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Sailer R, Strauss WS, Emmert H, Stock K, Steiner R, Schneckenburger H. Plasma membrane associated location of sulfonated meso-tetraphenylporphyrins of different hydrophilicity probed by total internal reflection fluorescence spectroscopy. Photochem Photobiol 2000; 71:460-5. [PMID: 10824598 DOI: 10.1562/0031-8655(2000)071<0460:pmalos>2.0.co;2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sulfonated meso-tetraphenylporphyrins of different hydrophilicity were microspectrofluorimetrically examined in endothelial cells using total internal reflection (TIR) illumination or epi-illumination. Since the penetration depth of the evanescent field during TIR illumination is limited to a few hundred nanometers, photosensitizers were almost selectively examined in close vicinity to the plasma membrane. Pronounced fluorescence signals during TIR illumination were observed for the hydrophilic compounds meso-tetraphenylporphyrin tetrasulfonate (TPPS4) and meso-tetraphenylporphyrin trisulfonate (TPPS3), whereas the more lipophilic compounds meso-tetraphenylporphyrin disulfonate (TPPS2a) and meso-tetraphenylporphyrin monosulfonate (TPPS1) could only be detected under epi-illumination. Irradiation of TPPS1 and TPPS2a in the Soret band led to an increase in fluorescence intensity and formation of a photoproduct with an emission maximum around 610 nm, which was limited to intracellular compartments. In contrast, fluorescence spectra of TPPS3 and TPPS4 obtained by TIR and epi-illumination remained almost unchanged after irradiation in the Soret band. Extralysosomal location of TPPS3 and TPPS4 in close proximity to the plasma membrane was deduced from experiments with the lysosomal markers acridine orange (AO) or lysotracker yellow (LY), which were not detectable under TIR illumination. In conclusion, these results provide for the first time direct evidence for a plasma membrane-associated fraction of the hydrophilic compounds TPPS3 and TPPS4 in living cells.
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Abstract
The nursing outcome of holistic comfort encompasses physical, psychospiritual, social, and environmental aspects of human nature. The primary purpose of this study was to test four propositions about the nature of comfort: (a) Comfort has equal proportions of state and trait characteristics; (b) comfort is sensitive to changes over time; (c) when subjects are exposed to an effective intervention, they demonstrate differences in comfort that increase in a linear way compared to a control group; and (d) the whole (total comfort) is greater than the sum of its parts (relief plus ease plus transcendence). A secondary purpose of this study was to present preliminary concurrent validity between two types of comfort instruments, a traditional questionnaire with a Likert-type format and visual analog scales. Findings were positive for all theoretical propositions and moderate concurrent validity between the Radiation Therapy Comfort Questionnaire and the visual analog scale for total comfort was demonstrated.
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Abstract
Compromised urinary bladder syndrome (CUBS), a combination of frequency and incontinence, causes multiple discomforts for community-dwelling adults. A holistic intervention--audiotaped cognitive strategies--was designed to augment the effects of an educational program designed to treat CUBS. CUBS was operationalized with a voiding diary, and comfort related to bladder health was operationalized in a questionnaire. In this quasi-experimental design the outcomes were measured at four time points. Repeated measures multivariate analyses of variance and nonparametric analyses were conducted to assess differences between the two groups. Results indicated that the treatment group had more comfort and improved CUBS compared with the control group.
