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Biomedical subjects

M Freund

Publications and source records attributed to M Freund.

At least 73 records · Page 4Linked to original sources

Correlation of cytogenetic, molecular cytogenetic, and clinical findings in 59 patients with ANLL or MDS and abnormalities of the short arm of chromosome 12.

Abnormalities of the short arm of chromosome 12 (12p) are found in about 5% of acute nonlymphocytic leukaemias (ANLL) and myelodysplastic syndromes (MDS). They are described to be characteristic of secondary leukaemias, especially after prior mutagenic exposure, and to be associated with a poor prognosis. In our series of 59 patients with 12p abnormalities and ANLL or MDS, exposure to genotoxic agents was proven only in five patients, but in 13/44 patients ANLL evolved from an MDS. Patients with a small deletion del(12)(p11.2p13) having a mild clinical course were distinguished from those with a large del(12)(p11.2), additional chromosomal anomalies, and a poor clinical course. Among the 31 patients with translocations or dicentric chromosomes involving 12p, a group of eight with t/dic(12;13) was the most frequent and was associated with a poor prognosis. The clinical outcome was adverse in the majority of patients with complex karyotype abnormalities, but in some patients a milder clinical course seems likely. A new, hitherto undescribed, abnormality in an MDS case with a duplication dup(12)(p11.2p13) was the amplification of the signal of the yeast artificial chromosome (YAC) clone 964c10 (D12S736). In 38 cases with deletions or unbalanced translocations/dicentrics one YAC signal was lost. Five patients with balanced translocations demonstrated breakpoints within the YAC, containing the ETV6 (TEL) gene. The breakpoints were telomeric to the YAC 964c10 in seven cases and centromeric in one patient.

Adult↗

[Computerized tomography and magnetic resonance imaging findings in central neurocytoma].

PURPOSE: Analysis of our CT and MRI findings in patients with central neurocytomas in comparison with the relevant literature. MATERIALS AND METHODS: 5 patients were examined by CT and MRI. A retrospective analysis of the histologically confirmed tumors of our patient group and date from the literature was performed under the following criteria: 1. topography, 2. extent, 3. contrast medium behavior, 4. calcifications, 5. presence of intramural cysts, and 6. vascularization. These properties were evaluated according to a 5 point scale. RESULTS: All tumors originated in the roof of a lateral ventricles with participation of the pellucid septum and extended intraventricularly (5/5), showed cystic components (5/5), and took up contrast medium (5/5). Contrast medium uptake was visible in both CT and MRI. In contrast, only three of the 5 tumors revealed calcifications (3/5) and these were better visible in CT than in MRI, no pathological vessels were detected. Because of its multi-planar representations and better soft-tissue contrast, MRI was superior to CT for the exact determination of origin and position of the tumors. The small cystic, inhomogenous appearance in T2-weighted images was considered to be an especially typical feature. CONCLUSIONS: The typical appearance of central neurocytomas in CT and MRI provides information for the differential diagnosis from other intraventricular tumors. The definitive diagnosis is provided by neuropathological evaluation.

Adolescent↗

[Magnetization transfer contrast: experimental sequence optimization for study of the cerebral substantia alba].

PURPOSE: A new application for magnetization transfer (MT) MR imaging is the investigation of cerebral white matter. For that a pure MT effect is desirable. Our purpose was the optimization and testing of an MT sequence for investigations of cerebral white matter. MATERIAL AND METHODS: Experimental investigations were performed in phantom material and in 5 wistar rats using various frequency offsets (FO) (200 Hz-30,000 Hz). Relative signal suppression (rSS) for the phantom material and for callosal white matter of the rat was calculated. The optimized sequence was tested in 25 healthy volunteers. RESULTS: A relatively pure MT effect was achieved with FO > 4000 Hz. rSS for cerebral white matter structures was generally higher than rSS für cerebral gray matter structures. rSS for cerebral white matter structures ranged from 45-50%. CONCLUSION: We present a fast MT sequence with high rSS for cerebral white matter and a relatively pure MT effect. Owing to the high rSS-values we expect that this sequence improves differentiation of cerebral white matter lesions. Because of the confusing variety of MT sequence currently described in the literature we believe that standard parameters should be defined to make published results comparable.

