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H Schmitz

Publications and source records attributed to H Schmitz.

At least 19 recordsLinked to original sources
PubMed1995

Investigations on autologous T-cells for adoptive immunotherapy of AIDS.

We report on the preclinical results of an immunotherapeutic approach of AIDS mediated by ex vivo propagated CD4+ and CD8+ T-cells. A mean yield of 6.23 x 10(9) lymphocytes, containing 1.82 x 10(9) CD4+, 3.23 x 10(9) CD8+ T-lymphocytes and 8.39 x 10(6) CD34+ peripheral blood progenitor cells (PBPC) were be obtained by continuous flow cytapheresis (CFC) in 15 asymptomatic HIV infected patients (CD4-count > 350/mm3). The CD4/CD8 ratio (mean: 0.53, SD: +/- 0.15) in the cell concentrates reflected the distribution of the circulating lymphocyte subsets in vivo. Absolute lymphocyte counts decreased at a mean of 404/microliter (25%) immediately after CFC but were replaced from the extravascular pool within one hour. Neither the CD4/CD8 ratio nor p24-antigen and neopterin levels did change significantly after cell separation. No alteration of the number of proviral DNA copies (1/10(3)-1/10(6)) could be detected in peripheral T-helper cells by semiquantitative PCR after lymphapheresis. Cells were cryopreserved in liquid nitrogen without substantial loss of viability or function. Ex vivo propagation of T-cells in a strictly autologous manner in the presence of PHA + IL-2 for 14d resulted in a 50-fold expansion rate (140-fold in healthy controls, p < 0.001). Viral replication could be controlled but not completely eliminated by cocultivation with autologous CD8+ T-lymphocytes as measured by limiting dilution nested PCR (NPCR). The expanded cells showed the typical phenotype of highly activated memory type T-lymphocytes (CD3+ CD45RO+ CD25+ HLA-DR+). The distribution of CD4+ and CD8+ T-cells did not reveal significant changes before and after culture indicating that both subsets were equally expanded. Functionally important membrane or intracellular epitopes which were found to be decreased in HIV infected subjects (CD7, CD55, CD59) before culture were reconstituted after ex vivo propagation of T-cells. The functional importance of the up-regulation of complement regulating epitopes (CD55, CD59) after culture could be proven by a significant inhibition of cytolysis of T-cells in the presence of autologous complement. The majority (75%) of expanded CD8+ T-cells stained positive with mAb TIA-1 which is directed to intracellular granules within cytotoxic T-cells. Furthermore, programmed cell death of expanded T-cells could be prevented by cocultivation with fibroblasts which are believed to secrete a cytokine pattern preventing activated T-cells from apoptosis after withdrawal of IL-2 and other stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1995

Determination of anti GAD65 autoantibodies with an ELISA before and after standardization with the new international reference serum.

The serum of a stiff-man syndrome patient was declared international GAD reference standard at the "1st GAD Antibody Workshop" held at the "12th International Immunology and Diabetes Workshop" in Orlando, Florida, USA 1993. A comparative study was performed with 123 diabetic and non-diabetic patients to evaluate whether standardization of this reference serum had changed the properties of a commercially available ELISA assay. All samples classified positive with the old test were confirmed with the new assay. Four additional samples with high "normal" values became positive with the new test. One of them was a control person having a family history of diabetes and genetic loci DR4/DR11. These findings might implicate a higher risk for the development of IDDM. The new standardization and adaptation of the ELISA seems to have influenced the sensitivity of the test positively.

Autoantibodies↗
PubMed1995

Enzyme- and mineralocorticoid receptor-controlled electrogenic Na+ absorption in human rectum in vitro.

