Effect of ferric citrate on amyloid-beta peptides behavior.

Amyloid beta (Aß) aggregation and oxidative stress are two of the central events in Alzheimer's Disease (AD). Both these phenomena can be caused by the interaction of Aß with metal ions. In the last years the interaction between ZnII , CuII , and Aß was much studied, but between iron and Aß it is still little known. In this work we determine how three Aß peptides, present in AD, interact with FeIII -citrate. The three Aß peptides are: full length Aß1-42, an isoform truncated at Glutamic acid in position three, Aß3-42, and its pyroglutamated form AßpE3-42. Conformation and morphology of the three peptides, aggregated with and without FeIII -citrate were studied. Besides, we have determined the strength of the interactions Aß/FeIII -citrate studying the effect of ethylenediaminetetraacetic acid as chelator. Results reported here demonstrate that FeIII -citrate promotes the aggregation in all the three peptides. Moreover, Aspartic acid 1, Glutamic acid 3, and Tyrosine 10 have an important role in the coordination with iron, generating a more stable complex for Aß1-42 compared to that for the truncated peptides.

Navigated knee kinematics after cutting of the ACL and its secondary restraint.

PURPOSE: The purpose of this study is to evaluate the kinematics changes of the knee after cutting of the ACL with or without injury of the anterolateral structures. METHODS: In this study, the role of the ACL and one of the secondary restraints in controlling knee stability using a navigation system was evaluated. The kinematics of the knee was evaluated in different conditions of instability: ACL intact, after dissection of the posterolateral (PL) bundle, after dissection of the anteromedial (AM) bundle, and after lesion of the lateral capsular ligament (LCL). Anterior tibial translation and rotation were measured with a computer navigation system in 10 fresh-frozen cadaveric knees by use of a manual maximum load. Anterior translation was evaluated at 30°, 60°, and 90° of flexion; rotation at 0°, 15°, 30°, 45°, 60°, and 90°. RESULTS: Cutting the PL bundle does not increase anterior translation and rotation of the knee. Cutting the AM bundle significantly increased the anteroposterior (AP) translation at 30° and 60° (P = 0.01), but does not increase rotation of the knee. Cutting the LCL increased anterior translation at 60° (P = 0.04) and rotation at 30°, 45°, and 60° (P = 0.03). CONCLUSIONS: Within the testing conditions of this study, the PL bundle does not affect anterior translation and rotation of the knee; the AM bundle is the primary restraint of the anterior translation but does not affect rotation of the knee while the lesion of the LCL increases tibial rotation and could be related to the pivot shift phenomenon, so it is more correct and biomechanical valid to assess and repair the associated lesion of the antero-lateral structure of the knee at the time of ACL surgery.

Biomechanical evaluation of different anterior cruciate ligament fixation techniques for hamstring graft.

BACKGROUND: A number of anterior cruciate ligament (ACL) fixation techniques are currently in use. Slippage or failure of the graft by excessive loading or aggressive rehabilitation may result in an unstable knee. Load and slippage of the ACL graft varies according to the fixation technique used. METHODS: Graft slippage, load to failure, and stiffness were evaluated using an animal model. Six soft tissue ACL fixation techniques and bone cement as a fixation device were tested: group A, Endo Button CL-Bio RCI; group B, Swing Bridge-Evolgate; group C, Rigidfix-Intrafix; group D, Bone Mulch-Washer Lock; group E, Transfix-Retroscrew; group F, Transfix-Deltascrew; group G, Kryptonite bone cement. Maximum failure load, stiffness, and slippage at the 1st and 1000th cycles and mode of failure were evaluated. RESULTS: The maximum failure load was significantly higher in group B (1030 N) and significantly lower in group E (483 N) than in the others. The stiffness of group B (270 N/mm) was significantly higher than the others. As for the mode of failure, group C showed failure in the femoral side in all tests (four device ruptures and two tendon ruptures on the femoral side). All failures of the other groups occurred on the tibial side except one test in group A. All failures in group G were due to slippage of the tendons. CONCLUSION: Load to failure and stiffness was significantly different between the ACL fixation techniques. All but one of the fixation techniques showed sufficient properties for adequate postoperative rehabilitation. Bone cement used as a fixation device in soft tissue grafts did not seem to provide adequate initial fixation suitable for early rehabilitation after ACL reconstruction.

Sequence specific peptidomimetic molecules inhibitors of a protein-protein interaction at the helix 1 level of c-Myc.

