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Babadjanov F, Specht U, Lukasczyk T, Mayer B. Heat Accumulation-Induced Surface Structures at High Degrees of Laser Pulse Overlap on Ti6Al4V Surfaces by Femtosecond Laser Texturing. Materials (Basel) 2023; 16:2498. [PMID: 36984383 PMCID: PMC10059092 DOI: 10.3390/ma16062498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 06/18/2023]
Abstract
In this work, femtosecond laser pulses at high repetition rates were used to fabricate unique microstructures on the surface of Ti6Al4V. We investigated the influence of pulse overlap and laser repetition rates on structure formation. Laser texturing with a high degree of overlap resulted in melting of the material, leading to the formation of specific microstructures that can be used as cavities for drug delivery. The reason for melt formation is attributed to local heat accumulation at high repetition rates. Such structures can be fabricated on materials with low thermal conductivity, which prevent heat dissipation into the bulk of the material. The heat accumulation effect has also been demonstrated on steel, which also has low thermal conductivity.
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Affiliation(s)
- Farkhod Babadjanov
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Str. 12, 28359 Bremen, Germany
| | - Uwe Specht
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Str. 12, 28359 Bremen, Germany
| | - Thomas Lukasczyk
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Str. 12, 28359 Bremen, Germany
| | - Bernd Mayer
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Str. 12, 28359 Bremen, Germany
- Faculty of Production Engineering, University of Bremen, 28359 Bremen, Germany
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Borcherding K, Marx D, Gätjen L, Bormann N, Wildemann B, Specht U, Salz D, Thiel K, Grunwald I. Burst Release of Antibiotics Combined with Long-Term Release of Silver Targeting Implant-Associated Infections: Design, Characterization and in vitro Evaluation of Novel Implant Hybrid Surface. Materials (Basel) 2019; 12:E3838. [PMID: 31766488 PMCID: PMC6926566 DOI: 10.3390/ma12233838] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/18/2019] [Accepted: 11/19/2019] [Indexed: 02/06/2023]
Abstract
Implant-associated infections represent a serious risk in human medicine and can lead to complications, revisions and in worst cases, amputations. To target these risks, the objective was to design a hybrid implant surface that allows a local burst release of antibiotics combined with long-term antimicrobial activity based on silver. The efficacy should be generated with simultaneous in vitro cytocompatibility. The investigations were performed on titanium K-wires and plates and gentamicin was selected as an illustrative antibiotic. A gentamicin depot (max 553 µg/cm2) was created on the surface using laser structuring. The antibiotic was released within 15 min in phosphate buffered saline (PBS) or agar medium. Metallic silver particles (4 µg/cm2) in a titanium dioxide layer were deposited using plasma vapor deposition (PVD). About 16% of the silver was released within 28 days in the agar medium. The local efficacy of the incorporated silver was demonstrated in a direct contact assay with a reduction of more than 99.99% (Escherichia coli). The local efficacy of the hybrid surface was confirmed in a zone of inhibition (ZOI) assay using Staphylococcus cohnii. The biocompatibility of the hybrid surface was proven using fibroblasts and osteoblasts as cell systems. The hybrid surface design seems to be promising as treatment of implant-associated infections, considering the achieved amount and release behavior of the active ingredients (gentamicin, silver). The generated in vitro results (efficacy, biocompatibility) proofed the concept. Further in vivo studies will be necessary translate the hybrid surface towards clinical applied research.
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Affiliation(s)
- Kai Borcherding
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Dennis Marx
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Linda Gätjen
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Nicole Bormann
- Julius Wolff Institute, BIH Center for Regenerative Therapies, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (N.B.); (B.W.)
| | - Britt Wildemann
- Julius Wolff Institute, BIH Center for Regenerative Therapies, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (N.B.); (B.W.)
