The strength of donor-specific antibody is a more reliable predictor of antibody-mediated rejection than flow cytometry crossmatch analysis in desensitized kidney recipients

The aim of this study was to evaluate the utility of donor-specific antibodies (DSA) and flow cytometry crossmatch (FCCM) as tools for predicting antibody-mediated rejection (AMR) in desensitized kidney recipients. Sera from 44 patients with DSA at the time of transplant were reviewed. Strength of DSA was determined by single antigen Luminex bead assay and expressed as mean fluorescence intensity (MFI). T- and B-cell FCCM results were expressed as mean channel shift (MCS). AMR was diagnosed by C4d deposition on biopsy. Incidence of early AMR was 31%. Significant differences in the number of DSAs (p = 0.0002), cumulative median MFI in DSA class I (p = 0.0004), and total (class I + class II) DSA (p < 0.0001) were found in patients with and without AMR. No significant difference was seen in MCS of T and B FCCM (p = 0.095 and p = 0.307, respectively). The three-yr graft survival in desensitized patients with DSA having total MFI < 9500 was 100% compared to 76% with those having total MFI > 9500 (p = 0.022). Desensitized kidney transplant recipients having higher levels of class I and total DSA MFI are at high risk for AMR and poor graft survival. Recipient DSA MFI appears to be a more reliable predictor of AMR than MCS of FCCM.     

Donor islet endothelial cells in pancreatic islet revascularization

OBJECTIVE

Freshly isolated pancreatic islets contain, in contrast to cultured islets, intraislet endothelial cells (ECs), which can contribute to the formation of functional blood vessels after transplantation. We have characterized how donor islet endothelial cells (DIECs) may contribute to the revascularization rate, vascular density, and endocrine graft function after transplantation of freshly isolated and cultured islets.

RESEARCH DESIGN AND METHODS

Freshly isolated and cultured islets were transplanted under the kidney capsule and into the anterior chamber of the eye. Intravital laser scanning microscopy was used to monitor the revascularization process and DIECs in intact grafts. The grafts’ metabolic function was examined by reversal of diabetes, and the ultrastructural morphology by transmission electron microscopy.

RESULTS

DIECs significantly contributed to the vasculature of fresh islet grafts, assessed up to 5 months after transplantation, but were hardly detected in cultured islet grafts. Early participation of DIECs in the revascularization process correlated with a higher revascularization rate of freshly isolated islets compared with cultured islets. However, after complete revascularization, the vascular density was similar in the two groups, and host ECs gained morphological features resembling the endogenous islet vasculature. Surprisingly, grafts originating from cultured islets reversed diabetes more rapidly than those originating from fresh islets.

CONCLUSIONS

In summary, DIECs contributed to the revascularization of fresh, but not cultured, islets by participating in early processes of vessel formation and persisting in the vasculature over long periods of time. However, the DIECs did not increase the vascular density or improve the endocrine function of the grafts.Clinical islet transplantation can restore endogenous insulin production and glycemic control in patients with type 1 diabetes, yet increased knowledge, and hence refinement, would allow for a wider application of this therapy (1). Pancreatic islets are interspersed by a dense and tortuous capillary network that facilitates an efficient exchange of oxygen, nutrients, and hormones between the endocrine cells and the bloodstream. Transplanted islets are revascularized by blood vessels that grow into the islets from the host organ via angiogenesis (2), although the acquired vasculature has a significantly lower vessel density compared with the endogenous islets (3). Furthermore, during the initial avascular engraftment period, a dramatic reduction in insulin content and high rate of cell death occur within the islets (4). Therapies that enhance the angiogenic capacity of islets by overexpression of vascular endothelial growth factor-A (VEGF-A) can increase the vascular density of islet grafts and improve metabolic function (5,6).Recently, we and others showed that donor islet endothelial cells (DIECs) can form functional vessels within transplanted islets (7,8). Immediately after isolation (i.e., in freshly isolated islets), a large number of intraislet endothelial cells (ECs) are present (7–9). However, if the islets are cultured, the intraislet ECs rapidly disappear, and by 4 days, only ∼5% of the initial content is detected (7). Therefore, freshly isolated islets, in contrast to cultured islets, contain an extra pool of ECs that potentially could promote islet revascularization and function after transplantation. Here, we have performed a detailed characterization of the role of DIECs in the revascularization of transplanted islets.     