Our work is focused in the broad area of strategies and efforts to inhibit protein-protein interactions. The possible strategies in this field are definitely much more varied than in the case of ATP-pocket inhibitors. In our previous work (10), we reported that a retro-inverso (RI) form of Helix1 (H1) of c-Myc, linked to an RI-internalization sequence arising from the third alpha-helix of Antennapedia (Int) was endowed with an antiproliferative and proapoptotic activity toward the cancer cell lines MCF-7 and HCT-116. The activity apparently was dependent upon the presence of the Myc motif. In this work, by ala-scan mapping of the H1 portion of our molecules with D-aa, we found two amino acids necessary for antiproliferative activity: D-Lys in 4 and D-Arg in 5 (numbers refer to L-forms). In the natural hetero-dimer, these two side chains project to the outside of the four alpha-helix bundle. Moreover, we were able to obtain three peptides more active than the original lead. They strongly reduced cell proliferation and survival (RI-Int-VV-H1-E2A,S6A,F8A; RI-Int-VV-H1-S6A,F8A,R11A; RI-Int-VV-H1-S6A,F8A,Q13A): after 8 days at 10 muM total cell number was approximately 1% of the number of cells initially seeded. In these more potent molecules, the ablated side chains project to the inside in the corresponding natural four alpha-helix bundle. In the present work, we also investigated the behavior of our molecules at the biochemical level. Using both a circular dichroism (CD) and a fluorescence anisotropy approach, we noted that side chains projecting at the interior of the four alpha-helix bundle are needed for inducing the partial unfolding of Myc-H2, without an opening of the leucine zipper. Side chains projecting at the outside are not required for this biochemical effect. However, antiproliferative activity had the opposite requirements: side chains projecting at the outside of the bundle were essential, and, on the contrary, ablation of one side chain at a time projecting at the inside increased rather than decreased biological activity. We conclude that our active molecules probably interfere at the level of a protein-protein interaction between Myc-Max and a third protein of the transcription complex. Finally, CD and nuclear magnetic resonance (NMR) data, plus dynamic simulations, suggest a prevalent random coil conformation of the H1 portion of our molecules, at least in diluted solutions. The introduction of a kink (substitution with proline in positions 5 or 7) led to an important reduction of biological activity. We have also synthesized a longer peptido-mimetic molecule (RI-Int-H1-S6A,F8A-loop-H2) with the intent of obtaining a wider zone of interaction and a stronger interference at the level of the higher-order structure (enhanceosome). RI-Int-H1-S6A,F8A-loop-H2 was less active rather than more active in respect to RI-Int-VV-H1-S6A,F8A, apparently because it has a clear bent to form a beta-sheet (CD and NMR data).

Conformation dependent pro-apoptotic activity of the recombinant human prion protein fragment 90-231.

The transition of prion protein from a mainly alpha-structured isoform (PrPC) to a beta sheet-containing protein (PrPSc) represents a major pathogenetic mechanism in prion diseases. To study the role of PrP structural conformation in prion-dependent neurodegeneration, we analysed the neurotoxicity of PrP in alpha and beta conformations, using a recombinant protein encompassing amino acids 90-231 of the human PrP (hPrP90-231). Using controlled thermal denaturation (53 degrees C, 1h) we converted hPrP90-231 in a structural isoform displaying PrPSc-related characteristics: high beta sheet content, increased aggregability and a slight increase in the resistance to protease K. In virtue of these structural changes, hPrP90-231 powerfully affected the survival of SH-SY5Y cells, inducing a caspase-3 and p38- dependent apoptosis. Conversely, in the native alpha-helix-rich conformation, hPrP90-231 did not show significant cell toxicity. The relationship between the structural state of hPrP90-231 and its neurotoxicity was demonstrated, inducing the thermal denaturation of the peptide in the presence of Congo red that prevented both the transition of hPrP90-231 into a beta-rich isoform and the acquisition of toxic properties. In conclusion, we report that the toxicity of hPrP90-231 is dependent on its three-dimensional structure, as is supposed to occur for the pathogen PrP during TSE.

An evaluation of the NCI Physician Data Query (PDQ) dissemination in Europe.

The Physician Data Query (PDQ) is a computerised medical database aimed at communicating cancer-related information through computer technology. PDQ has been distributed in Europe since 1988 and in the U.S. since 1985. A study aimed at evaluating whether PDQ had reached a wide medical community was conducted among European PDQ distributors in 1992 as part of an evaluation of PDQ use and impact. Results indicate that PDQ promotion was limited and that several countries were underserved. A preference was expressed for on-line systems. It was found that PDQ access was limited by the requirement of special equipment, by subscription costs and by language barriers. Subscribers were found mainly in the countries with the highest number of distributors. Among a total 12,205 reported subscribers, only 20% were physicians. The proportion of physicians subscribing to the system was, therefore, low (range 4-39.7/10,000). Altogether 453 searches (range 0-213) and 84.5 h of connection time (range 0-52.5) were reported per month for Europe. It is obvious that additional investigation is needed to further evaluate the impact of PDQ on clinical practice.

