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Biomedical subjects

H Ludwig

Publications and source records attributed to H Ludwig.

At least 91 records · Page 5Linked to original sources

Presence of a p53 gene deletion in patients with multiple myeloma predicts for short survival after conventional-dose chemotherapy.

In multiple myeloma (MM), previous studies showed that mutations of the p53 gene are rare events in patients with newly diagnosed disease, but it is not known whether deletions of p53 are of any significance in MM. To address this question, we used interphase fluorescence in situ hybridization (FISH) with a DNA probe specific for the p53 locus at 17p13 and investigated bone marrow plasma cells from 72 patients with MM (59 patients = 81.9% before therapy). By FISH, deletions of p53, which were found to be predominantly monoallelic, were detected in 32.8% and 54.5% of patients with newly diagnosed and relapsed MM, respectively. Karyotypes from six of the patients with a p53 deletion by FISH showed a structural abnormality of 17p in only one of them. Additional FISH studies including a distal-17p probe (specific for the D17S34 locus) provided evidence for an interstitial deletion on 17p resulting in loss of p53 hybridization signals in myeloma cells. Among all 59 patients with newly diagnosed MM, presence of a p53 deletion was associated with stage III (P = .054), but not with other laboratory and clinical parameters. Patients with a p53 deletion had significantly shorter survival time compared with those without a deletion, both from the time of diagnosis (median 13.9 v 38.7 months; P < .0001) and from the time of initiation of induction treatment consisting of conventional dose chemotherapy (median 15.9 months v median not reached at 38 months; P < .0002). On stepwise multivariate regression analysis, presence of a p53 deletion was the most significant independent parameter predicting for shortened survival (P = .002). We conclude that a p53 gene deletion, which can be identified by interphase FISH in almost a third of patients with newly diagnosed MM, is a novel prognostic factor predicting for short survival of MM patients treated with conventional-dose chemotherapy.

Adult↗

Fast-FISH technique for rapid, simultaneous labeling of all human centromeres.

Fluorescence in situ hybridization (FISH) has become a powerful tool in chromosome analysis. This report describes the systematic optimization of the Fast-FISH technique for centromere labeling of human metaphase chromosomes for radiobiological dosimetry purposes. For the present study, the hybridization conditions and the efficiency of two commercially available alpha-satellite DNA probes were compared ("human chromosome 1 specific", Oncor, Gaithersburg, MD, vs. "all-human chromosomes specific", Boehringer-Mannheim, Germany). These probes were hybridized to human lymphocyte metaphase plates by using a hybridization buffer without formamide and without any other equivalent denaturing chemical agents. The results indicate the suitability of the method for automated image analysis on the basis of thresholding. The optimal conditions concerning hybridization time and temperature were determined by a systematic quantitative evaluation of the fluorescent labeling sites after the hybridization procedures. Under defined "low stringency" conditions, we found that the "human chromosome 1 specific" DNA probe labeled not only the centromere of the human chromosome 1 but also the other human centromeres in the same way as the "all-human chromosome specific" DNA probe. The optimized conditions to complete all centromere labeling were applied to the detection of dicentric chromosomes on irradiated human lymphocyte samples (gamma-rays of 60Co source, 0.5 Gy/min, for doses of 1, 3, and 4 Gy). The yield of dicentrics was determined after Fast-FISH and compared with results obtained after Giemsa staining. These results are very compatible and indicate that, because of its simplicity, this optimized Fast-FISH procedure would be useful for fast screening purposes in biological dosimetry after accidental overexposure.

Cells, Cultured↗

Acute bilateral renal vein thrombosis complicating Netherton syndrome.

UNLABELLED: A 1-year old male infant suffering from Netherton syndrome with severe generalized erythroderma presented with acute renal failure due to bilateral renal vein thrombosis (RVT) after a short episode of enteritis. The imperceptible fluid loss through the skin and the additional enteric water loss had led to decompensation of the delicate fluid balance and had resulted in RVT as a sequel of haemoconcentration. Reperfusion of the left kidney could be achieved by treatment with urokinase and heparin. Prophylactic oral anticoagulation was instituted for several weeks. CONCLUSION: In severe Netherton disease meticulous surveillance of the fluid balance is important and aggressive treatment is indicated in case of additional fluid loss.

Diagnosis, Differential↗

Virological and molecular biological investigations into equine herpes virus type 2 (EHV-2) experimental infections.

