[Osteoporotic vertebral fractures of the thoracic and lumbar spine]

The frequency of osteoporotic vertebral fractures in the clinical routine is increasing due to the demographic change. They are the most frequent fractures associated with osteoporosis and affect an especially morbid and vulnerable group of patients. These fractures often occur after minor trauma or spontaneously. Pain is the predominant symptom, whereas mechanical stability is mostly sufficient, in comparison to vertebral fractures after high-energy trauma, and is not a predominant indication for surgery. These fractures can be described using the classification for fractures associated with osteoporosis and the corresponding treatment recommendations are guided by them. Besides the specific treatment of osteoporotic vertebral fractures, a holistic treatment of patients taking pre-existing comorbidities into consideration is decisive. A mobilization as quickly as possible and treatment of the underlying osteoporosis are important to prevent further fractures.

Molybdenum trioxide enhances viability, osteogenic differentiation and extracellular matrix formation of human bone marrow-derived mesenchymal stromal cells

BACKGROUND

Metals and their ions allow specific modifications of the biological properties of bioactive materials that are intended for application in bone tissue engineering. While there is some evidence about the impact of particles derived from orthopedic Cobalt-Chromium-Molybdenum (Co-Cr-Mo) alloys on cells, there is only limited data regarding the influence of the essential trace element Mo and its ions on the viability, osteogenic differentiation as well as on the formation and maturation of the primitive extracellular matrix (ECM) of primary human bone marrow-derived stromal cells (BMSCs) available so far.

METHODS

In this study, the influence of a wide range of molybdenum (VI) trioxide (MoO₃), concentrations on BMSC viability was evaluated via measurement of fluorescein diacetate metabolization. Thereafter, the impact of three non-cytotoxic concentrations of MoO₃ on the cellular osteogenic differentiation as well as on ECM formation and maturation of BMSCs was assessed.

RESULTS

MoO₃ had no negative influence on BMSC viability in most tested concentrations, as viability was in fact even enhanced. Only the highest concentration (10 mM) of MoO₃ showed cytotoxic effects. Cellular osteogenic differentiation, measured via the marker enzyme alkaline phosphatase was enhanced by the presence of MoO₃ in a concentration-dependent manner. Furthermore, MoO₃ showed a positive influence on the expression of relevant marker genes for osteogenic differentiation (osteopontin, osteocalcin and type I collagen alpha 1) and on the formation and maturation of the primitive ECM, as measured by collagen deposition and ECM calcification.

CONCLUSION

MoO₃ is considered as an attractive candidate for supplementation in biomaterials and qualifies for further research.

[Minimally invasive stabilization of sacral fractures]

BACKGROUND

Sacral fractures can be of traumatic origin and can also occur as insufficiency fractures. While the therapeutic target of mechanically stable insufficiency fractures is mainly pain relief, mechanically unstable insufficiency fractures and traumatic sacral fractures following high-energy trauma require biomechanical stabilization. Various surgical strategies are available for this, whereby minimally invasive techniques are now preferred whenever possible.

OBJECTIVE

This article presents the clinical challenges and options for minimally invasive treatment of sacral fractures.

MATERIAL AND METHODS

Selected important study data are discussed and our own treatment approach is presented.

RESULTS

The most important minimally invasive techniques for operative treatment of sacral fractures are presented: sacroiliac screw osteosynthesis, lumbopelvic stabilization and sacroplasty. The selection of the surgical technique should be made on an individual basis. While sacroiliac screw osteosynthesis is the international gold standard, diverse authors have also published minimally invasive techniques for lumbopelvic stabilization. The latter enables a higher mechanical stability. In contrast, sacroplasty should only be used as an alternative treatment in insufficiency fractures. Comparative studies of the described techniques are still missing.

CONCLUSION

All surgical options have their indications. Nevertheless, the biomechanical stability which can be achieved differs widely. Therefore, an exact analysis should be carried out of what is necessary with respect to reduction and retention and what should be achieved when treating sacral fractures.

Understanding Gender Differences in Resilience Among Veterans: Trauma History and Social Ecology

A social-ecological framework for resilience underscores the importance of conceptualizing individuals embedded within their context when evaluating a person's vulnerability and adaptation to stress. Despite a high level of trauma exposure, most veterans exhibit psychological resilience following a traumatic event. Interpersonal trauma is associated with poorer psychological outcomes than noninterpersonal trauma and is experienced more frequently across the lifespan by women as compared to men. In the present study, we examined gender differences in trauma exposure, resilience, and protective factors among veterans. Participants included 665 veterans who completed a baseline survey assessing traumatic events; 544 veterans (81.8%) completed a 1-year follow-up survey assessing resilience, combat exposure, deployment social support, deployment preparedness, and military sexual trauma (MST). Principal component analyses revealed the Traumatic Life Events Questionnaire categorized into four meaningful components: sexual abuse, interpersonal violence, stranger violence, and accidents/unexpected trauma. Women reported greater exposure to sexual abuse, d = 0.76; interpersonal violence, d = 0.31; and MST, Cramer's V = 0.54; men reported greater exposure to stranger violence, accidents/unexpected trauma, and combat exposure, ds = 0.24-0.55. Compared to women, men also reported greater social support during deployment, d = 0.46. Hierarchical linear regression indicated that men's resilience scores were higher than women's, β = .10, p = .032, yet this association was no longer significant once we accounted for trauma type, β = .07, p = .197. Results indicate that trauma type is central to resilience and suggest one must consider the social-ecological context that can promote or inhibit resilient processes.

