In Vitro Maturation of Oocytes Obtained from Ovarian Cortex Among Postpubertal Hematological Cancer Patients Undergoing Fertility Preservation.

Purpose: In vitro maturation (IVM) of oocytes obtained from ovarian tissue during ovarian tissue cryopreservation (OTC) is a technique for fertility preservation in patients with cancer obviating the need to postpone chemotherapy initiation. Little is known about IVM outcomes in hematological malignancies, especially post-chemotherapy. The purpose of this study was to evaluate the effect of cytotoxic treatment on the potential to retrieve immature oocytes and mature them in vitro and examine the association between serum inflammatory markers and these results. Methods: In this retrospective study, we evaluated inflammation markers, including B symptoms and IVM outcomes of 78 chemotherapy-naive and exposed patients diagnosed with Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), acute lymphoblastic leukemia (ALL), or acute myeloid leukemia (AML). Results: The mean number of oocytes found was 7.2 ± 7.2. The average number of oocytes matured by IVM was 2.8 ± 3.5, and a mean IVM rate was 32.1 ± 27.7%. All patients in the ALL and AML groups had previous exposure to chemotherapy before OTC, compared with 50.0% (7/14) and 31.9% (15/47) in the NHL and HL groups, respectively. Among patients with lymphoma, chemotherapy exposure was associated with the reduced number of retrieved oocytes (9.8 ± 7.7 vs. 5.3 ± 5.7 oocytes, p = 0.049) in the HL group but not with the number of mature oocytes or IVM rate. B symptoms were not associated with IVM outcomes. Lymphocyte count (ß = 1.584; p = 0.038) and lactate dehydrogenase (ß = 0.009; p = 0.043) were the only significant parameters associated with the number of matured oocytes in a linear regression model. Conclusion: IVM is a promising assisted reproductive technology, which holds great potential for patients in need of urgent fertility preservation or those who cannot receive hormonal stimulation. Our results demonstrate the feasibility of the technique even in the presence of B symptoms and elevated inflammation markers and in patients with previous exposure to chemotherapy.

Changes in Sperm Parameters with Time in Men with Normal and Abnormal Baseline Semen Analysis.

The association between paternal age and sperm quality in the population level has been previously studied. Only limited data exists regarding the intra-personal variations in semen parameters among fertile and infertile men over time. We aimed to assess trends over time in semen parameters among men with normal and abnormal baseline sperm parameters and investigate potential risk factors for sperm quality deterioration. This retrospective cohort study was conducted at a university-affiliated medical center in vitro fertilization (IVF) unit. Patients with at least two semen analyses (SA) performed > 1 year apart, with the last SA done between 2017 and 2021, were included. The study consisted of two main analyses-comparison of intra-patient's sperm parameters changes in men with normal and abnormal baseline SA (BSA) and analysis of risk factors for developing abnormal semen parameters over time in men who had normal BSA parameters. This study included a total of 902 men assessed for infertility with normal and abnormal BSA. The average time interval between tests was 1015 days (range 366-7709 days). Among individuals with normal BSA, there was a mild decline in most parameters-concentration (- 6.53 M/ml), motility (- 7.74%), and total motile count (TMC) (- 21.80 M) (p < 0.05 for all parameters). In contrast, a slight improvement in most parameters, except for concentration, was noted in men with abnormal BSA-volume (+ 0.21 ml), motility (+ 8.72%), and TMC (+ 14.38 M) (p < 0.05 for all parameters). Focusing on men with normal BSA, 33.5% of individuals developed abnormality in one or more of their sperm parameters over time, within a mean time of 1013 ± 661 days. We also found that only time between tests emerged as an independent prognostic factor for the development of abnormal SA later. Interestingly, sperm deterioration in participants in their third, fourth, and fifth decades of life with normal initial semen analysis was similar. Our study provides evidence of a decline in semen quality over time in individuals with normal BSA, in contrast to men with abnormal BSA. Longer time intervals between tests independently increase the risk of sperm abnormalities.

Femoral neck shortening as a sequela of internal fixation for femoral neck fractures and its effect on the coronal alignment of the limb: a pilot study.

