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Biomedical subjects

C Pohl

Publications and source records attributed to C Pohl.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Primary biliary cirrhosis--cellular mechanisms and role of enterobacterial antigens].

The nature of primary biliary cirrhosis (PBC) is still unknown. In this study the diagnostic value of the expression of MHC proteins and adhesion molecules in bile duct epithelia, the different amount of inflammatory cells around the bile ductules and the evidence of enterobacterial antigens were tested in liver tissue of patients with PBC, chronic hepatitis B and C, autoimmune hepatitis and cellular or ductopenic liver transplant rejection. There was a significant difference according MHC and adhesion molecules between PBC and rejections at the one and the cases of chronic hepatitis at the other hand. According to inflammatory infiltrate there was no difference. The enterobacterial antigen lipid-A was found more often in centrolobular hepatocytes of PBC/PSC cases but not in the portal bile duct region. The possible pathogenetic role of enterobacterial antigens in the disease are discussed.

Antigens, Bacterial↗
PubMed1995

Relations between verbal and nonverbal memory performance: evidence of confounding effects particularly in patients with right temporal lobe epilepsy.

Confounding left hemisphere verbalization strategies can be suggested as being a major problem in the evaluation of the assumed involvement of right temporo-limbic structures in "nonverbal" visual/figural memory processing. We addressed this issue by evaluating the easily-verbalized Benton-visual-retention-test in 60 patients with either left (LTLE) or right temporal lobe epilepsy (RTLE) and 30 healthy controls. We formally estimated the informational (verbal) content of each item which hypothetically would be needed to solely retain the item from verbal memory. The results indicated confounding of verbal learning and figural memory only in the presence of right temporal lobe dysfunctions. Selective visual/figural learning deficits in RTLE patients became obvious when the verbal load of the figural material exceeded their verbal learning capacity. Instead of excluding verbalization by the use of abstract figural items, its inclusion provides a possibility to control compensatory strategies which overshadow the presence of visual/figural memory deficits.

Adult↗
PubMed1994

Cure of xenografted human tumors by bispecific monoclonal antibodies and human T cells.

Tumor immunotherapy should increase both the number of T cells that kill the tumor and the likelihood that those cells are activated at the tumor site. Bispecific monoclonal antibodies (Bi-mAbs) were designed that bound to a Hodgkin's tumor-associated antigen (CD30) on the tumor and to either CD3 or CD28 on the T cell. Immunodeficient mice were cured of established human tumors when mice were treated with both the CD3-CD30 and the CD28-CD30 Bi-mAbs and then given human peripheral blood lymphocytes that had been incubated with the CD3-CD30 Bi-mAb and cells that expressed CD30. The enrichment of human T cells within the tumor and the fact that established tumors can be cured may indicate in situ activation of both the T cell receptor and the costimulatory pathway.

Animals↗
PubMed1994

Scintigraphic localization of the bleeding site of a large retroperitoneal hematoma following renal angioplasty.

Although the scintigraphic detection of a few soft tissue hematomas have been reported, these usually have been serendipitous discoveries that were small and self-limited. The authors report a case of a large, rapidly expanding retroperitoneal hematoma that occurred following a left renal angioplasty. While the hematoma was initially detected by CT imaging, the precise source of the bleeding could not be definitively localized. Scintigraphy with labeled RBC cells, however, identified the left femoral artery puncture site as the bleeding source, which was subsequently surgically repaired.

Aged↗
PubMed1994

Contrast-enhanced MR imaging of the breast: comparison of two different doses of gadopentetate dimeglumine.