A targeted neuropsychological examination of children with a history of sport-related concussion

Experimental research suggests that sport-related concussion can lead to persistent alterations in children's neurophysiology and cognition. However, the search for neuropsychological tests with a similar ability to detect long-term deficits continues.

PRIMARY OBJECTIVE

The current study assessed whether a target battery of neuropsychological measures of higher cognition and academic achievement would detect lingering deficits in children 2 years after injury.

RESEARCH DESIGN

Cross-sectional.

METHODS AND PROCEDURE

A total of 32 pre-adolescent children (16 concussion history, 16 control) completed a targeted battery of neuropsychological and academic tests.

MAIN OUTCOMES AND RESULTS

Children with a history of concussion exhibited selective deficits during the Raven's Coloured Progressive Matrices, Comprehensive Trail-Making Test, and the mathematics sub-section of the WRAT-3. Deficit magnitude was significantly related to age at injury, but not time since injury.

CONCLUSIONS

The current results suggest that neuropsychological measures of higher cognition and academic achievement may be sensitive to lingering deficits, and that children injured earlier in life may exhibit worse neuropsychological and academic performance.

[Surgical treatment of acute mediastinitis]

Despite modern intensive care management, acute mediastinitis is still associated with a high morbidity and mortality (up to approximately 40 %). Effective antibiotic therapy, intensive care management, elimination of the causative sources of infection and drainage of the affected mediastinal compartments are the cornerstones of therapy in a multidisciplinary treatment concept. Early diagnosis, prompt and uncompromising initial therapy and planned computed tomography (CT) control after the first stages of therapy in order to decide on the necessity for surgical re-interventions are essential for achieving optimal results. Knowledge of the specific anatomical characteristics is crucial for the understanding of this disease and its treatment; therefore, the current knowledge on fascial layers and interstitial spaces from the neck to the mediastinum is described and discussed. A possible foudroyant spread of the infection, especially within the posterior mediastinum, has to be anticipated. The approach to the mediastinum depends on the mediastinal compartments affected, on the causative disease and on the patient's clinical situation. The surgical approach should be adapted to the particular clinical situation of the individual patient and to the surgical experience of the surgeon. When in doubt, the more invasive approach to the mediastinum, such as bilateral thoracotomy, is recommended. An ascending mediastinitis due to pancreatitis is a very rare condition; however, as chest pains are often the main clinical sign surgeons should be aware of this differential diagnosis. An intraoperative brown-black serous fluid in the mediastinal tissue is virtually pathognomonic. The treatment results of esophageal perforation as the most frequent cause of mediastinitis have been improved by integration of various interventional procedures. Hyperbaric oxygen therapy or immunoglobulin treatment can play an auxiliary role in selected patients with acute mediastinitis.

Lymphabstromszintigraphie bei einem artefiziellen Ödem des Unterschenkels

Es wird über eine junge Frau berichtet, die nach einem Trauma über ca. 2 Monate wiederholt zur stationären Diagnostik aufgenommen wurde, bevor die arte-fizielle Genese eines Ödems des linken Beines geklärt werden konnte. Die Lymphszintigraphie zeigte eine starke Beschleunigung des Lymphabstroms aus dem geschwollenen Bein.

[Limb salvage or amputation after severe trauma to the lower extremities : Evidence from the LEAP Study]

Deciding between reconstruction and primary amputation after severe high-energy trauma to the lower extremities is difficult and consequential. The Lower Extremity Assessment Project (LEAP) prospectively included and investigated patients with severe, limb-threatening injuries below the femur, with third-grade open fractures, defined soft-tissue damage and amputation wounds. This paper aims to review the key results of the LEAP study, which were published in several parts, in due consideration of the newer relevant literature, and to deduce the consequences for clinical practice. The main results are as follows: No score is sufficiently reliable to predict the success of reconstruction. Loss of muscle seems to be more momentous than loss of bone. Any accompanying injuries that should be taken into account in the individual treatment concepts are crucial to the results, in addition to comorbidities and other individual patient-related factors, such as alcoholism, smoking, insurance, and social background. Psychological impairment is frequent after these injuries and should therefore be addressed regularly with regard to rehabilitation.

The Sheep Grimace Scale as an indicator of post-operative distress and pain in laboratory sheep

The EU Directive 2010/63/EU changed the requirements regarding the use of laboratory animals and raised important issues related to assessing the severity of all procedures undertaken on laboratory animals. However, quantifiable parameters to assess severity are rare, and improved assessment strategies need to be developed. Hence, a Sheep Grimace Scale (SGS) was herein established by observing and interpreting sheep facial expressions as a consequence of pain and distress following unilateral tibia osteotomy. The animals were clinically investigated and scored five days before surgery and at 1, 3, 7, 10, 14 and 17 days afterwards. Additionally, cortisol levels in the saliva of the sheep were determined at the respective time points. For the SGS, video recording was performed, and pictures of the sheep were randomized and scored by blinded observers. Osteotomy in sheep resulted in an increased clinical severity score from days 1 to 17 post-surgery and elevated salivary cortisol levels one day post-surgery. An analysis of facial expressions revealed a significantly increased SGS on the day of surgery until day 3 post-surgery; this elevated level was sustained until day 17. Clinical severity and SGS scores correlated positively with a Pearson´s correlation coefficient of 0.47. Further investigations regarding the applicability of the SGS revealed a high inter-observer reliability with an intraclass correlation coefficient of 0.92 and an accuracy of 68.2%. In conclusion, the SGS represents a valuable approach for severity assessment that may help support and refine a widely used welfare assessment for sheep during experimental procedures, thereby meeting legislation requirements and minimizing the occurrence of unrecognized distress in animal experimentation.

