Biomedical subjects

H Bartels

Publications and source records attributed to H Bartels.

At least 19 recordsLinked to original sources

PubMed1995

Large-cell anaplastic lymphoma-specific translocation (t[2;5] [p23;q35]) in Hodgkin's disease: indication of a common pathogenesis?

Chromosomal aberrations are characteristic and specific events; the detection of chromosomal abnormalities often provides information on diagnosis and prognosis of disease. Some patients with large-cell anaplastic lymphoma (Ki 1 lymphoma) have the translocation t(2;5) (p23; q35), involving a possible growth-regulating tyrosine kinase. We found this translocation in 11 patients with Hodgkin's disease of nodular sclerosis and mixed-cellularity types. This finding has implications for the understanding of the relation between large-cell anaplastic lymphoma and Hodgkin's disease, diseases with morphological and immunophenotypical similarities. Study of this translocation may help understanding of the origins of cancer and cancer growth. It also allows a more precise definition of Hodgkin's disease and may be used as an indicator for clonality--which has long been sought.

Actins↗

PubMed1995

Ultrastructure and protein transport of M cells in the rabbit cecal patch.

BACKGROUND: The gut-associated lymphoid tissue of the rabbit cecum includes a single lymphoid patch located close to the ileocecal orifice. Vimentin immunoreactivity, which can now be regarded as a marker for M cells in rabbits, has identified a subpopulation of epithelial cells as M cells in the domes of this patch. The aim of the present study was to demonstrate that these M cells are capable of antigen transport and to characterize their ultrastructure. METHODS: M cells of the rabbit cecal lymphoid patch were studied by scanning, thin section, and freeze-fracture electron microscopy. The transcytosis across these M cells was investigated using horseradish peroxidase as a soluble tracer protein. RESULTS: The M cells were concentrated at the flanks of the domes and had long, thick, branched microvilli, a well-developed terminal web, and a deep invagination of their apical membrane. Numerous small vesicles lay beneath the terminal web in close vicinity to the base of the invagination. These vesicles transported the luminally applied horseradish peroxidase through the M cells. In contrast to adjacent enterocytes, the glycocalyx of M cells was thin, stub-like, and had very few glycocalyceal bodies. Bacteria adhered to the surface of M cells and were also found in the apical invagination. CONCLUSIONS: The M cells of the rabbit cecal lymphoid patch differ from those of Peyer's patches of the small intestine in their ultrastructure and route of antigen transport. These differences might be related to the situations resulting from differences in the microbial populations at these locations.

Animals↗

PubMed1995

Relationships between endothelial cells, pericytes, and osteoblasts during bone formation in the sheep femur following implantation of tricalciumphosphate-ceramic.

BACKGROUND: The origin of osteoblasts is still controversial. Whereas several authors consider the stromal fibroblast of the bone marrow as the osteoprogenitor cell, others propose that the osteoblasts can be derived from the "capillary system." The present study examines the replacement of tricalciumphosphate (TCP)-ceramic implanted into an artificial bone defect by newly formed bone. The results support the hypothesis that osteogenic cells can be derived from invading blood vessels. METHODS: The spongiosa of the trochanter major of sheep was removed and the defect was filled with TCP-ceramic. Two months after surgery the ceramic implants together with the surrounding bone were removed and processed for transmission electron microscopy. Serial ultrathin sections of three newly formed osteons were examined. RESULTS: The osteons contain one or two small sprouting capillaries, a peripheral layer of osteoblasts, and in between, a network of glycogen-rich cells. Some of the glycogen-rich cells are completely or partly surrounded by the endothelial basal lamina and are thereby characterized as pericytes. Weibel-Palade bodies, which are considered to be a marker of endothelial cells, were occasionally observed in glycogen-rich pericytes. CONCLUSIONS: Since pericytes differentiate into osteoblasts under in vivo and in vitro conditions, and have thus been regarded as osteoprogenitor cells, the presence of Weibel-Palade bodies in these cells suggest that osteogenic cells can be derived from endothelial cells.

Animals↗

PubMed1995

Reinforced poly(L-lactic acid) fibres as suture material.