- Experimental Trauma Surgery, Department of Trauma, Hand and Reconstructive Surgery, University Hospital Jena, 07747 Jena, Germany
| | - Uwe Specht
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Dirk Salz
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Karsten Thiel
- Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), 28359 Bremen, Germany; (D.M.); (L.G.); (U.S.); (D.S.); (K.T.)
| | - Ingo Grunwald
- Industrial and Environmental Biology, Hochschule Bremen-City University of Applied Sciences, Neustadswall 30, 28199 Bremen, Germany;
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Rossi de Aguiar KMF, Specht U, Maass JF, Salz D, Picon CA, Noeske PLM, Rischka K, Rodrigues-Filho UP. Surface modification by physical treatments on biomedical grade metals to improve adhesion for bonding hybrid non-isocyanate urethanes. RSC Adv 2016. [DOI: 10.1039/c6ra05397a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This work aims to improve the adhesion of a hybrid non-isocyanate polydimethylsiloxane urethane (PDMSUr) coating by producing active layers on titanium alloy (Ti6Al4V) and stainless steel (SS316L) applying pulsed Nd:YAG laser and oxygen plasma.
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Affiliation(s)
| | - U. Specht
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
- Bremen
- Germany
| | - J. F. Maass
- Pontifical Catholic University of Rio Grande do Sul
- Porto Alegre
- Brazil
| | - D. Salz
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
- Bremen
- Germany
| | - C. A. Picon
- Engineering Faculty
- State University Julio de Mesquita Filho
- Ilha Solteira
- Brazil
| | - P.-L. M. Noeske
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
- Bremen
- Germany
| | - K. Rischka
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
- Bremen
- Germany
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Rollnik JD, Sailer M, Kiesel J, Karbe H, Harms J, Busch C, Eckhardt R, Spranger M, Rixecker D, Knickenberg RJ, Weber R, Hesselschwerdt HJ, Scheidtmann K, Köhler M, Müller C, Platz T, Specht U, Schmelter T, Hoff-Emden H, Urbach D, Lecheler J. [The MEmbeR Multicenter Study on medical-occupational rehabilitation]. REHABILITATION 2013; 53:87-93. [PMID: 24254520 DOI: 10.1055/s-0033-1347231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION MEmbeR is a prospective multi-center study on medical-occupational rehabilitation in Germany. METHODS 196 neurological, psychiatric, orthopaedic, and internal medicine patients from 21 rehabilitation centres all across Germany have been enrolled and followed-up for 2 years after discharge. Primary outcome parameter was defined as return to work. Further, the SF-12 and a Mini-ICF-Rating have been used. RESULTS Mean age was 34.1 (9.9) years, length of stay 150.0 (223.5) days. Prior to occupational rehabilitation, 69.9% were unable to work, 2 years after discharge only 5.6%. Rate of participants seeking a job was reduced from 19.7% to 3.1%. In summary, 78.1% returned to work. Employed participants were younger (32.8 [9.7] vs. 38.5 [9.4] years, p=0.001) and less disabled (Degree of Disablement [GdB]: 20.0 [31.2] vs. 36.1 [33.7], p<0.05). CONCLUSION The multicenter cohort study MEmbeR provides further knowledge about the outcome of medical-occupational rehabilitation in Germany.
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Affiliation(s)
- J D Rollnik
- Institut für neurorehabilitative Forschung (InFo) der BDH-Klinik Hessisch Oldendorf, Akademisches Lehrkrankenhaus der Medizinischen Hochschule Hannover
| | | | | | - H Karbe
- Neurologisches Rehabilitationszentrum Godeshöhe, Bonn-Bad Godesberg
| | - J Harms
- SRH-Klinikum Karlsbach-Langensteinbach
| | | | - R Eckhardt
- RKU Universitäts- und Rehabilitationskliniken Ulm
| | | | - D Rixecker
- ATZ/RPK-Zentrum für psychiatrische Rehabilitation, Saarland Heilstätten, Saarbrücken
| | | | | | | | | | | | | | - T Platz
- BDH-Klinik Greifswald, An-Institut der Ernst-Moritz-Arndt-Universität Greifswald
| | - U Specht
- Krankenhaus Mara, Epilepsie-Zentrum Bethel, Bielefeld
| | - T Schmelter
- Erthal Sozialwerk, Haus St. Michael, Eisingen
| | | | - D Urbach
- Klinik und Rehabilitationszentrum Lippoldsberg
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Lahr D, Specht U. Relevanz der Neuropsychologie für die Rehabilitation von Epilepsiepatienten. Akt Neurol 2010. [DOI: 10.1055/s-0029-1223434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Inadequate adherence to a prescribed medication regimen, so-called noncompliance (NC), occurs in 30-50% of patients with epilepsy and is thought to be a major cause of insufficient seizure control. This article gives an overview on how NC can be diagnosed, its causes, which patient groups are at risk, and which interventions are suitable to improve or maintain compliance.