PURPOSE: To optimize detection and diagnosis of breast lesions with contrast-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: A three-dimensional fast low-angle shot pulse sequence was used for a group comparison consisting of 76 high-dose (0.16 mmol gadopentetate dimeglumine per kilogram of body weight) and 76 low-dose (0.1 mmol/kg) examinations. Intraindividual comparisons were possible in a subgroup of 20 patients. RESULTS: Enhancement with the high dose was about 1.5 times higher for benign and malignant tissues. With the lower dose, no false-positive findings could be avoided and definition of a threshold that excluded false-negative findings was problematic. Conspicuity of malignant lesions was much improved with the higher dose (a good to excellent rating in 81% vs 26% with the lower dose). Three small foci were visible only with the higher dose. CONCLUSION: The higher dose of contrast material allowed much better results. Dose comparison studies are also recommended for other techniques.

Breast↗
PubMed1994

Mimicry of the Hodgkin-associated IRAC antigen by an anti-idiotype network: potential use in active immunotherapy of Hodgkin's lymphoma.

The murine monoclonal antibody anti-IRac, defining a surface-antigen structure (MW 70 kDa) on Hodgkin-Reed-Sternberg and interdigitating reticulum cells, was used to generate a cascade of anti-idiotypic antibodies as well as a cellular immunity against Hodgkin-Reed-Sternberg cells in syngeneic BALB/c-mice. The anti-idiotypic antibody monoclonal antibody 4B4 demonstrated characteristics of an "internal image" or network antibody (Ab2 beta). Ab2 beta 4B4 bound specifically to anti-IRac and inhibited anti-IRac-binding to antigen-bearing cells effectively. 4B4 induced an IRac-specific humoral polyclonal immune response in BALB/c-mice and New Zealand white rabbits as judged by Flow cytometric and histochemical analysis. Moreover, BALB/c-mice immunized with 4B4 showed statistically significant (p > 0.01) delayed-type hypersensitivity reaction against IRac-expressing Hodgkin cell-lines. Ab2 beta 4B4 induced in syngeneic BALB/c mice a monoclonal anti-anti-idiotypic antibody (Ab3) termed 3G10, which mimicked the specificities of Ab1 anti-IRac and thus confirms the internal image nature of Ab2 beta 4B4. The anti-idiotype-induced tumor cell specific T- and B-cell mediated immune response even across species barriers via the Hodgkin related IRac-antigen may play an important part in active specific immunotherapy of Hodgkin's disease.

Animals↗
PubMed1993

A CD16/CD30 bispecific monoclonal antibody induces lysis of Hodgkin's cells by unstimulated natural killer cells in vitro and in vivo.

In order to target NK cells against the Hodgkin's-derived cell line L540, we developed bispecific monoclonal antibodies (Bi-MAbs) by somatic hybridization of the 2 mouse hybridoma cell line HRS-3 and A9 which produce monoclonal antibodies (MAbs) with reactivity against the Hodgkin and Reed-Sternberg cell-associated CD30 antigen and the CD16 antigen (Fc gamma III receptor), respectively. The CD16 MAb-producing cell line A9 was selected as a partner for HRS-3 because of its efficiency in inducing lysis of the A9 hybridoma cells by resting NK cells. The hybrid hybridoma cell line HRS-3/A9 produced the supernatant with the strongest bispecific reactivity and was repeatedly subcloned and used for ascites production. Crude supernatant and purified HRS-3/A9 Bi-MAb triggered specific lysis of the CD30+ Hodgkin's-derived cell line L540, but not of the CD30- cell line HPB-ALL by unstimulated peripheral-blood lymphocytes and NK-cell-enriched populations. Moreover, treatment of SCID mice bearing heterotransplanted human Hodgkin's tumors with HRS-3/A9 and human peripheral blood lymphocytes induced specific complete tumor regression in 10/10 animals. We thus report successful tumor treatment in an in vivo model using NK-cell-associated Bi-MAbs and show that the Bi-MAb HRS-3/A9 is an efficient promoter of the anti-tumor effects of NK cells in vitro and in vivo.

Animals↗
PubMed1993

CD30-antigen-specific targeting and activation of T cells via murine bispecific monoclonal antibodies against CD3 and CD28: potential use for the treatment of Hodgkin's lymphoma.