Animals↗

Mantle-cell lymphomas have more widespread disease and a slower response to chemotherapy compared with follicle-center lymphomas: results of a prospective comparative analysis of the German Low-Grade Lymphoma Study Group.

PURPOSE: To compare mantle-cell lymphomas (MCLs) and follicle-center lymphomas (FCLs) for their features of clinical presentation, response to chemotherapy, and prognosis on the basis of a prospective randomized clinical trial. PATIENTS AND METHODS: Patients with MCL and FCL who entered onto the prospective randomized comparison of cyclophosphamide, vincristine, and prednisone (COP) versus prednimustine and mitoxantrone (PmM) followed by a second randomization for interferon (IFN) maintenance versus observation only. RESULTS: One hundred sixty-five of 234 patients had FCL and 45 of 234 patients had MCL. With FCL, both sexes were equally affected (men, 47%); patients with MCL were predominantly men (78%; P < .0004) and had a higher median age (64 v 53 years; P < .0001). Patients with MCL also had more widespread disease, reflected by the proportion of patients with two or greater extranodal manifestations (43% v 21%; P < .005) and nine or greater involved nodal areas (64% v 45%; nonsignificant [NS]). Response to chemotherapy was significantly lower in patients with MCL (complete remission [CR] + partial remission [PR], 69% v 88%; P < .05) and occurred at a slower pace. Patients with MCL also had a shorter event-free interval (median, 8 v 24 months; P < .0001) and overall survival (median, 28 v 77 months; P < .0001). In both subtypes, however, patients with less than two residual lymphoma manifestations in remission experienced a relatively good prognosis with an estimated 5-year survival of greater than 60% for MCL and greater than 75% for FCL. CONCLUSION: MCL and FCL differ substantially in their features of presentation, response to chemotherapy, and long-term prognosis. The extent of residual disease after completion of chemotherapy discriminates patients with different prognosis and may be used for the stratification of postremission strategies.

Adult↗

[Changes in hemostasis of dogs with acute lymphoblastic leukemia].

Twelve dogs suffering from acute lymphoblastic leukaemia were investigated concerning the following tests: platelet count, prothrombin time (PT, standard test, modified test), activated partial thromboplastin time (APTT), activity of the individual coagulation factors II, V, VII, X, VIII:C, IX, XI, XII, prekallikrein, and high-molecular weight kininogen, the activity of antithrombin III (AT III), protein C, plasminogen, and alpha 2-antiplasmin as well as concentration of fibrinogen, soluble fibrin and fibrin(ogen) degradation products (FDP). All patients showed a decreased platelet count due to suppression of megakaryopoesis by infiltration of the bone marrow with leukaemic cells. In addition, in most of the patients a moderate activity decrease of one or more individual coagulation factors has been found, especially regarding factor II (median, x0.50 = 51%, p = 0.0001), but also factors X (x0.50 = 71%, p = 0.0003) and XI (x0.50 = 68%, p = 0.0006). This was reflected by the APTT and the PT activity (modified test), which were prolonged or decreased, respectively, in the majority of the cases. Furthermore, the activity of AT III and of plasminogen was distinctly diminished (p < 0.001). Like the concentration of FDP, the plasma level of soluble fibrin was significantly higher than in normal dogs (p < 0.001). This indicates that besides thrombocytopenia disseminated intravascular coagulation occurs frequently in dogs with acute lymphoblastic leukaemia and is a main cause for the decreased activity of several plasmatic components of the haemostatic system. The lack of correlation between the concentration of soluble fibrin as an indicator of intravascular coagulation and the total blast cell count (rS = 0.011) shows the importance of other factors like degree of cell lysis as well as participation of organs such as the liver for generation of consumption coagulopathy in dogs with acute lymphoblastic leukaemia.

Angiotensins↗

Simultaneous determination of homologues of vitamin E and coenzyme Q and products of alpha-tocopherol oxidation.

