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Biomedical subjects

P Clemens

Publications and source records attributed to P Clemens.

At least 19 recordsLinked to original sources
PubMed2003

Questions on life satisfaction (FLZM) in inflammatory bowel disease.

BACKGROUND AND AIMS: When assessing quality of care the outcome in terms of quality of life (QOL) is of major significance. This study examined QOL in IBD outpatients and the contribution of individual expectations and various other factors including disease activity. PATIENTS AND METHODS: The study included 306 outpatients with Crohn's disease and 109 with ulcerative colitis (UC). General and health-related QOL was quantified using the instrument Questions on Life Satisfaction(Modules). Disease activity was assessed by a questionnaire. Data were compared with a normal population sample. RESULTS: Life satisfaction scores on general items and on health-related items were significantly lower than in a control sample (60.5+/-37.3 and 74.4+/-41.5, respectively) among both CD patients (54.3+/-33.2, 59.1+/-38.8) and UC patients (45.4+/-34.0, 52.1+/-40.7). Scores were significantly related to severity of disease activity. IBD patients attributed particular importance to health-related issues. CONCLUSION: Both health-related and general life satisfaction is compromised in IBD outpatients, and health-related topics have major impact. Not surprisingly, inflammatory activity compromises QOL, which underlines the importance of anti-inflammatory strategies. The importance attributed to health-related features is higher in IBD patients than in the normal population.

Adult↗
PubMed2001

Pancreatic neuroendocrine tumor with extensive vascularisation and parathyroid hormone-related protein (PTHrP)--associated hypercalcemia of malignancy.

We report the case of a 34 year old male presenting with symptomatic hypercalcemia due to excessive PTHrP secretion from a pancreatic neuroendocrine carcinoma with extensive hypervascularization and without any evidence for metastatic disease. In the early phase of the disease conventional chemotherapy with streptozocin and doxorubicin was able to control functional activity as well as tumor growth. However, after 2 years tumor escape was indicated by severe therapy-resistant hypercalcemia. Therapeutic options were reduced due to the excessive tumor vascularization and the patient died from his disease after a short period of intensified therapy. The role of PTHrP in hypercalcemia of malignancy (HHM) and its association with neuroendocrine pancreatic tumors as well as possible therapeutic options are reviewed.

Adult↗
PubMed1998

Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene is associated with coronary artery plaque calcification as assessed by intravascular ultrasound.

OBJECTIVES: We evaluated the influence of the insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme (ACE) gene on coronary plaque morphology and calcification in patients with angiographically documented coronary artery disease (CAD). BACKGROUND: The ACE I/D polymorphism has been associated with an increased risk of myocardial infarction in patients with the DD genotype but not with the presence of native CAD. METHODS: We studied 146 patients undergoing percutaneous transluminal coronary angioplasty for stable angina pectoris by means of preinterventional intravascular ultrasound (IVUS). Qualitative and quantitative criteria were used to classify the target lesions as poorly or highly echoreflective or as calcified. Genomic deoxyribonucleic acid was analyzed by polymerase chain reaction (PCR) to identify the I/D polymorphism, with a second insertion-specific PCR in DD genotypes to prevent mistyping. RESULTS: The ACE genotype groups (DD 46, ID 68, II 32) were well matched for the basic characteristics. Patients with the DD genotype had significantly more calcified lesions (DD 80%, ID 57%, II 66%; unadjusted odds ratio [OR] 2.88, 95% confidence interval [CI] 1.30 to 6.92, p = 0.008) and more calcifications >180 degrees of the vessel circumference (DD 22%, ID 10%, II 6%; OR 2.80, 95% CI 1.05 to 7.63, p = 0.03). The prevalence of myocardial infarction was not significantly associated with coronary calcification (OR 1.44, 95% CI 0.72 to 2.88, p = 0.31). CONCLUSIONS: Patients with CAD and the ACE DD genotype have a significantly higher incidence and greater extent of coronary lesion calcification, as determined by IVUS. This finding indicates that the ACE I/D gene polymorphism is related to the development or progression of atherosclerotic plaque calcification.

Aged↗
PubMed1998

Lack of association between the insertion/deletion polymorphism of the angiotensin-converting-enzyme gene and diabetic nephropathy in IDDM patients.

The insertion/deletion (I/D) polymorphism of the angiotensin-converting-enzyme (ACE) gene has been reported to be associated with diabetic nephropathy in IDDM. We studied the relationship between this polymorphism and diabetic nephropathy in 210 IDDM patients. Their DNA was analyzed by polymerase chain reaction to type for the presence (I) or absence (D) of the 287 bp fragment in intron 16 of the ACE gene. The relative frequency of the different genotypes was 33.8% (DD), 43.8% (ID), and 22.4% (II). There were no significant differences between the genotypes in age, body-mass-index, blood pressure, plasma total cholesterol and triglycerides. The prevalence of microalbuminuria or nephropathy was 23.9% in the DD, 16.3% in the ID, and 17% in the II genotypes. The higher percentage of microalbuminuria or nephropathy in the DD genotypes was due to an increasing frequency of DD genotypes in the IDDM patients with long diabetes duration. After matching for diabetic retinopathy, gender, and diabetes duration, there was no association between the ACEI/D polymorphism and diabetic nephropathy. In conclusion, these results suggest that the ACE DD genotype cannot be regarded as a risk factor for diabetic nephropathy, but may even be associated with diabetes duration and thus longevity in IDDM patients.

