chevron ostetomy was the indication for treatment. The mean American Orthopaedic Foot & Ankle Society Hallux-Metatarsophalangeal-Interphalangeal score increased from an average of 35 pre-operatively to an average of 74 at final follow-up (range 67–100), with 20 (64.5%) joints rated good to excellent. One (3.5%) joint was fused 6 months after the arthroplasty procedure. Based on these results, we concluded that first MTPJ total joint Gelfoam™-based interpostion arthroplasty is a cheap alternative to other joint replacement systems for the MTP joint. The results appear similar to those achieved using more expensive devices.     

Activation mechanism of the β2-adrenergic receptor

A third of marketed drugs act by binding to a G-protein-coupled receptor (GPCR) and either triggering or preventing receptor activation. Although recent crystal structures have provided snapshots of both active and inactive functional states of GPCRs, these structures do not reveal the mechanism by which GPCRs transition between these states. Here we propose an activation mechanism for the β(2)-adrenergic receptor, a prototypical GPCR, based on atomic-level simulations in which an agonist-bound receptor transitions spontaneously from the active to the inactive crystallographically observed conformation. A loosely coupled allosteric network, comprising three regions that can each switch individually between multiple distinct conformations, links small perturbations at the extracellular drug-binding site to large conformational changes at the intracellular G-protein-binding site. Our simulations also exhibit an intermediate that may represent a receptor conformation to which a G protein binds during activation, and suggest that the first structural changes during receptor activation often take place on the intracellular side of the receptor, far from the drug-binding site. By capturing this fundamental signaling process in atomic detail, our results may provide a foundation for the design of drugs that control receptor signaling more precisely by stabilizing specific receptor conformations.     

Significant Delay in the Detection of Desaturation between Finger Transmittance and Earlobe Reflectance Oximetry Probes during Fiberoptic Bronchoscopy: Analysis of 104 Cases

Purpose

There is clinical significance to a delay in response time for detecting desaturation by pulse oximetry. Our aim in this study was to compare the response time of the reflectance and transmittance saturation probes during fiberoptic bronchoscopy (FOB) under monitored anesthesia care.

Methods

A prospective study included 104 patients scheduled for FOB. Patients were monitored with transmittance (finger) and reflectance (ear) oximetry probes. The response time was evaluated during desaturation and resaturation. We also acquired blood tests for arterial oxygen saturation to assess the agreement with the oximetry probes.

Results

Ninety patients had a desaturation episode during FOB and were included in the final analysis. Mean time difference between the reflectance ear probe (reference probe) and transmittance finger probe for the detection of desaturation (SpO2 = 90%) was + 36 s (CI 27.0–45.0, P < 0.001). The time difference between probes at end of desaturation episode (SpO2 = 95%) was + 31 s (CI 19.0–43.0; P < 0.001). A significant difference in response time was evident throughout the episode in all saturation values. The reflectance ear probe showed better agreement with arterial blood gases. The bias (and precision) for the earlobe and finger oximeters were of 0.24 (1.04) and 2.31 (3.37), respectively.

Conclusion

The data displayed by a centrally located reflectance probe are more accurate and allows for earlier identification, treatment, and resolution of desaturation events. In light of these data and the added value of the reflectance probe ability to measure transcutaneous PCO₂, we recommend monitoring bronchoscopy by a reflectance oximetry probe.

     

Role of embryo quality in predicting early pregnancy loss following assisted reproductive technology

Early pregnancy loss (EPL) significantly reduces the initial success rate of assisted reproduction treatments and increases the psychological burden on the patient. The aim of the current study was to investigate the association between embryo quality and EPL in IVF. A retrospective study of 1471 women undergoing IVF between July 2000 and October 2004 was performed. Multivariate logistic regression models evaluated the effect on EPL of the woman's age, type and cause of infertility, endometrial thickness on the day of oocyte retrieval, performance of intracytoplasmic sperm injection, number of transferred embryos, embryo quality as assessed by the number of blastomeres in the leading transferred embryo at day 3, and the percentage of fragmentation. The 2902 oocyte retrieval-embryo transfer cycles resulted in 816 pregnancies (28.1%; 705 women) constituting the study cohort. Of these, 259 pregnancies (31.7%) ended in EPL and 557 (68.3%) in ongoing pregnancies. EPL risk was significantly associated with advanced (>35 years) maternal age (OR=1.53; 95% CI 1.12-2.09) and five or fewer blastomeres in the leading embryo transferred at day 3 (OR=1.82; 95% CI 1.16-2.85). In conclusion, the quality of transferred embryos, as assessed by the total number of blastomeres in the leading transferred embryo, and maternal age are predictors of EPL.     

Antimyeloma effects of arsenic trioxide are enhanced by melphalan, bortezomib and ascorbic acid

Arsenic trioxide (ATO) induces apoptosis of malignant plasma cells through multiple mechanisms, including inhibition of DNA binding by nuclear factor kappa-B, a key player in the development of chemoresistance in multiple myeloma (MM). This activity suggests that ATO may be synergistic when combined with other active antimyeloma drugs. To evaluate this, we examined the antimyeloma effects of ATO alone and in combination with bortezomib, melphalan and ascorbic acid (AA) both in vitro and in vivo using a severe combined immunodeficient (SCID)-hu murine myeloma model. Marked synergistic antimyeloma effects were demonstrated when human MM Los Angeles xenograft IgG lambda light chain (LAGlambda-1) cells were treated in vitro with ATO and any one of these agents. SCID mice bearing human MM LAGlambda-1 tumours were treated with single-agent ATO, bortezomib, melphalan, or AA, or combinations of ATO with either bortezomib or melphalan and AA. Animals treated with any of these drugs alone showed tumour growth and increases in paraprotein levels similar to control mice, whereas animals treated with ATO-containing combinations showed markedly suppressed tumour growth and significantly reduced serum paraprotein levels. These in vitro and in vivo results suggest that addition of ATO to other antimyeloma agents may result in improved outcomes for patients with relapsed or refractory MM.