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Steiner R, Ever L, Don J. MEIG1 localizes to the nucleus and binds to meiotic chromosomes of spermatocytes as they initiate meiosis. Dev Biol 1999; 216:635-45. [PMID: 10642798 DOI: 10.1006/dbio.1999.9520] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Meiosis, the fundamental evolutionarily conserved differentiative process by which haploid gametes are produced, is a complex and tightly regulated nuclear process. The murine Meig1 gene was previously shown to have a germ cell-specific transcript which is abundantly expressed during meiosis, in both males and females, suggesting that it is involved in meiotic processes. Protein analysis revealed that MEIG1 appears in multiple phosphorylated forms, including two dimeric forms of M(r) 31,000 and 32,000, which exhibit a developmentally regulated switch in their relative abundance. The tyrosine-phosphorylated M(r) 31,000 form becomes the dominant form once the cells enter meiosis. In this study we show that the M(r) 31,000 dimeric form appears in the nuclear fraction of testicular protein extract, whereas the M(r) 32,000 dimeric form and the monomeric forms of MEIG1 remain cytoplasmic. The appearance in the nuclear fraction is developmentally regulated, coinciding with progression of the first spermatogenic wave through meiotic prophase I. Utilizing immunocytochemistry we show that nuclear localization is apparent in primary spermatocytes through their maturation into elongated spermatozoa, but not in either somatic cells or germ cells from early postnatal pups. We also show that MEIG1 associates specifically with meiotic chromosomes in vivo. These results indicate that in germ cells, the M(r) 31,000 dimeric form enters the nucleus during the first meiotic prophase and binds to the meiotic chromatin. Possible nuclear functions, as well as possible modes of nuclear localization, are discussed.
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Ahmad A, Kahler SG, Kishnani PS, Artigas-Lopez M, Pappu AS, Steiner R, Millington DS, Van Hove JL. Treatment of pyruvate carboxylase deficiency with high doses of citrate and aspartate. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 87:331-8. [PMID: 10588840 DOI: 10.1002/(sici)1096-8628(19991203)87:4<331::aid-ajmg10>3.0.co;2-k] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A patient with severe pyruvate carboxylase deficiency presented at age 11 weeks with metabolic decompensation after routine immunization. She was comatose, had severe lactic acidemia (22 mM) and ketosis, low aspartate and glutamate, elevated citrulline and proline, and mild hyperammonemia. Head magnetic resonance imaging showed subdural hematomas and mild generalized brain atrophy. Biotin-unresponsive pyruvate carboxylase deficiency was diagnosed. To provide oxaloacetate, she was treated with high-dose citrate (7.5 mol/kg(-1)/day(-1)), aspartate (10 mmol/kg(-1)/day(-1)), and continuous drip feeding. Lactate and ketones diminished dramatically, and plasma amino acids normalized, except for arginine, which required supplementation. In the cerebrospinal fluid (CSF), glutamine remained low and lysine elevated, showing the treatment had not normalized brain chemistry. Metabolic decompensations, triggered by infections or fasting, diminished after the first year. They were characterized by severe lactic and ketoacidosis, hypernatremia, and a tendency to hypoglycemia. At age 3(1/2) years she has profound mental retardation, spasticity, and grand mal and myoclonic seizures only partially controlled by anticonvulsants. The new treatment regimen has helped maintain metabolic control, but the neurological outcome is still poor.
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Regan E, Groutso T, Metson JB, Steiner R, Ammundsen B, Hassell D, Pickering P. Surface and bulk composition of lithium manganese oxides. SURF INTERFACE ANAL 1999. [DOI: 10.1002/(sici)1096-9918(199912)27:12<1064::aid-sia676>3.0.co;2-s] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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107
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Scheidegger P, Weiglhofer W, Suarez S, Kaser-Hotz B, Steiner R, Ballmer-Hofer K, Jaussi R. Vascular endothelial growth factor (VEGF) and its receptors in tumor-bearing dogs. Biol Chem 1999; 380:1449-54. [PMID: 10661874 DOI: 10.1515/bc.1999.187] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The molecular biology of the angiogenic growth factor, vascular endothelial growth factor (VEGF), has been studied in the dog. All major isoforms of VEGF are present in the dog. The amino acid sequences are identical between human and dog in the loop regions that are responsible for receptor binding. Accordingly, the VEGF receptors of dogs and humans are very similar and permit functional exchange of the growth factor. Here we show that canine VEGF activates human endothelial cells to the same extent as human VEGF. Similarly, the two proteins display identical cell binding properties. The VEGF receptor 1 (Flt-1) shows the same alternative splicing in humans and dogs and is overexpressed in the majority of tumors in both species. VEGF occurs also in canine tumors in similar relative quantities as in human malignancies. Based on the literature and our study we suggest that the molecular biology and the function of the VEGF signaling system are virtually identical in humans and canines and in healthy as well as in disease conditions.
