Christian Conradt

Circulating Vascular Cell Adhesion Molecule-1 Correlates With the Extent of Human Atherosclerosis in Contrast to Circulating Intercellular Adhesion Molecule-1, E-Selectin, P-Selectin, and Thrombomodulin

Secondary prevention of atherosclerosis, especially before the onset of symptoms, appears desirable and could be possible with a serum marker detecting atherosclerosis. Circulating, shedded forms of adhesion molecules may serve as such because their expression is upregulated in atherosclerotic plaques. In 52 patients with peripheral arterial vascular disease (Fontaine class IIa, 7 patients; class IIb, 29 patients; and class III, 16 patients), the extent of atherosclerosis was evaluated on the basis of angiograms of a large portion of the arterial system. The area diseased by atherosclerosis was determined by the percentage of vessel wall irregularities of the following calculated segments: aorta (distal from the kidney arteries), common iliac artery, external iliac artery, common femoral artery, lateral circumflex femoral artery, and popliteal artery. The maximal surface area that could exhibit atherosclerotic changes was 250 cm2. The serum concentration of circulating vascular cell adhesion molecule-1 (VCAM-1) correlated with the extent of atherosclerosis (r = .8, P < .001). In contrast, circulating intercellular adhesion molecule-1, E-selectin, P-selectin, and thrombomodulin (as markers for endothelial cell damage) did not correlate with the extent of atherosclerosis. Furthermore, circulating VCAM-1 could be used to indicate stages of atherosclerosis with a high degree of statistical significance. The potential bias of factors such as age, diabetes mellitus, hypercholesterolemia, arterial hypertension, renal failure, and history of myocardial infarction on the correlation of circulating VCAM-1 with the extent of atherosclerosis could be excluded by multivariate analysis. These findings suggest an important role of VCAM-1 in atherosclerosis and may serve as the basis for further evaluation of circulating VCAM-1 as a potential serum marker for atherosclerosis.

Frequency and predictors of osteoporotic fractures after cardiac or liver transplantation: a follow-up study

BACKGROUND Osteoporosis and related fractures are a major complication after organ transplantation. The aim of this study was to find out the frequency and predictors of osteoporotic fractures after cardiac or liver transplantation. METHODS 235 consecutive patients who had a cardiac transplant (n=105; 88 men, 17 women) or a liver transplant (130; 75 men, 55 women) were followed. Vertebral fractures were assessed by a standardised analysis of spinal radiographs before and annually after transplantation. Clinical and non-vertebral fracture data were noted from hospital records. FINDINGS In the first and second years after transplantation, the proportion of patients (Kaplan-Meier estimates) who had at least one vertebral fracture was slightly higher in the cardiac group (first year 21%, second year 27%) than in the liver group (first year 14%, second year 21%). In the third and fourth years, one third of patients from both groups had had one or more vertebral fractures. Non-vertebral fractures occurred in nine patients (7%) after liver transplantation and avascular necrosis of the hip head in three patients (3%) after cardiac transplantation. In both groups, no dose-dependent effect of immunosuppressive therapy on fracture development could be identified. Independent predictors assessed by multivariate analysis were age (hazard ratio [95% CI] increase of 5 years, 1.71 [1.1-2.7]) and lumbar bone-mineral density (decrease of 1 SD t score, 1.97 [1.2-3.2]) in cardiac transplantation patients, and vertebral fractures before transplantation (6.07 [1.7-21.7]) in the liver group. INTERPRETATION The high frequency of osteoporotic fractures in the 2 years after transplantation and the limitations of reliable fracture-risk predictions, show the need to investigate preventive therapies.

Results of interleukin-2-based treatment in advanced melanoma: a case record-based analysis of 631 patients.