INTRODUCTION: Femoral neck shortening is a common phenomenon following osteosynthesis for femoral neck fractures, which was shown to have a negative effect on hip function. There is paucity of literature on the effect of shortening on the ipsilateral limb mechanical axis and knee coronal alignment. We hypothesized that postoperative femoral neck shortening can alter the limb's mechanical axis into valgus. METHODS: Of 583 patients screened, 13 patients with severe neck shortening (< 10 mm) following femoral neck fracture fixation, were found eligible and agreed to participate. A full-length lower limb radiographs were obtained and radiographic parameters (offset, neck-shaft angle, HKA, mLPFA, mDLFA, mMPTFA, MAD, MAD-r) as well as functional scores were obtained. RESULTS: Statistically significant differences in mechanical axis deviation ratio (MAD-r) were found between the ipsilateral and the contralateral extremities (0.41 ± 0.16 versus 0.55 ± 0.11, p = 0.03). A correlation between femoral neck length differences and MAD was not statistically significant although a tendency towards lateral deviation of the mechanical axis was noted (r = - 0.5, p = 0.077). A negative correlation was found between a greater difference in the femoral neck length and the SF12 score, both in the physical and the mental parts (r = - 0.69, p = 0.008; r = - 0.58, p = 0.035, respectively). CONCLUSION: We found a more lateralized mechanical axis in limbs that demonstrated post-operative ipsilateral femoral neck severe shortening. These findings may provide a possible explanation and rationale for knee pain and perhaps for the development of knee osteoarthritis as a sequalae of femoral neck shortening. Further investigation and larger cohort, long-term studies are needed to further explore this hypothesis.

Efficacy of single-shot adductor canal block before Versus after primary total knee arthroplasty - Does timing make a difference? A randomized controlled trial.

BACKGROUND: Total knee arthroplasty (TKA) is associated with severe postoperative pain. Multimodal analgesia, including peripheral nerve block, is recommended for post-operative pain relief. Administration of some pain medications prior to surgery has shown to be more effective than after the operation. This is a prospective, randomized controlled trial designed to compare the analgesic efficacy of the adductor canal block (ACB) performed immediately before or immediately after primary total knee arthroplasty (TKA). We hypothesized that ACB before the surgery will reduce postoperative pain and improve knee function. METHODS: A total of 50 patients were enrolled and randomized into 2 groups, with 26 patients receiving a preoperative ACB and 24 receiving a postoperative ACB. RESULTS: Treatment groups were similar in terms of gender (p = .83), age (p = 0.61) weight (p = .39) and ASA score. Average visual analogue scale (VAS) on arrival to the post-anesthesia care unit (PACU) were 4.9 ± 3.2 in the preoperative ACB versus 3.4 ± 2.8 for the postoperative ACB (p = .075). VAS scores at different time points as well as the mean, minimal and maximal reported VAS scores were not significantly different between the two groups. The cumulative quantities of Fentanyl administered by the anesthesia team was comparable between the groups. Similarly, the dosage of Morphine, Tramadol, Acetaminophen and Dipyrone showed only small variations. The Quality of Recovery Score, Knee Society Scores and knee range of motion did not differ between the groups. CONCLUSIONS: Our findings demonstrate no significant differences in patient total narcotics consumption, pain scores and functional scores, between preoperative and postoperative ACB in patients undergoing TKA. TRIAL REGISTRATION: The trial was registered at www.clinicaltrials.gov and was assigned the registration number NCT02908711. LEVEL OF EVIDENCE: level I randomized controlled trial.

The effect of timing of intravenous paracetamol on perioperative pain and cytokine levels following laparoscopic bariatric surgery, a randomized controlled trial.

