Identification of Predictors for Progression of Scoliosis in Rett Syndrome.

Rett syndrome is a neurodevelopmental disorder in which scoliosis is a common orthopedic complication. This explorative study aims to identify predictors for rapid progression of scoliosis in Rett syndrome to enable variable selection for future prediction model development. A univariable logistic regression model was used to identify variables that discriminate between individuals with and without rapid progression of scoliosis (>10 ∘Cobb angle/6 months) based on multi-center data. Predictors were identified using univariable logistic regression with OR (95% CI) and AUC (95% CI). Age at inclusion, Cobb angle at baseline and epilepsy have the highest discriminative ability for rapid progression of scoliosis in Rett syndrome.

The significance of pretransplant donor-specific antibodies reactive with intact or denatured human leucocyte antigen in kidney transplantation.

Antibodies recognizing denatured human leucocyte antigen (HLA) can co-react with epitopes on intact HLA or recognize cryptic epitopes which are normally unaccessible to HLA antibodies. Their specificity cannot be distinguished by single antigen beads (SAB) alone, as they carry a mixture of intact and denatured HLA. In this study, we selected pretransplant sera containing donor-specific HLA class I antibodies (DSA) according to regular SAB analysis from 156 kidney transplant recipients. These sera were analysed using a SAB preparation (iBeads) which is largely devoid of denatured HLA class I, and SAB coated with denatured HLA class I antigens. A total of 241 class I DSA were found by regular SAB analysis, of which 152 (63%) were also found by iBeads, whereas 28 (11%) were caused by reactivity with denatured DNA. Patients with DSA defined either by regular SAB or iBeads showed a significantly lower graft survival rate (P = 0·007) compared to those without HLA class I DSA, whereas reactivity to exclusively denatured HLA was not associated with decreased graft survival. In addition, DSA defined by reactivity to class I SAB or class I iBeads occurred more frequently in female patients and in patients with historic HLA sensitization, whereas reactivity to denatured HLA class I was not associated with any of these parameters. Our data suggest that pretransplant donor-specific antibodies against denatured HLA are clinically irrelevant in patients already sensitized against intact HLA.

Pretransplant donor-specific HLA class-I and -II antibodies are associated with an increased risk for kidney graft failure.

Pretransplant risk assessment of graft failure is important for donor selection and choice of immunosuppressive treatment. We examined the relation between kidney graft failure and presence of IgG donor specific HLA antibodies (DSA) or C1q-fixing DSA, detected by single antigen bead array (SAB) in pretransplant sera from 837 transplantations. IgG-DSA were found in 290 (35%) sera, whereas only 30 (4%) sera had C1q-fixing DSA. Patients with both class-I plus -II DSA had a 10 yr graft survival of 30% versus 72% in patients without HLA antibodies (p < 0.001). No significant difference was observed in graft survival between patients with or without C1q-fixing DSA. Direct comparison of both assays showed that high mean fluorescence intensity values on the pan-IgG SAB assay are generally related to C1q-fixation. We conclude that the presence of class-I plus -II IgG DSA as detected by SAB in pretransplant sera of crossmatch negative kidney recipients is indicative for an increased risk for graft failure, whereas the clinical significance of C1q-fixing IgG-DSA could not be assessed due to their low prevalence.

Evidence for an additional effect of whole-body vibration above resistive exercise alone in preventing bone loss during prolonged bed rest.

