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A Marx

Publications and source records attributed to A Marx.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Anatomy of the dorsal mid-hand arteries--anatomic study and review of the literature].

By dissections of 20 cold-preserved hands, we investigated the dorsal metacarpal arteries (DMA) with regard to reliability, origin and anastomoses. The first dorsal metacarpal artery showed a trifurcation with three vessels: Ramus ulnaris (A. metacarpalis dorsalis I), Ramus medialis and Ramus radialis (A. ulnodorsalis pollicis). The DMA II to IV were observed medially in their respective intermetacarpal spaces. The A. metacarpalis dorsalis V was unreliable in reaching the skin of dorsal proximal phalanges as in the DMA IV. Most reliable for reaching the skin of dorsal proximal phalanges were the radial arteries--first, second and third dorsal metacarpal arteries. The dorsal digital arteries originate close to one another at the level of the metacarpophalangeal joints. There was an increase of epifascial position, from radial to ulnar. Irregular palmar intermetacarpal anastomoses were found proximal to the ligamentum metacarpale transversum profundum but nearly consistently in the web space.

Arteries↗
PubMed2001

[Covering defects of the basal finger area by pedicled flaps anastomosed to the doral metacarpal arteries].

Between 1993 and 1998, 12 distally based dorsal metacarpal artery flaps were used to cover defects of the fingers and palm. All flaps were raised from the dorsum of the hand. Eleven flaps allowed direct closure of the donor site area; one case required a full-thickness skin graft. Nine flaps healed uneventfully. Distal marginal flap necrosis occurred in three cases. All of these were used to cover defects at the distal part of the middle phalanx.

Adolescent↗
PubMed2001

Evidence for distinct mechanisms in the shaping of the CD4 T cell repertoire in histologically distinct myasthenia gravis-associated thymomas.

The major histocompatibility complex (MHC) class II is involved both in thymocyte maturation and peptide presentation and might thus play a key role in the pathogenesis of paraneoplastic myasthenia gravis (MG) in thymomas. To further investigate this issue, we analyzed and scored the expression of epithelial class II expression in 35 thymomas (medullary, MDT; mixed, MXT; cortical and well differentiated thymic carcinoma, CT/WDTC) and correlated it with the histological tumor subtype, prevalence of MG and thymocyte maturation, which was analyzed by flow cytometry and RT-PCR. Our results show that both MHC class II expression and thymocyte maturation are highly dependent on the histological tumor subtype. CT/WDTC retain features of the normal outer thymic cortex, namely substantial MHC class II expression together with normal early thymocyte maturation until late phases of positive selection, but disturbed terminal thymopoiesis. By contrast, MDT and MXT retain features of the normal inner cortex and the medulla with low to absent class II expression and highly abnormal early thymocyte maturation including impaired positive selection, while terminal T cell maturation in MXT appeared undisturbed. There was no correlation between MHC class II expression and MG status for a given tumor subtype. In conclusion, our results provide evidence for a different histogenesis of cortical thymomas and well differentiated carcinomas on the one hand and mixed and medullary thymomas on the other. Decreased expression levels of MHC class II, although of crucial importance for abnormal intratumorous maturation, are not sufficient to explain the emergence of paraneoplastic MG.

CD4-Positive T-Lymphocytes↗
PubMed2001

Psychological reactions among family members of patients with implantable defibrillators.

OBJECTIVE: To describe psychological reactions among family members of patients receiving an implantable cardioverter/defibrillator (ICD) during the first 9 months after implantation. METHODS: Eighty-two family members (age 56+/-12 years, 74 percent female, 79 percent married, 88 percent Caucasian) of ICD patients completed questionnaires regarding their mood (Profile of Mood State), cognitive illness appraisals (Meaning of Illness Questionnaire) and coping strategies (Jalowiec Coping Scale) prior to ICD implantation, and as well as 1 and 9 months postoperatively. RESULTS: Total mood disturbance score (TMD), threat appraisal, and emotion- and problem-focused coping were highest prior to ICD implantation, and decreased during the first postoperative month showing stable values thereafter. There was no change in challenge appraisal. Multiple regression analysis found that the use of psychotropic drugs (anxiolytics, sedatives; Beta = .25), emotion-focused coping (Beta = .37), and challenge appraisal (Beta =-.21) at 1 month accounted for 26 percent of variance in TMD at 9 mon ths. CONCLUSION: A spouse's ICD implantation is a major stressful event for family members leading to a diminished mood state prior ICD implantation. Reduction in emotion-focused coping and the use of challenge appraisal may improve mood state in family members of ICD patients during early follow-up.

Adaptation, Psychological↗
PubMed2000

Thymomas alter the T-cell subset composition in the blood: a potential mechanism for thymoma-associated autoimmune disease.

