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Biomedical subjects

R Ziegler

Publications and source records attributed to R Ziegler.

At least 235 records · Page 13Linked to original sources
PubMed1994

Parathyroid hormone-related protein and life expectancy in hypercalcemic cancer patients.

We determined the effect of raised serum levels of midregional (53-84) parathyroid hormone-related protein (PTHrP) on life expectancy in 59 cancer patients with first presentation of hypercalcemia. The patients were stratified according to the serum PTHrP levels measured on day 0 after fluid repletion prior to bisphosphonate therapy. Twenty-nine patients were assigned to group N (PTHrP < or = 21 pmol/L) and 30 to group E (PTHrP > 21 pmol/L). Breast cancers were more common in group N, squamous cell cancers predominated in group E (p < 0.02). More patients with normal PTHrP had skeletal metastases, whereas group E was characterized by a higher incidence of prognostically unfavorable visceral involvement (p < 0.001). Bisphosphonates (pamidronate or BM.210955) were administered on day 0. Within one week, normocalcemia (serum calcium < or = 2.6 mmol/L) was restored in 96% of patients in group N, compared to 70% of patients in group E (p < 0.01). On day 12, 7 patients with elevated PTHrP were still hypercalcemic. Although a comparable number of patients in the two groups received cytostatic treatment after day 12, objective tumor responses were seen only in group N (n = 6; p < 0.05). Calculated from the first occurrence of hypercalcemia, the median survival was 66 days in group N and 33 days in group E (log-rank test: p = 0.0456; Wilcoxon-Breslow test: p = 0.0475). We conclude that in hypercalcemia of malignancy raised serum levels of PTHrP indicate a reduced hypocalcemic response to bisphosphonates, a more advanced tumor state and, therefore, an extremely poor prognosis.

Adult↗
PubMed1994

Vascular origin of Kaposi's sarcoma. Expression of leukocyte adhesion molecule-1, thrombomodulin, and tissue factor.

We studied seven cases of Kaposi's sarcomas (KS) obtained from patients with AIDS and one KS from a patient without HIV infection. Antigen expression was studied by immunocytochemistry and mRNA expression by in situ hybridisation. The markers tested were endothelial leukocyte adhesion molecule-1, thrombomodulin, and tissue factor. In all tumors (AIDS and non-AIDS associated) these markers reacted positive, indicating transcription and translation of these genes in KS. The synthesis and expression of tissue factor and thrombomodulin suggests that KS is a tumor that has tissue factor-mediated thrombin formation under the control of thrombomodulin. The expression of thrombomodulin and endothelial leukocyte adhesion molecule-1 provides evidence for the vascular origin of KS.

Acquired Immunodeficiency Syndrome↗
PubMed1994

[Therapeutic concepts in the treatment of postmenopausal osteoporosis].

Postmenopausal osteoporosis is not a well-defined disease, but summarizes women with different severity of changes in bone metabolism and different clinical complaints. The only common feature in women with 'postmenopausal osteoporosis' is the deficiency of estrogen. Postmenopausal women can be subdivided into four groups, according to their risk for fractures: 1. women without evident increase of fracture risk (bone mineral content between 0 and 2 SD of age-related normal range, no known risk factors from history); 2. women with possible increase of fracture risk (bone mineral content between 0 and -2 SD of age-related normal range, with or without known risk factors from history); 3. women with clear increase of fracture risk (bone mineral content below age-related normal range, with or without known risk factors from history); 4. women with already occurred fracture (manifest osteoporosis). Therapeutic intervention in postmenopausal women should be adapted to the risk for fracture. In all four groups a secondary prevention or basic therapy should be performed, focusing on calcium intake, vitamin D supply and sufficient physical activity. Calcium intake should be 1500 mg/day in women without estrogen substitution and 1000 mg in women with estrogen substitution. In patients living mainly inside or with malnutrition, a daily substitution of 500 E. Vitamin D3 is recommended. In group 2, regular control of bone mass is recommended to start additional estrogen replacement therapy, if accelerated loss of bone mass occurs. In group 3, estrogen replacement therapy is recommended urgently and is the therapy of first choice to prevent development of fractures. In group 4 (manifest osteoporosis), therapy should aim on improvement of the patient's symptoms and on increase of bone stability to avoid further fractures. The symptomatic therapy includes pain medications and an intensive physical therapy adapted to the patient's needs. Physical therapy should be performed for long time to reduce complaints and to improve musculoskeletal function in order to prevent falls. Different agents influencing bone metabolism by inhibition of bone resorption (estrogens, calcitonin, bisphosphonates) or stimulation of bone formation (fluoride) are used in manifest osteoporosis to increase bone stability. But the present efficacy to avoid further fractures has not been shown sufficiently for all available agents, so that a final evaluation and recommendation can't be done. Therapy decisions in manifest osteoporosis are often influenced by the possible side effects of the drugs (bleeding, gastrointestinal problems, joint pain), other, not bone-related effects of the drugs (improvement of climacteric complaints, pain relief) and other concomitant diseases and medications.