Incidence of Mental Health Diagnoses in Veterans of Operations Iraqi Freedom, Enduring Freedom, and New Dawn, 2001-2014

OBJECTIVES

To evaluate gender, age, and race/ethnicity as predictors of incident mental health diagnoses among Operations Iraqi Freedom, Enduring Freedom, and New Dawn veterans.

METHODS

We used US Veterans Health Administration (VHA) electronic health records from 2001 to 2014 to examine incidence rates and sociodemographic risk factors for mental health diagnoses among 888 142 veterans.

RESULTS

Posttraumatic stress disorder (PTSD) was the most frequently diagnosed mental health condition across gender and age groups. Incidence rates for all mental health diagnoses were highest at ages 18 to 29 years and declined thereafter, with the exceptions of major depressive disorder (MDD) in both genders, and PTSD among women. Risk of incident bipolar disorder and MDD diagnoses were greater among women; risk of incident schizophrenia, and alcohol- and drug-use disorders diagnoses were greater in men. Compared with Whites, risk incident PTSD, MDD, and alcohol-use disorder diagnoses were lower at ages 18 to 29 years and higher at ages 45 to 64 years for both Hispanics and African Americans.

CONCLUSIONS

Differentiating high-risk demographic and gender groups can lead to improved diagnosis and treatment of mental health diagnoses among veterans and other high-risk groups.

[Sagittal Balance of the Spine--Clinical Importance and Radiographic Assessment]

Sagittal deformities of the spine frequently result in back pain, as patients have to expend much energy in compensation. The sagittal alignment of the spine is defined by its curvatures (lordosis and kyphosis) relative to the position of the pelvis. Diagnostic assessment is based on full spine a. p. and lateral X-rays. The sagittal balance is primarily described by different angles that can be measured, e.g. lumbar lordosis, pelvic incidence, pelvic tilt and thoracic kyphosis. The quality of life can best be estimated by subtracting lumbar lordosis from the pelvic incidence. However, initial evaluation of the sagittal balance can also be based on the sagittal vertical axis. The severity of imbalance can be described by the sagittal vertical axis and the pelvic tilt, but surgical therapy necessitates a more profound analysis, which can be based on the SRS-Schwab classification.

Outcome expectations and associated treatment outcomes in motivational enhancement therapy delivered in English and Spanish

BACKGROUND AND OBJECTIVES

The relationship between patients' baseline expectations regarding treatment outcome and actual outcomes has not been widely studied within the field of substance use disorders. We hypothesized that outcome expectations would be unrelated to outcomes in a study investigating motivational enhancement therapy delivered in English (MET-E) consistent with our earlier work, and conducted exploratory analyses in a separate study that investigated the same treatment delivered in Spanish (MET-S).

METHODS

These secondary analyses compared patient outcome expectations and substance use treatment outcomes in two large, multisite randomized controlled clinical trials that evaluated three sessions of MET-E or MET-S. The MET-E sample included 461 participants and the MET-S sample included 405 participants. Outcome expectations were measured by a single item regarding expectations about abstinence prior to initiating treatment.

RESULTS

Outcome expectations were strongly associated with most substance use outcomes in the MET-S trial (but not in MET-E), even after controlling for severity of substance use at baseline. In MET-S, those who indicated that they were "unsure" that they would achieve abstinence during treatment submitted a greater percentage of drug-positive urine toxicology screens during the treatment period than those who were 'sure' they would achieve abstinence (F = 18.83, p < .001).

DISCUSSION AND CONCLUSIONS

Patients' outcome expectations regarding the likelihood of abstinence may be an important predictor of drug use treatment outcomes among Spanish-speakers, but not necessarily for English-speakers.

SCIENTIFIC SIGNIFICANCE

Individual differences and cultural factors may play a role in the association between outcome expectations and treatment outcomes.

Percutaneous dilatational tracheostomy (PDT) in trauma patients: a safe procedure

PURPOSE

Percutaneous dilatational tracheostomy (PDT) is a standard procedure routinely performed on intensive care units. While complication rates and long-term outcomes have been studied in different patient populations, there are few studies known to these authors involving PDT in trauma patients and the complications which may result.

METHODS

Between March 2007 and August 2013, all instances and peri-procedural complications during PDT occurring on the trauma intensive care unit, a unit specialized in the care of injured patients and especially polytrauma patients, were documented. PDTs were performed by a surgeon with the assistance and supervision of another, using bronchoscopic guidance performed by the respiratory medicine department.

RESULTS

289 patients were included in the study, 225 men and 64 women with a mean age of 49 ± 21 years. Complications occurred in 37.4 % of cases. The most common complication, bleeding, occurred in 26.3 % of patients ranging from little to severe bleeding. Fracture of tracheal cartilage occurred in 6 % of PDT cases. Additional complications such as dislocation of the guidewire, hypotension, and oxygen desaturation were observed. Most complications did not require treatment. The second tracheal intercartilaginous space was successfully intubated in 82 % of cases.

CONCLUSIONS

PDT is a safe procedure in trauma patients. When considering the severity of complications such as major blood loss, pneumothorax, or death, this evidence suggests that PDT is safer in trauma patients compared to other patient cohorts.