SUMMARY: The addition of whole-body vibration to high-load resistive exercise may provide a better stimulus for the reduction of bone loss during prolonged bed rest (spaceflight simulation) than high-load resistive exercise alone. INTRODUCTION: Prior work suggests that the addition of whole-body vibration to high-load resistive exercise (RVE) may be more effective in preventing bone loss in spaceflight and its simulation (bed rest) than resistive exercise alone (RE), though this hypothesis has not been tested in humans. METHODS: Twenty-four male subjects as part of the 2nd Berlin Bed Rest Study performed RVE (n = 7), RE (n = 8) or no exercise (control, n = 9) during 60-day head-down tilt bed rest. Whole-body, spine and total hip dual X-ray absorptiometry (DXA) measurements as well as peripheral quantitative computed tomography measurements of the tibia were conducted during bed rest and up to 90 days afterwards. RESULTS: A better retention of bone mass in RVE than RE was seen at the tibial diaphysis and proximal femur (p ≤ 0.024). Compared to control, RVE retained bone mass at the distal tibia and DXA leg sub-region (p ≤ 0.020), but with no significant difference to RE (p ≥ 0.10). RE impacted significantly (p = 0.038) on DXA leg sub-region bone mass only. Calf muscle size was impacted similarly by both RVE and RE. On lumbar spine DXA, whole-body DXA and calcium excretion measures, few differences between the groups were observed. CONCLUSIONS: Whilst further countermeasure optimisation is required, the results provide evidence that (1) combining whole-body vibration and high-load resistance exercise may be more efficient than high-load resistive exercise alone in preventing bone loss at some skeletal sites during and after prolonged bed rest and (2) the effects of exercise during bed rest impact upon bone recovery up to 3 months afterwards.

Additive impact of alfacalcidol on bone mineral density and bone strength in alendronate treated postmenopausal women with reduced bone mass.

OBJECTIVES: Assessment of additive impact of alfacalcidol 1 µg daily (Alfa) on bone mineral density (BMD) and on bone strength in postmenopausal women treated with alendronate 70 mg weekly + 500 mg calcium daily. SUBJECTS AND METHODS: In a randomized, double-blind, placebo controlled study, 279 postmenopausal women with osteoporosis or osteopenia participated (intention to treat analysis [ITT]; aged 73.6∓4.7 years) and were treated with 70 mg alendronate (ALN) weekly and 500 mg calcium daily for 36 months. In addition, these patients received either 1 µg alfacalcidol (Alfa) or placebo (PLC) daily. BMD was measured with Dual-Energy-X-ray-Absorptiometry (DXA) at the lumbar spine and proximal femur and at forearm and tibia with peripheral quantitative computed tomography (pQCT) at regular intervals for 36 months. RESULTS: DXA-BMD of lumbar spine (L1-4) increased after 36 months, by 6.65% (p<0.0001) in the Alfa/ALN group versus 4.17% (p<0.0001) in the PLC/ALN group. Group difference was significant after 3 years (p=0.026). At the end of the study, significant differences were found in favor of the Alfa/ALN group in trabecular density (tibia) (p=0.002), cortical density (midshaft tibia) (p=0.043), and bone strength (p=0.001). The remaining parameters showed no differences between the treatment arms, apart cortical bone density at midshaft radius. CONCLUSIONS: Alfacalcidol significantly increases the efficacy of alendronate treatment in osteopenic/osteoporotic postmenopausal women on spinal DXA-BMD, cortical and trabecular BMD of the tibia and also bending stiffness of the tibia.

The 2nd Berlin BedRest Study: protocol and implementation.

Long-term bed-rest is used to simulate the effect of spaceflight on the human body and test different kinds of countermeasures. The 2nd Berlin BedRest Study (BBR2-2) tested the efficacy of whole-body vibration in addition to high-load resisitance exercise in preventing bone loss during bed-rest. Here we present the protocol of the study and discuss its implementation. Twenty-four male subjects underwent 60-days of six-degree head down tilt bed-rest and were randomised to an inactive control group (CTR), a high-load resistive exercise group (RE) or a high-load resistive exercise with whole-body vibration group (RVE). Subsequent to events in the course of the study (e.g. subject withdrawal), 9 subjects participated in the CTR-group, 7 in the RVE-group and 8 (7 beyond bed-rest day-30) in the RE-group. Fluid intake, urine output and axiallary temperature increased during bed-rest (p < .0001), though similarly in all groups (p > or = .17). Body weight changes differed between groups (p < .0001) with decreases in the CTR-group, marginal decreases in the RE-group and the RVE-group displaying significant decreases in body-weight beyond bed-rest day-51 only. In light of events and experiences of the current study, recommendations on various aspects of bed-rest methodology are also discussed.