Aged↗
PubMed1994

Elevated thrombomodulin plasma levels as a result of endothelial involvement in plasmodium falciparum malaria.

We used thrombomodulin (TM) to assess the participation of the vascular endothelium in human Plasmodium falciparum (P.F.) malaria. Before therapy TM plasma levels were elevated in P.F. malaria and fell to normal values during therapy. Parasitemia, TNF alpha, elastase and TAT levels correlated directly with TM. Elevated TM levels can not be explained by increased synthesis, since incubating HUVEC with pretherapy serum of patients with P.F. malaria, but not reconvalescence serum, suppressed TM transcription. This was partially prevented by adding a TNF alpha neutralizing antibody to patient serum before incubation with HUVEC. However, TNF alpha does not release TM from cultured HUVEC in vitro. Coincubation of HUVEC with pretherapy serum together with neutrophils resulted in endothelial cell destruction, which could be partly prevented by a TNF alpha neutralizing antibody. Hence the increase of TM during P.F. malaria might reflect the concerted action of cytokines and neutrophils on HUVEC.

Antimalarials↗
PubMed1993

The ABCD (Appropriate Blood Pressure Control in Diabetes) trial. Rationale and design of a trial of hypertension control (moderate or intensive) in type II diabetes.

OBJECTIVE: The primary objective of the ABCD (Appropriate Blood Pressure Control in Diabetes) Trial is to determine the efficacy of intensive versus moderate antihypertensive control on the outcome of type II diabetic end-organ complications in normotensive and hypertensive populations. The secondary objective is to determine whether any differential effect on end-organ complications exists between an angiotensin converting enzyme inhibitor (enalapril) and a calcium channel blocker (nisoldipine). DESIGN: The ABCD Trial is a prospective, controlled, randomized, double-blind trial, with a planned follow-up of 5 years. SETTING: All patients are seen at the Colorado Prevention Center, site of the ABCD Trial, for follow-up visits. PATIENTS: Patients are type II diabetic males and females between the ages of 40 and 74 years with entry diastolic blood pressures > or = 80 mmHg. Patients were recruited from University of Colorado-affiliated hospitals, several health maintenance organizations, and mailing lists from the Colorado affiliate of the American Diabetes Association. INTERVENTIONS: Patients were randomized to intensive antihypertensive drug therapy or moderate antihypertensive drug therapy. Patients were also randomized to nisoldipine or enalapril, with open-label medications added if further blood pressure control was necessary. MAIN OUTCOME MEASURES: The primary outcome measure is glomerular filtration rate as assessed by 24-hour creatinine clearance. Secondary outcome measures are microalbumin urinary excretion, left ventricular hypertrophy, retinopathy, and neuropathy. Cardiovascular morbidity and mortality will also be evaluated. CONCLUSION: Given the data showing the impact of hypertension on diabetic complications, the ABCD Trial was designed to determine if intensive antihypertensive therapy will be more efficacious than moderate antihypertensive therapy on the outcome of these complications. Results from the ABCD Trial are expected to lend interpretable and clinically relevant findings with regards to the treatment of hypertension in type II diabetes.