[Infiltration of the superior vena cava in NSCLC: results of surgical intervention]

The benefits of surgical therapy of locally advanced non-small cell lung cancer (NSCLC) with infiltration of the superior vena cava (SVC) remains controversial. Here we describe our therapeutic approach and results of our intervention.A retrospective analysis of 22 patients with NSCLC who underwent SVC replacement (n = 17) or reconstruction (n = 5) between 1998 and 2013 was performed. Pneumonectomy was necessary in 16 patients, lobectomy in 8. Preoperative chemotherapy was administered to 3 patients, 16 received postoperative radiation treatment. The clinical course and survival were analyzed.Major postoperative morbidities were found in 13 patients. Graft thrombosis did not occur. Thirty-day mortality was 7 % in pneumonectomy patients and 0 % following lobectomy. Local recurrence was found in 4.5 %, distant metastases developed in 54.5 % of the patients (p = 0.0008). One- and five-year survival probabilities for all patients were 63.6 and 27.9 %. Five-year survival probability was 33 % for patients with SVC reconstruction and 25 % for patients with SVC replacement (p = 0.22). Five-year survival rates after pneumonectomy and lobectomy were 21.4 % and 37.5 %, respectively (p = 0.18).Radical resection involving the SVC in carefully selected patients with NSCLC results in excellent local tumor control. Due to the high rate of distant metastases, application of induction and adjuvant chemotherapy should be carefully assessed.

Toward empirical identification of a clinically meaningful indicator of treatment outcome: features of candidate indicators and evaluation of sensitivity to treatment effects and relationship to one year follow up cocaine use outcomes

BACKGROUND

Selection of an appropriate indictor of treatment response in clinical trials is complex, particularly for the various illicit drugs of abuse. Most widely used indicators have been selected based on expert group recommendation or convention rather than systematic empirical evaluation. Absence of an evidence-based, clinically meaningful index of treatment outcome hinders cross-study evaluations necessary for progress in addiction treatment science.

METHOD

Fifteen candidate indicators used in multiple clinical trials as well as some proposed recently are identified and discussed in terms of relative strengths and weaknesses (practicality, cost, verifiability, sensitivity to missing data). Using pooled data from five randomized controlled trials of cocaine dependence (N=434), the indicators were compared in terms of sensitivity to the effects of treatment and relationship to cocaine use and general functioning during follow-up.

RESULTS

Commonly used outcome measures (percent negative urine screens; percent days of abstinence) performed relatively well in that they were sensitive to the effects of the therapies evaluated. Others, including complete abstinence and reduction in frequency of use, were less sensitive to effects of specific therapies and were very weakly related to cocaine use or functioning during follow-up. Indicators more strongly related to cocaine use during follow-up were those that reflected achievement of sustained periods of abstinence, particularly at the end of treatment.

CONCLUSIONS

These analyses did not demonstrate overwhelming superiority of any single indicator, but did identify several that performed particularly poorly. Candidates for elimination included retention, complete abstinence, and indicators of reduced frequency of cocaine use.

CXCR4-SERINE339 regulates cellular adhesion, retention and mobilization, and is a marker for poor prognosis in acute myeloid leukemia

The CXCR4 receptor is a major regulator of hematopoietic cell migration. Overexpression of CXCR4 has been associated with poor prognosis in acute myelogenous leukemia (AML). We have previously shown that ligand-mediated phosphorylation of the Serine339 (CXCR4-S339) residue of the intracellular domain by PIM1 is implicated in surface re-expression of this receptor. Here, we report that phosphorylation of CXCR4-S339 in bone marrow (BM) biopsies correlated with poor prognosis in a cohort of AML patients. To functionally address the impact of CXCR4-S339 phosphorylation, we generated cell lines-expressing CXCR4 mutants that mimic constitutive phosphorylation (S339E) or abrogate phosphorylation (S339A). Whereas the expression of CXCR4 significantly increased, both CXCR4-S339E and the CXCR4-S339A mutants significantly reduced the BM homing and engraftment of Kasumi-1 AML cells in immunodeficient mice. In contrast, only expression of the CXCR4-S339E mutant increased the BM retention of the cells and resistance to cytarabine treatment, and impaired detachment capacity and AMD3100-induced mobilization of engrafted leukemic cells. These observations suggest that the poor prognosis in AML patients displaying CXCR4-S339 phosphorylation can be the consequence of an increased retention to the BM associated with an enhanced chemoresistance of leukemic cells. Therefore, CXCR4-S339 phosphorylation could serve as a novel prognostic marker in human AML.

[Differential diagnosis of Parkinson's disease: current consensus criteria and outlook]

Parkinsonian-syndrome, clinically based on the combination of cardinal symptoms, could be the clinical manifestation of different, neuropathological defined entities. Because of the different prognostic, therapeutical and scientific implications a reliable differential diagnostic of the entities in early course of disease is desirable. For this purpose standardized clinical diagnostic criteria with sufficient validation against the gold standard of the neuropathological diagnostic are important. In this article, the clinical diagnostic criteria of atypical Parkinsonian-syndrome and their validity were discussed.