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Affiliation(s)
- U Specht
- Rehabiliationsabteilung für Anfallskranke und Abteilung für junge Erwachsene, Epilepsie-Zentrum Bethel/Kliniken, Krankenhaus Mara, Maraweg 21, Bielefeld, Germany.
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Abstract
The low thermal stability of nanoparticles typically restricts their use in catalytic and other applications to low- to moderate-temperature conditions. We present a novel approach to the stabilization of nanosized noble metal particles by embedding them in a high-temperature stabilized hexa-aluminate matrix. The simple 'one-pot' approach is based on a microemulsion-templated sol-gel synthesis and yields mesoporous nanocomposite materials with pure textural porosity and excellent high-temperature stability up to about 1200 °C. To our knowledge, this is the first time that metal nanoparticles have been stabilized to such high temperatures. We furthermore find that the microemulsion templating allows a tailoring of the ceramic matrix without influencing the size of the embedded Pt particle. This opens up the possibility of a true multiscale engineering of nanocomposite materials. We see these novel materials therefore not only as very promising candidates for a broad range of high-temperature catalytic applications, but generally view this versatile synthesis route as a first step towards expanding the parameter range for nanoparticle applications.
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Affiliation(s)
- M Kirchhoff
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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Abstract
Medication noncompliance (NC) is thought to be a major cause of insufficient seizure control. In an explorative study we investigated whether postictal serum levels (PISLs) of antiepileptic drugs (AEDs) are a reliable indicator of NC. Young adults with epilepsy on a stable AED regimen were asked to contact medical service as soon as possible when a seizure occurred to obtain serum levels of their AEDs. PISLs were compared with the mean value of two routine serum levels of the same medication. PISLs lower than 50% of the individual reference value were regarded as an indicator of NC. PISL samples in 61 seizures of 52 patients treated mainly with carbamazepine, valproic acid, or lamotrigine were evaluated. A drop in serum levels >50% indicating NC was noted in 44.3% of the seizures. Determination of PISLs seems to be a simple and useful method for detecting or ruling out irregular intake patterns as a cause of "breakthrough" seizures.
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Affiliation(s)
- U Specht
- Rehabilitation Unit and Clinic Mara 1, Bethel Epilepsy Center, Maraweg 21, D-33617 Bielefeld, Germany.
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Abstract
The knowledge of patients with epilepsy about their own condition is poor, and thus the need for educational programs for people with epilepsy has long been recognized. However, no such programs have been established in their routine care. The Modular Service Package Epilepsy (MOSES) now tries to fill this gap for patients in German-speaking countries. The program was developed by a multidisciplinary group (neurologists, nonmedical professional helpers, and representatives of national epilepsy associations) for people with epilepsy older than 16 years, independent of the kind and severity of their epilepsy. MOSES is designed for group education and can be used in inpatient and outpatient settings in epilepsy centers, in clinics, and by neurologists in private practice. The program aims to help patients achieve a better understanding of their disease, to gain more self-confidence, and to take over responsibility, thus supporting patients to become experts in managing their own illness. Being modular in structure, MOSES includes nine units: living with epilepsy, epidemiology, basic knowledge, diagnostics, therapy, self-control, prognosis, psychosocial aspects, and network epilepsy. MOSES consists of a workout manual for patients and a trainer manual. For potential trainers, special "train-the-trainer seminars" are offered and considered mandatory. About 400 patients have participated in a MOSES training program in Germany, Switzerland, and Austria. The efficacy of the program is currently been evaluated.
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Affiliation(s)
- S Ried
- Schweizerische Epilepsie-Klinik, Zürich, Switzerland
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Abstract
OBJECTIVE Experimental data indicate inhibitory effects of the cerebellum on seizure activity. Structural damage such as cerebellar atrophy, which is a common finding in patients with chronic epilepsy, may reduce these effects. METHODS Outcome after temporal lobectomy was studied in 78 consecutive patients, with or without cerebellar atrophy diagnosed by MRI. RESULTS Thirty five patients (45%) showed cerebellar atrophy. At a mean follow up of 14.6 (range, 6-40) months, 50 patients (64%) had no postoperative seizures. In these patients, the frequency of cerebellar atrophy was significantly lower (34%) than in patients who relapsed (64%, p < 0.01). Occurrence of generalised tonic-clonic seizures (GTCS) within two years before surgery, occurrence of GTCS at any time preoperatively, long duration of epilepsy, and older age at surgery were also associated with recurrence of seizures. Multiple logistic regression analysis suggested occurrence of GTCS within two years before surgery and cerebellar atrophy as the main predictive indicators. When both factors were present, the percentage of patients remaining seizure free since surgery fell to 30%, compared with 60% when only GTCS were present, 78.6% when only cerebellar atrophy was present, and 87.5% when both factors were absent. CONCLUSIONS Cerebellar atrophy shown by MRI was a frequent finding in surgically treated patients with temporal lobe epilepsy. The presence of cerebellar atrophy seems to worsen the prognosis after temporal lobe resection.