OBJECTIVE: Bariatric surgeries involve manipulation of the viscera and are associated with significant postoperative pain. Paracetamol is a nonopioid analgesic with a rapid onset, and it is effective and safe. The study compared the effects of pre- and postincisional intravenous paracetamol administration for optimal postoperative pain management in patients undergoing bariatric surgeries. METHODS: This is a prospective, double-blinded, placebo-controlled randomized clinical trial of adult patients, admitted electively for laparoscopic bariatric surgery. The patients were randomly divided into two groups. One group of patients was given paracetamol at the beginning of the operation, prior to the surgical incision, the other group of patients received the same treatment at the end of the operation. RESULTS: Patients who were given preincisional intravenous paracetamol presented significantly lower visual analog scale (VAS) scores following the surgery compared with patients who were given intravenous paracetamol in the last 30 minutes of the operation (VAS, median [IQR] = 2 [2-3] vs. 5 [3-6]; p < 0.001). They also required fewer postoperative opioids and tramadol (in milligrams, respectively, 1 [0-5] vs. 7.5 [5-10] and 300 [100-400] vs. 400 [200-500]) compared with later analgesia administration (p < 0.001 and p = 0.03). The levels of inflammatory markers measured at fixed intervals from paracetamol administration were not statistically different between the study groups. CONCLUSION: Early analgesia with intravenous paracetamol, given before the surgical incision, may result in lower VAS scores postoperatively compared with the same treatment administered toward the end of the operation.

Age as a Predictive Factor in Severity of Injuries in Riders of Electric Bikes and Powered Scooters: A Retrospective Cross-Sectional Study.

The growth in worldwide popularity of electric bikes (E-bikes) and powered scooters (P-scooters) has been accompanied by an increase in injuries associated with their use. The aim of this study was to evaluate the contribution of rider age to injury severity, represented by need for hospitalization. A retrospective review of the database of a tertiary medical center yielded 1234 patients (75.7% male) who attended the emergency department (ED) in 2014−2020 for injuries sustained while riding an E-bike or P-scooter. Mean age was 31.52 ± 14.77 years: 23% were aged <20 years; 33%, 21−30 years; 23%, 31−40 years; 10%, 41−50 years; 11%, >51 years. Ninety patients (7.3%) were hospitalized. Older age was significantly associated with the need for hospitalization on univariate analysis (p <.001), but significance was not maintained on binary logistic regression (OR = 1.02, 95%CI 0.99−1.06; p = 0.11). Patients who underwent imaging evaluation in the ED were at lower risk of hospitalization, and patients who had surgery or a relatively long operative procedure were at higher risk of hospitalization. The study shows that older age (>51 years) is not associated with a significantly increased probability of severe injury in E-bike and P-scooter riders. This finding has important implications for insurers and healthcare administrators.

A Similarity-Based Method for Predicting Enzymatic Functions in Yeast Uncovers a New AMP Hydrolase.

Despite decades of research and the availability of the full genomic sequence of the baker's yeast Saccharomyces cerevisiae, still a large fraction of its genome is not functionally annotated. This hinders our ability to fully understand cellular activity and suggests that many additional processes await discovery. The recent years have shown an explosion of high-quality genomic and structural data from multiple organisms, ranging from bacteria to mammals. New computational methods now allow us to integrate these data and extract meaningful insights into the functional identity of uncharacterized proteins in yeast. Here, we created a database of sensitive sequence similarity predictions for all yeast proteins. We use this information to identify candidate enzymes for known biochemical reactions whose enzymes are unidentified, and show how this provides a powerful basis for experimental validation. Using one pathway as a test case we pair a new function for the previously uncharacterized enzyme Yhr202w, as an extra-cellular AMP hydrolase in the NAD degradation pathway. Yhr202w, which we now term Smn1 for Scavenger MonoNucleotidase 1, is a highly conserved protein that is similar to the human protein E5NT/CD73, which is associated with multiple cancers. Hence, our new methodology provides a paradigm, that can be adopted to other organisms, for uncovering new enzymatic functions of uncharacterized proteins.

An Unusual Presentation of HCC in a Patient with No Underlying Liver Disease: A Case Study.

Pedunculated hepatocellular carcinoma (P-HCC) is a rare subtype of HCC. P-HCC may occur in patients without underlying liver cirrhosis and can be present with negative serum tumor markers. With a growing worldwide incidence of nonalcoholic fatty liver disease, non-cirrhotic HCC will likely become more prevalent. We report a patient presenting to the hospital with nonspecific symptoms of weight loss, abdominal discomfort, and early satiety. Abdomen palpation found a large firm mass in the right middle abdomen. Computed tomography imaging showed a large right abdominal mass without evidence of liver attachment. The patient underwent a diagnostic laparotomy where a single 17 cm exophytic mass originating from the left liver lobe was found and resected. Clear margins were attained, and pathology demonstrated HCC. Early diagnosis of HCC is critical to achieving curative treatment, and physicians should keep P-HCC in mind when presented with a similar patient.

