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Biomedical subjects

W Kopp

Publications and source records attributed to W Kopp.

At least 19 recordsLinked to original sources
PubMed2002

Development of a closed-system process for clinical-scale generation of DCs: evaluation of two monocyte-enrichment methods and two culture containers.

BACKGROUND: Clinical immunotherapy trials using DCs depend on large-scale methods for DC generation that fulfil current good manufacturing practice requirements. Our goal was to develop data on two variables, monocyte-enrichment method and culture container, which could be used to design a closed-system process for ex vivo generation of immature DCs. METHODS: Mononuclear cells were collected by leukapheresis and enriched for monocytes by either counterflow centrifugal elutriation, or immunomagnetic selection using Isolex, an automated closed-system device. Monocytes were cultured for 7 days in serum-free medium with GM-CSF and IL-4, using either plastic flasks or gas-permeable Stericell bags. Monocytes and cultured DCs were evaluated for yield, flow cytometric phenotype, and in vitro function in MLR, and autologous recall responses to tetanus toxoid and influenza virus. RESULTS: Enriched monocyte products from elutriation and immunomagnetic selection were equivalent in yield and purity, and were capable of generating immature DCs in either flasks or bags. DCs from all four culture conditions were equivalent in yield, phenotype, and in vitro function. Mean DC yield was 67-80% per seeding monocyte, and 11-13% per starting mononuclear cell (MNC). A leukapheresis product containing 5 x 10(9) MNCs processed by this method could therefore yield approximately 5 x 10(8) immature DCs. DISCUSSION: In this manufacturing process, the Isolex system was equivalent to elutriation, and Stericell bags were equivalent to flasks. Together, the Isolex system and Stericell bags can be incorporated into a closed-system process to generate immature DCs.

Adoptive Transfer↗
PubMed2001

Three-color flow cytometric assay for the study of the mechanisms of cell-mediated cytotoxicity.

Cytotoxic lymphocytes kill tumor or virus-infected target cells utilizing two mechanisms (1) release of lytic granules (containing perforin and granzymes) and (2) Fas ligand (FasL)/Fas or TNF initiated apoptosis. We have examined mechanisms of target cell lysis using a new Flow Cytometric Cytotoxicity Assay (FC Assay). Target cells were labeled with PKH 67 dye. Cell death was estimated by 7-amino-actinomycin (7-AAD) inclusion and annexin V-PE binding. A strong direct correlation has been found between the percentage of dead target cells in the FC Assay and the results of 51Cr release assay when human LAK and CTL were used as a model system. We have shown that both NK and CTL kill tumor cells mostly by granule-mediated mechanisms, as lysis was blocked by a perforin inhibitor Concanamycin A (Folimycin) but was significantly less sensitive to zVAD-FMK caspase inhibition. The FC assay allows accurate measurement of cell-mediated cytotoxicity as individual target cell death is detected directly.

Annexin A5↗
PubMed2001

Development of a clinical-scale method for generation of dendritic cells from PBMC for use in cancer immunotherapy.

BACKGROUND: There is growing interest in the use of dendritic cells (DCs) for treatment of malignancy and infectious disease. Our goal was to develop a clinical scale method to prepare autologous DCs for cancer clinical trials. METHODS: PBMC were collected from normal donors or cancer patients by automated leukapheresis, purified by counterflow centrifugal elutriation and placed into culture in polystyrene flasks at 1 x 10(6) cells/mL for 5-7 days at 37 degrees C, with 5% CO(2), with IL-4 and GM-CSF. Conditions investigated included media formulation, supplementation with heat in activated allogeneic AB serum or autologous plasma and time to harvest (Day 5 or Day 7). DCs were evaluated for morphology, quantitative yield, viability, phenotype and function, including mixed leukocyte response and recall response to tetanus toxoid and influenza virus. RESULTS: DCs with a typical immature phenotype (CD14-negative, CD1a-positive, mannose receptor-positive, CD80-positive, CD83-negative) were generated most consistently in RPMI 1640 supplemented with 10% allogeneic AB serum or 10% autologous plasma. Cell yield was higher at Day 5 than Day 7, without detectable differences in phenotype or function. In pediatric sarcoma patients, autologous DCs had enhanced function compared with monocytes from which they were generated. In this patient group, starting with 8.0 +/- 3.7 x 10(8) fresh or cryopreserved autologous monocytes, DC yield was 2.1 +/- 1.0 x 10(8) cells, or 29% of the starting monocyte number. DISCUSSION: In the optimized clinical-scale method, purified peripheral monocytes are cultured for 5 days in flasks at 1 x 10(6) cells/mL in RPMI 1640, 10% allogeneic AB serum or autologous plasma, IL-4 and GM-CSF. This method avoids the use of FBS and results in immature DCs suitable for clinical trials.