Two 18-month-old naturally reared ponies were used to investigate the pathogenicity of EHV-2. After dexamethasone treatment, pony 1 was inoculated intranasally with EHV-2 strain T16, which has been isolated from a foal with keratoconjunctivitis superficialis and pony 2 was similarly inoculated with strain LK4 which was originally isolated from a horse with upper respiratory tract disease. Following virus inoculation, pyrexia was not detected in either pony but both developed conjunctivitis, lymphadenopathy, and coughing. EHV-2 was detected in nasal mucus samples up to day 12 post infection (p.i.), in eye swabs up to day 10 p.i., and in buffy coat cells throughout the investigation in both animals. EHV-2-specific antibody titres were raised significantly 18 days p.i. Following the administration of dexamethasone, 3 months p.i., infectious virus was again detected in nasal mucus and conjunctival swabs from both ponies for 7 days. The tissue distribution of EHV-2 genome was studied post mortem, by means of a nested PCR. EHV-2 was detected in lymphoid tissues, lung, conjunctiva, trigeminal ganglia and olfactory lobes of pony 2, whereas in pony 1 only the conjunctiva of the left eye was PCR positive.

Animals↗

Letrozole, a new oral aromatase inhibitor: randomised trial comparing 2.5 mg daily, 0.5 mg daily and aminoglutethimide in postmenopausal women with advanced breast cancer. Letrozole International Trial Group (AR/BC3).

BACKGROUND: The study compares letrozole and aminoglutethimide (AG), a standard therapy for postmenopausal women with advanced breast cancer, previously treated with antioestrogens. PATIENTS AND METHODS: 555 women were randomly assigned letrozole 2.5 mg once daily (n = 185), letrozole 0.5 mg once daily (n = 192) or aminoglutethimide 250 mg twice daily with corticosteroid support (n = 178) in an open-label, multicentre trial. The primary endpoint was objective response rate (ORR), with time events as secondary. ORR was analysed nine months after enrollment of the last patient, while survival was analysed 15 months after the last patient was enrolled. We report the results of these analyses plus an extended period of observation (covering a total duration of approximately 45 months) to determine the duration of response and clinical benefit. RESULTS: Overall objective response rates (complete + partial) of 19.5%, 16.7% and 12.4% were seen for letrozole 2.5 mg, 0.5 mg and AG respectively. Median duration of response and stable disease was longest for letrozole 2.5 mg (21 months) compared with letrozole 0.5 mg (18 months) and AG (14 months). Letrozole 2.5 mg was superior to AG in time to progression, time to treatment failure and overall survival. Treatment-related adverse events occurred in fewer patients on letrozole (33%) than on AG (46%). Transient nausea was the most frequent event with letrozole (7% on 0.5 mg, 10% on 2.5 mg, 10% on AG), rash with AG (11%, 1% on 0.5 mg, 3% on 2.5 mg letrozole). CONCLUSIONS: Letrozole 2.5 mg offers longer disease control than aminoglutethimide and letrozole 0.5 mg in the treatment of postmenopausal women with advanced breast cancer, previously treated with anti-oestrogens.

Administration, Oral↗

Absence of p53 deletions in bone marrow plasma cells of patients with monoclonal gammopathy of undetermined significance.

We have recently shown that presence of a p53 deletion in multiple myleoma is an independent predictor for short survival. We therefore investigated whether or not this chromosomal abnormality can be identified in patients with monoclonal gammopathy of undetermined significance (MGUS). Using a triple staining method combining staining for cytoplasmic immunoglobulins and fluorescence in situ hybridization (FISH) with chromosome 17-centromere and p53-gene specific probes, we studied plasma cells from 15 patients with MGUS. In all patients, concordant signal numbers with both probes were obtained (including one patient with trisomy 17), indicating that allelic loss of p53 does not occur in MGUS.

Bone Marrow Cells↗

In situ study on the pathogenesis and immune reaction of equine herpesvirus type 1 (EHV-1) infections in mice.

