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Biomedical subjects

J Fuchs

Publications and source records attributed to J Fuchs.

At least 55 records · Page 3Linked to original sources
PubMed1998

Potentials and limitations of the natural antioxidants RRR-alpha-tocopherol, L-ascorbic acid and beta-carotene in cutaneous photoprotection.

Sun exposure has been linked to several types of skin damage including sun burn, photoimmunosuppression, photoaging and photocarcinogenesis. In view of the increasing awareness of the potentially detrimental long term side effects of chronic solar irradiation there is a general need for safe and effective photoprotectants. One likely hypothesis for the genesis of skin pathologies due to solar radiation is the increased formation of reactive oxidants and impairment of the cutaneous antioxidant system. Consequently, oral antioxidants that scavenge reactive oxidants and modulate the cellular redox status may be useful; systemic photoprotection overcomes some of the problems associated with the topical use of sunscreens. Preclinical studies amply illustrate the photoprotective properties of supplemented antioxidants, particularly RRR-alpha-tocopherol, L-ascorbate and beta-carotene. However, clinical evidence that these antioxidants prevent, retard or slow down solar skin damage is not yet convincing. The purpose of this review is to provide the reader with current information on cutaneous pathophysiology of photoxidative stress, to review the literature on antioxidant photoprotection and to discuss the caveats of the photo-oxidative stress hypothesis.

Antioxidants↗
PubMed1998

Effects of prior aspirin and anti-ischemic therapy on outcome of patients with unstable angina. TIMI 7 Investigators. Thrombin Inhibition in Myocardial Ischemia.

Both aspirin and beta-adrenergic blocking drugs have been shown to reduce the risk of death or acute myocardial infarction (AMI) in patients with unstable angina, but their effect during chronic use on the presentation of acute coronary syndromes is less well defined. Calcium antagonists and oral nitrates are also widely prescribed for patients with coronary disease, but their effect on presentation of acute myocardial ischemia is unknown. We retrospectively examined the effects of prior aspirin and anti-ischemic medical therapy on clinical events in 410 patients hospitalized for unstable angina. Ischemic pain occurred at rest for a duration of 5 to 60 minutes. During hospitalization, 97% of patients received aspirin and all received the direct thrombin inhibitor bivalirudin for at least 72 hours. Despite being older and more likely to have risk factors for coronary disease and poor outcome, patients receiving aspirin before admission were less likely to present with non-Q-wave AMI (5% vs 14% in patients not on aspirin, p = 0.004). Prior beta blocker, calcium antagonist, or nitrate administration did not appear to modify presentation as unstable angina or non-Q-wave AMI. In a multivariate model, the combined incidence of death, AMI not present at enrollment, or recurrent angina was best predicted by age (adjusted odds ratio [95% confidence interval] 2.38 [1.14 to 3.98]) and presence of electrocardiographic changes with pain on presentation (adjusted odds ratio 2.83 [1.50 to 5.35]) but was not related to prior or in-hospital medical therapy. Thus, aspirin but not anti-ischemic therapy before hospitalization of patients with unstable angina was associated with a decreased incidence of non-Q-wave AMI on admission.

Adrenergic beta-Antagonists↗
PubMed1998

The role of oxygen in cutaneous photodynamic therapy.

Photodynamic therapy (PDT) is based on the dye-sensitized photooxidation of biological matter in the target tissue, and utilizes light activated drugs for the treatment of a wide variety of malignancies. Skin is a target organ for PDT, because of the increasing incidence of skin cancers and the easy accessibility to photosensitizing drugs and light. Skin oxygen tension changes dramatically during and after PDT and seems to be an important treatment parameter. Experimental approaches to modulate oxygen tension (e.g., hyperbaric oxygenation, hyperthermia, or perfluorocarbons) have been studied mainly in animals, and some of these techniques may have the potential to be applied in humans to improve the efficacy and safety of PDT. The main purpose of this review is to provide the reader with current information on cutaneous oxygen physiology and oximetry, the role of oxygen and singlet oxygen (1O2) in PDT, and approaches to modulate skin oxygen tension. The literature indicates that it may be possible to utilize transcutaneous oxygen measurements as a valuable measure of the clinical effectiveness of PDT and as an in situ predictor of the energy required to elicit a biological response. Consequently the effectiveness of PDT can be manipulated by modulating skin oxygen tension.

Antineoplastic Agents↗
PubMed1998

Cutaneous tolerance to nitroxide free radicals in human skin.

No data are available on the irritant effect of nitroxide free radicals in human skin. Nitroxides are important biomedical skin probes used in Electron Paramagnetic Resonance spectroscopy and imaging. Our purpose was to study the skin irritation potential of different nitroxide free radical structures in skin of healthy human subjects. We investigated the following nitroxides: Tempo (2,2,6,6-tetramethyl-1-piperidinoxy), Doxo (2,2,5,5-tetramethyl-3-oxazolidinoxy), Proxo (2,2,5,5-tetramethyl- -dihydro-pyrrolinoxy), and Imidazo (2,2,3,4,5,5-hexamethyl-imidazoline-1-yloxyl). Cutaneous irritation was determined in human skin following a single application and after repetitive applications in comparison to the standardized irritant sodium lauryl sulfate (SLS). The response was evaluated clinically as well as by a bioengineering method analyzing transepidermal water loss (TEWL) and skin hydration (capacitance). The nitroxides were classified clinically from nonirritant (Imidazo, Proxo), to slightly irritant (Doxo, 100 mM), or moderately irritant (Tempo 100 mM) after a single application. The TEWL values were significantly increased by Doxo and Tempo, but capacitance values were not changed significantly. In the cumulative irritation test Tempo was scored as a slight irritant (10 mM). TOLH (2,2,6,6-tetramethyl-1-hydroxypiperidin), the hydroxylamine of Tempo, which is the major skin metabolite, did not cause skin irritation after a single or repetitive applications. This may indicate that a loss of cellular reducing equivalents may be involved in the inflammation process caused by Tempo. The order of nitroxide irritation potency (Tempo > Doxo >> Imidazo = Proxo) is inverse to the order of nitroxide biostability in human skin (Imidazo = Proxo >> Doxo > Tempo). In conclusion, nitroxide free radicals are classified as nonirritant to moderately irritant in human skin. Particularly, the pyrrolidine and imidazoline type nitroxides have a low potential to cause acute or subacute skin toxicity.