In this study, reinforced poly(L-lactic acid) (PLLA) fibers made by a dry-spinning/hot-drawing process were evaluated for use as a suture. The initial tensile strength of the PLLA fibers was lower than the initial tensile strength of the commercially available sutures: PDS, Vicryl, silk, and Ethilon. However, after 12 weeks immersion in a phosphate saline buffer at 37 degrees C, PDS sutures have lower tensile strength than PLLA sutures and the tensile strength of Vicryl was unmeasurable because of fragmentation. Initially, PLLA fibers disintegrated into fibrils during degradation triggering an inflammatory response comparable to degradable multifilament sutures. However, the intensity of the inflammatory response against the PLLA fibers decreased and after 80 weeks implantation in the muscle layer of the abdominal wall of rats it was comparable to the one against Ethilon. The inflammatory response against Ethilon, which is considered to be nondegradable, increased in the same period, probably due to the change in shape. In practice, the handling characteristics of PLLA sutures are superior to the monofilament sutures like PDS and Ethilon and comparable with the multifilament sutures like Vicryl and silk. The knot security of PLLA sutures are expected to be better than the knot security of the monofilament sutures, but this remains to be investigated. It is concluded that dry-spun/hot-drawn (reinforced) PLLA fibers have the potential for use as long-term degradable suture material.

Animals↗

PubMed1995

Structural organization and epithelial cells types of the intestinal diverticula (protopancreas) of ammocoetes of southern hemisphere lampreys: functional and phylogenetic implications.

Larvae of the two southern hemisphere lamprey genera, Mordacia and Geotria, possess one and two intestinal diverticula, respectively, each originating at the oesophageal-intestinal junction. These diverticula comprise an inner layer of simple columnar epithelium composed solely of zymogen and mucous cells, a middle layer consisting mainly of a blood sinus, and an outer serosa layer covered by a simple squamous epithelium (mesothelium). The inner surface is highly folded only in Mordacia. The secretion of mucus probably protects the epithelium from the effects of digestive enzymes secreted by the zymogen cells and/or bile, which enters the diverticulum at its tip. Unlike the situation in southern hemisphere lampreys, the zymogen cells of the larvae of holarctic lampreys are located in the anterior intestine, a condition considered to be "primitive". It is thus proposed that intestinal diverticula were developed during the evolution of southern hemisphere lampreys. The relocation of zymogen cells in the diverticula increases the area for these cells, and thus the capacity for the synthesis and secretion of digestive enzymes, particularly in Mordacia where the inner surface is folded.

Animals↗

PubMed1995

Cytogenetic findings in 179 patients with myelodysplastic syndromes.

Cytogenetic analyses were performed on 266 bone marrow and peripheral blood samples from 179 patients with myelodysplastic syndromes (MDS). According to the FAB classification, 42 patients presented with RA, 18 with RARS, 37 with RAEB, 22 with CMML, and 29 with RAEB-T. Nine patients showed a secondary MDS (S MDS). FAB classification was not available for 22 patients. Clonal karyotype anomalies were found in 92 patients (51.4%). Complex chromosome abnormalities occurred in 17 (18.5%) of them. An evolution of the karyotype was detected in 16 cases (17.4%). Cytogenetically independent cells or cell clones were found in eight patients. Nonclonal chromosome abnormalities were uncovered in 29 (16.2%) of the 179 MDS patients. Consecutive studies were performed in 48 patients and revealed a good correlation of initial karyotype and clinical course. The most frequent single anomalies were 5q- in 29 (31.5%), -7 in 22 (23.9%), trisomy 1q in 14 (15.2%), and +8 in 13 (14.1%) of 92 patients respectively. Our cytogenetic findings are presented in detail and discussed in relation to patients' age, morphological classification, clinical course, and prognostic impact. The contribution of cytogenetic findings to the delineation of multistep pathogenesis of MDS with special emphasis to karyotype instability is demonstrated.

Adult↗

PubMed1995

A comparison of polychemotherapy and melphalan/prednisone for primary remission induction, and interferon-alpha for maintenance treatment, in multiple myeloma. A prospective trial of the German Myeloma Treatment Group.