Intraoperative ultrasound assistance for excision of impalpable musculoskeletal soft tissue tumors

Intraoperative ultrasonography is a useful tool for the detection and extirpation of liver metastases, breast masses, and melanoma. However, the efficacy of this technology in intraoperative localization and resection of small soft tissue tumors has not been addressed. The purpose of this study is to report on the efficacy of intraoperative ultrasound assistance in excising impalpable musculoskeletal soft tissue tumors. Twenty-two soft tissue tumors <3 cm (range, 0.7-3 cm) were resected with intraoperative ultrasound assistance. All tumors were localized in the deep panniculus, fascia, or muscle. Surgical time and length of incisions was recorded in all the cases. Intra- and postoperative reregistration was made to confirm the tumor resection. Ultrasound assistance was successful in obtaining an accurate localization in all treated cases. Mean surgical time was 30 minutes (range, 13-87 minutes). Average incision length was 5.7 cm (range, 2.5-10.6 cm). Reregistration allowed intraoperative confirmation of the adequacy of the excision. The procedure allowed recognized and excised additional nodules not previously diagnosed in 3 cases. Postoperative echography done in all patients confirmed complete extirpation of the tumors, and histopathology confirmed adequate margins obtained. Intraoperative ultrasound can be used as an efficient tool to localize and treat impalpable small soft tissue tumors.     

Long-term culture of Japanese human embryonic stem cells in feeder-free conditions

Human pluripotent embryonic stem cells (hESCs) have great promise for research into human developmental biology, development of cell therapies for the treatment of diseases, toxicology, and drug discovery. Traditionally, undifferentiated hESCs are maintained on mouse embryonic fibroblasts (MEFs), which impede the clinical applications of hESCs. Here we have examined the long-term stability of the Japanese hESC line (KhES-1) in feeder-free culture. KhES-1 cells were cultured with MEF conditioned medium (CM) and different doses of basic fibroblast growth factor (bFGF) in six-well-plates of which the surface was coated with Matrigel. KhES-1 cells were maintained for at least 40 passages. In this culture system, the cells maintained stable proliferation rates and steadily expressed Oct-4, Nanog, and alkaline phosphatase. In addition, KhES-1 cells maintained without direct feeder contact formed embryonic bodies with expression of markers from the three germ layers. Here we demonstrated that Japanese human embryonic stem cells KhES-1 were cultured long term in a feeder-free method, while retaining pluripotency in vitro.     

The impact of work hour restrictions on surgical resident education

OBJECTIVE: Resident work-hour restrictions were instituted in July 2003 based on ACGME mandates. The American Board of Surgery In-Training Examination (ABSITE), American Board of Surgery Qualifying Examination (ABSQE), and operative volume traditionally have been measures of surgical resident education and competency. The objective of this study was to determine the effect of reduced work hours on resident standardized test scores and operative volume at our institution. DESIGN: We reviewed ABSITE scores, ABSQE scores, and operative logs from 1997 to 2005 of all general surgery residents. Linear mixed-effects models were fitted for each component ABSITE score (total, basic science, and clinical management), and they were compared using a chi-squared likelihood ratio. Operative logs of graduating residents were compared before and after the work restrictions and were evaluated for association with ABSITE score. p-values less than 0.05 were considered significant. RESULTS: The program was compliant with ACGME mandates within 6 months of institution. ABSITE scores improved significantly after the restriction of work hours in both basic science (p = 0.003) and total score (p = 0.008). Clinical management scores were not affected. The number of major cases recorded by graduating residents did not change. A positive correlation was found between number of cases performed during residency and clinical management ABSITE scores (p = 0.045). ABSQE scores were not impacted by operative volume during residency. CONCLUSIONS: ABSITE scores improved significantly after the restriction of resident work hours. Resident operative experience was not affected. An unexpected consequence of work-hour restrictions may be an improvement in surgical resident education.     