Cell Culture Techniques↗
PubMed2001

Epithelioid hemangioendothelioma of the maxilla: case report and review of literature.

Epithelioid Hemangioendothelioma (EH) is a rare, low-grade malignant vascular tumor, first defined as a soft tissue tumor by Enzinger and Weiss in 1982. The tumor was later reported in virtually all sites, including liver, lung, brain, and bone. The epithelioid neoplastic cells are of endothelial origin, staining positive for Factor VIII and CD-34. In our review of EH of bone medline literature, and including the present case report, a total of 73 cases were found. Forty-one (56%) patients had multifocal bone involvement and thirty-two (44%) patients had solitary EH of bone. Resection was the primary recommended treatment. Visceral involvement appears to affect prognosis and survival adversely. We report a case of EH of the maxilla, which occurred in a 32-year-old male.

Adult↗
PubMed2000

Etiologic and early marker studies in the prostate, lung, colorectal and ovarian (PLCO) cancer screening trial.

The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, which is randomizing 74,000 screening arm participants (37,000 men, 37,000 women; ages 55-74) and an equal number of nonscreened controls, is a unique setting for the investigation of the etiology of cancer and other diseases and for the evaluation of potential molecular markers of early disease. At entry, baseline information is collected by questionnaire on dietary intake, tobacco and alcohol use, reproductive history (for women), family history of cancer, use of selected drugs, and other selected risk factors. Blood samples collected at the baseline screening exam are aliquoted to serum, plasma, red blood cell, and buffy coat fractions. At the next two annual screening visits, serum samples are collected. At the third annual reexamination, cryopreserved whole blood is obtained, in addition to serum, plasma, red blood cell, and buffy coat fractions. At the fourth and fifth years, serum, plasma, and buffy coat are collected. All blood samples are shipped to a central repository for long-term storage at -70 degrees C. Dietary questionnaires and buccal cells for DNA analysis are obtained from nonscreened controls. Cancer cases are identified through annual follow-up questionnaires, and all deaths are identified through vital status tracing mechanisms. Procedures are being developed to obtain archival pathologic material for selected cases of cancer and related diseases. Initial investigations are focusing on the etiology of colorectal cancer and on the operative characteristics of tests for the early detection of colorectal and prostate cancer.

Aged↗
PubMed1999

The immunoassay of cytokines and growth factors in biological fluids.

There are a number of problems associated with the development of standards suitable for use in the most commonly used assays to detect cytokines in biological fluids. These problems include: (i) the failure of some MoAbs used in immunoassays to detect all different < > of recombinant or natural material; (ii) the use of many different MoAbs, with different specificities, in different immunoassay kits, and (iii) the detection of non-active cytokines (fragments, inhibitors, receptor antagonists, etc.) in these immunoassays. As a result, it is possible to have biologically active material which is not detected in these immunoassays. Alternatively, biologically inactive material can be detected in these assays and is indistinguishable from biologically active material. In addition, the use of different antibodies with different specificities, affinities and avidities in different kits designed to detect the same biological materials results in markedly different sensitivities and specificities. Many of these same concerns can be raised for the use of bioassays for detection of molecules in biological fluids. The solution will not be simple (if possible at all). In most cases, the immunoassay kits are designed to detect < > material in biological fluids, but are made with MoAbs against recombinant material. Because of the markedly different specificities, affinities, etc. of the MoAbs in these kits, their standardization is possible only with a highly purified preparation of natural material. For the assay of recombinant materials, immunoassays should be specifically designed with the recombinant material in mind (i.e. the MoAbs made specifically against the recombinant material to be detected or shown to bind effectively with the recombinant material). Importantly, it should be made clear to investigators using different immunoassays that: (i) the reporting of biological material detected using immunoassays can only be made in units of weight (i.e. ng/ml); (ii) because of the detection of biologically active and inactive material using immunoassay kits these assays cannot be directly compared to bioassays or their results represented as < >; (iii) because of the difference in specificity and sensitivity of the different reagents used in different immunoassays, the results from different assays cannot be directly compared, and (iv) because of these same considerations, comparison of different > of materials within a single immunoassay is also not possible. The use of specific immunoassays for recombinant material in combination with bioassays and the use of cytokine standards, made from highly purified natural material, would help to standardize the results in this field.