406 untreated multiple myeloma patients of stage I (n = 54), II (n = 148) and III (n = 204) were enrolled in the trial. 51/54 stage I and 60/148 stage II patients were asymptomatic and followed without treatment until disease progression (progression free survival: 60% after 4 years for stage I versus 50% after 1 year for stage II). Symptomatic patients of stage I (n = 3/54) and II (n = 88/148) presenting with tumour progression, received melphalan 15 mg/m2 intravenously (i.v.) and prednisone 60 mg/m2 oral days 1-4 (MP). Stage II disease remission rate was 59%, and 50% tumour related survival (TRS) was 59 months. Stage III patients were randomised to receive MP or VBAMDex (vincristine/BCNU/doxorubicin/melphalan/dexamethasone) treatment. 43% of MP treated patients responded compared with 64% of the VBAMDex group. 50% TRS was 36 months in both groups without a detectable difference. 117 responders of stage II and III with stable disease were randomised to receive either IFN-alpha (5 x 10(6) IU, subcutaneous (S.C.) 3 times per week) or no maintenance treatment. The relapse rate in both groups was 50% after 13 months. No survival benefit for IFN alpha treated patients was observed (50% TRS: 45 months).

Aged↗

PubMed1995

Prognostic factors of resected adenocarcinoma of the esophagus.

BACKGROUND: The main purpose of this study was to determine prognostic factors in patients with surgical treatment of adenocarcinoma of the esophagus. METHODS: Within a 12.5-year period, esophageal adenocarcinoma was resected in 165 patients by radical transhiatal esophagectomy (n = 134) or transthoracic en bloc esophagectomy (n = 31). Tumors were analyzed according to the 1992 UICC classification with respect to pTNM stage, residual tumor (R) status, grading, and ratio of infiltrated to resected lymph nodes (lymph node ratio); both univariate and multivariate analysis of prognostic factors were performed. RESULTS: The 30-day mortality rate was 6.1%. A complete removal of the tumor was achieved in 83% of the patients. Lymph node metastases were not detected in mucosal cancer (pT1a) but were detected in 18% of submucosal cancer (pT1b), 77% of pT2, 83% of pT3, and 96% of pT4. The overall 5-year survival rate was 34%; for patients without postoperative residual tumor (R0) it was 41%, and for those without lymph node metastases (pN0, R0) 63%. The 5-year survival rate for patients (pN1) with less than 30% invaded lymph nodes was 45%, compared with 0% for more than 30% invaded nodes. Independent prognostic factors for R0 resected patients excluding postoperative fatal outcome were pT and lymph node ratio. CONCLUSIONS: Long-term survival after resection of esophageal adenocarcinoma is mainly associated with complete tumor removal, limited esophageal wall penetration, and ratio of infiltrated to removed lymph nodes of less than 0.3.

Adenocarcinoma↗

PubMed1995

[Extremely severe complication during ESWL caused by unsuspected asymptomatic pheochromocytoma].

In 0.1% the pheochromocytoma is the reason of a systemic hypertension. The symptoms of a persistent or paroxysmal hypertension with headache, excessive sweating and palpitations lead in 90% to the diagnosis pheochromocytoma. Very rarely a patient with pheochromocytoma may be asymptomatic. We introduce a 68-year-old man whose pheochromocytoma primarily rose up while ESWL and furthermore in anaesthesia. The problems to determine the diagnosis will be scrutinized as following.

Adenocarcinoma↗

PubMed1995

Linear arrays of intramembranous particles characterize a subpopulation of epithelial cells in the rabbit caecum.

Linear arrays of particles, identical to those in the cup cells of the small intestine, characterize the brush border membrane of a subpopulation of surface epithelial cells in freeze-fracture replicas of the rabbit caecum. Although these cells lack a cup-like indentation of their brush border, we propose that all intestinal epithelial cells showing this arrangement of intramembranous particles in their apical membrane belong to a distinct subpopulation of the epithelial cells. A specific function of this cell type that is related to the linear arrays of particles remains to be determined.

Animals↗

PubMed1994

Translocation (X;8)(q2?6;q21.3) in a case of systemic mastocytosis.

Mastocytosis is a rare disease which occasionally progresses into mast cell leukemia or other myeloid neoplasms. Here we report on a patient with systemic mastocytosis who was found to have a clone with t(X;8)(q2?6;q21.3) and two copies of der(8)t(X;8). In accordance with these results, interphase cytogenetic analysis revealed that 93% of bone marrow cells contained three centromeric regions of chromosome 8. We suggest that the t(X;8) and the duplication of the translocation chromosome 8 may play a role in the progression of the diseases.

Aged↗

PubMed1994

Folding and stability of the active N-terminal domain of tissue inhibitor of metalloproteinases-1 and -2.