Physical fitness effect on bone mass is mediated by the independent association between lean mass and bone mass through adolescence: a cross-sectional study

We studied 278 adolescents (169 females) aged 13.0–18.5 years to elucidate whether an independent effect of physical fitness and lean mass in the differences between male and female bones can be detected. Lean and fat masses and bone mineral content (BMC) were measured with DXA. Physical fitness was evaluated with six different tests included in the EUROFIT test battery (flexibility, isometric, dynamic and endurance strength, speed, and cardiovascular fitness). To test the independent relationship between physical fitness and bone mass, multiple regression analysis was applied, including lean mass, age, and Tanner development as covariates. The males had a 43% lower fat mass and 40% and 16% higher lean mass and total BMC compared with the females (all P < 0.05). After adjustment for differences in body size and lean mass, the females exhibited a 7.4% higher BMC than the males (P < 0.05). The multiple regression analysis showed that lean mass had an independent relationship with bone mass (P < 0.001), explaining 67% of the total variance in whole-body BMC. In males, change in R ² was 0.658 for hand grip and 0.035–0.151 for the rest of physical fitness-related variables; but 0.019–0.042 in females (all P–0.001); however, the independent relationships between physical fitness and bone disappeared after controlling for lean mass. In conclusion, it is likely the differences between male and female in bone mass could be explained by differences in lean mass and physical fitness.     

Arthroscopy of the trapeziometacarpal and metacarpophalangeal joints

Indications for small joint arthroscopy in the hand remain poorly understood. This is due to a paucity of articles discussing these techniques in the literature, as well as inadequate hands-on training in the pearls and pitfalls regarding this application within the routine "scope" of hand surgery. Despite the fact that small joint arthroscopes have been available for more than a decade, hand surgeons have been slow to adopt this technique for the treatment of both traumatic and degenerative conditions involving the thumb and the digital metacarpophalangeal joints. An arthroscopic classification for basal joint osteoarthritis provides additional clinical information and can direct further treatment depending on the stage of disease. This article will also review the brief history of trapeziometacarpal arthroscopy and provide insight as to how this technique can be incorporated into a treatment algorithm in managing this common affliction. Metacarpophalangeal joint arthroscopy is even less commonly utilized, while traumatic and overuse injuries are frequently seen in the thumb and constitute ideal indications in certain scenarios. Painful conditions affecting the metacarpophalangeal joints of the fingers are less commonly seen, yet the small joint arthroscope presents a much clearer picture of the pathology compared with other imaging techniques or even open, potentially deleterious surgery. The application of this technology to the smaller joints will soon make the treating surgeon realize that a myriad of pathologies are readily visible and can augment treatment, as well as diagnosis. Similar to the wrist, small joint arthroscopy may one day supplant imaging techniques such as magnetic resonance imaging or computed tomography for establishing an accurate diagnosis.     