The hollow fibre model in cancer drug screening: the NCI experience

The in vivo hollow fibre model was developed by the National Cancer Institute (NCI) in the United States of America (USA) at a time when the number of potential anti-cancer drugs arising from in vitro screening efforts exceeded the available capacity for testing in traditional xenograft models. Updated analysis of the predictive value of the hollow fibre model continues to indicate that the greater the response in the hollow fibre assay, the more likely it is that activity will be seen in subsequent xenograft models. The original 12 cell line hollow fibre panel has been supplemented with histology-specific panels, and we begin here to analyse their utility in predicting activity in subsequent in vivo models. The key goal of using the hollow fibre model as a way to decrease the cost, both financial and in the number of animals used, to evaluate initial evidence of a compound's capacity to act across physiological barriers continues to be reinforced with our enlarging experience.

The small bovine amelogenin LRAP fails to rescue the amelogenin null phenotype

Amelogenins are the most abundant secreted proteins in developing dental enamel. These evolutionarily-conserved proteins have important roles in enamel mineral formation, as mutations within the amelogenin gene coding region lead to defects in enamel thickness or mineral structure. Because of extensive alternative splicing of the primary RNA transcript and proteolytic processing of the secreted proteins, it has been difficult to assign functions to individual amelogenins. To address the function of one of the amelogenins, we have created a transgenic mouse that expresses bovine leucine-rich amelogenin peptide (LRAP) in the enamel-secreting ameloblast cells of the dental organ. Our strategy was to breed this transgenic mouse with the recently generated amelogenin knockout mouse, which makes none of the amelogenin proteins and has a severe hypoplastic and disorganized enamel phenotype. It was found that LRAP does not rescue the enamel defect in amelogenin null mice, and enamel remains hypoplastic and disorganized in the presence of this small amelogenin. In addition, LRAP overexpression in the transgenic mouse (wildtype background) leads to pitting in the enamel surface, which may result from excess protein production or altered protein processing due to minor differences between the amino acid compositions of murine and bovine LRAP. Since introduction of bovine LRAP into the amelogenin null mouse does not restore normal enamel structure, it is concluded that other amelogenin proteins are essential for normal appearance and function.

A model of mucopolysaccharidosis IIIB (Sanfilippo syndrome type IIIB): N-acetyl-alpha-D-glucosaminidase deficiency in Schipperke dogs

Mucopolysaccharidosis III (MPS III) is characterized by lysosomal accumulation of the glycosaminoglycan (GAG) heparan sulphate (HS). In humans, the disease manifests in early childhood, and is characterized by a progressive central neuropathy leading to death in the second decade. This disease has also been described in mice (MPS IIIA and IIIB), dogs (MPS IIIA), emus (MPS IIIB) and goats (MPS IIID). We now report on dogs with naturally occurring MPS IIIB, detailing the clinical signs, diagnosis, histopathology, tissue enzymology and substrate levels. Two 3-year-old Schipperke dogs were evaluated for tremors and episodes of stumbling. Examination of the animals found signs consistent with cerebellar disease including dysmetria, hind limb ataxia and a wide-based stance with truncal swaying. There were mildly dystrophic corneas and small peripheral foci of retinal degeneration. Magnetic resonance imaging of the brain and skeletal radiographs were normal. Intracytoplasmic granules were found in the white cells of peripheral blood and cerebral spinal fluid, and in myeloid lineages in bone marrow. Electrophoresis of urinary GAGs indicated the presence of HS, while assays of cultured fibroblasts found N-acetyl-alpha-D-glucosaminidase (Naglu) activity of between 4.3% and 9.2% of normal. Owing to neurological deterioration, both dogs were euthanized, and post-mortem examinations were performed. Biochemical studies of liver and kidney from both animals demonstrated profound deficiency of Naglu activity and abnormally high GAG levels. Pathology of the brain included severe cerebellar atrophy, Purkinje cell loss, and cytoplasmic vacuolation in neurons and perithelial cells throughout the central nervous system. Pedigree analyses and Naglu levels of family members supported an autosomal recessive mode of inheritance. Using an obligate heterozygote, a breeding colony has been established to aid in understanding the pathogenesis of MPS IIIB and testing of potential therapies.

Integration of neuropsychological and cognitive theory in rehabilitation

Clinical neuropsychology has focused on the diagnosis and localization of brain damage. Much of the early progress in the field relied upon an atheoretical-actuarial approach. Recently a link between neuropsychology and cognitive psychology has emerged. From the early focus upon brain-behavior relationships, neurocognitive theories have emerged to explain observed brain functions. Although many researchers have enjoyed the collaboration between neuropsychology and cognitive psychology, others continue to investigate functions without considering the merging of finds. This article reviews integrative elements of cognitive and neuropsychological research and the emergence of cognitive neuropsychology.

Amelogenin-deficient mice display an amelogenesis imperfecta phenotype

Dental enamel is the hardest tissue in the body and cannot be replaced or repaired, because the enamel secreting cells are lost at tooth eruption. X-linked amelogenesis imperfecta (MIM 301200), a phenotypically diverse hereditary disorder affecting enamel development, is caused by deletions or point mutations in the human X-chromosomal amelogenin gene. Although the precise functions of the amelogenin proteins in enamel formation are not well defined, these proteins constitute 90% of the enamel organic matrix. We have disrupted the amelogenin locus to generate amelogenin null mice, which display distinctly abnormal teeth as early as 2 weeks of age with chalky-white discoloration. Microradiography revealed broken tips of incisors and molars and scanning electron microscopy analysis indicated disorganized hypoplastic enamel. The amelogenin null phenotype reveals that the amelogenins are apparently not required for initiation of mineral crystal formation but rather for the organization of crystal pattern and regulation of enamel thickness. These null mice will be useful for understanding the functions of amelogenin proteins during enamel formation and for developing therapeutic approaches for treating this developmental defect that affects the enamel.