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Heiss S, Mahler V, Steiner R, Spitzauer S, Schweiger C, Kraft D, Valenta R. Component-resolved diagnosis (CRD) of type I allergy with recombinant grass and tree pollen allergens by skin testing. J Invest Dermatol 1999; 113:830-7. [PMID: 10571741 DOI: 10.1046/j.1523-1747.1999.00796.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The diagnosis of Type I allergy is based on the measurement of allergen-specific IgE antibodies and on provocation with allergens, most frequently conducted by skin testing. Both forms of diagnosis are currently performed with allergen extracts that are difficult to standardize regarding their allergen contents, and which contain additional undefined nonallergenic components. We report the expression in Escherichia coli and purification of some of the most relevant timothy grass- and birch pollen allergens. Recombinant timothy grass- (rPhl p 1, rPhl p 2, rPhl p 5) and birch pollen (rBet v 1, rBet v 2) allergens were purified and used for the measurement of allergen-specific IgE and IgG subclass responses as well as for skin prick testing in 55 pollen allergic patients and 10 nonatopic individuals. Results obtained showed that the recombinant allergens allowed in vivo allergy diagnosis in 52 of 54 of the grass pollen and in 35 of 36 of the birch pollen allergic patients. Positive skin reactions were observed almost exclusively in patients containing detectable allergen-specific IgE antibodies but not in the nonatopic group; however, sensitivity to a given allergen as measured by skin reactivity was weakly correlated with the levels of allergen-specific IgE. Our results demonstrate that recombinant allergens can be used for component-resolved skin test diagnosis (CRD) of the patients' allergen sensitization profile, whereas allergen extracts at best allow to identify allergen-containing sources. CRD may thus represent the basis for novel forms of patient-tailored immunotherapy.
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Steiner R. Some notes on the 'heroic self' and the meaning and importance of its reparation for the creative process and the creative personality. THE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS 1999; 80 ( Pt 4):685-718. [PMID: 10478307 DOI: 10.1516/0020757991598990] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The author discusses a few points in a long clinical history from which he has derived the notion of 'heroic self', describing how it manifested through 'heroic' projective and introjective identifications. He also demonstrates the importance of repairing both the heroic self and the internal objects, and how essential it is for the analyst to differentiate between the heroic self and its megalomaniac psychopathic manifestations, and to recover the heroic self when it appears to be lost, as in the case of severe, quasi-melancholic, depression. By heroic self and heroic projective and introjective identifications, he means the creative person's specific need to associate himself with, to compete with and excel the heroes of his own cultural tradition. The creative person is able to do so via these projections and introjections, and the need is based on the creator's inner awareness of naturally possessing unusual, or even outstanding, gifts; in other words, the creative person has an awareness of being, or of the possibility of becoming, a creative hero. Brief reference is made throughout to other clinical material, and in the final section further support is given to the author's views on the heroic self with short quotations and examples from non-psychoanalytic sources that provide further interesting evidence of the existence and functioning of the heroic self. With particular reference to Segal's work in this field (1952, 1991), and her notion of 'meaningful form', the author tries to further develop its implications in the light of the heroic self and of the heroic projective and introjective identifications, as far as the creator and those who respond to and evaluate his or her work are concerned.
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Eickhoff H, Haberer T, Kraft G, Krause U, Richter M, Steiner R, Debus J. The GSI Cancer Therapy Project. Strahlenther Onkol 1999; 175 Suppl 2:21-4. [PMID: 10394389 DOI: 10.1007/bf03038880] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
At the Heavy Ion Research Institute GSI in Darmstadt an experimental cancer treatment program with a five years duration has been developed. A new method for cancer treatment with ions is applied, using rasterscan method in addition to an active pulse to pulse variation of ion beam properties, including the energy, intensity and focusing. An overview of this Cancer Therapy Project is presented, that covers both accelerator aspects to provide the required beam variations within a short time and the installations at the treatment place for rasterscan control. In addition to a description of the technical design (control-hard- and software) experimental results will be shown, containing the achieved beam properties and measurements of rasterscan performance.