Psoas Attenuation and Mortality of Elderly Patients Undergoing Nontraumatic Emergency Laparotomy.

BACKGROUND: Emergency laparotomy (EL) is an increasingly common procedure in the elderly. Factors associated with mortality in the subpopulation of frail patients have not been thoroughly investigated. Sarcopenia has been investigated as a surrogate for frailty and poor prognosis. Our primary aim was to evaluate the association between easily measured sarcopenia parameters and 30-day postoperative mortality in elderly patients undergoing EL. Length of stay (LOS) and admission to an intensive care unit were secondary end points. METHODS: We conducted a retrospective cohort study, over a 5-year period, of patients aged 65 y and older who underwent EL at a tertiary university hospital. Sarcopenia was evaluated on admission computed tomography scan by two methods, first by psoas muscle attenuation and second by the product of perpendicular cross-sectional diameters (PCSDs). The lowest quartile of PCSDs and attenuation were defined as sarcopenic and compared with the rest of the cohort. Attenuation was stratified for the use of contrast enhancement. Multivariant logistic regression was performed to determine independent risk factors. RESULTS: During the study period, 403 patients, older than 65 y, underwent EL. Of these, 283 fit the inclusion criteria and 65 (23%) patients died within 30 d of surgery. On bivariate analysis, psoas muscle attenuation, but not PCSDs, was found to be associated with 30-day mortality (OR = 2.43, 95% CI = 1.34-4.38, P = 0.003) and longer LOS (35.7 d versus 22.2 d, Δd 13.5, 95% CI = 6.4-20.7, P < 0.001). In a multivariate analysis, psoas muscle attenuation, but not PCSDs, was an independent risk factor for 30-day postoperative mortality (OR = 2.35, 95% CI = 1.16-4.76, P = 0.017) and longer LOS (Δd = 14.4, 95% CI = 7.7-21.0, P < 0.001). Neither of the sarcopenia parameters was associated with increased admission to an intensive care unit. DISCUSSION: Psoas muscle attenuation is an independent risk factor for 30-day postoperative mortality and LOS after EL in the elderly population. This measurement can inform clinicians about the operative risk and hospital resource utilization.

Spatiotemporal Proteomic Analysis of Stress Granule Disassembly Using APEX Reveals Regulation by SUMOylation and Links to ALS Pathogenesis.

Stress granules (SGs) are cytoplasmic assemblies of proteins and non-translating mRNAs. Whereas much has been learned about SG formation, a major gap remains in understanding the compositional changes SGs undergo during normal disassembly and under disease conditions. Here, we address this gap by proteomic dissection of the SG temporal disassembly sequence using multi-bait APEX proximity proteomics. We discover 109 novel SG proteins and characterize distinct SG substructures. We reveal dozens of disassembly-engaged proteins (DEPs), some of which play functional roles in SG disassembly, including small ubiquitin-like modifier (SUMO) conjugating enzymes. We further demonstrate that SUMOylation regulates SG disassembly and SG formation. Parallel proteomics with amyotrophic lateral sclerosis (ALS)-associated C9ORF72 dipeptides uncovered attenuated DEP recruitment during SG disassembly and impaired SUMOylation. Accordingly, SUMO activity ameliorated C9ORF72-ALS-related neurodegeneration in Drosophila. By dissecting the SG spatiotemporal proteomic landscape, we provide an in-depth resource for future work on SG function and reveal basic and disease-relevant mechanisms of SG disassembly.

Foramen of Winslow hernia years after a Ladd's procedure: A case report.