PURPOSE In patients with stage IV melanoma, durable responses have been reported with treatment regimens that involve high-dose interleukin-2 (IL-2). We analyze long-term results of 631 melanoma patients from 12 institutions who had received IL-2 alone, in combination with interferon alfa 2a or 2b (IFNalpha), or with cytotoxic drugs. METHODS Case records that contained pretreatment parameters, response data, and updated survival information were collected. After univariate analysis, the multivariate evaluation of the impact of pretreatment parameters on response and survival was performed by logistic regression and Coxs regression, respectively. RESULTS Patients were divided into four groups according to treatment: IL-2 alone (n=117), IL-2 and chemotherapy (n=49), IL-2 and IFNalpha (n=153), and IL-2, chemotherapy, and IFNalpha (n=312). The median survival of all patients was 10.5 months and the 2- and 5-year survival rates were 19.9% and 10.4%, respectively. Independent prognostic factors for response and survival were entirely different, treatment group being the only significant factor for response, and serum lactate dehydrogenase (LDH), metastatic site, and performance predicting survival. The addition of IFNalpha to IL-2 was associated with prolonged survival, but the effect of additional chemotherapy was less obvious. CONCLUSION Serum LDH, metastatic site, and performance status are useful stratification factors for randomized trials in metastatic melanoma. The improved long-term survival rates observed in melanoma patients treated with IL-2/IFNalpha-containing regimens are notable in contrast to the reported 5-year survival rates of 2% to 6% achieved with chemotherapy, but because selection bias cannot be ruled out, the impact of IL-2, as well as all other components of the treatment regimens, on survival needs to be confirmed in prospective randomized trials.

TP53 DNA contact mutations are selectively associated with allelic loss and have a strong clinical impact in head and neck cancer

Recent studies have suggested that different mutation types within the core domain of the tumour suppressor protein p53, i.e. DNA contact mutations and structural mutations, confer different biological properties. We have analysed in 86 head and neck squamous cell carcinomas (HNSCC), whether these p53 mutation types have a differential clinical impact. Thirty-seven missense mutations were identified. Thirteen of these (36%) were DNA contact mutations, occurring in the L3 loop, in the H2 loop sheet helix motif, in the S10 β strand and in Zinc binding residues. Microsatellite marker analysis revealed a selective association between these mutations and the loss of wild-type alleles (100% LOH vs 50% LOH in tumours with structural mutations; P=0.0034, Fishers exact, 2-tailed). In comparison to structural mutations or to the absence of mutations in the core domain, DNA contact mutations were associated with higher tumour stages (84.6% vs 62%), a higher incidence of lymph node metastasis (91.7% vs 56%; P=0.014, Fishers exact, 2-tailed), a shortened recurrence-free survival (8.1 months vs 23.7 months, P=0.047, log rank test) and overall survival (11 months vs 29.2 months; P=0.003, log rank test). The latter was also the case when only stage IV tumours were analysed (P=0.0055, log rank test). These data indicate that in HNSCC, TP53 DNA contact mutations confer a strong selection pressure to eliminate wild-type alleles, and that they result in an accelerated tumour progression and reduced therapeutic responsiveness.

Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study.

PURPOSE Herbal medicines are widely used for the treatment of pain, although there is not much information on their effectiveness. This study was designed to evaluate the effectiveness of willow (Salix) bark extract, which is widely used in Europe, for the treatment of low back pain. SUBJECTS AND METHODS We enrolled 210 patients with an exacerbation of chronic low back pain who reported current pain of 5 or more (out of 10) on a visual analog scale. They were randomly assigned to receive an oral willow bark extract with either 120 mg (low dose) or 240 mg (high dose) of salicin, or placebo, with tramadol as the sole rescue medication, in a 4-week blinded trial. The principal outcome measure was the proportion of patients who were pain-free without tramadol for at least 5 days during the final week of the study. RESULTS The treatment and placebo groups were similar at baseline in 114 of 120 clinical features. A total of 191 patients completed the study. The numbers of pain-free patients in the last week of treatment were 27 (39%) of 65 in the group receiving high-dose extract, 15 (21%) of 67 in the group receiving low-dose extract, and 4 (6%) of 59 in the placebo group (P <0.001). The response in the high-dose group was evident after only 1 week of treatment. Significantly more patients in the placebo group required tramadol (P <0.001) during each week of the study. One patient suffered a severe allergic reaction, perhaps to the extract. CONCLUSION Willow bark extract may be a useful and safe treatment for low back pain.