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Abstract
The area under the time-plasma concentration curve (AUC) was measured for prednisolone (the major active metabolite of prednisone) after ingestion of 15 mg of prednisone (phase 1) and again after 3 d of oral diltiazem (180 mg/d) followed by the same dose of oral prednisone (phase 2) in eight normal adult patients. Diltiazem increased the prednisolone AUC by 21% (range 3-38%), from 1297 +/- 157 ng/h/mL to 1560 +/- 169 ng/h/mL (p = 0.001). This effect was associated with a greater decrease from baseline in CD3+ lymphocyte number at 4 h after prednisone ingestion (596 +/- 175 vs. 516 +/- 140, p = 0.05), a larger percentage decrease of circulating CD3+ lymphocytes at 8 h (43 +/- 19% vs. 53 +/- 19%, p = 0.04), and a decrease in the number of CD3+ CD8+ T cells at 4 h post-prednisone ingestion (279 +/- 81 vs. 236 +/- 51, p = 0.04). Diltiazem retards prednisolone metabolism and when used chronically with prednisone could conceivably, in some patients, enhance its immunologic and other clinical effects. Potentiation of prednisone side-effects by diltiazem may be of special interest in pediatric patients, and possible diltiazem-prednisone interactions merit study in this population.
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112
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Acosta PB, Yannicelli S, Marriage B, Steiner R, Gaffield B, Arnold G, Lewis V, Cho S, Berstein L, Parton P, Leslie N, Korson M. Protein status of infants with phenylketonuria undergoing nutrition management. J Am Coll Nutr 1999; 18:102-7. [PMID: 10204824 DOI: 10.1080/07315724.1999.10718836] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The objectives of this study were to determine if Phenex-1, amino-acid modified medical food with iron maintained normal indices of protein status in infants with phenylketonuria (PKU) and to investigate factors that influence plasma amino acid concentrations. METHODS A study was conducted for six months in 35 infants with classical PKU diagnosed in the neonatal period. Diet diaries and plasma amino acid concentrations were obtained monthly. Blood for analysis of plasma albumin, blood urea nitrogen (BUN), retinol binding protein (RBP) and transthyretin was obtained at one, three and six months of study. RESULTS Mean (+/-SEM) total daily intake of medical food and nutrients was 79+/-4 g; 17.3+/-0.6 g protein, 660+/-18 kcal, 255+/-10 mg phenylalanine (Phe), and 1423+/-56 mg tyrosine (Tyr). Mean concentrations of plasma amino acids, except cystine (during entire study), glycine (first month) and Phe were in the normal range. Mean concentrations of plasma Phe were in the treatment range (120 to 360 micromol/L). Plasma concentrations of arginine, methionine, Phe, tryptophan, Tyr, and valine were positively correlated with intakes at various months of study. Concentrations of aspartic and glutamic acids, Phe, and Tyr were positively correlated and 17 amino acids were negatively correlated with the interval between feeding and blood draw. At six months of study, concentration of plasma albumin was 4.1+/-0.1 g/dL, RBP was 3.74+/-0.2 mg/dL, transthyretin was 17.9+/-0.9 mg/dL, and urea nitrogen was 11.9+/-0.5 mg/dL. CONCLUSION During study, all mean plasma indices of protein status were in normal reference ranges. Phenex-1 supports normal mean plasma amino acid, albumin, RBP, transthyretin, and BUN concentrations when fed in adequate amounts.