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Affiliation(s)
- U Specht
- Klinik Mara 1, Epilepsy Centre, Bielefeld, Germany
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Specht U, May TW, Rohde M, Wagner V, Schmidt RC, Schütz M, Wolf P. Cerebellar atrophy decreases the threshold of carbamazepine toxicity in patients with chronic focal epilepsy. Arch Neurol 1997; 54:427-31. [PMID: 9109744 DOI: 10.1001/archneur.1997.00550160063017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Cerebellar atrophy (CA) is a frequent finding in patients with chronic epilepsy. Since gaze-evoked nystagmus, dizziness, and ataxia are some of the typical adverse effects (AEs) of the dose-dependent toxicity of carbamazepine, preexisting CA could possible explain in part the interindividual variation in the tolerance of high serum concentrations of carbamazepine. OBJECTIVE To determine whether CA reduces the threshold for overdose symptoms with carbamazepine in patients with chronic focal epilepsy in a prospective study. DESIGN Cohort study. SETTING A fourth-level epilepsy center to which patients were referred. PATIENTS Twenty-six consecutive patients with chronic focal epilepsy were prospectively studied while they were receiving high-dose monotherapy with carbamazepine. Patients were slowly titrated to doses at which the first toxic AEs of carbamazepine occurred. The determination of multiple serum levels was carried out, together with an evaluation of toxicity that comprised a standardized neurologic examination, a questionnaire for AEs, and posturography. MAIN OUTCOME MEASURES Serum concentrations of carbamazepine at the occurrence of the first dose-dependent AEs were related to the presence or absence of CA in magnetic resonance imaging studies as rated by 2 independent and blinded neuroradiologists. RESULTS In 9 patients (35%), magnetic resonance imaging scans revealed moderate (n = 7) or severe (n = 2) CA. In these patients, gaze-evoked nystagmus (P = .001, log rank test), dizziness (P = .008), and ataxia of stance as measured by posturography (P = .02) occurred at significantly lower serum concentrations of carbamazepine compared with patients without CA. This was also found for the first individually observed AE (P = .03). CONCLUSION Cerebellar atrophy occurs in a considerable percentage of patients with chronic focal epilepsy and obviously increases the susceptibility for cerebellar AEs of carbamazepine.
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Affiliation(s)
- U Specht
- Klinik Mara 1, Bethel Epilepsy Center, Bielefeld, Germany
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Abstract
Therapy with traditional antiepileptic drugs is associated with a wide range of pharmacokinetic drug-drug interactions. In particular, enzyme induction, enzyme inhibition and displacement from protein binding may result in important changes in serum concentrations of antiepileptics. Relevant interactions have also been described for some new antiepileptics. Felbamate increases serum concentrations of phenytoin, phenobarbital and valproic acid (sodium valproate). On the other hand, it reduces concentrations of carbamazepine and increases concentrations of its metabolite carbamazepine-10,11-epoxide. Concentrations of felbamate itself are reduced by phenytoin and carbamazepine. Concentrations of lamotrigine are considerably increased by valproic acid and decreased by phenytoin, carbamazepine and phenobarbital (phenobarbitone). Vigabatrin reduces serum concentrations of phenytoin by approximately 20%. On the other hand, some new antiepileptics have the important advantage of not interfering with the metabolism of other antiepileptics; this is the case for gabapentin, lamotrigine and oxcarbazepine. Furthermore, the pharmacokinetics of gabapentin, oxcarbazepine and vigabatrin are independent of concomitant drugs. These aspects are especially important as, until now, new antiepileptics have been most often utilised as add-on therapy.