Late increase in luminal diameter of aortocoronary venous bypass grafts associated with an increase in the vascular region under supply.

In a previous study, a significant inverse relation was found between the luminal size of aortocoronary venous bypass grafts and the vascular resistance of the coronary region that was perfused by the bypass graft in late stages after bypass surgery. This observation suggested that changes in the graft-dependent vascular area could influence the luminal size of the vein graft, even when they occurred several years after operation. Whereas it is well established today that aortocoronary vein grafts often decrease in luminal diameter after implantation, an increase in the bypass lumen has so far not been reported. Therefore, changes in luminal diameter of 27 vein grafts in 21 patients who underwent at least two postoperative angiographic studies (first study 8 +/- 5 months after surgery, second study 58 +/- 32 months after surgery) were compared with the size of the vascular region supplied by the bypass. The graft diameter was found to be unchanged between the two studies (3.3 +/- 0.6 versus 3.4 +/- 0.7 mm, p = NS) when the dependent vascular area was unchanged. A significant increase in graft diameter from 2.8 +/- 0.8 to 3.9 +/- 0.9 mm (p less than 0.001) was observed in nine patients in whom the area of perfusion had increased between the two studies because of the development of occlusion or obstruction of major coronary branches that were now perfused from the grafted vessel by way of collateral vessels. These data support the contention that the luminal size of aortocoronary vein grafts can adapt to the needs of the dependent myocardial vascular region even late after operation rather than being the result of a nonreversible degenerative process as commonly assumed.

Chemosensitization of myeloma plasma cells by an antisense-mediated downregulation of Bcl-2 protein.

An antisense oligodeoxynucleotide (ODN) complementary to the first six codons of the Bcl-2 mRNA, G3139 (oblimersen sodium; Genasense), has been shown to downregulate Bcl-2 and produce responses in a variety of malignancies including drug-resistant lymphoma. Incubation of ex vivo purified plasma cells from patients with multiple myeloma (MM) with carboxyfluorescein (FAM)-labeled antisense ODNs resulted in a time- and dose-dependent uptake in the cytoplasm and nucleus. No major differences in uptake of Bcl-2 antisense ODNs were observed among patients' samples. Incubation of purified myeloma plasma cells with G3139, but not solvent or reverse polarity control ODNs, resulted in a reduction (>75%) of Bcl-2 mRNA levels after 2 and 4 days, as measured by Real-Time PCR. Treatment with G3139 led to a sequence-specific reduction of Bcl-2 protein levels within 4 days of exposure in 10 out of 11 clinical samples from patients with chemosensitive and multidrug-resistant disease, without significant reduction of alpha-Actin, Bax, Bcl-XL, or Mcl-1 proteins. This resulted in a significantly enhanced sensitivity of the myeloma tumor cells to dexamethasone or doxorubicin-induced apoptosis. G3139 can consistently enter myeloma cells, downregulate the expression of Bcl-2, and enhance the efficacy of myeloma therapy. These data support further clinical evaluation of G3139 therapy in multiple myeloma.

Extra-domain-A fibronectin: a new marker of fibrosis in cutaneous graft-versus-host disease.