Foramen of Winslow hernias form 8% of all internal hernias. They present with non-specific findings and are often diagnosed late in disease progression. Delayed diagnosis of the hernia is associated with an estimated mortality of 50%. This rare event has yet to be described in the literature as a follow-up complication to a Ladd's procedure. Here, we present a young male patient with a surgical history of a Ladd's procedure with a chief complaint of an acute-onset, severe abdominal pain accompanied by episodes of emesis. Prompt clinical analysis, imaging and fluid resuscitation was conducted. A computed tomography (CT) scan showed a mesenteroaxial gastric volvulus and air was identified within the Falciform Ligament. Consequently, the patient underwent an exploratory laparotomy and the foramen of Winslow hernia was identified. An excision and anastomosis procedure was performed, and the cecum was fixed in the lower left quadrant. The procedure had no complications and the patient was discharged from the hospital on the fifth post-operative day. The purpose of this case report is to present an unusual patient who experienced a foramen of Winslow hernia involving the small bowel six years following a Ladd's procedure. While a causative relation cannot be made between these two events, we theorize that gastrointestinal hypermobility, being one of the three properties leading to herniation, played a role in both pathologies. Therefore, a vigilant surgeon should keep in mind that intra-abdominal congenital malrotation can put patients at greater risk for future herniation.

Prediction of readmissions in the first post-operative year following hip fracture surgery.

PURPOSE: To define risk factors for rehospitalization following fragility hip fractures and to create a predictive model. METHODS: A retrospective cohort study of patients 65 years and older, who were treated operatively following fragility hip fractures between 01.2011 and 06.2016. Patients were allocated into two study groups based on the occurrence of recurrent hospitalizations in the year following surgery. Demographic information, comorbidities, and in-hospital characteristics were collected, as was information regarding 1-year readmissions. Multivariate analysis of factors predictive of rehospitalizations was performed, followed by a logistic regression using all predictors with p < 0.05. A stepwise backwards elimination method was used to create the predictive model. RESULTS: Eight hundred and fifty-one patients were included; 369 (43.4%) had recurrent hospitalizations within the first post-operative year. Patients who were rehospitalized were more likely to be males, to use a walking aid and to live dependently. They had a higher age-adjusted Charlson's comorbidity index (ACCI) score, a higher perveance of atrial fibrillation, lower hemoglobin, worse renal function, less platelets, and longer time to surgery. Prevalence of in-hospital complications was similar. Six variables were found to independently influence the chance for readmissions: male gender, the use of a walking aid, higher ACCI score, lower hemoglobin, atrial fibrillation, and a longer surgical delay. Only the first four were found to be adequate predictors and were added to the prediction formula. CONCLUSION: High 1-year readmission rates are seen following discharge in patients with fragility hip fractures. Addressing risk factors might aid to better rehabilitate patients and reduce morbidity.

The Role of 18F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography in the Diagnosis of Postoperative Hardware-Related Spinal Infections.

BACKGROUND: Implant-related spinal infections are a surgical complication associated with high morbidity. Due to infection, hardware removal may be necessary, which could lead to pseudarthrosis and the loss of stability and alignment. OBJECTIVES: To evaluate the accuracy and diagnostic value of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT) in the workup of patients with suspected implant-related infections of the spine and to assess the clinical impact of PET/CT results on the management of these infections. METHODS: The study included nine consecutive patients with a history of spinal surgery who underwent PET/CT for evaluation of suspected spinal implant related infection. All imaging studies were performed between January 2011 and December 2013. All 18F-FDG PET/CT scans were performed on an 8 slice PET/CT following an 18F-FDG injection. Images were scored both visually and semi-quantitatively by a radiology expert. Results were compared to additional imaging studies when available, which were correlated to clinical and bacteriological findings allowing calculation of sensitivity, specificity and accuracy. RESULTS: Among the patients, five experienced hardware-related spinal infection. 18F-FDG PET/CT sensitivity was 80%, specificity 100%, and accuracy 88.9%. One scan produced a false negative; however, a second PET/CT scan revealed an infection. CONCLUSIONS: PET/CT was found to be valuable for the diagnosis of postoperative hardware-related spinal infection, especially when other imaging modalities were uninformative or inconclusive. As such, PET/CT could be useful for management of infection treatment.

Iron affects Ire1 clustering propensity and the amplitude of endoplasmic reticulum stress signaling.