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Affiliation(s)
- B Rambeck
- Department of Biochemistry, Gesellschaft für Epilepsieforschung, Bielefeld, Federal Republic of Germany
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Abstract
Cerebellar atrophy (CA) is a frequent finding in patients with chronic epilepsy. To find out whether the existence of CA has an influence on the tolerance of high-dose monotherapy with carbamazepine, we compared the lowest individual toxic serum levels in patients with complex focal seizures, with CA (n = 27) and without CA (n = 20) in computerized tomography (CT). There was no statistical difference between the groups, even after separating patients with mild CA (n = 20) from those with more severe damage (n = 7). In addition, other clinical, EEG and CT data also seemed to have no influence on the individual toxic threshold serum levels of carbamazepine.
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Affiliation(s)
- U Specht
- Klinik Mara 1, Epilepsy-Center Bethel, Bielefeld, Germany
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Jahn S, Bauer B, Schwab J, Kirchmair F, Neuhaus K, Kiessig ST, Volk HD, Mau H, von Baehr R, Specht U. Immune restoration in children after partial splenectomy. Immunobiology 1993; 188:370-8. [PMID: 8244444 DOI: 10.1016/s0171-2985(11)80220-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Splenectomy (SE) is recognized to be a therapeutical approach in treating children with severe autoimmune diseases (chronic idiopathic thrombocytopenia; hemolytic anemia) or hypersplenism because of portal hypertension. Nevertheless, removal of a main immune organ results in elevated infection risk for these patients. Partial splenectomy (PSE) was developed as a therapeutical compromise to retain immunologically active spleen tissue. Here, we document the analysis of immune parameters obtained from children after both partial and total splenectomy, which have been followed up for a period of more than 6 years: (i) Lymphocytes from both groups of patients failed to produce IgG in response to pokeweed mitogen in vitro. This was observed in 11/20 splenectomized patients even 10 years after operation, whereas in PSE patients a restoration of this parameter after 1-2 years was seen. (ii) In patients after PSE, but not in splenectomized persons, an elevated number of HLA-class II positive cells had been detected suggesting a different situation of immune regulation following this operation. However, in parallel with an improvement of B cell in vitro activity this parameter was found to achieve normal values. Our findings indicate that partial splenectomy may be a therapeutical alternative, if the therapeutic goal can be achieved by this procedure.
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Affiliation(s)
- S Jahn
- Institute for Medical Immunology, Medical Faculty (Charité), Humboldt University, Berlin, Germany
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Bartho S, Schulz HJ, Bollmann R, Specht U. [Prenatally diagnosed mesenchymal hamartoma of the liver]. Zentralbl Pathol 1992; 138:141-4. [PMID: 1610766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Reported in this paper is the case of a female newborn with mesenchymal hamartoma of the liver. High-accuracy ultrasonography diagnostics were applied to the mother admitted for examination for suspicion of fetal hydronephrosis in the 31st week of pregnancy. A 7 x 4 cm compartmental process was delineable in the abdominal region of the foetus and was variably viewed in ultrasonography in cystic or solid form. A girl, 2,650 g in body weight and 47 cm in body length, was delivered by caesarean section in the 35th week of pregnancy. Postnatal nutritional disorders were accompanied with recurrent vomiting. Sonography, computed tomography and scintigraphy were performed, and the prenatally diagnosed process was identified as a cystic growth in the right liver lobe with enclosure of the V. cava inferior. A typical hepatolobectomy was performed on the newborn on her 15th day of age, with the V. cava enclosing part being left unextirpated. Mesenchymal hamartoma of the liver was the histological diagnosis. Only one prenatally diagnosed case of this kind had been known from literature before.
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Affiliation(s)
- S Bartho
- Abteilung Pränatale Diagnostik und Therapie der Frauenklinik, Medizinischen Fakultät (Charité), Humboldt-Universität zu Berlin, Deutschland
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Abstract
The objective of this study was to identify genes, preferentially of the plastid, which are rapidly expressed during the initial phase of blue-light-induced chloroplast development in suspension-cultured cells (Chenopodium rubrum L.) and to analyse the encoded proteins. A cDNA library (lambda gt 10) was constructed using total RNA from plastid preparations of dark-grown cells exposed to blue light for 3, 6 and 12 h. By differential screening, at least three clones were identified which correspond to rapidly light-induced plastid genes. For these and a number of nuclear genes represented by other clones, a temporary accumulation of the specific mRNA was observed between 12 and 48 h of blue-light exposure. With regard to their nucleotide sequence and derived amino-acid sequence they seem to represent a novel group of genes distinctive in structure and encoded product.