Clinical trials and quality of life assessment: the nurses' viewpoint.

The rationale for quality of life assessment has been largely developed in the literature. Quality of life is an important concept in the oncology environment because the physical, psychological and social wellbeing of patients are affected both by the disease and the related treatments. The relevance of quality of life assessment to nursing clinical practice has been discussed by several authors. There is a need to use more valid and reliable instruments to plan appropriate nursing care, to evaluate and document the effect of nursing interventions. In clinical trials, quality of life assessment is being used increasingly to predict patients' outcomes and to evaluate medical and nursing interventions. Nurses' viewpoints of potential benefits and pitfalls related to quality of life assessment are discussed. Among the benefits, it is usually considered that therapeutic interventions might be improved. These could be adjusted and individualised and the need for supportive care interventions might be evaluated more accurately. As for the pitfalls, the quality of life evaluation causes an extra burden if its implementation is not properly co-ordinated and if poor or incomplete guidelines are provided to patients and staff. Proposals for implementing effective quality of life assessment in clinical trials are discussed. Basic requirements, such as preliminary instructions, guidelines for administration of the questionnaire and proposals for reducing missing evaluations, are presented.

Morphological, phenotypic and karyotypic characterization of a novel natural-killer-cell target - evidence of involvement of MHC class-I molecules in NK cell recognition.

A new cell line from a neoplastic ascites was established. This strain, designated PAT-206, was characterized by plastic adherence and a high proliferative potential without any specific growth factor requirement. Karyotype analysis showed that the line was of human chromosomal constitution and aneuploid. Surface marker analysis showed that CD45, CD33 and CD15 were positive. In addition, the presence of human cytokeratins was detected by cytoplasmic immunofluorescence. Interestingly, the cell line did not express major hystocompatibility complex (MHC) class I and II, and was more sensitive than the 'classic' K562 cell line, to killing mediated by fresh uncultured peripheral blood lymphocytes. Following differentiation with interferon-gamma, the cell line expressed MHC class I antigens and resulted resistant to natural killing mediated lysis. This novel NK cell target seems to be suitable for further studies on NK cell specificities.

Response to STI571 in chronic myelomonocytic leukemia with platelet derived growth factor beta receptor involvement: a new case report.

Based on its ability to inhibit the tyrosine kinase activity of ABL, as well as the c-kit and the Platelet Derived Growth Factor Receptor tyrosine kinases, the spectrum of diseases that may respond to STI571 is increasing. A recently recognized subgroup of myeloproliferative disorders/myelodysplastic syndromes (MPD/MDS) has a t(5;12)(q33;p13) with the activation of the gene for PDGFBR which encodes a receptor tyrosine kinase. Here, we present the case of a patient, with MPD/MDS, and eosinophilia, carrying a translocation t(5;12)(q33;p13) who achieved a complete remission following treatment with STI571, 400 mg daily. At the time of writing he still remains in complete remission with an excellent performance status. There is clearly a need for further studies of STI 571in MPD/MDS with chromosomal translocations involving PDGFBR to confirm this promising initial result.

The role of thalidomide in the treatment of refractory chronic graft-versus-host disease following bone marrow transplantation in children.

Chronic graft-versus-host disease (cGVHD) is a frequent complication of allogeneic bone marrow transplantation (BMT). Thalidomide was found to have immunosuppressive properties and it has been used in a limited number of children with cGVHD. We report our experience with refractory and/or high-risk cGVHD in 14 children. Six children showed complete clinical response to thalidomide in a median time of 2 months. Four children had partial responses and four failed. Side-effects were usually mild (somnolence, constipation) and only two patients developed sensory peripheral neuropathy. An increased incidence of infectious complications attributable to thalidomide was not observed. Nine out of 10 responding patients are alive 49-111 months post-BMT. Thalidomide can be effective particularly in children with prevailing mucocutaneous cGVHD. All patients should be carefully monitored to detect peripheral neuropathy early.

Long-term effects of bone marrow transplantation on dental status in children with leukaemia.