Relationships between drug activity in NCI preclinical in vitro and in vivo models and early clinical trials

An analysis of the activity of compounds tested in pre-clinical in vivo and in vitro assays by the National Cancer Institute's Developmental Therapeutics Program was performed. For 39 agents with both xenograft data and Phase II clinical trials results available, in vivo activity in a particular histology in a tumour model did not closely correlate with activity in the same human cancer histology, casting doubt on the correspondence of the pre-clinical models to clinical results. However, for compounds with in vivo activity in at least one-third of tested xenograft models, there was correlation with ultimate activity in at least some Phase II trials. Thus, an efficient means of predicting activity in vivo models remains desirable for compounds with anti-proliferative activity in vitro. For 564 compounds tested in the hollow fibre assay which were also tested against in vivo tumour models, the likelihood of finding xenograft activity in at least one-third of the in vivo models tested rose with increasing intraperitoneal hollow fibre activity, from 8% for all compounds tested to 20% in agents with evidence of response in more than 6 intraperitoneal fibres (P< 0.0001). Intraperitoneal hollow fibre activity was also found to be a better predictor of xenograft activity than either subcutaneous hollow fibre activity or intraperitoneal plus subcutaneous activity combined. Since hollow fibre activity was a useful indicator of potential in vivo response, correlates with hollow fibre activity were examined for 2304 compounds tested in both the NCI 60 cell line in vitro cancer drug screen and hollow fibre assay. A positive correlation was found for histologic selectivity between in vitro and hollow fibre responses. The most striking correlation was between potency in the 60 cell line screen and hollow fibre activity; 56% of compounds with mean 50% growth inhibition below 10^–7.5 M were active in more than 6 intraperitoneal fibres whereas only 4% of compounds with a potency of 10^–4 M achieved the same level of hollow fibre activity (P< 0.0001). Structural parameters of the drugs analysed included compound molecular weight and hydrogen-bonding factors, both of which were found to be predictive of hollow fibre activity. © 2001 Cancer Research Campaign www.bjcancer.com

Nanocrystalline metal oxides as unique chemical reagents/sorbents

A new family of porous inorganic solids based on nanocrystalline metal oxides is discussed. These materials, made up of 4-7 nm MgO, CaO, Al2O3, ZnO, and others, exhibit unparalleled destructive adsorption properties for acid gases, polar organics, and even chemical/biological warfare agents. These unique sorption properties are due to nanocrystal shape, polar surfaces, and high surface areas. Free-flowing powders or consolidated pellets are effective, and pore structure can be controlled by consolidation pressures. Chemical properties can be adjusted by choice of metal oxide as well as by incorporating other oxides as monolayer films.

Establishment of an in vivo model for pediatric Ewing tumors by transplantation into NOD/scid mice

Ewing tumors are a clinically heterogeneous group of childhood sarcomas that represent a paradigm for understanding solid tumor biology, as they are the first group of sarcomas for which a chromosome translocation has been characterized at the molecular level. However, the biologic organization of the tumor, especially the processes that govern proliferation, differentiation, and metastasis of primitive tumor stem cells is poorly understood. Therefore, to develop a biologically relevant in vivo model, five different Ewing tumor cell lines and primary tumor cells from three patients were transplanted into immune-deficient mice via intravenous injection. NOD/scid mice that carry a complex immune deficiency and thus nearly completely lack the ability to reject human cells were used as recipients. Overall, 26 of 52 mice (50%) transplanted with VH-64, WE-68, CADO-ES1, TC-71, and RM-82 cells and 4 of 10 mice (40%) transplanted with primary tumor cells engrafted. Moreover, primary cells that did not grow in vitro proliferated in mice. The pattern of metastasis was similar to that in patients with frequent metastases in lungs (62%), bone marrow (30%), and bone (23%). Using limiting dilution experiments, the frequency of the engraftment unit was estimated at 1 Ewing tumor-initiating cell in 3 x 10(5) VH-64 cells. These data demonstrate that we have been able to establish an in vivo model that recapitulates many aspects of growth and progression of human Ewing tumors. For the first time, this model provides the opportunity to identify and characterize primitive in vivo clonogenic solid tumor stem cells. This model will, therefore, be instrumental in studying many aspects of tumor cell biology, including organ-selective metastasis and tumor angiogenesis.

Unexpected Fe local order in iron oxide coated nanocrystalline magnesium oxides with exceptional reactivities against environmental toxins

Mg oxide nanoparticles are very reactive materials used to mitigate atmospheric pollution and to sequester polluting molecules. Using Fe K-edge XAFS, we have studied the structure of iron oxide-coated MgO nanoparticles before and after reaction with CCl4. Before reaction, the local structure around Fe is totally different from that in iron oxide coatings on SrO and CaO nanoparticles, although these coated materials were prepared in the same way. In SrO and CaO, the iron oxide coating has been shown to be well separated from the bulk of the nanoparticle, whereas in MgO, Fe was found to mix with MgO. After reaction with CCl4, Fe-Cl bonds can be detected when the coated nanoparticle is saturated. Such Fe-Cl EXAFS signals have not been observed in previously studied nanoparticles.