The truncated forms of tissue inhibitor of metalloproteinase-1 and -2 (delta TIMP-1 and -2), comprising the N-terminal active domain, are ideal molecules for structural analysis by intrinsic fluorescence as each contains a single conserved tryptophan residue. In this paper we describe studies on their conformational stability, unfolding/refolding kinetics and the environment of the unique tryptophan as judged by its fluorescence properties in the native state and exposure to an external quencher, acrylamide. Two forms of delta TIMP-2 were studied: delta TIMP-2 T21 derived from the full-length cDNA clone isolated from a mixed-tumour library, and delta TIMP-2 A21 containing the highly conserved V18IRAK22 sequence. In all three delta TIMP proteins the tryptophan environments in the native state appeared to be similar, but substantial differences were seen in their conformational stabilities and refolding kinetics. delta TIMP-1 was approximately twice as stable as delta TIMP-2 T21 and 1.4-fold more stable than delta TIMP-2 A21. This stability difference between delta TIMP-1 and delta TIMP-2 was shown to be independent of N-linked glycosylation. delta TIMP-1 and delta TIMP-2 A21 both showed simple two-state refolding kinetics, whereas delta TIMP-2 T21 refolding was more complex and biphasic in character. These differences between delta TIMP-2 T21 and A21 suggest that residue 21 is a structurally important site in the TIMP protein. All three truncated molecules can be considered as stable independent folding domains ideally suited for further structural analysis.

Base Sequence↗

PubMed1994

Serum levels of end products of nitric oxide synthesis correlate positively with tumor necrosis factor alpha and negatively with body temperature in patients with postoperative abdominal sepsis.

Nitric oxide (NO) has been implicated as the principal mediator of the catecholamine resistant vasodilation in septic shock. In this pilot study, we wanted to know if the serum values of nitrite/nitrate (NO2/NO3), the stable endproducts of NO biosynthesis, are elevated in patients with septic shock. Furthermore, we investigated whether there is a correlation between NO2/NO3 serum levels and tumor necrosis factor alpha or interleukin 6. NO2/NO3 serum values were significantly elevated in septic patients compared to controls (72.1 +/- 6.1 vs. 35.7 +/- 9.2 microM, p < .001). There was a significant positive correlation between serum values of NO2/NO3 and tumor necrosis factor alpha (rs = 0.59, p < .001). In contrast, no correlation between NO2/NO3 and interleukin 6 was found. With the exception of body core temperature, which showed a negative correlation with NO2/NO3 levels, no clinical variable turned out to be significantly related to NO biosynthesis. These data indicate a potential role for NO in the clinical course of abdominal sepsis, but points out that more specific data has to be evaluated by prospective clinical studies in order to understand the complex pathophysiologic role of this novel mediator.

Abdomen↗

PubMed1994

Combined immunophenotyping and karyotyping in peripheral T cell lymphomas demonstrating different clonal and nonclonal chromosome aberrations in T helper cells.

Combined immunophenotyping and karyotyping was performed in seven cases of peripheral T cell lymphoma with complex aberrant clones. Various lymphocytic cell populations entered mitosis, whereas all aberrant cells belonged to the T helper/inducer cell population. Lymphomas with the same recurrent chromosome aberrations, i.e. inversion inv(14)(q11q32.1) and isochromosome i(8)(q10), had a very similar immunophenotype. The aberrant cells in these cases expressed CD3+, CD4+, CD7+, CD45RO+. The immunophenotypic similarity is underlined in one case of T prolymphocytic leukemia, in whom the aberrant cells lost the CD8 antigen originally present, during cultivation with PHA. In one case of Sézary's syndrome, two or possibly even three different clones as well as nonclonal aberrations were identified within the T (helper/inducer) cell population, providing further evidence that chromosomal instability is a characteristic feature of cutaneous T cell lymphoma.

Adult↗

PubMed1994

Characterization of human TUR leukemia cells: continued cell cycle progression in the presence of phorbol ester is associated with resistance to apoptosis.