Thymomas are the only tumors that are proven to generate mature T cells from immature precursors. It is unknown, however, whether intratumorous thymopoiesis has an impact on the peripheral T-cell pool and might thus be related to the high frequency of thymoma-associated myasthenia gravis. This study shows, using fluorescence-activated cell sorting-based analyses and T-cell proliferation assays, that thymopoiesis and T-cell function in thymomas correspond with immunologic alterations in the blood. Specifically, the proportion of circulating CD45RA(+)CD8(+) T cells is significantly increased in patients with thymoma compared with normal controls, in accordance with intratumorous T-cell development that is abnormally skewed toward the CD8(+) phenotype. Moreover, it is primarily the proportion of circulating CD45RA(+)CD8(+) T cells that decreases after thymectomy. The results also demonstrate that T cells reactive toward recombinant autoantigens are distributed equally between thymomas and blood, whereas T-cell responses to foreign antigen (ie, tetanus toxoid) are seen only among circulating T cells and not among thymoma-derived T cells. These functional studies support the hypothesis that thymopoiesis occurring within thymomas alters the peripheral T-cell repertoire. Because many thymomas are enriched with autoantigen-specific T cells, a disturbance of circulating T-cell subset composition by export of intratumorous T cells may contribute to paraneoplastic autoimmune disease arising in patients with thymoma. (Blood. 2000;96:3872-3879)

Adolescent↗
PubMed2000

The influence of the radicality of resection and dose of postoperative radiation therapy on local control and survival in carcinomas of the upper aerodigestive tract.

PURPOSE: To evaluate dose concepts in postoperative irradiation of carcinomas of the upper aerodigestive tract according to the radicality of resection. PATIENTS AND METHODS: In a retrospective analysis, the charts of 257 patients with histologically-proven carcinoma of the upper aerodigestive tract (40 T1, 80 T2, 53 T3, 84 T4 tumors, with nodal involvement in 181 cases) were reviewed according to the radicality of resection and dose of irradiation administered. Sixty-four patients had tumor-free resection margins (> 3 mm), 66 patients had close resection margins (< 3 mm), and 101 patients had R1 resections, and 26 patients had R2 resections. A median dose of 56 Gy was applied to the primary tumor bed and the cervical lymphatics (2 Gy/fraction, 5 fractions/week). In cases of R1 or R2 resection, or of close margins (< 3 mm), the tumor bed or, respectively, tumor residuals were boosted with doses up to a median of 66 Gy. Locoregional tumor control and survival was investigated by uni- and multivariate analyses according to T-, N-stage, grade of resection, total dose of radiation, and presence or absence of extracapsular tumor spread and lymphangiosis carcinomatosa. RESULTS: An overall 3- and 5-year survival rate of 60% and 45%, respectively, was achieved. Rates for freedom from locoregional recurrence were 77% and 72% at 3 and 5 years, respectively. The survival rates according to the grade of resection at 5 years were 67% for patients resected with tumor-free margins, 59% for patients resected with close margins, 26% for patients with R1 resection, and 27% for patients with R2 resection. Within a median follow-up period of 4.7 years for living patients, a total of 67 recurrences (26%) were observed (in 9% of patients resected with tumor-free margins, in 27% with close margins, in 37% of R1 resected, and in 19% of R2 resected patients). Freedom from locoregional recurrence at 3 years was achieved in 100% of the patients resected with tumor-free margins, in 92% of patients resected with close surgical margins, in 87% of R1 and 69% of R2 resected patients. In multivariate Cox-regression analysis, the variables grade of resection (p = 0.00031) and total dose of irradiation (p = 0.0046) were found as factors influencing locoregional control. Variables influencing survival according to multivariate analysis are T-stage (p = 0.0057), N-stage (p = 0.024), grade of resection (p = 0.000015), total dose of irradiation (p < 0. 000000). Extracapsular tumor spread and lymphangiosis carcinomatosa are factors of borderline significance (p = 0.055, p = 0.066). CONCLUSION: In postoperative radiotherapy of head and neck carcinomas, doses adapted to the risk of locoregional recurrent disease should be applied. Patients with R1 and R2 resections should be treated with doses of more than 68 Gy (2 Gy/fraction, 5 fractions/week) (with close margins [< 3 mm] more than 66 Gy) to achieve an improvement in locoregional control and survival.

Adult↗
PubMed2000

Widespread paralytic poliomyelitis in Pakistan: A case-control study to determine risk factors and implications for poliomyelitis eradication.