Minimal data about oral and dental health in long-term survivors after BMT are available. We studied the dental status of 27 children (19 males, eight females) with leukaemia, followed up with a routine oral examination, panoramic tomogram and, when necessary, an endoral radiograph at a median of 2 years (range 1-10) after BMT. Community periodontal index treatment necessity (CPITN), dental caries, missing or filled permanent teeth (DMFT) and dento-facial alterations according to WHO criteria were registered and evaluated. Median age of the patients at BMT was 9 years (range 1.1-17.9). The mean DMFT score ranged from 1.6 to 12.4 according to age at examination and was slightly higher than that which we previously reported in children who received chemotherapy alone. CPITN showed the presence of soft deposits in 77.7%, serious gingivitis in 59.2% and parodontal involvement in 3.7% of cases. Dento-facial abnormalities were found in 55.5% of patients, while 62.9% of the patients had tooth abnormalities or agenesis. Nine out of 27 patients (33%) had root hypoplasia. A negative impact on DMFT index due to multiple post-BMT factors was found. Age is the crucial factor in determining a developmental defect of enamel and root. The follow-up of long-term survivors after BMT should include regular dental examination.

Fibrin sealing of mucoperichondrial flaps in endonasal-transsphenoidal pituitary surgery: technical note.

We describe a simple technique that helps to avoid nasal septum perforations and the related complications after endonasal-transseptal transsphenoidal pituitary surgery. At the end of the Hirsch procedure, the mucoperichondrium is fixed to the septal cartilage with a thin layer of fibrin glue. Two silicone splints are applied to both sides of the septum and left in place for 2 days. The technique is very useful in preventing possible displacement of the mucoperichondrium, which may lead to compression and ischemia of the doubled mucosa between the septal cartilage and the silicone splints. A firm fixing of the margins of a mucoperichondrial laceration to the septal cartilage creates conditions for optimal healing and reduces nasal-packing time and nasal-splinting time. The technique is recommended for all patients with and without mucosal tears and is also recommended for the transsphenoidal reoperations.

Comparison between the QOLIE-31 and derived QOLIE-10 in a clinical trial of levetiracetam.

PURPOSE: to determine whether the QOLIE-10, an abbreviated quality of life questionnaire, provides results similar to the more detailed QOLIE-31 instrument when the ten items are derived from the QOLIE-31. METHODS: the QOLIE-31 was completed by 246 patients participating in UCB protocol N132 at baseline and after 18 weeks of treatment with levetiracetam (LEV 1000 or 3000 mg) or placebo added to standard therapy. QOLIE-10 components and total scores were calculated from the QOLIE-31 data. RESULTS: baseline QOLIE-10 components and total score correlated highly with corresponding QOLIE-31 scores, both at baseline and follow-up (range 0.70-0.95). Changes from baseline to follow-up were significantly different (ANCOVA) among treatment groups for both the QOLIE-10 and QOLIE-31 for the total score (P = 0.02, P = 0.009, respectively), seizure worry (P = 0.005, P = 0.0003) and cognitive functioning (P = 0.01, P = 0.01). One subscale (overall QOL) showed significant change with the QOLIE-31 (P = 0.04), but not with the QOLIE-10 (P = 0.07). Differences in QOLIE-10 scores were found between responders (> or = 50% partial onset seizure reduction) and non-responders for the total score (P = 0.0001) and two components (overall QOL P = 0.002, social function P = 0.0003). In the QOLIE-31, the total score and six subscale scores (all except medication effects) were significantly different. Both instruments were able to detect change over time. Responsiveness assessed by effect sizes (- 0.1 for non-responders, 0.4 for responders, 0.8 for seizure-free patients) and the Guyatt statistic (0.1, 0.6 and 1.0, respectively) was similar for both instruments. CONCLUSIONS: although the QOLIE-10 was designed as a screening tool, it can be scored and used in research. The total score did discern differences among treatments in a clinical trial. Nonetheless, questionnaires with multiple, multi-item subscales provide more detailed information than abbreviated forms. The QOLIE-31 is preferred where time and resources are available.

Bilateral anomalous course of the ulnar nerve at the wrist causing ulnar and median nerve compression syndrome. Case report.

The case of a patient with a bilateral compression syndrome of the ulnar and median nerves at the wrist is described. Both ulnar nerves, which were surgically explored at different times, followed an anomalous course and passed into the canalis carpi side by side with the median nerve. This variation in the course of the ulnar nerve is extremely rare and causes a unique syndrome with characteristic electromyographic patterns.

Intradural neurotropic spread of malignant mesothelioma. Case report and review of the literature.

This 54-year-old man with a history of right-sided malignant mesothelioma presented with signs of a partial spinal cord syndrome. The tumor had invaded the lower trunk of the brachial plexus and spread along the T-1 nerve root beneath the arachnoid onto the spinal cord itself. Mesothelioma, despite its known predilection for local spread, is rarely encountered within the spinal canal. Neurotropism is commonly encountered in facial malignancies; however, it has never been reported to affect the brachial plexus and spinal cord.