Aberrant p21CIP1/WAF1 protein accumulation in head‐and‐neck cancer

p21CIP1/WAF1 is an inhibitor of cyclin‐dependent kinases and, in normal tissues including squamous epithelia, has been associated with cell‐cycle exit and differentiation. As shown in this pilot study, however, the majority of head‐and‐neck squamous‐cell carcinomas (HNSCC) display aberrant p21CIP1/WAF1 expression: of 42 tumors analyzed by immunohistochemical staining, 28 (67%) over‐expressed the p21CIP1/WAF1 protein. Accumulation of p21CIP1/WAF1 was independent of the histological grade of the tumors as well as the genetic status of the p53 gene. In many cases, most notably in poorly differ‐ entiated or undifferentiated HNSCC, p21CIP1/WAF1‐positive cells were actively proliferating tumor cells, since they also expressed proliferating‐cell nuclear antigen (PCNA) and Ki‐67. Accumulation of p21CIP1/WAF1 occurred through a post‐transcriptional mechanism since, in contrast to immunohistochemical analysis of the p21CIP1/WAF1 protein, in situ hybrid‐ ization showed no increase of mRNA levels as compared with cells in normal mucosa (n = 25). Clinically, among the patients with p21CIP1/WAF1‐over‐expressing tumors, there was increased recurring disease (p = 0.03; χ2‐test), shortened disease‐free survival (p = 0.0019; log‐rank test) and shortened overall survival (p = 0.0071; log‐rank test). These in vivo data indicate that in many HNSCC, accumulated p21CIP1/WAF1 is compatible with increased tumor‐cell proliferation, and they provide preliminary evidence that p21CIP1/WAF1 may be of prognostic and predictive significance. Int. J. Cancer 74:383–389, 1997.

Heparin Inhibits Ligand Binding to the Leukocyte Integrin Mac-1 (CD11b/CD18)

BACKGROUND The clinical benefits of heparin reach beyond its anticoagulative properties. Recently, it has been described that leukocytes adhere on immobilized heparin mediated by the integrin Mac-1 (CD11b/CD18, alphaMbeta2, or CR3). Because inhibition of this versatile adhesion molecule could explain various aspects of the beneficial clinical effects of heparin, we evaluated whether soluble heparin modulates Mac-1 function in vitro and in vivo. METHODS AND RESULTS Binding of unfractionated heparin to Mac-1 on PMA-stimulated monocytes and granulocytes was directly demonstrated in flow cytometry, whereas no binding of heparin was detected on unstimulated leukocytes. Unfractionated heparin inhibited binding of the soluble ligands fibrinogen, factor X, and iC3b to Mac-1. Adhesion of the monocytic cell line THP-1 and of peripheral monocytes and granulocytes to immobilized ICAM-1 was impaired by unfractionated heparin, to the same extent as with inhibition of Mac-1 by monoclonal antibodies such as c7E3. Low-molecular-weight heparin also inhibits binding of fibrinogen to Mac-1. Additionally, flow cytometry of whole blood preparations of patients treated with unfractionated heparin revealed an inhibitory effect of heparin on the binding of fibrinogen to Mac-1 that correlates (n= 48, r=0.63, P<0.001) to the extent of prolongation of the activated partial thromboplastin time. CONCLUSIONS We describe a pharmacologically relevant property of heparin that may contribute to its benefits in clinical use. The binding of heparin to Mac-1 and the resulting inhibition in binding of Mac-1 ligands may directly modulate coagulation, inflammation, and cell proliferation.

In vitro radiosensitivity of primary human fibroblasts. Lack of correlation with acute radiation toxicity in patients with head and neck cancer