Cross-linking of specific tumor antigens with the T-cell-associated CD3 and CD28 antigens can increase IL-2 secretion, proliferation and antigen-specific cytotoxicity in resting T cells. This cross-linking can be achieved effectively by bispecific monoclonal antibodies (BiMAb) with specificity for both the tumor antigen and CD3 or CD28 antigen, respectively. To take advantage of the enhanced activation of CD3 pre-activated T cells by additional activation via the CD28 antigen, BiMAb OKT3/HRS-3 with reactivity to both CD3 and the Hodgkin's-lymphoma-associated CD30 antigen and the BiMAb 15E8/HRS-3 with reactivity to both CD28 and CD30 antigen were generated by hybridoma fusion. Resting T cells, represented by Jurkat cells (CD3+/CD28+) were specifically activated to produce IL-2 by co-cultivation with an EBV-transformed B-cell line (LAZ509, CD30+/CD19+) only in the presence of the CD30/CD28 cross-linking BiMAb and an additional cross-linking anti-CD3/CD19 BiMAb (OKT3/6A4). Neither the cross-linking BiMAbs alone nor any combination of the monospecific parental MAbs induced a comparable IL-2 production by Jurkat cells in the presence of LAZ509. In addition, using a combination of these BiMAbs, an antigen-dependent cytotoxicity was induced by targeting APC-depleted peripheral blood lymphocytes to CD30+ L540 cells. T cells, previously specifically activated by CD3/CD30 in the presence of CD30 antigen, were cytotoxic to CD30+ cell lines only after incubation with BiMAb anti-CD28/CD30. Neither of the BiMAbs nor any of the parental antibodies induced a comparable effect. Our results indicate that such BiMAbs may offer a new approach for specific immunotherapy of Hodgkin's lymphoma, which takes advantage of cytokine secretion and cytotoxicity of activated T cells.

Antibodies, Monoclonal↗
PubMed1993

CD30-specific AB1-AB2-AB3 internal image antibody network: potential use as anti-idiotype vaccine against Hodgkin's lymphoma.

The tumor-associated CD30 antigen is presently under study as a target for active specific immunotherapy of Hodgkin's lymphoma with anti-idiotypic antibodies. Internal image antibodies (Ab2 beta) 9G10 and 14G9 against the CD30-specific antibody HRS-4 (Ab1) have been described, which induce a CD30-specific T- and B-cell response in BALB/c mice and New Zealand white rabbits. In extension of this work, murine monoclonal anti-idiotypic Ab2 beta 9G10, mimicking structures of the nominal CD30 antigen, was used to generate monoclonal Ab3 in mice and polyclonal Ab3 in rabbits with specificity for CD30. The Ab2 beta 9G10-specific murine monoclonal Ab3 4A4 bound specifically to the 120-kDa band of CD30 present on Hodgkin cell lines and Hodgkin tumor tissue, and effectively inhibited binding of Ab1 HRS-4 to Ab2 9G10 as well as to CD30+ cells. Monoclonal Ab3 4A4 was cytotoxic for CD30+ cell lines in vitro and effectively prevented the s.c. growth of L540 cell tumors after passive i.v. administration in a SCID mouse tumor model. While this cytotoxic effect of the IgM subclass monoclonal Ab3 4A4 was due to complement activation, the murine monoclonal Ab1 HRS-4 and a polyclonal Ab3 preparation of IgG-subclass from New Zealand white rabbits were cytotoxic by an antibody-dependent cell-mediated mechanism in vitro. In conclusion, Ab2 beta 9G10 is able to induce a CD30-specific cytotoxic IgG and IgM response. Cytotoxicity was shown to be mediated by complement activation and antibody-dependent cell-mediated cytotoxicity in vitro and in vivo and across species barriers. Thus, the CD30-like Ab2 beta 9G10 may hold promise for effective active specific immunotherapy of human Hodgkin's lymphoma.

Animals↗
PubMed1993

[Threatening thiamine deficiency in severe hyperemesis gravidarum].