A sensitive procedure is described for the simultaneous determination of vitamin E and coenzyme Q homologues and alpha-tocopherol oxidation products using two-isocratic step high pressure liquid chromatography (HPLC) and electrochemical detection in the oxidative mode. Zinc-catalyzed reduction in a post-column reactor allows the detection of alpha-tocopherolquinone, epoxy-tocopherolquinone, and ubiquinones. This technique was used to quantify lipophilic antioxidants in the liver tissue of rats treated or not with alpha-tocopherolquinone and in a plant oil. Alpha-tocopherolquinone and its epoxide derivatives, formed from alpha-tocopherol during iron-catalyzed phospholipid peroxidation, were also determined in a liposome suspension. The high selectivity and sensitivity of the coulometric detection system enabled use of low oxidation potentials giving little baseline noise, while a fast isolation procedure and quantitative recoveries of all oxidized and reduced forms made it possible to measure a high ubiquinol/ubiquinone ratio in liver tissue. Administration of alpha-tocopherolquinone to rats did not alter the antioxidant status of the liver, despite strong accumulation of both this quinone and its reduced form, alpha-tocopherolhydroquinone. These results indicate the presence of an efficient reductase and suggest that it could contribute to the protection of cellular membranes from oxidative stress.

Animals↗

[Pheochromocytoma associated with pregnancy. Report of 2 cases and review of the literature].

Pheochromocytoma is rarely observed during pregnancy and not easily diagnosed, especially since the clinical manifestations may mimic common gravid hypertension. The maternal and fetal prognosis depends on early diagnosis and multidisciplinary management preparing for tumor resection. Appropriate laboratory tests easily provide the positive diagnosis, if they are ordered. The tumor is localized by ultrasonography or magnetic resonance imaging (MRI). By prescribing an alpha-blocker, it is possible to prepare the resection as a function of term, before or after delivery. This strategy allows a reduction in maternal and fetal mortality which is high if the pheochromocytoma goes undiagnosed.

Adrenal Gland Neoplasms↗

Adenovirus mediated alpha interferon (IFN-alpha) gene transfer into CD34+ cells and CML mononuclear cells.

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Interferon-alpha (IFN-alpha) has been used in the management of leukemia but its diverse adverse activities with multiple potential side effects, possibly unrelated to therapeutic targets, may negatively influence the ability of IFN-alpha to treat this disorder. Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal (CD34+ cells) and chronic myelogenous leukemia (CML) bone marrow mononuclear cells (BMMNC) and the transient overexpression of IFN-alpha in these cells. Ad-cytomegalovirus promoter driven IFN-alpha (AdCMV-IFN-alpha) at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture, and optimal transduction of CD34+ cells was achieved using 120 plaque forming units. Flow cytometric determinations revealed that there was no significant difference in cell viability for the 4 h or 24 h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells. Transient expression of the IFN-alpha gene did not suppress proliferation of CD34+ progenitors as indicated by BFU-E or colony forming units-granulocyte-macrophage (CFU-GM) growth. Reverse transcriptase/polymerase chain reaction analysis of RNA from CD34+ harvested CFU-GM progenitor cells demonstrated transient IFN-alpha mRNA expression. Similarly, CML BMMNC were transfected with AdCMV-IFN-alpha under similar conditions as described for CD34+ cells. BMMNC cells exposed to adenovirus for 24 h and 48 h were found to express IFN-alpha at a substantial level. This in vitro data suggest that Ad-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha gene can be translated into its specific mRNA in CD34 progenitor cells.

Adenoviridae↗

Long-term follow up of children with head injuries-classified as "good recovery" using the Glasgow Outcome Scale: neurological, neuropsychological and magnetic resonance imaging results.