Gastrointestinal stromal tumours: a broad spectrum of clinical presentations

Gastrointestinal stromal tumours, though rare, are the most common mesenchymal neoplasms affecting the gastrointestinal tract. The most frequent sites of origin are the stomach and the small bowel, but they can occur anywhere in the gastrointestinal tract. Mesenteric and retroperitoneal forms have been described. The Authors present their personal experience with the treatment of gastrointestinal stromal tumours, with particular reference to the broad spectrum of clinical presentations and to the consequent therapeutic implications. We report on a retrospective analysis of the clinical presentations and courses, surgical management and pathological features of 27 patients with such tumours treated in our institution from 1993 to 2005. The variables analysed were the morphological and clinical characteristics of the tumours, demographic data, type of surgical treatment and postoperative course. Long-term survival was evaluated on the basis of clinical and/or telephonic follow-up in all patients. One tumour was located in the oesophagus, 14 in the gastric area, 7 in the small bowel, 2 in the colon-rectum, and 3 in the peritoneum. All patients studied received radical surgical treatment. In 7 patients surgical resection was extended to other organs. No postoperative mortality or major postoperative complications were observed. Twenty-two patients are still alive at follow-up. Three patients died as a result of neoplastic relapse and 2 of other causes. The median survival was 36 months. The actuarial 3- and 5-year survival rates were 89.7% and 67.8%, respectively. Our experience indicates that the site of origin of gastrointestinal stromal tumours with their broad spectrum of clinical presentations may influence both the therapeutic choice (neoadjuvant utilisation of imatinib mesylate) and the surgical treatment (wedge resection vs enlarged operations).     

Endoluminal treatment for traumatic aortic rupture. Case report and literature review

Traumatic rupture of the thoracic aorta is a near-lethal event presenting on-scene mortality rates of 80% and 60-80% perioperatively with an overall survival rate of 15%. Conventional treatment includes thoracotomy with aortic clamping and aortic replacement but this implies high complication and mortality rates with extended inpatient care. Endoluminal treatment has recently become an attractive treatment option with advantages such as lower death and complication rates as well as shorter inpatient care. We present an 18-year-old female victim of a frontal automobile crash who presented mediastinal enlargement and underwent CT evaluation confirming pericardial effusion, left hemothorax and a contained traumatic rupture of the thoracic aorta. She was sent to our hospital where aortography was performed identifying the injury, and a preperitoneal left iliac artery approach was made to insert a Medtronic Talent 24F endograft. Under fluoroscopic guidance the graft was placed below the subclavian ostium. There was no endoleak after the procedure. A left iliac-femoral bypass was performed and a chest tube was inserted. The patient was managed in the ICU, being later operated by reconstructive and orthopedic surgeons for injuries related to the initial trauma. The patient was released from the hospital on the 10th postoperative day after a satisfactory evolution. We present also a brief review of recent articles.     

Expression of Eya1 and Six1 is decreased in distal airways of rats with experimental pulmonary hypoplasia

Background/Purpose

Pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH) represents one of the major challenges in neonatal intensive care. Eyes absent 1 (Eya1) and sine oculis homebox 1 (Six1) have been identified as essential components of the gene network that regulates foetal lung development. Eya1 and Six1 are expressed in distal epithelial tips of branching airways as well as in surrounding mesenchymal cells, highlighting their important role during branching morphogenesis. Lungs of Eya1^−/− and Six1^−/− knockouts display PH with reduced epithelial branching, appearing to be arrested in the pseudoglandular stage. We hypothesized that Eya1 and Six1 expression is decreased in branching airways of nitrofen-induced PH.

Methods

Time-mated rats received either nitrofen or vehicle on E9.5. Foetal lungs were dissected on E15.5 and divided into control and nitrofen groups, whereas lungs harvested on E18.5 were divided into controls, PH without CDH [PH(−)], and PH with CDH [PH(+)]. Pulmonary gene expression levels of Eya1 and Six1 were analyzed by quantitative real-time PCR. Immunofluorescence staining was performed to investigate Eya1 and Six1 protein expression and localization by confocal laser scanning microscopy (CLSM).

Results

Relative mRNA expression of Eya1 and Six1 was significantly decreased in PH(−) and PH(+) on E18.5 compared to controls. CLSM confirmed markedly diminished immunofluorescence of Eya1 and Six1 in distal airway epithelium as well as in surrounding mesenchymal cells of nitrofen-induced PH on E18.5 compared to controls.

Conclusions

Downregulation of Eya1 and Six1 gene expression in nitrofen-induced PH suggests that decreased Eya1 and Six1 expression during the late pseudoglandular stage may interfere with epithelial branching and distal airway maturation, thus resulting in PH.