We report the case of a patient with severe hyperemesis gravidarum. During parenteral nutrition the patient developed threatening thiamine deficiency. Wernicke's encephalopathy and tachycardia were predominant in the clinical course. Severe lactic acidosis and prolonged prothrombin time were the leading laboratory features. Thiamine deficiency as a cause of severe metabolic acidosis or coma can be easily ruled out or validated by intravenous thiamine administration.

Acidosis, Lactic↗
PubMed1993

Cisapride increases gallbladder volume in gallstone patients before and after extracorporeal shock wave lithotripsy.

We have previously shown that oral cisapride causes a dose-related increase of fasting gallbladder volume in healthy subjects. The present study investigates the effect of cisapride on gallbladder motility in 16 patients with gallbladder stones; 8 patients had no biliary symptoms, but the other 8 patients with symptomatic gallstone disease were studied before and 6 weeks after extracorporeal shock wave lithotripsy (ESWL). For each study the patients received a single oral dose of 20 mg cisapride; fasting gallbladder volume was measured by ultrasound before, and for 120 minutes after, drug administration. In the 8 asymptomatic patients a mean maximal increase of the fasting volume to 152.7 +/- 7.6% of the initial value was observed at a mean 97.5 +/- 8.3 minutes after cisapride ingestion. Similarly, in the 8 patients with biliary pain mean fasting volume after cisapride ingestion increased to 141.3 +/- 5.7% before ESWL treatment and to 145.0 +/- 5.8% after ESWL and 6 weeks of oral litholytic therapy. There were no significant differences between the results in the symptomatic and asymptomatic patients. Our results indicate that cisapride increases the gallbladder volume in gallstone patients regardless of biliary symptoms. Similar volume changes were observed before therapy and after ESWL with bile acid therapy. The therapeutic efficacy of litholytic agents could be diminished by simultaneous cisapride administration.

Administration, Oral↗
PubMed1993

Immunophenotyping of low-grade B-cell lymphoma in blood and bone marrow: poor correlation between immunophenotype and cytological/histological classification.

Results of immunophenotypic examinations of peripheral blood and/or bone marrow (BM), involved in low-grade B-cell non-Hodgkin's lymphomas, were compared with the results of cytomorphological and histopathological examinations in 133 adult patients. 69 cases of chronic B-lymphocytic leukaemia (B-CLL), 16 centrocytic (CC) lymphomas, 14 centroblastic-centrocytic (CB/CC) lymphomas, 15 immunocytomas (IC), 10 cases of hairy cell leukaemia (HCL), four prolymphocytic leukaemias (PLL), two B-CLL in transformation, one splenic lymphoma with villous lymphocytes (SLVL), one hairy cell leukaemia variant (HCL-V), and one lymphocytic lymphoma (LC) were classified according to the Kiel and/or FAB classification. Leukaemic disease was found in 105 cases. The following markers were used for immunocytology (APAAP technique) of blood and/or BM smears: CD19, CD5, CD10, CD11c, CD14, CD21, CD22, CD23, CD25, CD38 and TdT. All cases tested showed CD19, but no TdT expression. Every case of HCL had a distinct phenotype with expression of CD11c, CD22 and CD25 and the lack of CD5 and CD23 antigens. In all other NHL cases a very heterogenous expression of CD-antigens with no significant correlations to the cytomorphological subtypes was found. The expression of CD5 is a frequent but inconstant finding in lymphoproliferative diseases other than B-CLL, so 50% of CB/CC, 75% of CC and 80% of IC were CD5 positive. Our results indicate that, with the exception of HCL, the diagnostic relevance of immunophenotyping for the classification of cytomorphologically and histopathologically defined subtypes in blood and/or BM is of very limited value.

Aged↗
PubMed1992

Anti-idiotype vaccine against Hodgkin's lymphoma: induction of B- and T-cell immunity across species barriers against CD30 antigen by murine monoclonal internal image antibodies.