UNLABELLED: The primary issues addressed in this study were: (1) determination of the significance of the classification "good outcome" utilizing the Glasgow Outcome Scale (GOS) in children at least 1 year after brain injury; (2) detection of residual lesions of brain parenchyma in these children upon follow up MRI scans; and (3) detection of relationships between neuropsychological test performance and MRI results. Selection criteria included children 6-15 years of age at the time of testing who received an initial CT scan at the time of their head injury and who had been injured at least 12 months prior to the follow up test. Only children who did not demonstrate neurological disability at the time of follow up examination were selected. The children showed a status of "good outcome" as defined by the GOS. Neurological examination, neuropsychological tests and an MRI were done. The test results of 59 patients were compared to those of a matched control group. Children, after receiving head injuries, showed significantly poorer results with respect to cognitive, motor and fine motor skills. Of all MRI-scans 66% revealed pathological findings. Cortical lesions were detected on MRI in 14% of cases; subcortical injuries were detected in 12% and, deep white matter lesions in 31%. Furthermore, corpus callosum damage was observed in 26% of cases. Pathological MRI findings were also observed in children with mild head injuries. All of the children with normal MRI findings showed abilities comparable to those of children in the control group. Patients with cortical lesions exhibited only motor deficits, whereas motor and cognitive deficits were seen in patients with deep white matter lesions. Children with multiple lesions demonstrated test results in all variables 1 to 2 standard deviations below those of the control group. CONCLUSION: Children suffering a brain injury who 1 year later are classified within the "good outcome" group according to the Glasgow Outcome Scale often have significant morphological and functional brain deficits.

Adolescent↗

[CT of the talus: the importance of 2- and 3-dimensional reconstructions].

PURPOSE: To evaluate the clinical value of sagittal 2D- and 3D-reformations of the talus with and without electronic disarticulation compared to axial slices. MATERIAL AND METHODS: 23 patients with suspected traumatic lesions of the talus underwent 26 diagnostic CT examinations. Axial slices, sagittal reformations, and 3D-reformations without and with electronic disarticulation were performed. The sagittal 2D- and both types of 3D-reformations were compared to the axial slices with regard to their diagnostic information. RESULTS: Axial slices showed involvement of articular facets in 25 cases. Sagittal and 3D-reformations after electronic disarticulation depicted 23 fractures (23/25), 3D-reformations without electronic disarticulation showed none (0/23). Subluxation of the talocalcaneal joint was only visualised on axial slices three times. One complete luxation of this joint was shown on axial slices, sagittal and 3D-reformations without disarticulation. It was not visualised on 3D-reformations after disarticulation. CONCLUSION: The diagnosis must be made based on the axial slices, supported by sagittal reconstructions. 3D-reformations after electronic disarticulation provide a graphic, detailed and readily recognised image of the anatomy of transchondral fractures, and are very helpful in preoperative planning.

Adolescent↗

[The plain-film radiological changes in the cervical spine following a ventral fusion operation with bone cement].

PURPOSE: The usual treatment in cervical nerve root compression syndrome is the ventral fusion with bone cement. We examined the influence of this interponate on the postoperative changes of the cervical spine. MATERIALS AND METHODS: 33 patients were followed-up postoperatively over 6 months, who were treated with 39 ventral fusions because of cervical myelopathy. The lateral view of the cervical spine was used to measure the size of the bone cement interponate, the height of the intervertebral body space and the angle of both vertebral bodies. RESULTS: There was no change on the size of the interponate. Postoperatively there was a slight enlargement of the intervertebral body space. During further follow-up examinations there was a decrease to the preoperative size because of the destruction of the endplates. Similar to this observation, there was a change of the angle in the operated segment. First there was a decrease of the angle, later an increase. 6 months postoperatively the preoperatively status was re-attained. Clinical examination of the patients revealed new neurologic deficits in 10% of the cases. CONCLUSION: We conclude that the postoperative deficits can be only partially explained because the structural changes occur with both the uncomplicated postoperative courses and in patients with postoperative deficits.

Adult↗

[Digital chest x-rays with a selenium detector: a prospective comparison with a conventional film-screen combination].

PURPOSE: To compare a new digital chest radiography system that uses amorphous selenium as the x-ray detector, with conventional radiography for the detection of pathological alterations of the chest. MATERIAL AND METHODS: Two observers analysed pairs of posteroanterior and lateral chest radiographs of 95 patients. One pair of radiographs was obtained with the digital selenium chest radiography system, and the other with conventional film-screen technique. 9 criteria were rated using a 4 point scale. Technical parameters were standardised. Radiation dose was measured in both techniques and compared. RESULTS: A total of 855 criteria were rated. 740 findings were diagnosed in accordance on both techniques (740/855 = 87%). 115 criteria (115/855 = 13%) showed deviations. The mean radiation dose for the selenium detector was 0.02 cGy and for the conventional system 0.11 cGy. CONCLUSION: The exposure of radiation is lower using a selenium x-ray detector compared to conventional film-screen technique in chest radiography. The digital selenium system performs well in a clinical setting, providing visualisation of pathological findings as good as a standard screen-film system.