One of the major complications that limit the success of allogeneic stem cell transplantation is graft-versus-host disease (GVHD). The major target organ in GVHD is the skin. Cutaneous GVHD can eventually lead to fibrosis of the skin. Fibronectin mediates a variety of cellular interactions with the extracellular matrix. The molecular and functional diversity of fibronectin (FN) arises from alternative splicing of pre-mRNA. In normal circumstances endothelial cells and fibroblasts synthesize FN without the ED-A domain. In tissue repair and pathologic circumstances such as fibrosis, the ED-A domain is expressed. We hypothesize that expression of ED-A FN is upregulated in patients with cutaneous GVHD. In frozen skin biopsies the expression of ED-A FN was measured at the protein level by immunohistochemistry and at the mRNA level by quantitative real-time PCR (qPCR). In normal control skin, immunohistochemistry showed slight deposits of ED-A FN just under the basal layer. The expression of ED-A FN significantly increased in acute cutaneous GVHD (p<0.05) and ED-A FN was strongly deposited in chronic cutaneous GVHD (p<0.001). Quantitative PCR also showed increased expression of ED-A FN mRNA in acute and chronic cutaneous GVHD compared with normal control skin (p=0.07 and 0.039, respectively). The expression of ED-A FN is increased in the skin of patients with cutaneous GVHD measured both with immunohistochemistry and qPCR. ED-A FN is a new marker of fibrosis in the skin of patients with cutaneous GVHD.

A thresholding method for automatic cell image segmentation.

An algorithm for automatic segmentation of PAP-stained cell images and its digital implementation is described. First, the image is filtered in order to eliminate the granularily and small objects in the image which may upset the segmentation procedure. In a second step, information on gradient and compactness is extracted from the filtered image and stored in three histograms as functions of the extinction. From these histograms, two extinction thresholds are computed. These thresholds are suitable to separate the nucleus from the cytoplasm, and the cytoplasm from the background in the filtered image. Masks are determined in this way, and finally used to analyse the nucleus and the cytoplasm in the original image.

Treatment of extensive aortic aneurysms by a new multiple-stage approach.

A new multiple-stage approach to extensive aneurysmal disease of the aorta is presented. The method is designed to obviate the proximal graft-to-aorta anastomosis in second-stage and third-stage aortic replacement to simplify and facilitate these operative steps. Since 1981 a total of 17 such procedures were performed in seven patients with dissecting and nondissecting aneurysms without deaths or complications related to the method.

Risk of replacement of descending aorta with a standardized left heart bypass technique.

Replacement of the descending aorta for aneurysms (51%) and dissection (49%) was performed in 132 patients with a highly standardized left heart vortex-pump bypass. No adjuncts other than staged aortic clamping and intercostal artery reconnection were used to reduce spinal cord injury in extensive involvement. Four patients (3%) died early, two of cardiac cause, and nine (7%) died late. Complications of vital organ function occurred in eight patients, two having reversible renal failure and six spinal cord injury that was permanent in three (2.3%). Cord injury occurred only in replacement beyond thoracic segment 8 and could not be completely avoided despite distal intercostal artery reconnection in two cases; in the other four cases such vessels either did not appear worth reconnecting or were sacrificed in emergency operations. We conclude that left heart bypass effectively unloads the proximal circulation during aortic occlusion while maintaining adequate perfusion of distal vital organs as evidenced by low rates of early mortality and renal failure. The remaining risk of spinal cord damage may be lowered by more aggressive reconnection of all distal intercostal arteries and by extending the permissible cord ischemic period by means of hypothermia.

Surgical treatment of active infective endocarditis with paravalvular involvement.

Aortic root infection remains a challenging problem in the surgical treatment of both native and prosthetic valve endocarditis. Between 1980 and 1991, 73 patients with active aortic valve endocarditis and paravalvular infection underwent operation. Indications for operation included congestive heart failure and uncontrolled sepsis. Aortic root abscesses were located in the noncoronary anulus or in the aorticomitral junction in 45% of cases, followed by the subannular interventricular septum in 23%. Two patients had an aorticoatrial fistula, seven an interventricular septal defect. Total or partial left ventricular-aortic dehiscence was observed in 27 patients. All patients underwent aortic valve replacement, nine with simultaneous mitral valve operations. Two of the latter required patch reconstruction of the destroyed aorticomitral septum with double valve replacement. Reconstruction of the aortic base was possible in 16 patients, whereas in 12 total replacement of the aortic root was necessary. In one patient, supracoronary aortic valve replacement was used. Recently, topical application of antibiotics in fibrin sealant was used in 25 patients. The operative mortality rate was 21% and correlated to preoperative uncontrolled sepsis and the presence of extensive root destruction. Operation for active endocarditis of the aortic root requires radical, individualized techniques and results in an acceptable operative and long-term risk. The use of an antibiotic fibrin compound appears to be a useful prophylactic tool to prevent postoperative residual endocarditis.