The mouse model was used to study the pathogenesis of equine herpesvirus type 1 (EHV-1) after primary and secondary intranasal infections. Within a few hours after infection, EHV-1 was found in nasal and olfactorial epithelium and sub-epithelial cells of the respiratory mucosa, but antigen-specific immune cells were never detected. Next to the lung, EHV-1 was transmitted early and directly to the brain, both via the olfactory route and the trigeminal nerve, but traces of degenerative or inflammatory processes were not detected there. In the lung, the immune cells residing or invading the parenchyma did not contain viral DNA or proteins. The primary immune response in the lungs was an alveolar and interstitial inflammation, dominated by the sequential appearance of neutrophils and macrophages, while the number of T and B lymphocytes remained unaltered. Within 24 hr after re-infection, lymphocytes accumulated around the blood vessels, outnumbering monocytes more than twofold, without neutrophils appearing. The lymphocytes comprised of little more B than T cells and the T cells were predominantly CD8+ cells. Those and B cells infiltrated the parenchyma. These results show the route of virus distribution and demonstrate the lack of antigen-specific immune cells in the lungs of mice after primary intranasal infection with EHV-1.

Animals↗

A viro-psycho-immunological disease-model of a subtype affective disorder.

Borna Disease Virus (BDV) infections are widespread in animal species. This neurotropic, negative and single-stranded enveloped RNA virus spreads via axonal and transsynaptic pathways quite specifically into olfactoric and limbic structures. The symptoms in BDV-infected animals range from unapparent or subtle clinical manifestations to fatal neurological disorders. The severe and fulminant course of the infection, which is often accompanied by neurobehavioral and "emotional" disturbances, occurs sporadically and, at least in experimentally infected animals (rats), is thought to be mediated by immunopathology. Increases in serum-BDV antibodies have also been detected in neuropsychiatric patients. In addition, viral antigen and viral RNA have been observed in acutely ill major depressive patients, leading to the conclusion that BDV was causally related to psychiatric disorders, in particular to affective disorders. A number of studies have meanwhile furnished evidence of abnormal immune functions in mentally ill patients. In addition, stress has been shown to decrease immune responses to viral infections. On the basis of these findings it is hypothesized that human BDV infection represents a co-factor in the development or course of psychiatric diseases. Stress may cause immunosuppression and thus induce activation of persisting BDV in the limbic system, resulting in an inflammatory reaction of these structures. These neuropathological changes might influence the serotonergic or dopaminergic neurotransmitter systems. In addition, a specific affinity of BDV structural elements for aspartate and glutamate receptors in the hippocampal formation might directly induce an imbalance of these transmitter system interactions, causing affective and behavioral disturbances. The possible interactions between stress-induced immunosuppression, BDV infection and affective disorders in humans, and the theoretical and clinical aspects of this concept are discussed.

Animals↗

Dendritic cells presenting equine herpesvirus-1 antigens induce protective anti-viral immunity.

Equine herpesvirus-1 (EHV-1) causes rhinopneumonitis, abortion and CNS disorders in horses. Using intranasal inoculation, the mouse model of this disease mimics the major pathogenic and clinical features of the equine disease. The aim of this study was to investigate whether murine dendritic cells (DC) can be infected with EHV-1 and whether they can be used as cellular vaccines for the induction of prophylactic anti-EHV-1 immunity. It was found that the DC lines FSDC, D2SC1, 18 (all H-2d) and 80/1 (H-2k), when incubated with the Ab4 strain of EHV-1, do not change their morphology and phenotype but sustain virus replication and induce proliferation of naive, syngeneic T cells. An even stronger proliferation of T cells was seen when DC were used that had been pre-exposed to heat-inactivated virus. DC lines were therefore pulsed with inactivated virus and were then administered intranasally to either BALB/c or C3H mice on days -25, -15 and -5. Control groups received either medium, unpulsed DC or inactivated virus only. Animals were challenged with EHV-1. Whereas mice of control panels showed clinical signs of EHV-1 disease and 27% died, animals immunized with the pulsed DC lines showed only subtle clinical symptoms, lost significantly less weight, exhibited a reduced virus load in their lungs and CNS and did not succumb to the disease during the observation period. These results show that murine DC can present EHV-1 and initiate a protective anti-viral immunity in vivo.

Administration, Intranasal↗

Neutralization of borna disease virus depends upon terminal carbohydrate residues (alpha-D-man, beta-D-GlcNAc) of glycoproteins gp17 and gp94.