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Steiner R. Who influenced whom? And how?--a brief series of notes on E. Weiss, M. Klein (and I. Svevo) and the so-called 'origins' of 'projective and introjective identification'. THE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS 1999; 80 ( Pt 2):367-75. [PMID: 10363188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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114
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Skyllouriotis P, Skyllouriotis-Lazarou M, Natter S, Steiner R, Spitzauer S, Kapiotis S, Valent P, Hirschl AM, Guber SE, Laufer G, Wollenek G, Wolner E, Wimmer M, Valenta R. IgG subclass reactivity to human cardiac myosin in cardiomyopathy patients is indicative of a Th1-like autoimmune disease. Clin Exp Immunol 1999; 115:236-47. [PMID: 9933448 PMCID: PMC1905170 DOI: 10.1046/j.1365-2249.1999.00807.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies performed in mice together with the demonstration of increased levels of heart-specific autoantibodies, cytokines and cytokine receptors in sera from cardiomyopathy (CMP) patients argued for a pathogenic role of autoimmune mechanisms in CMP. This study was designed to analyse the presence of IgG anti-heart antibodies in sera from patients suffering from hypertrophic and dilatative forms of CMP as well as from patients with ischaemic heart disease and healthy individuals. Patients' sera were analysed for IgG reactivity to Western-blotted extracts prepared from human epithelial and endothelial cells, heart and skeletal muscle specimens as well as from Streptococcus pyogenes. The IgG subclass (IgG1-4) reactivity to purified human cardiac myosin was analysed by ELISA. While sera from CMP patients and healthy individuals displayed comparable IgG reactivity to a variety of human proteins, cardiac myosin represented the prominent antigen detected strongly and preferentially by sera from CMP patients. Pronounced IgG anti-cardiac myosin reactivity was frequently found in sera from patients with dilatative CMP and reduced ventricular function. ELISA analyses revealed a prominent IgG2/IgG3 anti-cardiac myosin reactivity in CMP sera, indicating a preferential Th1-like immune response. Elevated anti-cytomegalovirus, anti-enterovirus IgG titres as well as IgG reactivity to nitrocellulose-blotted S. pyogenes proteins were also frequently observed in the group of CMP patients. If further work can support the hypothesis that autoreactivity to cardiac myosin represents a pathogenic factor in CMP, specific immunomodulation of this Th1- towards a Th2-like immune response may represent a promising therapeutic strategy for CMP.
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Ever L, Steiner R, Shalom S, Don J. Two alternatively spliced Meig1 messenger RNA species are differentially expressed in the somatic and in the germ-cell compartments of the testis. CELL GROWTH & DIFFERENTIATION : THE MOLECULAR BIOLOGY JOURNAL OF THE AMERICAN ASSOCIATION FOR CANCER RESEARCH 1999; 10:19-26. [PMID: 9950214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Previous studies regarding the transcriptional pattern of the murine Meig1 gene (formally designated meg1) suggested that its transcription is restricted to germ cells at the first meiotic prophase, in both primary spermatocytes and primary oocytes. However, protein analysis revealed that certain forms of the MEIG1 protein exist in testes of early postnatal pups at stages that have no germ cells in the testis, excluding very few primitive type A spermatogonia cells. This suggested that MEIG1 expression is not confined to germ cells. In this study, we show that testicular somatic cells do, indeed, express MEIG1. This is especially evident in Leydig cells, where this protein is highly abundant. We also demonstrate that alternatively spliced mRNAs of Meig1 are differentially transcribed in the germ cell and the somatic compartments of the testis. There is a very low level of somatic transcript, whether labile or transcriptionally regulated, in contrast to the abundant MEIG1 protein in the somatic cells. This implies that the somatic transcript is very efficiently translated and reconfirms that protein levels do not necessarily reflect transcript abundancy. Structural features of the Meig1 transcript that would be expected to inhibit translation are discussed in light of the efficient translation of this RNA species.
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116
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Beck G, Akgün N, Rück A, Steiner R. Design and Characterisation of a Tissue Phantom System for Optical Diagnostics. Lasers Med Sci 1998. [DOI: 10.1007/s101030050070] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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117
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Pastorelli G, Steiner R, Haller U. [Cervical pregnancy. A gynecologic-obstetric emergency situation]. GYNAKOLOGISCH-GEBURTSHILFLICHE RUNDSCHAU 1998; 37:209-15. [PMID: 9609929 DOI: 10.1159/000272856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cervical pregnancy is defined as the implantation of the blastocyst into the cervical canal. The characteristic clinical sign is a severe asymptomatic uterine bleeding in early pregnancy or during curettage. Prior to 1978, correct preoperative diagnosis was rare and in almost all cases a hysterectomy was performed. Today, transvaginal sonography allows early diagnosis, and conservative treatment (two-time treatment: first treatment with systemic or intraamniotic methotrexate, secondly with curettage or ligature of the uterine arteries) improves the prospects of fertility.