Animals↗
PubMed1997

Keratoameloblastoma of the maxilla. A case report and review of the literature.

The keratoameloblastoma is a rare histologic variant of the ameloblastoma. Review of the English language literature revealed five case reports of keratoameloblastoma. We report the sixth case of this tumor. The tumor developed in the right posterior maxilla of a 26-year-old African-American man and demonstrated aggressive clinical behavior, analogous to conventional ameloblastoma. The initial biopsy specimen showed extensive cyst formation, which histologically resembled odontogenic keratocyst. However, the lining epithelium varied in thickness and there was separation and edema between the basal cells and the rest of the epithelium. The basal cells were strongly adherent to the underlying stroma unlike the basal layer of the odontogenic keratocyst, where cleavage often occurs in this area. Additionally, although the basal cells were palisaded and demonstrated nuclear polarization in areas, they were cuboidal rather than columnar. The excision specimen revealed more of a solid ameloblastic component in addition to the cystic component seen on the initial biopsy. Nevertheless, it is possible that the ameloblastoma had developed in an odontogenic keratocyst. Alternatively, it can be postulated that the keratoameloblastoma consists of both cystic and solid components, the former being analogous to the cysts of the conventional ameloblastoma.

Adult↗
PubMed1994

Rapid diagnosis of Chlamydia trachomatis with a nucleic acid probe in male and female patients.

To evaluate a commercially available DNA hybridization test, the Gen-Probe Pace 2 assay (GP) was compared with the Chlamydiazyme (CZ) for the detection of Chlamydia trachomatis in urethral and endocervical specimens. Samples were collected from 300 persons, including 199 registered and 43 nonregistered female prostitutes, examined for screening purposes, as well as 22 male and 36 female symptomatic sexually transmitted disease (STD) patients. The overall prevalence of C. trachomatis was 7.3% in all persons examined with an infection rate of 20.9% in the nonregistered prostitutes, 2.5% in the registered prostitutes and 13.8% in the STD patients. The overall concordance of both diagnostic methods was 98.7% in all samples examined, 100% in male and 98.6% in female samples. Specimens with discordant results were further analyzed by a direct immunofluorescence test (MicroTrak) and by the probe competition assay (PCA). All samples only positive in the GP assay could be confirmed by the PCA while one result which was positive in the CZ could not be confirmed by any other test. The GP assay was superior to the CZ, when compared with true-positive and -negative results. The data demonstrate that the GP assay can be recommended as an alternative diagnostic technique to the CZ for Chlamydia diagnosis.

Chlamydia Infections↗
PubMed1994

[Hepatitis B in persons at high risk for sexually transmitted diseases. Screening and vaccination campaign--acceptance and results].

The prevalence of HBV-markers in our patients in STD high-risk groups was markedly higher than the average in Vienna. 19% of the registered prostitutes, 44% of the illegal prostitutes, 29% of the bar hostesses and 39% of the STD patients were found to be positive in at least one HBV marker. I.v. drug abuse. African origin and irregular condom use were the most important risk factors in our patients. The hepatitis B vaccination campaign was successful to a high degree. 69% of the registered prostitutes and 85% of the regularly examined bar hostesses accepted the vaccination. Promotion programmes should focus on institutions caring for STD risk persons rather than on the persons themselves.

Adult↗
PubMed1992

Anti-CD3 monoclonal antibody treatment of patients with CD3-negative tumors: a phase IA/B study.