High-dose etoposide phosphate and G-CSF mobilizes peripheral blood stem cells in patients that previously failed to mobilize

Ten consecutive patients in our unit who had failed to mobilize a sufficient stem cell yield after either an initial or several mobilization regimens received high-dose etoposide phosphate (1500-2000 mg/m2) followed by granulocyte colony-stimulating factor (G-CSF; 10 micrograms/kg per day) to stimulate mobilization. Eight of the ten patients were apheresed. A median of 2.1 x 10(6) CD34+/kg (range 0-5.2) was collected. The number of CD34+ cells/microliter peripheral blood (pB) was significantly increased compared to the first-line mobilization [median 13.0 (range 2.68-29) versus median 4.76 (range 1.36-12); P < 0.05]. Besides hematotoxicity and four cases of infection (WHO grade 3), no major side effects were seen. The median duration of neutropenia was short (5 days, range 0-10), which is important in heavily pretreated patients. These results indicate that high-dose etoposide phosphate with G-CSF is safe, well tolerated, and may be effective in peripheral blood stem cell (PBSC) mobilization in patients who had previously failed to mobilize.

Porcine Choroid plexus epithelial cells in culture: regulation of barrier properties and transport processes

The epithelial cells of the choroid plexus are the structural basis of the blood-cerebrospinal fluid (CSF)-barrier. Here we summarise our recent efforts to culture those cells mainly on permeable supports in vitro. Isolated from porcine brains, we report a simple protocol for the primary culture using cytosine arabinoside as an additive that is cytotoxic for other cells except the plexus epithelial cells. Enhanced barrier properties are obtained by withdrawal of serum from the culture medium after confluency is reached. Cells improve their polarity, permeability for hydrophilic substrates is lowered, electrical resistance is increased tenfold, and a pH-gradient is built up across the cell monolayer. Polarised secretion of proteins and most importantly fluid secretion into the apical filter compartment was attained and proven to be dependent on the Na(+),K(+)-ATPase activity. Active transport processes (penicillin G, riboflavin, myo-inositol, ascorbic acid) were studied and clearly showed the involvement of the organic anion transporter. The permeability of the barrier was found to be regulated by cyclic adenosine monophosphate (cAMP). Moreover, we report that cell proliferation and differentiation is controlled by components of the extracellular matrix. The present culture model could now be used as an in vitro system to quantify drug transport across the blood-CSF-barrier.

Expression of the elastin promoter in novel tissue sites in transgenic mouse embryos

We have previously shown in a transgenic mouse line, in which 5.2 kb of the elastin promoter was linked to the reporter enzyme chloramphenicol acetyltransferase (CAT), that the highest levels of expression were found in embryonic lungs and aorta, while lower levels were detected in other elastin-containing tissues. Furthermore, in general, expression of the transgene showed developmental regulation similar to that of the endogenous gene. However, the precise location of cellular expression could not be determined in this model. To overcome this limitation, we have developed a similar model, but replaced CAT with the reporter enzyme beta-galactosidase. Enzyme activity was readily detected in the transgenic mouse embryos in expected regions of tissue forming elastic fibers, including the dermis and elastic cartilage. Of considerable interest, however, was the novel finding of expression in specific areas of neuroepithelium of the brain and in the perichondrium surrounding areas destined to form hyaline cartilage in endochondral bone formation. These latter areas included all the bones of the limbs, the spine and rib cage. It appeared that these segments of elastin expression demarcated the border between the developing cartilage and the surrounding mesenchymal tissue. Elastin promoter expression was also found in developing somites, in the mesenchymal layer of the forming cornea of the eye, in the genital tubercle and in the epithelium destined to form the olfactory epithelium. These findings indicate that the elastin promoter is activated during embryonic development in a variety of tissues, suggesting that elastin gene expression may play a role in organizing cutaneous, skeletal and neural structures.

Open field is more sensitive than automated activity monitor in documenting ouabain-induced hyperlocomotion in the development of an animal model for bipolar illness

1. Intracerebroventricular (i.c.v.) administration of ouabain to rats induces motor hyper- and hypoactivity that have been hypothesized to model the mania and depression of bipolar illness, respectively. 2. The extent of ouabain-induced change in activity may vary according to the test environment. 3. To determine the degree of differential response to i.c.v. ouabain in the open field and automated activity monitors, the authors examined a large number of animals (n=40) in both environments. 4. I.c.v. ouabain produced a four-fold increase in open field activity versus i.c.v. artificial cerebrospinal fluid (aCSF) (mean +/- SD: 258.7 +/- 316.61 vs. 84.8 +/- 86.16 squares traversed) (t = 2.648, P = 0.011), but did not alter horizontal activity in automated activity monitors (8193.5 +/- 4902.52 vs. 7088.47 +/- 3046.85 beam interruptions) (t = 0.847, P = 0.4). This increase in activity persisted for at least one week (161.0 +/- 186.35 for i.c.v. ouabain vs. 46.1 +/- 47.46 for i.c.v. aCSF, P = 0.065). 5. Open field is superior to automated activity monitors in capturing ouabain-induced hyperlocomotion response.

Cytotoxic effect of methotrexate and its solvent on osteosarcoma cells in vitro

Bone tumours may recur locally even after wide surgical excision and systemic chemotherapy. Local control of growth may be accomplished by the addition of cytostatic drugs such as methotrexate (MTX) to bone cement used to fill the defect after surgery and to stabilise the reconstructive prosthesis. We have studied the elution kinetics of MTX and its solvent N-methyl-pyrrolidone (NMP) from bone cement and their biological activities in five cell lines of osteosarcoma and in osteoblasts, and compared them with the effects of the parent compounds alone and in combination. Our findings show that MTX is released continuously over months at concentrations highly cytotoxic to osteosarcoma cells and suggest that the impregnated bone cement would be effective in the long term. Proliferating osteoblasts, however, were much less sensitive towards MTX. The dose-response relationship for NMP and experiments with MTX/NMP-mixtures show that the eluted concentrations of solvent are not toxic and do not influence the effects of MTX. We suggest that bone cement containing MTX dissolved in NMP releases the drug in a suitable and effective way and may be of value in the treatment of bone tumours.