In vivo electrogenic Na+ absorption (JeNa) in the human rectum is controlled by acute variation of aldosterone in nanomolar concentration range. In this study we report both the induction of JeNa in human rectum epithelium by nanomolar aldosterone added in vitro and the enzymatic control of glucocorticoid action on JeNa. JeNa was measured as amiloride-sensitive short-circuit current 8 h after addition of the respective steroid. Aldosterone (10 nM) caused JeNa of 5.7 +/- 1.4 mumol.h-1.cm-2. Cortisol in the same concentration did not induce significant JeNa. Because cortisol is readily inactivated by 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), the true mineralocorticoid activity of cortisol was evaluated after inhibition of 11 beta-HSD by carbenoxolone. Carbenoxolone alone did not exhibit mineralocorticoid activity. If cortisol (10 nM) was given together with carbenoxolone (1 microM), the resulting JeNa (4.5 +/- 0.4 mumol.h-1.cm-2) was not significantly different from that after 10 nM aldosterone, indicating equal intrinsic mineralocorticoid activity of cortisol and aldosterone. The same mechanisms were found in rat late distal colon. Kinetic data of carbenoxolone at 10 nM cortisol resulted in a Michaelis constant of 0.3 microMs, maximal absorption of 8.4 mumol.h-1.cm-2, and a Hill coefficient of 1.8. The effects of carbenoxolone and glycyrrhetinic acid did not differ. We conclude that JeNa is under complete control of mineralocorticoid action. "Spontaneous" JeNa in the beginning of the in vitro period can be explained by elevated steroid levels before tissue removal.(ABSTRACT TRUNCATED AT 250 WORDS)

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1995

Antibody-dependent complement-mediated cytotoxicity in sera from patients with HIV-1 infection is controlled by CD55 and CD59.

Various immune mechanisms have been reported to contribute to the progressive destruction of Th cells in HIV-1-infected patients. Among these, complement mediated lysis of infected cells has been suggested. An increased sensitivity of lymphocytes from HIV-1-infected patients to lysis by monoclonal antibodies directed to MHC class I antigen and complement has been directly correlated with a decreased expression of the decay accelerating factor (CD55). It also has been reported that the expression of the membrane inhibitor of reactive lysis (CD59) is decreased during HIV-1 infection. We examined the effect of antibodies in the serum of HIV-1-positive individuals and normal human serum (NHS) as source of complement on several HIV-1-infected cell lines differing in their expression of CD55 and CD59. When HIV-1-infected target cells without membrane expression of CD55 and CD59 were used, a highly significant cytotoxic effect was observed in the presence of heat inactivated anti-HIV-1-positive sera and NHS, while heat-inactivated anti-HIV-1-negative sera and NHS were unable to induce cytolysis. Similar results were obtained using purified IgG isolated from HIV-1-positive sera and either NHS or guinea pig serum as source of complement. Lysis of HIV-1-infected cells correlated with expression of viral antigens on the cell surface. HIV-1-infected CD55 and CD59 positive target cells showed specific lysis, when the function of these molecules was abrogated by blocking antibodies to CD55 and CD59. The finding of anti-HIV-1-specific cytotoxic antibodies in sera from HIV-1-infected patients should be considered in the pathogenesis of the HIV-1-infection.

Acquired Immunodeficiency Syndrome↗
PubMed1995

[Splenopeptides for climacteric complaints. Comparison of ovarian stimulation with transdermal estradiol substitution].

256 women aged 45 to 60 years with climacteric complaints participated in an open randomized clinical study comparing spleno-peptides (SPS 1187, Solcosplen) with transdermal estrogen (CAS 50-28-2, E2) substitution (4 mg) in respect of efficacy and tolerability. The primary criterion, defined as the Kupperman Index, and the safety parameter of the drugs were estimated prior to and after 1, 4 and 8 weeks of therapy. In the pre-, peri- and early postmenopause the results of treatment with the spleno-peptides were comparable to those with transdermal E2 substitution (4 mg). Pretreatment with estrogens impaired the results of treatment significantly. Although the menopausal status (in most cases < 3 years) did not influence the results essentially, the efficacy of SPS 1187 is expected to decrease 2 to 3 years postmenopause. Therefore SPS 1187 should be used in pre-, peri- and early postmenopause only. The tolerance of SPS 1187 was found to be significantly better than that of the E2 patch. With respect to the claimed indication, i.e. climacteric complaints in the pre-, peri- and early postmenopause, SPS 1187 having an equivalent efficacy compared to that of the E2 patch shows a better tolerability (total collectives) and better benefit/risk ratio.

Administration, Cutaneous↗
PubMed1994

Follicular dendritic cells retain HIV-1 particles on their plasma membrane, but are not productively infected in asymptomatic patients with follicular hyperplasia.