Borna disease virus (BDV) is an enveloped, nonsegmented, negative-stranded RNA virus that causes infections of the brain in a wide range of animal species and man. The third open reading frame codes for a protein of 17 kD (gp17) that is N-glycosylated and contains terminal alpha-D-mannose and N-acetyl-beta-D-glucosamine residues. Rat sera raised against these carbohydrates (anti-sugar antisera) show high in vitro neutralization activity and were capable of precipitating BDV. The neutralizing capacity of sera derived from experimentally BDV-infected rabbits, in turn, decreased after adsorption with those carbohydrates. They partially inhibited infection of primary young rabbit brain cells in a dose-dependent manner. Furthermore, the anti-sugar antisera recognized a second virus-specific glycoprotein with an apparent molecular mass of 94 kD (gp94), providing indirect evidence that gp94 is involved in virus adsorption and/or entry into cells. Neutralization of BDV comprises a complex event and, as shown for the first time, involves the carbohydrate residues of both glycoproteins of BDV.

Acetylglucosamine↗

Effects of dioxins and furans on liver enzymes, lipid parameters, and thyroid hormones in former thermal metal recycling workers.

A cross-sectional study was performed to examine the internal exposure of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDF) in former workers in a nonferrous metal recycling facility. Liver enzymes, lipid parameters, and thyroid hormones were measured to check possible biologic effects. Compared to background levels, the international toxicity equivalent levels of exposed workers were slightly elevated (median 42 ppt, range 13-281 ppt). The workers also had higher total PCDF concentrations (median 128 ppt, range 30-1138 ppt). Correlation analyses demonstrate significant associations with only one liver enzyme, alanine aminotransferase. There were no such associations with serum cholesterol levels or with serum thyroid hormones. Because of the cross-sectional design of the study, firm conclusions cannot be drawn. For further evaluation, a follow-up examination appears necessary.

Adult↗

Fast-painting of human metaphase spreads using a chromosome-specific, repeat-depleted DNA library probe.

For chromosome painting, in situ suppression of repetitive DNA sequences has been well established. Such standard protocols usually require large amounts of Cot-I DNA. Recently, it has become possible to deplete repetitive DNA sequences from library probes by magnetic purification and PCR-assisted affinity chromatography. These "repeat-depleted library probes" appear to be extremely useful for Fast-FISH, a technique that omits denaturing chemical agents such as formamide in the hybridization buffer, resulting in a substantial acceleration and simplification of the complete protocol. Shown here is the application of Fast-FISH to a repeat-depleted, directly fluorochrome-labeled library probe of the q-arm of chromosome 15 (Fast-Painting) for human lymphocyte metaphase spreads. Following painting without Cot-I DNA and without formamide, visual inspection revealed sufficient chromosome painting after a few hours of hybridization. The fluorescence signals of the labeling sites were analyzed after hybridization times of 1 and 2 h (in one case, 4 h) using digital fluorescence microscopy. The painting efficiency expressed in values of relative fluorescence signal ratios was quantitatively evaluated by image analysis using line-scan procedures and area-morphometry of mean luminance. Two preparation protocols (ethanol dehydration without and with RNase A treatment followed by pepsin digestion for four different exposure times) were compared. These results indicated that RNase A treatment and pepsin digestion are steps that can be omitted.

Adult↗

Anemia in cancer patients.

Chronic anemia in cancer patients is caused by several pathophysiologic mechanisms. Reduced numbers of erythroid progenitor cells in the bone marrow and increased levels of inflammatory cytokines, which suppress erythropoiesis, result in a lower proliferative response of the erythron to erythropoietin stimulation. Erythropoietin production by the kidney in response to tissue hypoxia is often blunted; as a result, serum erythropoietin levels may be inappropriately low with regard to the degree of anemia. Red blood cell survival may be shortened; impaired iron utilization is manifested by enhanced retention of iron in the reticuloendothelial system. Chronic anemia also may be induced by cancer treatment, such as nephrotoxic chemotherapy.

Anemia↗

Anemia of cancer patients: patient selection and patient stratification for epoetin treatment.

Epoetin alfa is being used to treat patients with symptomatic anemia of cancer and to prevent or postpone chemotherapy-induced anemia in cancer treatment. As only approximately 50% of unselected anemic cancer patients respond sufficiently to epoetin alfa treatment, careful patient selection according to reliable prediction criteria is of great importance. Predictions of response to epoetin alfa treatment are based either on the degree of blunted erythropoietin response to the anemic condition or on indicators of responsiveness during the early treatment phase. The most accurate predictions of responsiveness, however, are derived from combinations of predictive factors. Combinations of synergistically acting hematopoietic growth factors, particularly epoetin alfa and granulocyte colony-stimulating factor, are beneficial to selected patients with myelodysplastic syndrome and may prolong survival in certain cases. Correction of anemia in cancer patients is particularly important because highly significant correlations have been reported between hemoglobin levels and quality of life in these patients.