Adult↗
PubMed1993

[Diagnostic significance of parathyroid hormone-related protein in tumor patients with hypercalcemia].

The clinical utility of measuring parathormone-related protein (PTHrP) was investigated in 94 patients (48 men, 46 women, mean age 56 [18-82] years) with tumour-associated hypercalcaemia, using a radioimmunoassay directed against the middle portion (53-84) of PTHrP (reference range < 5-21 pmol/l). Increased levels of the middle portion of PTHrP were found in 44 of the 73 patients (60%) with hypercalcaemia associated with solid tumours (median 49 [22-333] pmol/l). There was a positive correlation between the serum calcium concentration and the PTHrP (P = 0.018). The frequency of a raised PTHrP, indicating hormone-induced hypercalcaemia, was similar in patients with and without bone metastases (48% vs 66%). Elevated PTHrP was particularly frequent in patients with squamous cell carcinomas (17 out of 21; 81%), while PTHrP levels were normal in 18 out of the 21 patients with hypercalcaemia associated with haematological malignancies. PTHrP levels were normal in 37 out of 38 normocalcaemic tumour patients and in 30 out of 32 patients with primary hyperparathyroidism. Hypercalcaemia associated with benign disease was found in only one case, a female with marked benign breast hypertrophy.--The measurement of PTHrP allows the demonstration of a pathogenetic factor in tumour-associated hypercalcaemia, and differentiation from other causes of hypercalcaemia, in particular primary hyperparathyroidism.

Adolescent↗
PubMed1993

[The prognostic importance of calcitonin screening in familial medullary thyroid carcinoma].

In 34 of 139 patients (63 men, 76 women, mean age 41.2 +/- 15.6 years) with medullary thyroid carcinoma (MTC) the disease was of the familial variety. 13 of the 34 cases were discovered in the preclinical stage by screening (calcitonin stimulation with pentagastrin). This group was on average younger (16.8 +/- 10.7 years) than the 21 clinically manifest patients with MTC (28.0 +/- 11.9 years) or the 105 patients with sporadic MTC (45.7 +/- 13.6 years). The patients diagnosed through the screening programme had a more favourable tumour stage (12 in stage I or II) and were thus more likely to be cured. Their survival rate was higher (100% at both 5 and 10 years) than the survival rate of the patients with clinically manifest tumour (94 and 87%, respectively). But the group with manifest familial MTC did not differ from those with sporadic occurrence as regards the tumour stage (predominantly advanced stages), limited chance of cure and survival rate (5 years: 94%, 10 years: 81%). These data show that screening of family members decisively improves the prognosis of MTC of the familial variety.

Adult↗
PubMed1993

Mitogenic responsiveness of human bone cells in vitro to hormones and growth factors decreases with age.

Bone loss with aging may at least in part be due to inadequate bone formation. In this study, we examined whether the proliferation of osteoblast-like cells in vitro in response to local and systemic factors might be attenuated with age. A total of 36 cultures of osteoblast-like cells were obtained from outgrowths of human trabecular bone. Parathyroid hormone, growth hormone, calcitonin, transforming growth factor beta, insulin-like growth factor I, and platelet-derived growth factor BB dose dependently increased DNA synthesis in all cultures. Increases in DNA synthesis with each of these factors were significantly negatively correlated with donor age in cultures obtained from the iliac crest bone of 50- to 70-year-old women. Cells from 61- to 70-year-old donors required approximately 10-fold higher concentrations of growth factors and hormones to yield comparable increases in DNA synthesis than cells from 51- to 60-year-old donors. A significant negative correlation between age and mitogenic responsiveness to platelet-derived growth factor and growth hormone, but not toward the other factors, was also observed in cultures from the femoral head trabecular bone of 60- to 90-year-old women. Our findings suggest that bone loss with aging may be partially due to a decreased capacity of osteoblasts to proliferate in response to systemic or locally released osteotropic factors.