During HIV-1 infection, extensive alterations can be observed in the germinal centers (GCs) of lymphatic tissue. The initial hyperplasia of GCs is followed by disintegration and involution of these structures. The process is accompanied by progressive destruction of the network of follicular dendritic cells (FDCs). We investigated whether or not the destruction of GCs is caused by HIV-1 infection of FDCs in vivo. FDCs were purified by FACS or magnetic cell sorter (MACS) from enlarged lymph nodes (LNs) of four asymptomatic HIV-1-infected patients with persistent generalized lymphadenopathy. In situ hybridization demonstrated positive signals for HIV-1 RNA on the cell membrane of FDCs. Virus particles attached to the dendritic network could be demonstrated by electron microscopy, but budding was not seen. Furthermore, proviral DNA was detected by nested PCR (NPCR) in limiting dilution assays of FACS-purified FDCs (up to 1.0 x 10(4) cells) in only one cell fraction. In comparison, proviral DNA could be found in 5.0 x 10(3) to 2.5 x 10(5) FACS-purified Th cells obtained from peripheral blood and in 7.5 x 10(5) to 2.5 x 10(4) Th cells from LN of the same patients. In conclusion, FDCs retain HIV-1 particles on their cell membrane during HIV-1 infection, but the progressive destruction of FDC in vivo is probably not caused by a productive infection of FDCs with HIV-1.

Cell Membrane↗
PubMed1994

Oblique section 3-D reconstruction of relaxed insect flight muscle reveals the cross-bridge lattice in helical registration.

In this work we examined the arrangement of cross-bridges on the surface of myosin filaments in the A-band of Lethocerus flight muscle. Muscle fibers were fixed using the tannic-acid-uranyl-acetate, ("TAURAC") procedure. This new procedure provides remarkably good preservation of native features in relaxed insect flight muscle. We computed 3-D reconstructions from single images of oblique transverse sections. The reconstructions reveal a square profile of the averaged myosin filaments in cross section view, resulting from the symmetrical arrangement of four pairs of myosin heads in each 14.5-nm repeat along the filament. The square profiles form a very regular right-handed helical arrangement along the surface of the myosin filament. Furthermore, TAURAC fixation traps a near complete 38.7 nm labeling of the thin filaments in relaxed muscle marking the left-handed helix of actin targets surrounding the thick filaments. These features observed in an averaged reconstruction encompassing nearly an entire myofibril indicate that the myosin heads, even in relaxed muscle, are in excellent helical register in the A-band.

Animals↗
PubMed1994

Recovery of T-lymphocytes for adoptive immunotherapy by lymphapheresis of HIV-infected patients without alterations of virological, immunological or clinical parameters.

We performed repeated continuous flow cytaphereses (CFC) on 13 asymptomatic HIV-1-infected patients to study the feasibility of cell separation procedures to recover high yields of peripheral blood T-lymphocytes for adoptive immunotherapy in HIV-infected patients and to determine immunological and virological alterations following such procedures. A mean yield of 6.23 x 10(9) lymphocytes could be obtained by each cytapheresis, containing 1.82 x 10(9) CD4+, 3.23 x 10(9) CD8+ T-lymphocytes and 8.39 x 10(6) CD34+ peripheral progenitor cells. The CD4/CD8 ratio (mean 0.53, SD +/- 0.15) in the cell samples reflected the distribution of the lymphocyte subsets in vivo. Absolute lymphocyte counts decreased at a mean of 404/mm3 (25%) immediately after CFC but were replaced from the extravascular pool within 1 h. The CD4/CD8 ratios, p24-antigenaemia, HLA-DR expression and neopterin levels did not change significantly after cell separation. No alteration of the number of T-cells with integrated proviral DNA copies (1/10(3) to 1/10(6)) could be detected in peripheral T-helper cells by PCR after lymphapheresis. We conclude that high yields of peripheral T-lymphocytes can be obtained by continuous flow lymphapheresis for cell-mediated immunotherapy, without deterioration of virological or immunological parameters in HIV-infected patients. The separated T-cells are fully replaced from extravascular pools after 1 h.

CD4-CD8 Ratio↗
PubMed1994

Antibodies of symptomatic human immunodeficiency virus type 1-infected individuals are directed to the V3 domain of noninfectious and not of infectious virions present in autologous serum.