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Schneckenburger H, Sailer R, Gschwend MH, Strauss WS, Bauer M, Zipfl P, Steiner R. [Optical dual canal measuring system for the detection of disorders of mitochondrial metabolism in situ]. BIOMED ENG-BIOMED TE 1998; 42 Suppl:169-70. [PMID: 9517099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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119
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Russ D, Orth K, Hibst R, Dürr J, Steiner R. [Thermostatically controlled coagulation probe for laser-induced interstitial thermotherapy]. BIOMED ENG-BIOMED TE 1998; 42 Suppl:221-2. [PMID: 9517123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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120
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Strauss WS, Sailer R, Gschwend MH, Emmert H, Steiner R, Schneckenburger H. Selective examination of plasma membrane-associated photosensitizers using total internal reflection fluorescence spectroscopy: correlation between photobleaching and photodynamic efficacy of protoporphyrin IX. Photochem Photobiol 1998; 67:363-9. [PMID: 9523537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fluorescence spectra, fluorescence decay kinetics, photobleaching kinetics and photodynamic efficacy of protoporphyrin IX (PP) were investigated in endothelial cells in vitro after different incubation times. Fluorescence spectra and photobleaching kinetics were determined during total internal reflection (TIR) illumination or epi-illumination. Because penetration depth of the excitation light during TIR illumination was limited to about 100 nm, plasma membrane-associated PP was almost selectively examined. Spectra obtained by TIR fluorescence spectroscopy (FS) showed a very low background, whereas spectra obtained by epi-illumination exhibited considerable background by autofluorescence and scattered light. For photobleaching kinetics during TIR illumination after 1 h or 24 h incubation, a biexponential fluorescence decrease was observed with a rapidly and a slowly bleaching portion. After 1 h incubation, the rapidly bleaching portion was the predominant fraction, whereas after 24 h incubation comparable relative amounts of the rapidly and slowly bleaching portion were determined. The rapidly and slowly bleaching portion were assigned to PP monomers and aggregated species in close vicinity to the plasma membrane. Fluorescence decay measurements after epi-illumination support the decrease of PP monomers within the whole cell with increasing incubation time. In contrast to TIR illumination, photobleaching of PP during epi-illumination was characterized by slow monoexponential fluorescence decrease after 1 h or 24 h incubation. Photodynamic efficacy of PP using epi-illumination was found to depend strongly on incubation time. Considerable cell inactivation was determined for short incubation times (1 h or 3 h), whereas photodynamic efficacy was diminished for longer incubation times. Reduced photodynamic efficacy after long incubation times was assigned to the lower amount of photodynamically active monomers determined close to the plasma membrane as well as within the whole cell. In conclusion, TIRFS measurements are suggested to be an appropriate tool for the examination of the plasma membrane-associated photosensitizer fraction in living cells.
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Kampmeier J, Stock K, Hibst R, Lang GE, Steiner R, Lang GK. [Intracanalicular trabeculostomy--a new approach to glaucoma surgery]. Klin Monbl Augenheilkd 1998; 212:159-62. [PMID: 9592741 DOI: 10.1055/s-2008-1034853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND A new "ab externo" technique for glaucoma trabecular surgery creating multiple perforations of the trabeculum to improve outflow facility was tested. MATERIAL AND METHOD In order to perform a draining canal to the anterior chamber, a quartz fiber (phi: 300 microns) with a side-firing tip, coupled to an Er:YAG laser (2.94 microns), was inserted into Schlemm's canal of an enucleated human eye. RESULTS Eight pulses of 8 mJ each were sufficient to perforate the trabecular meshwork. Histologic analysis showed a rippled canal with 50 microns average diameter and a surrounding necrosis zone of 15-35 microns. CONCLUSIONS The Er:YAG laser trabeculostomy, in conjunction with special fibers, shows promise as a new "ab externo" technique for minimally invasive therapy of open angle glaucoma.