Aged↗
PubMed1993

Development and validation of an assay to measure bioactivity of human calcitonin in vitro using T47D cell membranes.

We have developed a "test-tube" assay to determine the biological activity of synthetic preparations of human calcitonin (hCT). The method is based on the dose-dependent accumulation of cyclic AMP in cell membrane preparations on stimulation with CT. As an unlimited cell source, we used the clonal cell line T47D, which possesses functional CT receptor-adenylate cyclase complexes. Half-maximal stimulation was achieved with 40-200 nmol/liter hCT. The method was able to precisely quantify the relative potencies of various hCT preparations. The intraassay and interassay coefficients of variation were 3.0 and 5.6%, respectively. The analytical performance, as estimated by additional recovery and specificity studies, was better than or comparable to the established in vivo rat hypocalcemia assay. Results obtained with these two methods were closely correlated (r = 0.83, P < 0.01). However, the in vitro membrane system allowed a higher throughput of samples, less preparation time, and better standardization and transportability of the assay, as large-scale membrane preparations were stable for at least 12 months in liquid nitrogen. This new in vitro membrane bioassay provides a convenient alternative to the currently performed in vivo rat hypocalcemia bioassays.

Animals↗
PubMed1993

Clinical features of type III hyperlipoproteinemia: analysis of 64 patients.

The clinical and biochemical characteristics of type III hyperlipoproteinemia are described in 64 patients (35 males and 29 females). Homozygosity for apolipoprotein E2, the presence of an abnormally cholesterol-rich very low density lipoprotein fraction (beta-VLDL) and an elevated ratio of very low density lipoprotein cholesterol to plasma triglycerides (> 0.3; normal ratio about 0.2) were the basis for the diagnosis. Mean serum cholesterol and triglyceride concentrations at the first visit in the clinic were 426 +/- 221 and 719 +/- 996 mg/dl, respectively. The mean age at diagnosis of the disorder was 49 years in males and 53 years in females. There was a high prevalence of obesity (72%), xanthomas (42%), and atherosclerosis (39%), especially peripheral vascular disease (31%). Early and correct diagnosis of this familial lipoprotein disorder seems necessary because of the prompt and beneficial response to therapeutic interventions.

Adult↗
PubMed1993

Levels of parathyroid hormone-related protein in hypercalcemia of malignancy: comparison of midregional radioimmunoassay and two-site immunoradiometric assay.

Overproduction of parathyroid hormone-related protein (PTHrP) is a major cause of hypercalcemia of malignancy in patients with solid tumors. We measured plasma levels of the protein by a radioimmunoassay (RIA) against PTHrP(53-84) and by an immunoradiometric assay (IRMA) against PTHrP (1-86). Of 16 affected patients 7 had elevated PTHrP levels in both assays and 4 had elevated levels in the RIA only. Median levels were about tenfold higher in these patients when measured by RIA (median of 34 versus 2.2 pmol/l). Measurements from both assays were, however, highly correlated with each other in this patient group (P < 0.01). PTHrP was not elevated in 10 normocalcemic patients with lung carcinoma. During long-term follow-up of a patient with a mesothelioma of the pleura, PTHrP levels measured with both assays decreased during chemotherapy in parallel with a normalization of serum calcium. In another hypercalcemic patient suffering from renal carcinoma, PTHrP measured by IRMA decreased by 40% within 12 h after nephrectomy, whereas PTHrP measured by RIA did not show a significant decline. Direct comparison of the assay results thus pointed to the existence of heterogeneity of circulating forms of PTHrP in plasma. In conclusion, both immunoassays detected elevated levels of PTHrP in a fraction of patients with hypercalcemia of malignancy and thus may be a tumor marker during treatment of malignancies.

Adult↗
PubMed1993

Relation of cardiovascular risk factors to atherosclerosis in type III hyperlipoproteinemia.