The present study was designed to determine the antibody specificity for the human immunodeficiency virus type 1 (HIV-1) V3 domains of infectious and noninfectious virions present in the serum of AIDS patients. To accomplish this, HIV-1 was isolated in the presence of autologous antibodies from the serum samples of six AIDS patients in HIV-1-negative donor peripheral blood mononuclear cells by short-term cultivation. The isolated virus, defined as the infectious cell-free virus (iCFV), was characterized by sequence analysis of the proviral DNA coding for the third hypervariable (V3) region of the external glycoprotein gp120. This was carried out by amplifying and cloning the V3 region. In all six cases studied, 20 randomly selected V3 clones derived from the proviral DNA of the iCFV, 20 clones from patient cell-free virus, and 20 clones from cell-integrated virus were sequenced to study the distribution and frequency of the intrapatient virus population. The number of major virus variants in the six patients ranged from three to nine. The various V3 sequences found in the AIDS patients showed the typical amino acid pattern of the syncytium-inducing and non-syncytium-inducing viral phenotypes characteristic for the late stage of infection. However, only one patient-specific iCFV variant was detected within the 20 V3 clones analyzed per virus isolation. For the six patients a total of 34 V3-loop variants, either iCFV or non-iCFV, was observed. All 34 V3-loop sequences were expressed as glutathione-S-transferase fusion proteins (V3-GST). The autologous antibody response to the V3-GST fusion proteins was studied by Western immunoblot analysis. A strong antibody response to almost all non-iCFV V3-GST proteins was found in the sera of the six patients. In contrast, the autologous antibody response to the six iCFV V3 loops was undetectable (in four patients) or very faint (in two patients) compared with that to the non-iCFV V3 loops. Five of the six iCFV loops showed positively charged amino acids at positions strongly associated with the syncytium-inducing phenotype. These findings suggest that our in vitro isolation system selects for virions which are not recognized by V3-specific antibodies and are infectious both in vitro and in vivo.

Acquired Immunodeficiency Syndrome↗
PubMed1994

[Virus diseases in patients returning from the tropics].

The high density of populations and insufficient sanitary conditions increases the risk to acquire viral diseases in tropical areas. This holds true for ubiquitous as well as for regional viral infections. Hepatitis and AIDS are found worldwide, but play a dominant role in tropical areas. Classical tropical viral infections are zoonoses. They are primarily infections of nonhuman vertebrates (e.g. rodents) and of arthropod vectors and can be transmitted to man. According to the clinical outcome these viral infections can be divided into three groups: influenza-like disease with arthralgia, encephalitis and hemorrhagic fevers. The majority of infections belong to the first group, followed by encephalitis cases. Viral hemorrhagic fevers are rare in visitors of tropical areas. Antibody detection is the method of choice in the diagnosis of tropical viral infections. In special situations (e.g. Lassa fever) the direct detection of the virus by PCR can be helpful. Tests for the detection of arboviruses, filoviruses and arenaviruses are only performed at a few centers worldwide.

Animals↗
PubMed1994

[Pathological-anatomical findings after serologic and molecular biologic evidence of Hantaan virus infection].

Post-mortem findings in a girl aged 2 years and 4 months who had been infected with Hantaan virus are reported. The child fell ill with acute renal failure in her 8th month of life and had to be subjected to chronic dialysis. There was a progressive cardiac insufficiency. Specific IgG and IgM antibodies to Hantaan virus were demonstrated by serology from the 18th month of life. Autopsy revealed endomyocardial fibrosis and cardiomegaly. Hantaan RNA could be demonstrated in formalin-fixed, paraffin-embedded specimens of lung, liver and spleen tissue by means of RT-PCR followed by DNA sequencing. A possible association between the Hantaan virus infection and the pathological findings in the heart are discussed.

Antibodies, Viral↗
PubMed1994

Endocrine effects of Lycopus europaeus L. following oral application.

Lycopus extracts are used in folk medicine for the treatment of hyperthyroid symptoms. Diverse effects on the pituitary thyroidal system as well as on the pituitary gonadal system could be confirmed in experimental studies. But till now endocrine effects of Lycopus extracts in experimental animals were observed after parenteral application only. Therefore in this investigation an ethanolic extract of Lycopus europaeus was applied orally to rats, diverse endocrine parameters were measured between 3 and 24 h later and the effects compared to an i.p. treated group. The plant extract given p.o. caused a long lasting (for a period of more than 24 h) decrease of T3 levels, presumably as a consequence of a reduced peripheral T4 deiodination. A pronounced reduction of T4 and thyroid stimulating hormone (TSH) concentrations was observed 24 h after application of the test solution by gavage. The luteinizing hormone (LH) decrease as well as the TSH decrease, which was pronounced in spite of reduced T4 and T3 levels indicate a central point of attack of the plant extract. Differences in the biological activity in dependence on the route of application may be explained e.g. by differences in absorption of plant constituents.