Adult↗

[CT morphology of fractured thoraco-lumbar vertebrae after transpedicular spongiosaplasty and use of internal fixator].

PURPOSE: An analysis of the CT morphology of fractured thoraco-lumbar vertebrae after treatment with internal fixation and transpedicular spongiosaplasty (SP). MATERIAL AND METHOD: 30 patients were examined following trauma and surgery after about 12 and 30 months by means of CT. The following were evaluated: width of the spinal canal; height of the vertebra and intervertebral space; degree of kyphosis; position, size and appearance of the SP and of the vertebral body. RESULTS: The width of the spinal canal was reconstituted in 91%; in 83% the anterior vertebral margin and in 35% the intervertebral space was reduced. A kyphosis of 8.9 degree was found on the followup examination. The SP showed a reduction in size (18/30) or could no longer be defined (6/30). Hypodense areas (28/30) with cavitation (12/30) were found in the vertebral body and the SP could be identified by a sclerotic margin (22/30). CONCLUSION: Treatment by this form of therapy was successful, reaction of the vertebral body against the spongiosaplasty could be identified.

Adolescent↗

[MR myelography in spinal canal stenosis].

PURPOSE: The purpose of this prospective study was to evaluate the clinical value of 3D-MR-myelography (3D-MRM) in comparison to myelography and intra-operative findings. MATERIAL AND METHODS: 25 patients with suspected lumbar spinal canal stenosis were studied via myelography and 3D-MRM (volume-data set, 3D-FISP sequence, TR 73 ms, TE 21 ms, flip angle 7 degrees, sagittal slices) besides the routinely acquired sagittal and axial T1- and T2-weighted images. Diagnoses were made by two radiologists and one neurosurgeon without knowing the clinical history and symptoms, in two separate sessions. Results were compared to intraoperative findings. RESULTS: 3D-MRM has the same diagnostic sensitivity (25/25 = 100%) as conventional X-ray myelography (25/25 = 100%) compared to intraoperative findings, but is not invasive and shows more diagnostic details than myelography. Especially in cases of high-grade spinal canal stenosis there is often a lack of intrathecal contrast medium distally of the stenosis. CONCLUSION: 3D-MRM is as good as conventional myelography in predicting intraoperative findings in patients with lumbar spinal canal stenosis. This new method is non-invasive and can be performed routinely on an outpatient basis.

Adult↗

Urticaria in idiopathic bilateral recurrent branch retinal arterial occlusion.

Idiopathic bilateral recurrent branch retinal arterial occlusion (IBRBRAO) is a rare syndrome characterized by migraine headaches, tinnitus, vertigo, hearing loss, and recurrent branch retinal artery occlusion of unknown etiology. Affected patients frequently undergo a wide range of medical evaluation and have no apparent pathologic findings. We present here a case of IBRBRAO, associated with urticarial rash, not described in this syndrome in previous publications.

Adult↗

Circadian blood pressure changes in untreated children with kidney disease and conserved renal function.

Ambulatory blood pressure monitoring over 24 h was applied in 31 children with kidney disease, aged 3-19 (median 11) years, in the absence of renal insufficiency and without antihypertensive therapy. Median creatinine clearance was 112 ml/min/1.73m2. Ambulatory blood pressure monitoring revealed that eight patients (26%) were hypertensive during the daytime, compared to 62% through casual recordings obtained in the office and 38% when blood pressure was taken at home. Nocturnal hypertension was detected by ambulatory monitoring in six patients, two of whom had normal blood pressure in the daytime. Median nocturnal dipping was 13% for systolic and 21% for diastolic blood pressure, i.e. similar to healthy children. Rhythm analysis recognized a distorted circadian pattern for systolic and/or diastolic blood pressure in eight patients. In conclusion, ambulatory blood pressure monitoring allows the evaluation of hypertension more reliably than casual recordings in the office. Nocturnal hypertension, as a major risk factor for renal deterioration, is detected in a similar proportion as daytime hypertension in almost 20% of untreated children with kidney disease and normal renal function.

Adolescent↗