The familial lipoprotein disorder type III hyperlipoproteinemia (HPL) carries a marked increase in the risk of accelerated and premature atherosclerosis, but there is considerable variation among affected individuals in susceptibility to cardiovascular disease (CVD). We studied the influence of independent risk factors for atherosclerosis in 67 patients with clinically overt type III HPL and homozygosity for apolipoprotein (apo) E2. Among the different risk factors (lipid and lipoprotein levels, age, sex, body mass index, smoking status, hypertension, and diabetes mellitus) there was only a statistically significant difference in age between 25 patients with atherosclerosis and 42 patients without atherosclerosis. Serum lipoprotein (a), [Lp, (a)], levels were 30.6% higher in the atherosclerosis group, but this was not statistically significant. We conclude that (in contrast to familial hypercholesterolemia) elevated Lp (a) concentrations may not be regarded as a component of the clinical syndrome of type III HPL.

Age Factors↗
PubMed1993

Formation of neutralizing antibodies after treatment with human calcitonin.

PURPOSE: Calcitonin is used for the treatment of Paget's disease of bone, hypercalcemia, and postmenopausal osteoporosis. The formation of antibodies against heterologous calcitonins, such as salmon calcitonin (sCT), has been described frequently. Neutralizing effects of these antibodies have been demonstrated in many cases. As far as antibody formation against human calcitonin (hCT) is concerned, only a single case has been reported in the literature; however, investigations concerning the biologic activity of the antibodies were not performed. We have now assessed the sera of 33 patients treated with hCT for postmenopausal osteoporosis for a period of at least 12 months to evaluate the occurrence of hCT-binding and hCT-neutralizing antibodies. PATIENTS AND METHODS: Binding antibodies were detected by incubation of patient sera with 125I-labeled hCT; neutralizing activity was assessed in an in vitro bioassay that measured the impairment of the hCT-induced cyclic adenosine monophosphate (cAMP) formation in the human breast cancer cell line T47D. RESULTS: Prior to hCT treatment, none of the patients showed evidence of the presence of either binding or neutralizing antibodies. During the course of treatment, binding antibodies occurred in a single patient. These antibodies had a neutralizing activity characterized by 15% impairment of cAMP formation after 6 months and 27% impairment after 12 months of treatment compared with pretreatment control values. The neutralizing effect observed in this particular patient was comparatively mild compared with the effects seen after the formation of neutralizing antibodies against sCT, so major clinical sequelae were not expected in this patient. This may be due to the lower antigenicity of hCT as compared with sCT. CONCLUSION: Although antibody formation against hCT is a rare phenomenon, we nonetheless recommend monitoring of postmenopausal osteoporosis patients treated with sCT or hCT for neutralizing antibody formation in order to evaluate the therapeutic effect of treatment.

Aged↗
PubMed1993

Foreign body granulomatous inflammation increases the sensitivity of splenocytes to immunomodulation by 1,25-dihydroxyvitamin D3.

1,25-dihydroxyvitamin D3, the active metabolite of vitamin D, partially inhibits antigen and mitogen-driven lymphocyte stimulation. We studied the effect of granulomatous inflammation on the sensitivity of lymphocytes to 1,25-dihydroxyvitamin D3 in vitro, measuring the inhibitory effect of 1,25-dihydroxyvitamin D3 on mitogenesis of splenocytes of mice with chronic inflammation induced by subcutaneous injection of talc. Systemic manifestations of the local inflammation included loss in body weight, splenomegaly, enhanced DNA synthesis by freshly isolated splenocytes and enhanced prostaglandin secretion by activated splenocytes. Splenocytes from animals with local inflammation were more susceptible to inhibition by 1,25-dihydroxyvitamin D3, but not by prostaglandin E2. This increased sensitivity to 1,25-dihydroxyvitamin D3 was abolished by blocking prostaglandin synthesis in splenocyte cultures with indomethacin and was restored by adding prostaglandin E2. This effect cannot be attributed to enhanced prostaglandin synthesis in the presence of 1,25-dihydroxyvitamin D3, but is probably due to a qualitative change in the response of splenocytes from inflamed animals to the combined action of 1,25-dihydroxyvitamin D3 and prostaglandin E2.

Adjuvants, Immunologic↗