Fibrin adhesive: an important hemostatic adjunct in cardiovascular operations.

Fibrin adhesive was applied 413 times in a group of 340 patients undergoing extracorporeal circulation whenever conventional suturing appeared impossible, difficult, or dangerous, with a success rate of 95%. Fibrin-presealed woven or knitted fabric was inserted in 60 heparitized patients, 45 of whom underwent cardiac procedures. There was perfect sealing of the fabric in all but one instance. Fibrin gluing has become a routine method, reducing man-hours and blood loss and occasionally salvaging patients' lives. Fibrin-presealed knitted prostheses are expected to replace woven fabric because of its known poor healing qualities.

Surgical treatment of airway complications after lung transplantation.

The treatment of dehiscence or stenosis of the bronchus after lung transplantation has to date consisted of endobronchial stenting or balloon dilation. Operative intervention has been limited to retransplantation with all its limitations. In our series of 121 anastomoses at risk, severe bronchial stenosis occurred in 11 (9%). In five instances the airway complications were treated surgically: two patients underwent retransplantation, one patient had a bilobectomy, and two required sleeve resection of the stenotic segment. All these procedures successfully removed the stenosis. This experience demonstrates that options other than bronchial anastomotic stenting and dilation may be successfully used to overcome posttransplantation anastomotic complications. Conventional resections may result in superior long-term graft function compared with retransplantation, avoiding the immunologically adverse effects of the latter procedure.

The mechanism of spinal cord injury after simple and double aortic cross-clamping.

Ischemic spinal cord injury after cross-clamping of the descending aorta can occur independently of aortic disease. In a previous study we had shown a precipitous uniform fall of spinal surface oxygen tension downstream to the clamping site irrespective of level. In the present paper, the hemodynamic changes in the spinal and aortic collateral circulation were investigated. Pressures were measured in the proximal, distal, and excluded aortic segments (descending thoracic and lumbar aorta) as well as in the intercostal and the lumbar arterial beds. Before high aortic occlusion, pressures in the intercostal and lumbar arterial beds were lower than aortic pressure. Along with the postclamping fall in distal arterial pressure, intercostal and lumbar arterial bed pressure decreased further but remained above aortic pressure. Exclusion of the thoracic aorta by double clamping restored intercostal bed pressure almost to control, whereas exclusion of the abdominal aorta hardly affected lumbar bed pressure. We conclude that spinal collateral circulation is more highly developed in the thoracic than in the lumbar region. After aortic cross-clamping, blood tends to drain away from the spinal cord rather than supplying it longitudinally. Under clinical conditions, therefore, retrograde bleeding into the opened aorta as well as into the aorta downstream to the distal clamp should be minimized and larger vessels originating from the aorta should promptly be anastomosed to the graft.

Direct measurements of oxygen tension on the spinal cord surface of pigs after occlusion of the descending aorta.

Spinal cord injury is the most dreaded complication of operative procedures on the descending aorta. Our previous experimental study on pigs indicated that an increase in the cerebrospinal fluid pressure after aortic cross-clamping did not influence the occurrence of spinal cord injury. We therefore concluded that the cause of spinal cord injury after aortic cross-clamping is due to primary oxygen deficiency in the spinal cord distal to the occlusion site, especially in the area supplied by the artery of Adamkiewicz. The aim of the present study is to examine the primary ischemic cause of spinal cord injury after aortic cross-clamping by directly measuring the oxygen tension on the spinal cord surface in pigs. During the occlusion phase, oxygen tension decreased significantly distal to the clamping site and especially in the areas supplied by the artery of Adamkiewicz both after occlusion of the high thoracic (Group I) and the lumbar aorta (Group II). The marked decrease in oxygen tension proves that hypoxia is the primary reason for spinal cord injury. The presence of a "steal phenomenon" should be discussed.