Human TUR leukemia cells were generated as a subclone of U937 monoblastoid leukemia cells. There was no obvious difference in the ultrastructure of both cell lines. Like in U937 cells, the expression of monocyte-specific surface markers such as CD14 was negligible in TUR cells. U937 cells and other human myeloid leukemia cell lines (HL-60, THP-1) can be induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) to differentiate along the monocytic pathway. In contrast, exposure to TPA had no effect on the induction of the differentiation program in TUR cells. Thus, the presence of leukocyte integrins including CD11 and CD18, which are significantly induced during TPA-induced differentiation of HL-60, U937 and THP-1 cells, remained nearly unchanged at low levels in both TUR and TPA-treated TUR cells. Furthermore, while expression of major histocompatibility complex (MHC) class II antigens on U937 and TPA-treated U937 cells is barely detectable, there was a significantly constitutive expression of MHC class II, particularly human lymphocyte antigen (HLA-DR) on the surface of TUR and TPA-treated TUR cells. Exposure of human myeloid leukemia cells to TPA is also associated with growth arrest resulting either in a retrodifferentiation process or in programmed cell death. In contrast, TUR cells continued to proliferate in the presence of TPA although the proliferative capacity was continuously reduced by increasing concentrations of TPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Apoptosis↗

PubMed1992

[Prognostic factors in diffuse peritonitis].

In order to evaluate their prognostic relevance for survival 46 variables were submitted to univariate as well as multivariate analysis in a group of 184 patients with diffuse peritonitis. In the univariate analysis a significant correlation with the outcome was found for the following parameters: age greater than or equal to 70 years, preexisting hepatic or cardiac disease, no eradication of the primary source of infection at first laparotomy for peritonitis, cardiovascular instability, respiratory failure, hyperbilirubinemia, thrombocytopenia, elevated serum creatinine and diminished creatinine clearance at the beginning and proof of pseudomonas aeruginosa in the peritoneal exsudate and of candida albicans in the blood culture during the course of the peritonitis. In the multivariate analysis the surgical eradication of the primary source of infection at the first laparotomy for peritonitis, serum creatinine at the beginning of peritonitis, age greater than or equal to 70 years and a preexisting hepatic disease proved to be the independent variables with significant prognostic relevance for survival of the patients.

Aged↗

PubMed1992

Co-localization of vimentin and cytokeratins in M-cells of rabbit gut-associated lymphoid tissue (GALT).

The occurrence of cytokeratins, vimentin, and desmin in the dome epithelia and adjacent non-dome epithelia in four locations of gut-associated lymphoid tissues (GALT) of adult and newborn rabbits (Peyer's patches, sacculus rotundus, caecal lymphoid patches and appendix) was studied with monoclonal antibodies, using the indirect immunoperoxidase technique. In all locations investigated in adult animals, antibodies specific for vimentin labelled (1) M-cells, which engulf intra-epithelial lymphocytes, (2) columnar epithelial cells at the base of the domes lacking an apparent contact with lymphocytes ("immature" M-cells), and (3) flat cells, which lie in the lamina propria under the dome epithelium, and which line the basal lamina with thin cytoplasmic processes. In newborn rabbits, columnar epithelial cells resembling the immature M-cells of adults were selectively stained with vimentin antibodies. In M-cells, the strongest immunoreactivity was present in the perinuclear region and close to the pocket membrane, whereas the most apical and most basal parts of the cytoplasm showed no vimentin-immunoreactivity. Enterocytes in the dome epithelium and in the non-dome epithelium were vimentin-negative. M-cells and enterocytes bound antibodies against cytokeratin peptides 18 and 19 in adult and newborn animals. Compared with enterocytes, M-cells showed less intense staining for cytokeratins. Dome epithelia and no-dome epithelia did not contain desmin-immunoreactive cells. The results suggest that vimentin is a sensitive marker for M-cells in rabbit GALT.

Animals↗

PubMed1992

Combination therapy with interferon alpha-2b plus low-dose interferon gamma in pretreated patients with Ph-positive chronic myelogenous leukaemia.

Between March 1988 and July 1990, 28 adults with chronic myelogenous leukaemia (CML) were treated with a combination of recombinant human interferon (IFN) alpha-2b s.c. (initial dose 4 x 10(6) U/m2) and recombinant human IFN gamma s.c. (50 micrograms totally) daily. All patients were in chronic phase disease and had been treated previously with chemotherapy or bone marrow transplantation. A complete haematologic remission was achieved in three patients (11%), a haematologic remission in 12 patients (43%), and a partial haematologic remission in seven patients (25%). Six patients did not respond to this schedule. Acute side-effects were flu-like symptoms, fever and chills. During long-term treatment six patients developed polyarthralgia. Haematotoxicity WHO grade III occurred in three patients, and WHO grade IV in two patients. One patient developed psychosis, and in another patient an exacerbation of a pre-existing sarcoidosis was observed. We conclude that this combination is tolerable and effective in inducing haematological remissions in pretreated CML patients.

Adolescent↗