Anemia↗

Bone resorption in multiple myeloma and in monoclonal gammopathy of undetermined significance: quantification by urinary pyridinium cross-links of collagen.

To quantify osseous breakdown in multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), and benign osteoporosis, we measured urinary levels of pyridinium cross-links of collagen in 50 patients with newly diagnosed and untreated MM, 40 patients with MGUS, 40 untreated patients with osteoporotic vertebral fractures, and 64 healthy adults. Ion-paired, reverse-phase high-performance liquid chromatography (HPLC) was used to measure total urinary excretion of pyridinoline (h-PYD) and deoxypyridinoline (h-DPD). Urinary excretion of free immunoreactive deoxypyridinoline (i-DPD) was determined with an enzyme immunoassay. MM patients had significantly (P < .0001) higher levels of h-PYD, h-DPD, and i-DPD than the healthy adults, patients with MGUS, or patients with osteoporosis. The MGUS and osteoporosis groups presented with elevated (P < .05) levels of urinary pyridinium cross-links when compared with healthy controls. In 20 MM patients who subsequently received chemotherapy, the percent changes in i-DPD did not correlate with the changes in the monoclonal protein. In one of three patients experiencing a transition of initial MGUS into stage I MM, i-DPD increased above the upper limit of the normal range. In 13 patients with stable MGUS, i-DPD remained normal in repeated measurements. Based on the upper limits of the normal range, the sensitivity of urinary pyridinium cross-links in stage I and II MM was low (<50%), but it was between 78% (h-DPD) and 93% (i-DPD) in stage III MM. Specificity in patients with MGUS was between 87% (h-PYD) and 97% (h-DPD). In conclusion, determining the urinary excretion of pyridinium cross-links seems to be a promising noninvasive and thus easily repeatable method for evaluating the actual degree of osseous breakdown. Although measurement of pyridinium cross-link levels is not useful in discriminating patients with MGUS from early-stage myeloma patients, determination of i-DPD levels may contribute importantly to clinical guidance, since increased i-DPD levels seem to identify patients who are particularly likely to benefit from osteoclast-inhibiting drugs such as bisphosphonates. The fact that in a number of patients paraprotein concentrations and i-DPD levels did not change in parallel but instead diverged strongly after chemotherapy might explain the observation that bone lesions sometimes progress even in patients who achieve complete remission.

Adult↗

Constitutive expression of Fas (Apo-1/CD95) ligand on multiple myeloma cells: a potential mechanism of tumor-induced suppression of immune surveillance.

The Fas (Apo-1/CD95) ligand (FasL) plays a central role in the elimination of target cells by effector T lymphocytes and in the suppression of cellular immune responses against nonmalignant and malignant cells. We show the expression of FasL on the surface of neoplastic plasma cells. We provide evidence that the FasL is functionally active because five of five neoplastic plasma cell lines tested killed CEM-C7H2 T-acute lymphoblastic leukemia (T-ALL) cells. The effect was mediated via the Fas (Apo-1/CD95) receptor molecule because blocking of Fas on the target cells or the FasL on the tumor cells by receptor- and ligand-specific monoclonal antibodies (MoAbs), respectively, protected T cells from being killed by myeloma cells. In addition, overexpression of the cowpox virus protein CrmA, a molecule with inhibitory potential on caspase-1 and caspase-8, specifically involved in Fas-induced signaling, protected T cells from being destroyed by the neoplastic cells or the agonistic anti-Fas MoAb. The potential of the malignant plasma cells to extinguish target T cells was independent of their own sensitivity to the agonistic anti-Fas MoAb, and FasL-positive (FasL+) CEM-C7H2 T cells were incapable of killing myeloma cells. Our results suggest that tumor cell-induced suppression of the immune system may be exerted via the FasL active on malignant plasma cells. Furthermore, loss of Fas expression or insensitivity to the agonistic anti-Fas MoAb do not seem to be prerequisites for myeloma cells to defeat T cells via Fas/FasL interaction.

Aged↗