The unfolded protein response (UPR) allows cells to adjust secretory pathway capacity according to need. Ire1, the endoplasmic reticulum (ER) stress sensor and central activator of the UPR is conserved from the budding yeast Saccharomyces cerevisiae to humans. Under ER stress conditions, Ire1 clusters into foci that enable optimal UPR activation. To discover factors that affect Ire1 clustering, we performed a high-content screen using a whole-genome yeast mutant library expressing Ire1-mCherry. We imaged the strains following UPR induction and found 154 strains that displayed alterations in Ire1 clustering. The hits were enriched for iron and heme effectors and binding proteins. By performing pharmacological depletion and repletion, we confirmed that iron (Fe3+) affects UPR activation in both yeast and human cells. We suggest that Ire1 clustering propensity depends on membrane composition, which is governed by heme-dependent biosynthesis of sterols. Our findings highlight the diverse cellular functions that feed into the UPR and emphasize the cross-talk between organelles required to concertedly maintain homeostasis.

Intramedullary nailing without curettage and cement augmentation for the treatment of impending and complete pathological fractures of the proximal or midshaft femur.

Metastases in the proximal femur and in the femoral diaphysis are usually treated with either cephalomedullary or intramedullary nailing. The benefit of curettage and augmentation of the nail with methyl methacrylate remains controversial. The authors retrospectively studied the outcomes with cephalomedullary and intramedullary nailing without curettage and methyl-methacrylate augmentation for lytic metastases of the proximal/diaphyseal femur. Twenty-one complete (11) or impending (10) pathological fractures in 19 consecutive patients were treated between January 2006 and August 2013. There were 11 women and 8 men. Their mean age was 62 years (range, 38 to 87). All patients received adjuvant chemotherapy or radiotherapy.The average postsurgical survival was 9.7 months (range 1-36 months). A single deep infection was debrided. Seventeen out of 19 patients were ambulatory, with or without a walking aid. No implant failure was noted. In other words, patients succumbed to the disease prior to hardware failure. Femoral nail insertion without curettage and cement augmentation provided satisfactory stabilization of proximal and diaphyseal femur fractures, impending or complete, even when there was massive bone destruction.

The generation and regulation of functional diversity of malignant plasma cells.

Cellular diversity, which is a hallmark of malignancy, can be generated by both genetic and nongenetic mechanisms. We describe here variability in the adhesive and migratory behavior of malignant plasma cell populations, including multiple myeloma-derived lines and primary patient samples. Examination of the plasma cell lines ARH-77, CAG, and AKR revealed two distinct subpopulations of cells, one displaying highly adhesive properties (type A) and the other consisting of poorly adhesive, floating cells (type F). In the ARH-77 cell line, type A cells attach better to fibronectin and to human bone fragments and form paxillin-rich focal adhesions, whereas type F cells are highly motile and exert integrin-dependent bone marrow homing capacity in nonobese diabetic/severe combined immunodeficient mice. Flow cytometry indicated that type A cells express significantly higher levels of CD45 and CD56 and lower levels of CD138 compared with type F cells. Interestingly, culturing of either type A or type F cells under nonselective conditions resulted in the development of mixed cell population similar to the parental ARH-77 cells. Analysis of bone marrow aspirates of multiple myeloma patients revealed that spicules within the aspirates are enriched with type A-like cells. Nonadherent cells within the aspirate fluids express a marker profile similar to type F cells. This study indicates that multiple myeloma patients contain heterogeneous populations of malignant plasma cells that display distinct properties. Diverse subpopulations of malignant plasma cells may play distinct roles in the different biological and clinical manifestations of plasma cell dyscrasias, including bone dissemination and selective adhesion to bone marrow compartments.

Free fibula flap elbow-joint hemiarthroplasty reconstruction for chronic osteomyelitis of the distal humerus.