Murine monoclonal antibody HRS-4 (Ab1), which defines the cell-bound and soluble CD30 antigen associated with Hodgkin's lymphoma, was used to generate monoclonal anti-idiotypic antibodies (Ab2) in syngeneic BALB/c mice. Murine monoclonal Ab2 14G9 and Ab2 9G10 directed against HRS-4 were shown to be anti-idiotypic Ab2 beta carrying the internal image of the CD30 antigen. These antibodies bound specifically to HRS-4 and effectively inhibited binding of HRS-4 to a CD30 antigen preparation at concentrations as low as 50 ng/ml. KLH-coupled Ab2 beta 14G9 and 9G10 induced in BALB/c mice and New Zealand white rabbits a specific polyclonal humoral response against the 120 kDa band of the CD30 antigen. Moreover, BALB/c mice immunized i.p. with KLH-coupled 14G9 and 9G10 exhibited a statistically significant (p less than 0.01) delayed-type hypersensitivity reaction against CD30 expressing Hodgkin-derived L540-cells. We conclude from these data that Ab2 beta 14G9 and 9G10, mimicking structures of the nominal CD30 antigen, are capable of inducing a CD30-specific T-cell- and B-cell-mediated immune response in mice and even across species barriers in rabbits. These CD30 anti-id antibodies may hold promise for use as vaccines against CD30-antigen-expressing lymphomas.

Animals↗
PubMed1992

Functional behaviour of mononuclear blood cells from patients with hypercholesterolemia.

Mononuclear cells were prepared from venous blood obtained from 20 patients with a newly diagnosed hypercholesterolemia and without clinical signs of vascular disease, and from 19 age and sex matched controls. Adhesiveness to plastic surface, phagocytic activity measured as ingestion of zymosan particles, and spontaneous motility of mononuclear cells from patients were significantly higher by 57%, 19% and 50%, respectively, when compared to controls. In controls chemotaxis induced by the chemotactic peptide FMLP was slightly higher than spontaneous motility measured in absence of FMLP, whereas in patients FMLP significantly inhibited cell motility by about 47%. With the exception of FMLP-induced chemotaxis the results indicate that mononuclear cells are hyperreactive in hypercholesterolemia.

Adult↗
PubMed1992

Ex vivo investigation of blood monocyte and platelet behaviour in pigs maintained on an atherogenic diet.

Domestic pigs aged 4 months were fed for 16 weeks an atherogenic diet rich in cholesterol and saturated fatty acid. The increase of plasma cholesterol and triacylglycerol levels was found to be accompanied by a significant increase in the number of blood monocytes and platelets when compared to control animals. Furthermore, the atherogenic diet produced a small but significant reduction in the blood monocyte phagocytic capacity and adhesion to plastic surface. No significant differences between both groups were found when spontaneous platelet aggregation in whole blood was studied. However, platelets from pigs fed the atherogenic diet had a smaller mean cell volume compared to controls. The results indicate than an atherogenic diet may affect blood monocytes and platelets in pigs.

Animals↗
PubMed1992

Soluble CD8, CD25 and CD30 antigens as prognostic markers in patients with untreated Hodgkin's lymphoma.

In a search for serum markers with prognostic value and specificity for disease activity in Hodgkin's lymphoma, we evaluated the clinical significance of soluble suppressor/cytotoxic T-cell antigen (sCD8), soluble interleukin-2 receptor (sCD25) and soluble Hodgkin's associated antigen (sCD30) levels in the serum of 90 patients with untreated Hodgkin's lymphoma (HD). HD patients in advanced stages had significantly higher sCD8 and sCD25 levels than normal controls. The rate of detectable sCD30, which was absent in healthy controls, depended on stage and histological subtype, and was 22% for the entire group. Low sCD25 levels (< 1000 U/ml) predicted an excellent prognosis (100% event-free survival), while patients with high sCD8 levels (> 750 U/ml) or the demonstration of sCD30 had a poor outcome. Therefore, all three markers have prognostic significance. However, only sCD30 correlated strictly with disease activity and seems to be of value for the follow-up of patients in remission.

Adolescent↗