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Strauss WSL, Sailer R, Gschwend MH, Emmert H, Steiner R, Schneckenburger H. Selective Examination of Plasma Membrane–Associated Photosensitizers Using Total Internal Reflection Fluorescence Spectroscopy: Correlation between Photobleaching and Photodynamic Efficacy of Protoporphyrin IX. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb05211.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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123
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Steiner R. Guest Editorial: New techniques for tissue ablation. MINIM INVASIV THER 1998. [DOI: 10.3109/13645709809152892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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124
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Rück A, Heckelsmiller K, Akgün N, Beck G, Kunzi-Rapp K, Schick E, Steiner R. Nonlinear Dynamics of Intracellular Methylene Blue During Light Activation of Cell Cultures. Photochem Photobiol 1997; 66:837-41. [PMID: 12269331 DOI: 10.1111/j.1751-1097.1997.tb03234.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methylene blue (MB+) is a well-known dye in medicine and has been discussed as an easily applicable drug for topical treatment in photodynamic therapy (PDT). Methylene blue can potentially be used as a redox indicator to detect the important redox reactions that are induced during PDT. The kinetics of this process was analyzed on a subcellular level with confocal laser scanning microscopy. BKEz-7 endothelial cells were incubated 4 h with 1 microM MB+. The fluorescence dynamics of MB+ during irradiation with 633 nm light was observed with subcellular resolution. Images were acquired at 0.5 s intervals (frame rate 1 image/0.5 s). Fluorescence was observed in the red channel of the laser scanning microscope. Synchronously, the phase-contrast image was visualized with the green channel. Morphological changes could therefore be correlated with the dynamics of MB+. In addition, the light-dose-dependent phototoxicity at 633 nm irradiation was determined by viable cell counting. After an induction period (phase I), fast fluorescent spikes could be observed in the whole cytoplasm, which decayed with a time constant of about 20 s (phase II), followed by a period of nearly constant fluorescence intensity (phase III) and exponential photobleaching (phase IV). Phase II exhibits highly nonlinear kinetics, which is hypothesized to correlate probably with a nonlinear quantal production of reactive oxygen species (ROS). Morphological cell changes were not observed during phase II. During phase III, a pycnotic cell nucleus developed. From the determination of viable cells we can conclude that a light dose applied within phase II was only sublethal in correlation with morphological observations. Overproduction of ROS leading finally to cell killing during phases III and IV is discussed.
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Orth K, Russ D, Steiner R, Beger HG. [Dynamic interstitial laser application for therapy of secondary liver tumors. An animal experiment study]. Chirurg 1997; 68:1268-73; discussion 1274. [PMID: 9483354 DOI: 10.1007/s001040050357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Laser-induced interstitial thermotherapy (LITT) is a promising method of treating different types of tumors. To increase the effectiveness of LITT, a new thermo-controlled application system for minimal invasive intervention was designed. This laser system consists of a laser applicator 3 mm in diameter, insertion equipment and an Nd:YAG laser source. The power of the laser source is controlled dynamically by thermosensors in a water-cooling system of the laser applicator. In in vivo experiments in five pigs, within 10 min we found homogeneous coagulation regions in the liver that were of 3 cm and 5 cm in diameter. Via ultrasound we observed in real time the increasing coagulation zone that appeared as a hyperechogenic halo. However, due to perifocal edema, the real coagulation area was smaller than detected by ultrasound. Macroscopically and microscopically, the coagulation zones showed well-demarcated borders of the coagulation lesions, and the surrounding tissue appeared vital. The reparative reaction after irradiation was early fibrosis. In the course of 4 weeks, the surrounding scar capsule, containing fibrocytes, biliary ductules and collagen fibers enlarged. As a result, the coagulation necrosis became more and more fragmented between collagen fibers and was largely resorbed. The absence of complications in our animal experiments suggest that the technique of thermo-controlled laser light application is safe and useful in therapy for metastases that are not resectable.
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