Animals↗
PubMed1993

Human Kupffer cells infected with HIV-1 in vivo.

Blood monocytes as well as cells of the macrophage-phagocytic system in several tissues are targets for HIV-1 in vivo and in vitro. However, the data on HIV-1 infection of liver macrophages/Kupffer cells (KCs), which make up the main pool of fixed-tissue macrophages, is controversial. We therefore studied HIV-1 infection of KCs in vivo. Blood and liver tissue was obtained from seven AIDS patients shortly after death. Liver tissue was minced before processing. Cell suspensions were further purified by density gradient centrifugation, stained with anti-CD14 (blood monocytes) or anti-macrophage 25F9 (KCs), and separated by fluorescence-activated cell sorting (FACS). These highly purified cell populations were then analyzed for HIV-1 proviral DNA by the polymerase chain reaction (PCR). By performing PCR on FACS-purified cell populations, we could show that both KCs and peripheral blood monocytes were HIV-1-infected in 3 of 7 patients. KCs harbored HIV-1 proviral DNA only if peripheral blood monocytes were infected. These data show that KCs of the liver are infected with HIV-1 in vivo.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Gonalgia: treatment with therapeutic local anesthesia. Results of a controlled comparative study versus diclofenac].

The effectiveness and tolerance of therapeutic local anesthesia (TLA) with lidocaine was compared with those of oral diclofenac in a controlled, open, randomized study involving 76 patients with gonalgia due to gonarthrosis or patellar chondropathy. During the course of the three-week (maximum) treatment, the summed score of pain at rest, pain on movement, and restricted mobility, taken as the target parameter of effectiveness, decreased significantly more markedly (p = 0.008) under TLA, than under diclofenac. Side effects involving mainly the gastrointestinal tract occurred significantly more frequently in the diclofenac group (p = 0.012). The results of this study indicate that in the treatment of localized joint pain of degenerative genesis, TLA with lidocaine is superior to NSAID treatment in terms of effectiveness and tolerance.

Adult↗
PubMed1991

Structural and functional studies on the human hepatic interleukin-6 receptor. Molecular cloning and overexpression in HepG2 cells.

cDNAs coding for the human hepatic interleukin-6 receptor (IL-6-R) have been isolated from a library made from poly(A) RNA of dexamethasone-treated human hepatoma cells (HepG2). We found the hepatic IL-6-R to be identical to the one expressed by leucocytes. A polyclonal antiserum was raised in rabbits against the IL-6-R protein expressed in Escherichia coli. Although the entire IL-6-R protein was used for immunization, only antibodies to the cytoplasmic domain of the IL-6-R were obtained. It is demonstrated by affinity cross-linking and subsequent immunoprecipitation with antibodies against the ligand as well as against the receptor that the cloned cDNA codes for the functional IL-6-R on HepG2 cells. When the hepatic IL-6-R cDNA was overexpressed in HepG2 cells, these cells became more sensitive to low concentrations of IL-6 with respect to the induction of gamma-fibrinogen mRNA.

Amino Acid Sequence↗
PubMed1991

[Therapeutic local anesthesia in acute back pain].

Therapeutic local lidocaine analgesia in the treatment of acute low back pain of functional or degenerative genesis was investigated in 310 patients, with account being taken of additional treatment with NSAIDs. In the overall group, an assessment of the evolution of five typical symptoms revealed response rates of between 85.2% and 91.1% with symptom elimination being achieved in 44.6% to 69.7%. The finger-to-floor test and Schober's sign improved in 87.6% and 81.2% of the patients, respectively. No side effects were observed. In 90 patients (29%), additional treatment, mainly with NSAIDs, was recorded. A comparative analysis of the subgroups with and without additional treatment revealed no evidence of therapy-relevant differences in results that would support the additional administration of NSAIDs. For the treatment of acute low back pain, lidocaine administered alone is adequately effective in most cases, and is well tolerated.

Adolescent↗