Future horizons of lung preservation by application of a platelet-activating factor antagonist compared with current clinical standards. Euro-Collins flush perfusion versus donor core cooling.

With the introduction of platelet-activating factor antagonists, a direct inhibition of ischemia-induced reperfusion injury can be achieved by prevention of platelet activation, reduction of microvascular leakage, and platelet-activating factor-induced bronchoconstriction. At present, two preservation methods are established for clinical lung preservation: (1) donor core cooling by extracorporeal circulation and (2) pulmonary artery flush with Euro-Collins solution and prostacyclin. We compared the quality of organ preservation obtained with these methods to the application of a platelet-activating factor antagonist (WEB 2170; 0.3 mg/kg) for the donor, perfusion solution, and throughout the first 6 hours of reperfusion in combination with prostacyclin (20 ng/kg/min) and Euro-Collins solution (60 ml/kg). Eighteen heterotopic heart and orthotopic left lung transplants were performed in three groups of six dogs each after 6 hours of cold ischemia (group I, donor core cooling; group II, Euro-Collins flush and prostacyclin; group III, Euro-Collins flush, prostacyclin, and WEB 2170). Myocardial preservation was achieved with St. Thomas' Hospital solution (20 ml/kg) in all groups. After transplantation, cardiorespiratory function was assessed at an inspired oxygen fraction of 0.4. After transplantation, superior results were observed in group III, as expressed by significantly improved oxygenation, while cardiac output and pulmonary artery pressures were similar in all groups. We concluded that the use of the platelet-activating factor antagonist WEB 2170 resulted in better lung preservation than current clinical standards.

The arteria radicularis magna anterior as a decisive factor influencing spinal cord damage during aortic occlusion.

Cross-clamping of the descending aorta immediately below the subclavian artery may result in damage to the spinal cord. Despite various protective procedures, the risk of such damage cannot be entirely eliminated. In an experimental study with 47 pigs, the influence of various factors on the genesis of spinal cord damage was examined. The pigs were divided into five groups: Groups I to IV--occlusion of the descending aorta for 45 minutes; Group I--no reduction in arterial blood pressure proximal to the site of occlusion; Group II--like Group I, plus drainage of the cerebrospinal fluid; Group III--reduction in arterial blood pressure; Group IV--like Group III, plus drainage of the cerebrospinal fluid; Group V--permanent ligation of the artery of Adamkiewicz. The degree of permanent spinal cord damage was 85.7% (Groups I to IV, six animals) and 71.4% (Group V, five animals). Thus there were no significant differences among the various groups. The frequency of spinal cord damage was independent of arterial blood pressure, intracranial pressure, and intraspinal pressure. The intracranial pressure and the intraspinal pressure were significantly dependent upon the central venous pressure but were independent of the arterial blood pressure.

Bronchial circulation after experimental lung transplantation. The effect of long-term administration of prednisolone.

The effect of corticosteroids on bronchial healing after modified left lung transplantation was investigated in pigs. In groups I (n = 6) and II (n = 6), animals received cyclosporine (15 mg/kg per day) and azathioprine (2 mg/kg per day). In group II, prednisolone (1 mg/kg per day) was also administered. Bronchial blood flow was estimated at the donor carina and donor second carina with laser Doppler velocimetry and radioisotopes 7 days postoperatively; macroscopic and microscopic assessments of graft airways were performed. Bronchial blood was calculated relative to the recipient carina. In group II, bronchial blood flow at the donor carina and donor second carina was significantly higher than that of group I. Macroscopic assessment revealed more pronounced ischemic changes in group I (5 of 6 animals) than in group II (2 of 6 animals, p = not significant). Microscopically, airway samples from the donor carina revealed marked destructive changes in five of six animals in group I. In group II, only mild ischemic changes, which were limited to the respiratory epithelium, were seen. We concluded that the administration of prednisolone results in improved bronchial blood flow and decreased bronchial ischemia after lung transplantation.