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Affiliation(s)
- U Specht
- Institut für Botanik, Universität Hannover, F.R.G
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Abstract
Frequent unwanted side effects and development of tolerance are the main disadvantages of clonazepam (CZP) in long-term treatment of epileptic patients. A review of the literature shows that CZP tolerance more often appears in severe forms of childhood epilepsy (West and Lennox-Gastaut syndromes) than in other epileptic syndromes. We prospectively studied the consequences of CZP discontinuation in 40 consecutive children with difficult-to-treat epilepsies and multiple-drug therapy. The CZP was reduced stepwise in a variable daily reduction rate (0.003-0.16 mg/kg), while serum levels of the comedication were kept unchanged. In only three children (7.5%), CZP was believed to have had some antiepileptic effect; in 30 (75%) it had been ineffective, whereas in six (15%), a decrease in seizure frequency after CZP discontinuation even suggested a negative therapeutic effect. Discontinuation symptoms, mostly in the form of a transitory exacerbation of seizure frequency, occurred in 19 children (47.5%). These children had a significantly higher CZP dose and longer duration of treatment than did children without discontinuation symptoms, but there was no difference between the two groups related to the rate of CZP discontinuance.
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Affiliation(s)
- U Specht
- Epilepsie-Zentrum Bethel, Kinderklinik Kidron, Bielefeld, F.R.G
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Jahn S, Grunow R, Kiessig ST, Specht U, Matthes H, Hiepe F, Hlinak A, Von Baehr R. Establishment of human Ig producing heterohybridomas by fusion of mouse myeloma cells with human lymphocytes derived from peripheral blood, bone marrow, spleen, lymph node, and synovial fluid. Effect of polyclonal prestimulation and cryopreservation. J Immunol Methods 1988; 107:59-66. [PMID: 3343518 DOI: 10.1016/0022-1759(88)90009-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
50 fusion experiments were carried out to analyse heterohybridization efficiencies on mouse myeloma cells of the P3 X63 Ag8/653 line with human lymphocytes derived from peripheral blood, bone marrow, lymph node, spleen or synovial fluid. We found higher yields of growing and human Ig-producing hybridoma lines when lymphocytes from spleen or lymph node were fused. Although primary hybridomas could be established from fusions with bone marrow-derived cells, only in nine out of 1616 initially seeded wells was Ig production registered. Four fusions using immune cells from synovial fluid were made without success. Independently of the source of lymphocytes pokeweed mitogen (PWM) prestimulation had no enhancing effect on the percentage of wells with cell growth and this did not alter the IgM:IgG ratio in primary hybridomas (9:1), although cells from all compartments used here (with the exception of bone marrow cells) could be stimulated with PWM to produce both IgG and IgM in cultures. Cryopreserved lymphocytes from different sources could be used for fusions with comparable results registered for the fresh material.
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Affiliation(s)
- S Jahn
- Institute for Medical Immunology, Humboldt-University, Berlin, G.D.R
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Jahn S, Kiessig S, Grunow R, Specht U, Mau H, von Baehr R. [Production of human monoclonal antibodies by heterohybridization of human B lymphocytes of the spleen with mouse myeloma cells]. Z Gesamte Inn Med 1986; 41:493-7. [PMID: 3492081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Human lymphocytes were derived from the spleen of a 15-year-old female patient after partial splenectomy. High cell yield and percentage of human B-lymphocytes (over 30%) gave useful conditions for their fusion to mouse myeloma cells (P3 X63/Ag8/653). Fusion efficiency (cultures with growth) was 96%. From 288 initially seeded cultures 176 showed IgM and only one IgG production as determined by enzyme immunoassays. Twenty primary cell lines were cloned with differing results and 17 heterohybridoma cell clones with high IgM production rates could be established for more than 6 months in vitro. The present results show the possibility to produce human monoclonal antibodies in heterohybrids derived from human spleen lymphocytes.
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Specht U. [Occupational noise in the iron and metal industry--systematics of determination, results obtained, follow up]. Zentralbl Arbeitsmed Arbeitsschutz Prophyl Ergonomie 1981; 31:225-33. [PMID: 7303992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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