Despite substantial efforts to eradicate poliomyelitis by administering oral poliovirus vaccine through routine immunization and annual national immunization days (NIDs), Pakistan reported 22% (1147) of the worldwide cases in 1997. Reasons for continued high poliomyelitis incidence include failure to vaccinate, vaccine failure, or inadequate immunization strategies. A case-control study was conducted to measure vaccination status and reasons for undervaccination among 66 poliomyelitis cases and 130 age- and neighborhood-matched controls. Cases were undervaccinated through routine immunization (matched odds ratio [MOR], 0.3; 95% confidence interval [CI], 0.1-0.5); however, NID immunization was similar for cases and controls (MOR, 0.6; 95% CI, 0.3-1.2). Reasons for undervaccination included not being informed, considering vaccination unimportant, and long distances to vaccination sites. Failure to vaccinate through routine immunization was a major risk factor for poliomyelitis in Pakistan. Successful NIDs alone will not interrupt poliovirus circulation in Pakistan, and children remain at risk unless routine immunization is strengthened or additional supplementary immunization is provided.

Case-Control Studies↗
PubMed2000

Response to nitrogen starvation in Corynebacterium glutamicum.

Proteins strongly synthesized in Corynebacterium glutamicum during nitrogen restriction were examined by two-dimensional gel electrophoresis and microsequencing. Two main groups of enzymes were identified beside miscellaneous proteins, enzymes involved (i) in protein synthesis, and (ii) in carbon metabolism. Biochemical measurements revealed an increase of oxygen consumption during nitrogen starvation, indicating an enhanced energy demand of the cells. By Northern hybridizations, an increased transcription for the gap and fda genes upon nitrogen deprivation was shown.

Amino Acid Sequence↗
PubMed2000

Aluminum Bis(trifluoromethylsulfonyl)amides: New Highly Efficient and Remarkably Versatile Catalysts for C - C Bond Formation Reactions.

Superacid-derived aluminum catalysts R(2)AlNTf(2) (2 - 5 mol%) are highly efficient and versatile and are suitable promoters for the allylation and pentadienylation of aldehydes, aldol reactions, aldol cross-coupling of ketones, and Michael additions (several products are shown). Furthermore, they can be converted into chemoselective Lewis acids. Tf=trifluoromethanesulfonyl.

Journal Article↗
PubMed2000

Mechanisms of ischemic preconditioning in skeletal muscle.

BACKGROUND: Ischemic preconditioning (IP) (one or more cycles each consisting of a short period of ischemia and a short period of reperfusion, before the sustained ischemia) reduces ischemia-related organ damage in heart and skeletal muscle but the underlying mechanisms are not clear. This study was intended to assess the possible involvement of K(ATP) channels and of adenosine receptors in IP of skeletal muscle in a rat model of skeletal muscle ischemia. MATERIALS AND METHODS: Groups of 8-15 rats were given the following in vivo treatments: ischemia-reperfusion (I-R: 2.5 h tourniquet-induced ischemia of the right hindlimb, then 2 h reperfusion); IP (three cycles of 5 min ischemia, then 5 min reperfusion) before I-R; cromakalim and I-R; glibenclamide, cromakalim, and I-R; glibenclamide, IP, and I-R; [R]-N(6)-[1-methyl-2-phenylethyl]adenosine (R-PIA) and I-R; adenosine and I-R; and glibenclamide, IP, and I-R. Parameters of muscle function (postischemic maximal force, performance, contraction index, and force after 1 min of stimulation) were then assessed in vitro in the extensor digitorum longus muscle. RESULTS: Pretreatment with either IP or the K(ATP) channel opener cromakalim significantly improved postischemic muscle function. The protective effect of cromakalim was not seen when the K(ATP) channel blocker glibenclamide was added. Glibenclamide, however, did not block IP-induced protection. Pretreatment with the adenosine A(1) receptor agonist 8-(p-sulfophenyl)-theophyllin (8-SPT) or with adenosine did not improve postischemic muscle function. The adenosine receptor agonist did not block IP-induced protection against ischemic damage. CONCLUSIONS: The results show significant improvements in postischemic skeletal muscle function after IP or cromakalim pretreatment but they do not support a role for K(ATP) channels or for adenosine receptors in IP of skeletal muscle.

Animals↗
PubMed2000

Monoclonal antibody-based enzyme immunoassay for mercury(II) determination.

A monoclonal antibody (K3C6) was developed against Hg(II) and applied in different enzyme immunoassay (EIA) formats to determine the test system with the highest sensitivity. A detection limit of 1. 0 microg/L Hg(II) could be achieved with a competitive format in contrast to a detection limit of 2.1 microg/L Hg(II) with a noncompetitive EIA. A competitive displacement EIA yielded the best detection limit of 0.4 microg/L Hg(II) and was well suited to measuring real samples. For this purpose different water samples were diluted at least 1:10 to avoid matrix effects and subsequently spiked with 1 microg/L HgCl(2). Recovery of the spiked samples was between 80 and 120%.

Absorption↗
PubMed2000

Characterization of Wue-1, a novel monoclonal antibody that stimulates the growth of plasmacytoma cell lines.