The vascularized fibula flap has become a major tool in upper limb reconstruction. Free fibula flap reconstructions of the humeral part of the shoulder and the radial part of the wrist joints are well-documented, but reports of elbow joint reconstruction are rare. The authors report a 53-year-old patient with chronic osteomyelitis of the distal humerus that was unsuccessfully treated by many local surgical debridements and long-term systemic antibiotics. The patient underwent a wide debridement of the distal two-thirds of the humerus, and a spacer was inserted to fill the bony humeral gap. At a second stage, the distal humerus was reconstructed with a free fibula flap that included the proximal fibular head. The fibular shaft was used to bridge the bony gap and the fibular head created an elbow joint with the olecranon process. At an 18-month follow-up after surgery, the patient has stable and sufficient function of his elbow joint with no signs of infection. The free fibula flap has an important role for distal humerus reconstruction, both for bridging the bony gap with a vascularized bone, and for restoring elbow joint function.

Vacuum-assisted wound closure after resection of musculoskeletal tumors.

UNLABELLED: Resection of musculoskeletal tumors may result in large soft tissue defects that cannot be closed primarily and require prolonged dressing changes and complex surgical interventions for wound coverage. We retrospectively reviewed 23 patients with such defects treated with a vacuum-assisted wound closure system and compared the outcome of these patients with a control group. The study group included 15 women and eight men who had their wounds located at the back (two), pelvic girdle (11), thigh (eight), and leg (two). Treatment included sealed wound coverage with polyurethane foam and overlying tape connected to a vacuum pump. This system was disconnected and changed every 48 hours for 7 to 19 days, after which all defects were reduced in size by an average of 25% and covered with a viable granulation tissue. This allowed primary closure in seven patients, primary closure with skin grafting in 14 patients, and healing by secondary intention in two patients. Compared with the control group, patients in the study group had shorter hospital stays and number of surgical interventions and greater rates of primary wound closure. The use of vacuum-assisted wound closure facilitates wound healing and primary wound closure in patients who have a large soft tissue defect after resection of a musculoskeletal tumor. LEVEL OF EVIDENCE: Therapeutic study, Level III (retrospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Resolving and classifying haematopoietic bone-marrow cell populations by multi-dimensional analysis of flow-cytometry data.

The study of normal or malignant haematopoiesis requires the analysis of heterogeneous cell populations using multiple morphological and molecular criteria. Flow cytometry has the capacity to acquire multi-parameter information of large haematopoietic cell populations, utilizing various combinations of >200 molecular markers (clusters of differentiation, CD). However, current flow cytometry analyses are based on serial gating of two-parametric scatter plots--a process that is inherently incapable to discriminate all subgroups of cells in the data. Here we studied the cellular diversity of normal bone marrows (BM) using multi-dimensional cluster analysis of six-parametric flow cytometry data (four CD, forward scatter and side scatter), focusing mainly on the myeloid lineage. Twenty-three subclasses of cells were resolved, many of them inseparable even when examined in all possible two-parametric scatter plots. The multi-dimensional analysis could distinguish the haematopoietic progenitors according to International Society of Haematotherapy and Graft Engineering criteria from other types of immature cells. Based on the defined clusters, we designed a classifier that assigns BM cells in samples to subclasses based on robust six-dimensional position and extended shape. The analysis presented here can manage successfully both the increasing numbers of haematopoietic cellular markers and sample heterogeneity. This should enhance the ability to study normal haematopoiesis, and to identify and monitor haematopoietic disorders.

Targeted delivery of progenitor cells for cartilage repair.

An approach for promoting the adherence of chondrogenic progenitor cells to specific matrix molecules has been tested in a cartilage defect model. Culture-expanded pre-chondrocytes fluorescently labeled with a vital dye were coated by a two-step method wherein lipidated protein G was first allowed to intercalate into cell membranes, and a second incubation in a solution of antibodies to cartilage matrix antigens allowed the binding of the antibodies to the protein G, on the external surface of the cell. The coating technique (termed "cell painting") does not effect cell viability or inhibit growth and chondrogenic potential. Painted cells were then added to rabbit cartilage explants that had a partial-thickness defect, washed, and prepared for histological examination and for confocal microscopy. The histological observations and the confocal observations and fluorescent intensity quantification consistently demonstrated that progenitor cells painted with multiple antibodies were capable of preferential binding to the exposed cartilage matrix within the defect. These results demonstrate that painting cell membranes with antibodies to matrix molecules is an effective method for promoting the adherence of stem or progenitor cells to a cartilage injury site.