BACKGROUND AND PURPOSE There is a considerable hope among clinicians and radiobiologists to detect genetically radiosensitive patients prior to radiotherapy. A predictive assay would enable adjustment of the total irradiation dose to the individual at a constant risk of normal tissue complications. In this prospective study, the clonogenic survival assay for primary human fibroblasts to determine radiosensitivity in vitro was evaluated and then correlated with clinically observed acute radiation reactions. MATERIALS AND METHODS One hundred twenty-five independent survival experiments with primary fibroblasts derived from 63 biopsies from 55 cancer and non-cancer patients were performed. RESULTS A wide variation of cell survival between biopsies was detected. Statistical analysis revealed a highly significantly larger interindividual than intraindividual variation of SF2 values. However, a considerable scatter of SF2 values in repeated experiments was observed in individual cases. Age, gender, disease status (cancer patient, non-cancer patient) and origin of fibroblasts (skin, periodontal tissue) were demonstrated not to be statistically significant confounding factors on the intrinsic radiosensitivity in vitro. In a prospective study, no correlation of the SF2 and acute reactions in 25 patients with head and neck cancer treated with a primary accelerated radiochemotherapy was detected. CONCLUSION Our data show that the clonogenic assay is able to distinguish between intrinsic radiosensitivities of primary human fibroblasts if a statistical approach is used but does not predict acute radiation toxicity.

Prognostic impact of total tumor volume and hemoglobin concentration on the outcome of patients with advanced head and neck cancer after concomitant boost radiochemotherapy

PURPOSE To identify prognostic clinical and treatment related factors for local control, distant metastasis-free survival, and survival by means of a multivariate analysis in patients with advanced squamous cell carcinoma of the head and neck after concomitant boost radiochemotherapy. PATIENTS AND METHODS From 1992 to 1995, 68 patients with squamous cell cancer of the head and neck (93% stage IV disease) were treated with a simultaneous radiochemotherapy with Carboplatin using a concomitant boost technique. The total tumor volume (TTV) was quantitatively determined based on computed tomography scans in 56 patients. A Cox proportional hazards regression analysis was performed for each of the above endpoints and statistical significance of the Cox models was verified using the likelihood ratio test and Bonferroni correction for multiple testing. RESULTS The survival and locoregional control rates at three years were 35 and 32%. The multivariate analysis revealed a significant association between the TTV and survival (P = 0.0008) and between the pretreatment serum hemoglobin concentration and locoregional control (P = 0.01) and survival (P = 0.05). The locoregional control was significantly associated with the N-stage (P = 0.007) and there was a good correlation between the N-stage and TTV in this study population. CONCLUSION Our data corroborate the prognostic relevance of the tumor volume and hemoglobin concentration. In studies comparing the survival of patients with advanced cancer of the head and neck, the use of the TTV as a covariable may improve the statistical power.

Efficacy of hydrolytic enzymes in preventing radiation therapy-induced side effects in patients with head and neck cancers.

Purpose: Based on in vitro and on clinical evidence of protection against acute side effects of radiation, a prospective randomized, open study was performed to determine the efficacy of an oral proteolytic enzyme preparation in patients with head and neck cancer receiving conventional fractionated radiation therapy. Methods: Patients with stage T3/T4 head and neck cancer were eligible. One hundred patients from two centres were entered into the study. 60Co gamma-radiation was delivered at a standard daily radiation dose of 2 Gy in 25–35 fractions over a period of 6–7 weeks. Two lateral parallel opposing fields were used with a portal area of 10 × 15 cm. Patients assigned to the test group arm additionally received enzyme tablets orally t.i.d. starting 3 days prior to radiation therapy, and continuing up to 5 days after completion of the course of radiation therapy. Patients in the control arm were not given any drug or placebo. Acute radiation side effects were described as mucositis, skin reaction, dysphagia, and were graded at each visit during and after radiation therapy, following RTOG/EORTC criteria. Results: The severity (maximum extent) of acute radiation therapy side effects was significantly less in enzyme-treated patients than in control patients: mucositis (mean: 1.3 vs 2.2, P < 0.001), skin reaction (1.2 vs 2.4, P < 0.001) and dysphagia (1.4 vs 2.2, P < 0.001). The duration of these side effects as well as the sum scores of side effects were also less in the study arm. Conclusions: Combination of enzyme therapy with conventional fractionated radiation therapy was feasible and well-tolerated. There was significant protection against acute side effects of radiation therapy in the study arm. Not only was the severity of acute side effects less but the duration was shorter and the time to onset was also delayed. Prospective randomized double-blind studies would verify this role of an oral enzyme therapy as standard co-medication with radiation therapy to the head and neck region.