Anti-CD3 monoclonal antibodies induce the proliferation of human T-cells in vitro and activate specific and nonspecific cytolysis by human T-cell clones and human peripheral blood lymphocytes. In vivo administration of anti-CD3 prevents tumor growth of a UV-induced mouse fibrosarcoma. We conducted a phase I trial to determine the toxicity and immunomodulatory properties of low doses of anti-CD3 in 36 patients with cancer. In 23 patients, anti-CD3 was given i.v. over 3 h at 1, 10, 30, and 100 mcg/patient. Five other patients received anti-CD3 at 30 mcg by i.v. bolus. Patients were treated every 3 days for a total of four doses. An additional eight patients received anti-CD3 daily for 14 days at 3 mcg by i.v. bolus, 3-h infusion, or 24-h infusion. Dose-limiting toxicity was headache. Headache was often accompanied by signs and symptoms of meningeal irritation leading to performance of a lumbar puncture in nine patients. The opening pressure was usually elevated, and six patients had a cerebrospinal fluid lymphocytosis with an elevated protein. Increased levels of interleukin 6 were identified in the cerebrospinal fluid. The maximum tolerated dose by 3-h infusion was 30 mcg. There were no objective tumor responses. There was a dose-related increase in the number of peripheral blood lymphocytes expressing the T-cell activation antigen CD69 (Leu 23), but no changes were seen in CD25 (interleukin 2 receptor) expression, and no changes were observed in the serum levels of the soluble interleukin 2 receptor. Even at these low doses of anti-CD3, 8 of 16 patients tested developed human anti-mouse antibodies.

Adult↗
PubMed1992

Relationship of large and small CD3- CD56+ lymphocytes mediating NK-associated activities.

We have defined a population of CD3-, CD56+ small lymphocytes (SLs) that exhibit the same phenotype and lytic capacity as natural killer (NK) cells. NK cells characteristically express the surface markers CD16 and CD56, mediate non-major histocompatibility complex (MHC)-restricted lysis, and have been equated with CD3- large granular lymphocytes (LGLs). In the present study we extended the observation that CD3-, CD56+ SLs can mediate NK- and antibody-dependent cellular cytotoxicity activity by studying the activation signals and lytic mechanisms that might be utilized by CD3-, CD56+ SLs in comparison to CD3- CD56+ LGLs. Our results show that CD3- SLs, similar to CD3- LGLs, exhibited activated killing in response to interleukin-2 (IL-2). In addition, after IL-2 activation, the CD3- SLs exhibited morphologic changes, including increases in size and granularity, and both morphologically and phenotypically became virtually indistinguishable from CD3- LGLs. Similar to CD3- LGLs, CD3- SLs could be directly activated by IL-2 alone to secrete significant quantities of interferon-gamma (IFN-gamma) and to express IL-2 receptor (IL-2R) p55. Examination of serine esterases and pore-forming protein (PFP) demonstrated that these cells exhibited a cytoplasmic distribution of perforin, which, unlike that of CD3- LGLs, was not associated with dense cytoplasmic azurophilic granules. Serine esterase levels were similar. However, after IL-2 activation PFP was concentrated in dense cytoplasmic granules, similar or identical to the situation in CD3-, CD56+ LGLs. These CD3-, CD56+ subsets appear to represent a continuum of activated cells that might represent various states of maturation of NK cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1992

Coincidence of hepatitis B-virus markers and other sexually transmitted diseases in different STD-risk groups.

To evaluate the prevalence of hepatitis-B-virus (HBV)-markers in STD patients and the significance of promiscuous heterosexual activity as a risk factor for the transmission of HBV, a serological screening was performed in 499 patients, in addition to the routine STD diagnostic programme. Two groups of patients were evaluated: group 1 (120 patients) was drawn from the STD clinic of the Public Health Office (PHO), group 2 (379 patients) from a private STD outpatient clinic. Promiscuous activity was reported significantly more often by persons of group 1 than by those attending the private clinic (59.3% vs. 5.1%). The infection rate of gonorrhea, syphilis and Chlamydia trachomatis was high in patients of the PHO (46.7%, 35.3%, 27.5%) whereas most of the STDs were seldom ascertained in patients of the private clinic (1.1%, 0%, 5.6%). Similar to other STDs, the prevalence of HBV markers differed significantly between patients of the PHO and those of the private clinic (33.3% vs. 6.3%; p = .0000). Comparison of HBV and other STDs showed the highest coincidence of HBV markers in patients with serological evidence of syphilis (44.2%), and in one third of patients with Neisseria gonorrhoeae as well as HIV infection. The data obtained in the present study demonstrate that also in Austria, in addition to homosexual preference and drug abuse, promiscuous heterosexual activity must be considered a substantial risk factor for the transmission of HBV.