Cytotoxic effect of methotrexate and its solvent on osteosarcoma cells in vitro

Bone tumours may recur locally even after wide surgical excision and systemic chemotherapy. Local control of growth may be accomplished by the addition of cytostatic drugs such as methotrexate (MTX) to bone cement used to fill the defect after surgery and to stabilise the reconstructive prosthesis. We have studied the elution kinetics of MTX and its solvent N-methyl-pyrrolidone (NMP) from bone cement and their biological activities in five cell lines of osteosarcoma and in osteoblasts, and compared them with the effects of the parent compounds alone and in combination.

Our findings show that MTX is released continuously over months at concentrations highly cytotoxic to osteosarcoma cells and suggest that the impregnated bone cement would be effective in the long term. Proliferating osteoblasts, however, were much less sensitive towards MTX. The dose-response relationship for NMP and experiments with MTX/NMP-mixtures show that the eluted concentrations of solvent are not toxic and do not influence the effects of MTX.

We suggest that bone cement containing MTX dissolved in NMP releases the drug in a suitable and effective way and may be of value in the treatment of bone tumours.

A serum-free in vitro model of renal microvessel development

The differentiation and organization of the embryonic renal vasculature is a crucial event in renal development. To study this process, we developed a serum-free in vitro model of renal microvessel development. Mouse embryonic kidney explants, when embedded specifically in type I collagen, demonstrate outgrowth of microvascular structures when stimulated by the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA, 10-50 ng/ml). Other polypeptide growth factors stimulated little, if any, microvessel outgrowth from the explants. Similar outgrowths were not observed when other embryonic tissue explants were used. The number of microvessels observed depended on the gestational age of the explants. We hypothesize that TPA induces the in situ differentiation of metanephric mesenchymal cells into endothelial cell precursors and that specific matrix proteins and cell-matrix interactions are necessary for the organization of these precursors into microvessels. Our model will allow us to examine in detail the responsiveness of metanephric kidney cells to both growth factors and extracellular matrix molecules and to understand how they influence renal endothelial cell differentiation.

[Protein A immunoadsorption al a new apheresis procedure for elimination of HLA antibodies]

The protein A immunoadsorption allows to remove antibodies of the classes IgG, IgM and IgA in special quantities from the plasma. IgG subclasses 1, 2 and 4 will be removed for 100% and IgG of class 3 for nearly 80%. For this reason immunoadsorptions are a useful therapeutic method especially for immunological diseases with antibodies of IgG type. The successful use of immunoadsorption in the removal of HLA antibodies in patients with acute myeloic leukemia and patients after kidney allograft is reported.

A role for the MEK/MAPK pathway in PMA-induced cell cycle arrest: modulation of megakaryocytic differentiation of K562 cells

In vitro megakaryocytic differentiation of the pluripotent K562 human leukemia cell line is induced by PMA. Treatment of K562 cells with PMA results in growth arrest, polyploidy, morphological changes, and increased cell-cell and cell-substrate adhesion. These PMA-induced changes in K562 cells are preceded by a rapid rise in the activity of MEK (MAP kinase/extracellular regulated kinases) that leads to a sustained activation of ERK2 (extracellular regulated kinase; MAPK). Blockade of MEK1 activation by PD098059, a recently described specific MEK inhibitor [D. T. Dudley et al. (1995). Proc. Natl. Acad. Sci. USA 92, 7686-7689], reverses both the growth arrest and the morphological changes of K562 cells induced by PMA treatment. These changes are not associated with a disruption of PMA-induced down-regulation of BCR-ABL kinase or early integrin signaling events but are associated with a block of the cell-surface expression of the gpIIb/IIIa (CD41) integrin, a cell marker of megakaryocytic differentiation. These results demonstrate that the PMA-induced signaling cascade initiated by protein kinase C activation requires the activity of the MEK/ERK signaling complex to regulate cell cycle arrest, thus regulating the program that leads to the cell-surface expression of markers associated with megakaryocytic differentiation.

Effect of serum proteins and osteoblasts on the surface transformation of a calcium phosphate coating: a physicochemical and ultrastructural study

Changes occurring at the surface of a calcium phosphate coating when in contact with osteoblasts versus those in acellular solutions were analyzed. The coating studied is one with a well-documented extensive effect on short-term bone growth stimulation. Precipitates associated with original crystals and organized in a weblike structure were observed after a 3-week culture with osteoblasts. The precipitates were identified as carbonated hydroxyapatite (c-HA). In contrast, no significant surface changes were detected after immersion in an acellular serum-containing solution. However, in an acellular serum-free solution simulating the ionic composition of plasma, precipitates, identified as c-HA, were abundantly formed. Dissolution of the original coating preceded precipitation. The data support the hypothesis that dissolution of synthetic calcium phosphate ceramics is an initial step in their transformation to a biologically equivalent apatite, and suggest that both solution-mediated (dissolution-precipitation) and cell-mediated mechanisms are involved in the surface transformation.