Post-traumatic cubitus varus. Long-term follow-up of corrective supracondylar humeral osteotomy in children.

The results in twenty-four patients who had had a supracondylar osteotomy of the humerus to correct post-traumatic cubitus varus were reviewed after the patients had completed skeletal growth. The average age of the patients was 7.9 years at operation and thirty-one years at the time of follow-up. The average duration of follow-up was twenty-three years. According to our grading system, seven patients had a good; six, a fair; and eleven, a poor result. All but two of the nineteen patients in whom the humero-ulnar angle had been measured preoperatively lost correction that had been obtained at operation. No correlation was found between the quality of the result and either the age of the patient at operation or the amount of correction that had been obtained at operation. The correction that was obtained at operation was maintained in the two patients in whom the cubitus varus deformity had been caused by malunion of a supracondylar fracture. However, when the deformity followed either physeal injury or supracondylar fracture with damage to the physis secondary to the initial trauma, the correction was not maintained. At the most recent follow-up, three patients were symptomatic, and fourteen were dissatisfied with the cosmetic result because of the residual deformity of the elbow or the postoperative scar, or both. In spite of the partial recurrence of the deformity, which was sometimes severe, all but the three symptomatic patients had a very good functional result. Many of these patients worked at heavy manual labor.

The abductor and adductor strength characteristics of professional baseball pitcherse.

The purpose of this investigation was to establish a data base regarding the isokinetic muscular performance characteristics of the abductor and adductor muscles of professional baseball pitchers. Eighty-three healthy professional baseball pitchers (mean age, 22.6 years; mean weight, 199 pounds) were evaluated by use of a Biodex isokinetic dynamometer. Isokinetic tests were performed concentrically at 180 and 300 deg/sec for both the throwing and nonthrowing shoulders. The testing protocol and test repetitions were standardized for each subject. Statistical analysis was performed using a paired t-test. Determination of the correlation coefficient was made at the P < 0.05 level of significance. Test results for bilateral comparisons of mean peak torque for the throwing and nonthrowing shoulders demonstrated a significant difference in adductor values between the dominant and nondominant shoulders at both test speeds. There were no significant differences between extremities for the shoulder abductor muscles. The abductor-to-adductor muscle ratios between the throwing and nonthrowing shoulders were also statistically significant at both test speeds. Throwing arm values were 82.5% at 180 deg/sec and 93.8% at 300 deg/sec compared with only 66.0% and 70.3%, respectively, for the nonthrowing shoulders.

The strength characteristics of internal and external rotator muscles in professional baseball pitchers.

The purpose of this study was to establish a data base regarding the isokinetic muscular performance characteristics of the external/internal rotator muscles of professional baseball pitchers. One hundred fifty healthy professional baseball pitchers were evaluated by use of a Biodex isokinetic dynamometer. The subjects tested had a mean age of 23.4 years and a mean body weight of 199 pounds. Isokinetic tests were performed concentrically at 180 and 300 deg/sec for both the throwing and nonthrowing shoulders. Testing procedures regarding positioning and stabilization followed established guidelines. The testing protocol and actual test repetitions were standardized for each subject. Statistical analysis was performed using the Pearson Product Moment Correlation and paired t-tests. Determination of the correlation coefficient was made at the P < 0.05 level of significance. Test results for bilateral comparison of mean peak torque for the throwing and nonthrowing shoulders indicated no statistically significant difference between the internal rotators at both test speeds, or for the external rotators at 300 deg/sec. There was a significant statistical difference at the 180 deg/sec test speed for the external rotators. The external/internal rotator strength ratio indicated a 65% ratio at 180 deg/sec and a 61% ratio at 300 deg/sec. Data were also collected for mean peak torque/body weight ratios of the throwing shoulder to establish a data base in professional throwers. This study offers clinical relevance in establishing a muscle performance profile for the professional thrower. This data base can therefore be used as criteria that should be met before an injured pitcher can be returned to throwing at the professional baseball level.

Cerebral abscesses: topic treatment with antibiotics.

The Authors, after a brief discussion of current therapies used in the treatment of cerebral abscesses, present a series of 10 cases treated topically with antibiotics (through drill-hole and puncturing of the abscess). The determining role of CT scan in this technique is emphasised.

Right occipital cerebral abscess caused by Aspergillus fumigatus.

A rare case of intracerebral abscess caused by aspergillus fumigatus located in the right occipital region is described; pathogenesis, prognosis and treatment of this particular infection are discussed.