Adult↗
PubMed1998

Evaluation of the insertion/deletion ACE gene polymorphism as a risk factor for carotid artery intima-media thickening and hypertension in young type 1 diabetic patients.

OBJECTIVE: To study the distribution of the insertion/deletion polymorphism of the ACE gene in young type 1 diabetic patients and to evaluate possible associations between the ACE genotype, arterial hypertension, and intima-media thickness (IMT) of the common carotid artery. RESEARCH DESIGN AND METHODS: Study participants were 148 type 1 diabetic patients (56 men and 92 women), aged 14-44 years, with a diabetes duration of > or = 2 years. HbA1c, albuminuria, and lipid status were assessed by standard laboratory techniques; the ACE genotypes were assessed by polymerase chain reaction. The patients were categorized according to the presence or absence of hypertension, nephropathy, and retinopathy. The IMT, which can be used to estimate early stages of atherosclerosis, was measured by high-resolution ultrasonography. RESULTS: The ACE genotypes were distributed as follows: 21% II, 37% ID, 42% DD. The IMT values did not differ among patients with various ACE genotypes (0.63 +/- 0.15 mm), but the prevalence of hypertension was significantly higher in patients with DD (odds ratio, 4.26 versus II + ID; 95% CI, 1.64-11.06). Multiple linear regression analysis showed that only age, hypertension, and sex were determinants for the IMT. CONCLUSIONS: Our results suggest a relationship between the prevalence of hypertension and the deletion polymorphism of the ACE gene in young type 1 diabetic patients, but we could not find an association between carotid artery IMT and ACE genotype in this population.

Adolescent↗
PubMed1995

The short-term effect of nicotine chewing gum in patients with Parkinson's disease.

Because of the inverse association of cigarette smoking with the risk of Parkinson's disease, we performed a short-term, double-blind, randomized controlled trial of nicotine polacrilex resin gum in patients with this disease. Forty-eight subjects were randomly assigned to chew either nicotine gum or placebo gum three times at 2-h intervals, with evaluation of symptoms before and after the trial. The nicotine gum was reasonably well tolerated, but there were no substantial differences in Parkinson's disease symptoms between the two treatment groups.

Aged↗
PubMed1992

Synthesis and biological studies of neutral technetium (V) complexes containing NNOS donor sets.

Complexation of ligands containing an N3S donor set has been affected with [99mTc]. These are part of a ligand series of analogous structures which exhibit similar chemistry and potentially interesting biology. The complexes which have been characterized with [99Tc] as [TcOL] are neutral and lipophilic and their biological behaviour has been assessed in rats. After HPLC purification of the no-carrier added preparation, brain uptake of the tracers was greater than 1% at 15 min p.i. Muscle activity was significant with slow blood clearance.

Animals↗
PubMed1992

Two hot spots of recombination in the DMD gene correlate with the deletion prone regions.

Genetic mapping has indicated that meiotic recombination occurs about 4 time more frequently in the dystrophin gene than expected on the basis of its length. To detect where recombinations occur within the gene, we have studied the CEPH families panel using highly polymorphic microsatellite markers located at the ends of the gene or flanking the major deletion hot spot in intron 44. We found a major hot spot of recombination between markers STR44 and STR50(1), i.e., between exons 44 and 51. Within this hot spot, a peak of recombination was located in the large intron 44. A second minor recombination prone region was found between DXS 206, (XJ, in the large intron 7) and the 5' end of the DMD gene. The distribution of the recombination events in the gene of healthy individuals was very similar to that of deletion breakpoints in DMD/BMD patients, suggesting that the two phenomenon may share a common mechanism. These results should also improve efficiency and accuracy of linkage analysis applied to carrier detection and prenatal diagnosis. In particular, if markers located at the very 3' end of the gene are not informative, the highly polymorphic ones located between exons 50 and 60 can be used instead of presently available extragenic markers, with a very low risk of diagnostic error due to recombination.

Dystrophin↗
PubMed1991

Technetium-99m-MRP20, a potential brain perfusion agent: in vivo biodistribution and SPECT studies in normal male volunteers.

The lipophilic neutral complex [99mTc][TcO(MRP20)] [MRP20 is (N-(2(1H pyrolylmethyl]N'-(4-pentene-3-one-2)ethane-1,2-diamine)] is known to cross the blood-brain barrier in non-primate animals. We report here its in vivo biodistribution, radiation dosimetry, and single-photon emission computed tomography (SPECT) characteristics in man. Following i.v. administration of 15-25 mCi of the tracer, the maximum uptake of activity in the brain peaked at 1 min p.i. Fifteen minutes p.i., the percentage retained in the brain was 5.2 +/- 1.6, which remained fairly constant over 24 hr. Blood clearance was relatively slow with an apparent affinity of the compound for the cellular fraction of the blood, however, soft-tissue and facial activity cleared at a rate four times faster than that of the brain. SPECT images obtained at 15 min, 1 hr, 3 hr, 7 hr, and 24 hr p.i. showed no redistribution of the tracer within the brain. The dosimetry is favorable for administration of 25-30 mCi of MRP20. Our results indicate that this compound is rapidly extracted and retained by the brain and may be used for SPECT imaging of regional blood flow.