A new monoclonal antibody, Wue-1, which specifically recognizes normal and malignant plasma cells, is characterized. Biochemical studies showed that monoclonal antibodies (mAbs) recognize a protein of 94 kDa. Using triple-staining flow cytometry and double-labeling immunohistochemical techniques, two populations of plasma cells, i.e. lymphoplasmocytoid plasma cells located in the germinal center of lymphoid organs and reticular plasma cells at the paracortex or medullary cords of secondary lymphoid tissues, were distinguished. Wue-1 is expressed when B-cell markers become lost and secretory activity with plasma cell morphology appears. Cell surface markers were identified on normal plasma cells and compared with their malignant counterpart in vivo. Terminal plasma-cellular differentiation of malignant low- and high-grade B-cell lymphoma and anaplastic plasmacytoma, otherwise difficult to identify with conventional B-cell markers on tissue sections or fluorescence-activated cell sorter analyses, were detectable by Wue-1. In cell culture, Wue-1 enhanced the proliferation of myeloma cell lines but not normal plasma cells in a dose-dependent manner. Since Wue-1-induced proliferation was increased by interleukin (IL)-6, Wue-1 recognizes a so far unidentified antigen with functional properties. Therefore, Wue-1 represents a useful new tool for therapy and for the in vivo and in vitro studying of B-cell lymphomas and the mechanisms of B-cell differentiation.

Animals↗
PubMed2000

Recurrent genetic aberrations in thymoma and thymic carcinoma.

Apart from single reported aberrant karyotypes, genetic alterations in thymic epithelial neoplasms have not been investigated so far. In this study, 12 World Health Organization classification type A thymomas (medullary thymomas), 16 type B3 thymomas (well-differentiated thymic carcinomas), and nine type C thymomas, all of them primary thymic squamous cell carcinomas, were analyzed by comparative genomic hybridization and fluorescence in situ hybridization. With the exception of one single case, type A thymomas did not reveal chromosomal gains or losses in comparative genomic hybridization. In contrast, all type B3 thymomas showed chromosomal imbalances, with gain of 1q, loss of chromosome 6, and loss of 13q occurring in 11 (69%), six (38%), and five (31%) of 16 cases, respectively. In primary thymic squamous cell carcinoma, the most frequent chromosomal losses were observed for 16q (six of nine cases, 67%), 6 (4 of 9, 44%), and 3p and 17p (three of nine each, 33%), whereas recurrent gains of chromosomal material were gains of 1q (5 of 9, 56%), 17q, and 18 (three of nine each, 33%). This study shows that the distinct histological thymoma types A and B3 exhibit distinct genetic phenotypes, whereas type B3 thymoma and primary thymic squamous cell carcinoma partially share genetic aberrations. In addition to the possible tumorigenic role, the deletion in type B3 thymoma of chromosome 6, harboring the HLA locus, might play a role in the pathogenesis of paraneoplastic autoimmunity characteristic of thymoma.

Adult↗
PubMed2000

Identification of major histocompatibility complex class II-associated peptides derived from freshly prepared rat Langerhans cells using MALDI-PSD and Edman degradation.

The isolation and identification is described of MHC class II-bound peptides derived from Langerhans cells. A combination of preparative micro-HPLC, MALDI-MS, Edman degradation was used for determining the amino acid sequence of MHC-associated peptides. Sample handling was crucial because fractions containing trace amounts of material require immediate storage at -80 degrees C to prevent peptide losses.

Animals↗
PubMed2000

Erdheim-Chester disease: evidence for a disease entity different from Langerhans cell histiocytosis? Three cases with detailed radiological and immunohistochemical analysis.

Erdheim-Chester (EC) disease is a rare pathological entity with a highly specific and characteristic pattern of radiographic bone changes. Histologically it resembles Langerhans cell histiocytosis (LCH), and it is still a matter of discussion whether EC disease is a distinct entity or a type of LCH. In this study, 3 cases of Erdheim-Chester disease were followed up over years and examined in detail both radiologically and immunohistochemically. All 3 cases showed the pathognomonic skeletal features for EC disease as well as an identical immunohistochemical phenotype quite different from LCH. Macrophages and Touton cells reacted strongly positive with the histiocytic marker CD 68, whereas staining with S100 and CD1a, markers for Langerhans cells, were negative. Both the immunohistochemical phenotype and the bone changes were clearly distinct from LCH.

Antigens, CD↗
PubMed2000

Small thymomas and myasthenia gravis: a poorly understood association.

Myasthenia gravis (MG) is associated with about 20% of all patients with thymomas, but the occurrence in patients with small thymomas is rare. The pathogenetic relevance of these small thymomas for MG is poorly understood until now. We report on the clinical course of a 39-year-old female patient suffering from MG and undergoing thymectomy for a small thymoma and discuss the pathogenetic importance of small thymomas for MG.

Adult↗