Adolescent↗
PubMed1992

Quinolones as an alternative treatment of chlamydial, mycoplasma and gonococcal urogenital infections.

We report the results of several trials aimed at evaluating the quinolones in urogenital infections. In Chlamydia trachomatis infections, ofloxacin (200 mg b.i.d. for 10 days) gave a cure rate of 98% (n = 66), and fleroxacin (400 mg s.i.d. for 7 days) provided a cure rate of 89% (n = 19). A double-blind study comparing fleroxacin (600 mg s.i.d.) to doxycycline (100 mg b.i.d.) for 7 days showed similar high cure rates for both regimens (100%; n = 23). In Mycoplasma hominis infections, ofloxacin (200 mg b.i.d. for 10 days) yielded a cure rate of 86% (n = 50) for M. hominis and 55% (n = 43) for Ureaplasma urealyticum. Gonococcal infections (n = 122) were all cured by a single dose of 200 mg ofloxacin. Both ofloxacin and fleroxacin were well tolerated and may be recommended for patients with chlamydial or uncomplicated gonococcal infections, although 600 mg fleroxacin showed a higher incidence of adverse events compared to doxycycline.

4-Quinolones↗
PubMed1991

CD8 gamma delta cells: presence in the adult rat thymus and generation in vitro from CD4-/CD8- thymocytes in the presence of interleukin 2.

Three to fifteen percent of peripheral T cells in adults express the recently described gamma delta T-cell antigen receptor (TcR) heterodimer. A small subpopulation of gamma delta cells express the CD8 accessory molecule. In this study, we analyzed the potential of highly purified CD4-/CD8-, double negative (DN) rat precursor thymocytes to give rise to gamma delta cells. We observed that in the presence of interleukin 2 (IL-2) and concanavalin A (ConA), both DN and CD8 cells expressing the gamma delta TcR were generated in vitro. We then examined the rat thymus for these cells and confirmed the presence of a previously undescribed CD8 TcR-alpha beta- subset in the rat thymus, expressing high levels of TcR-gamma and delta messages with no detectable TcR-alpha transcripts, similar to the cells generated in vitro in the presence of IL-2 and ConA.

Animals↗
PubMed1991

Cervical neoplasia and human papilloma virus infection in prostitutes.

OBJECTIVES: To evaluate the prevalence and incidence of PAP smears indicating cervical dysplasia as well as human papillomavirus (HPV) infection in prostitutes. DESIGN: Prevalence and incidence study of cervical dysplasia and HPV infection in prostitutes. For detection and typing of HPV-DNA In Situ Hybridisation (ISH) was performed in tissue samples with CIN gained by colposcopically directed punch biopsies. SETTING: Second Department of Obstetrics and Gynecology, University of Vienna Medical School and STD Clinic of the Public Health Office, Vienna. SUBJECTS: Registered prostitutes attending the STD Clinic of the Public Health Office and a control group. RESULTS: 978 prostitutes and 5493 women with unknown cytological anamnesis were compared. Frequency of positive PAP smears was significantly higher in prostitutes (6.13% versus 1.43%). To determine the pick-up rate of cervical dysplasia during one year after negative cytology we compared 722 prostitutes and 3162 controls. Prostitutes showed a significant higher dysplasia pick-up rate (3.05% to 1.07%) compared with controls. HPV detection rate in prostitutes was similar to that in the control group. The distribution of HPV types revealed a higher frequency of "high risk" HPV 16/18 and 31/33 in prostitutes. CONCLUSION: The results demonstrate a higher incidence and prevalence of cervical dysplasia in prostitutes and therefore suggest regular cervical PAP smear screening in registered prostitutes twice a year.

Cervix Uteri↗