Adult↗
PubMed1991

Technetium-99m-MRP20, a potential brain perfusion agent: in vivo biodistribution and SPECT studies in non-primate animals.

MRP20 (N-(2(1H pyrolylmethyl]N'-(4-pentene-3-one-2] ethane-1,2-diamine) complexes with technetium-99m, yielding a neutral, lipophilic species. This compound has been characterized as [TcO(MRP20)]. Biologic investigation of [99mTc][TcO(MRP20)] in female rats showed 2.35% ID in the brain 30 min p.i. with no significant wash-out over 3 hr. A single-photon emission computed tomography (SPECT) study in a dog demonstrated rapid tracer uptake in the brain, reaching a maximum within 1 min, with 2.24% i.d. 15 min p.i., decreasing to 1.7% after 4 hr. The complex undergoes hydrolysis in vitro forming a cationic species. This is possibly the trapping mechanism in the brain in vivo. The main excretory route of [99mTc][TcO(MRP20)] is via the hepatobiliary tract. There is evidence of some "in vivo" cell labeling and soft-tissue uptake.

Animals↗
PubMed1989

Screening of congenital hypothyroidism, phenylketonuria, galactosemia, homocystinuria, and maple syrup urine disease in moderate to severe mentally retarded Chinese children.

Five-hundred and fifty one mentally retarded children from seven institutes in Northern Taiwan were screened by dried blood spot for the detection of treatable congenital metabolic diseases, including congenital hypothyroidism, phenylketonuria, homocystinuria, maple syrup urine disease and galactosemia. We found 2 children (0.36%) with congenital hypothyroidism, 1 case (0.18%) of classical phenylketonuria and two cases (0.36%) of trisomy 21 associated with autoimmune thyroiditis. The results of our investigation suggest that congenital hypothyroidism and phenylketonuria can be the factors causing mental retardation among children in Taiwan and mass neonatal screening of these treatable inborn metabolic diseases is strongly indicated for efficiently circumventing mental retardation in our community.

Adolescent↗
PubMed1986

Metabolic conversion of L-[U-14C]phenylalanine to respiratory 14CO2 in healthy subjects, phenylketonuria heterozygotes and classic phenylketonurics.

Ten healthy volunteers, 12 classic phenylketonuria (PKU) heterozygotes, and 5 classic phenylketonurics have been loaded orally with a mixture of 5 microCi of L-[U-14C]phenylalanine plus 25 mg/kg of L-[2H5]phenylalanine. For 3 h thereafter, carbon-14 activity in expired air and total carbon dioxide were measured continuously and the levels of L-phenylalanine and L-tyrosine in plasma were determined in six blood samples. After 3 h, 15.1 +/- 2.1% of the applied dose of radioactivity was recovered in the expired air of the healthy subjects, compared to 10.1 +/- 2.2% for PKU heterozygotes and 0.32 +/- 0.18% for classic phenylketonurics. The integrated activity expired provides a discrimination between normals and PKU heterozygotes with a classification error of about 13% compared to an error of about 9% based on the fasting L-phenylalanine over L-tyrosine ratio. A combination of these two parameters in a two-dimensional discriminatory analysis reduces the classification error to less than 1%. An intraindividual correlation between the absolute activity expired and the formation of L-[2H4]tyrosine formed is shown, confirming that ring hydroxylation of L-phenylalanine to L-tyrosine is mandatory in the catabolism of L-phenylalanine to carbon dioxide.

Breath Tests↗
PubMed1986

Family study in familial hypercholesterolemia with a receptor-negative homozygous 9-year-old boy.

A 2-year-old boy showed massive xanthomas, especially tendon xanthomas and cutaneous xanthomas on the knees. When presented to us at the age of 9 years, his total cholesterol was 700-1100 mg/dl, LDL-cholesterol 600-1000 mg/dl, and triglycerides were normal, which is the constellation of hyperlipoproteinemia type IIa. LDL receptor studies showed 3% of normal binding activity, which defines the receptor-negative form of homozygous familial hypercholesterolemia (FH). Remarkably there was no sign of coronary heart disease in angiography. Three great-grandparents and the paternal grandfather (at 44 years) died from cardiovascular disease. The maternal grandmother is heterozygote for FH as well as three siblings of the father. In all family members we determined apolipoprotein B, apo-E-phenotype and the lipoprotein fraction Lp (a). In this family there seems to be no genetic coupling between the LDL receptor gene and the gene for Lp (a).- Therapy of heterozygous FH should start as early as possible, before symptoms appear. Therefore pediatricians should be very critical about the cholesterol values of their little patients.

Apolipoproteins B↗