Adult↗
PubMed1998

Cutaneous tolerance to nitroxide free radicals and nitrone spin traps in the guinea pig.

The attempts to use nitroxide free radicals and nitrone spin traps topically in skin requires analysis of their potential cutaneous adverse effects. The objective of this study was to investigate the skin irritation and sensitizing potential of nitroxides and nitrones in the guinea pig. The following unsubstituted nitroxides were investigated: 2,2,6,6-tetramethyl-1-piperidinoxyl (Tempo), 2,2, 5,5-tetramethyl-3-oxazolidinoxyl (Doxo), 2,2,5,5-tetramethyl-1-dihydro-pyrrolinoxyl (Proxo), 2,2,3,4,5,5-hexamethyl-imidazoline-1-yloxyl (Imidazo) and the nitrones: 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and N-tert.-butyl-phenylnitrone (PBN). Cutaneous irritation was determined following the modified Draize protocol. The response was evaluated clinically as well as by a biophysical method analyzing transepidermal water loss (TEWL). The nitroxides and nitrones were classified clinically from non-irritant (Proxo, Imidazo, DMPO) to slightly irritant (Tempo, Doxo, PBN) according to the Draize protocol. In agreement with the clinical scoring, the TEWL values were significantly increased by Tempo, Doxo and PBN. TOLH, the hydroxylamine of Tempo and its major skin metabolite, did not cause skin irritation. The sensitizing effect was evaluated according to the Magnusson and Kligman test. The results showed no cutaneous hypersensitivity to all nitroxides and nitrones, indicating a weak sensitizing potential. That concludes that the nitroxides and nitrones tested in this study have a low potential of acute skin intolerance.

Animals↗
PubMed1998

[Interventional therapy for hemangioendothelioma of the liver in a newborn infant using a central venous approach].

We report on a newborn (birth weight 3600 g) with high-output cardiac failure due to a large hepatic hemangioendothelioma requiring mechanical ventilation. One day post-partum therapy with steroids, furosemide, and digitalis was initiated. Despite this, the clinical condition deteriorated. Therefore, selective coil-embolization of the arterial vessels supplying the hemangioendothelioma was performed using a venous approach with passage to the arterial side via the ductus arteriosus. After the embolization the patient improved quickly and he was extubated 4 days postinterventionally. Follow-up sonography 4 months postinterventionally showed dramatic regression of the hepatic tumor. We conclude that the coil-occlusion of hepatic hemangioendothelioma should be performed early in symptomatic newborns as arterial puncture and its associated complications can be avoided by using a venous approach with passage to the arterial side via the ductus arteriosus. In addition, in this age group, access to the portal system can be gained through the umbilical vein to occlude portal venous supplies to the hepatic hemangioendothelioma.

Catheterization, Central Venous↗
PubMed1998

Assignment of linkage groups to pea chromosomes after karyotyping and gene mapping by fluorescent in situ hybridization.

Chromosomes of the pea (Pisum sativum L.) were submitted to fluorescent in situ hybridization (FISH) with probes specific for the oligonucleotides (AG)12, (AC)12, (GAA)10, and (GATA)7 and for the genes encoding 25S rRNA, 5S rRNA and the storage proteins legumin A, K and vicilin. A fourth 5S rRNA gene locus, apparently specific for an accession of the cultivar Grüne Victoria, was newly detected. This allowed all seven chromosome pairs to be distinguished by FISH signals of rRNA genes. The same was possible using a combination of oligonucleotide probes or of oligonucleotides and rRNA gene-specific probes in multicolour FISH. Rehybridization with the 5S rRNA gene-specific probe allowed us to assign vicilin genes to the short arm of chromosome 5, the single legumin A locus to the long arm of chromosome 3 and the legumin B-type genes (exemplified by legumin K) to one locus on the short arm of chromosome 6. Correlation of these data with an updated version of the pea genetic map allowed the assignment of most linkage groups to defined chromosomes. It only remains to be established which of linkage groups IV and VII corresponds to the satellited chromosomes 4 or 7, respectively.

Chromosome Mapping↗
PubMed1998

Diagnosis and current management of penile agenesis.

Penile agenesis is a rare congenital anomaly in which early gender reassignment is recommended. In the past, multiple operations were carried out to form feminized external genitalia. The authors performed a definite genital reconstruction in a neonate using the posterior sagittal approach. Preoperatively, a magnetic resonance imaging (MRI) scan demonstrated erectile tissue, which was preserved and incorporated into the genital plasty. The operation included bilateral orchiectomy, urethral reconstruction, sigmoid vaginal replacement, and formation of the labia. The authors discuss the controversy around gender assessment. They emphasize the urethral hypotrophy to be a main challenge in this anomaly and conclude that immediate complete reconstruction is possible and should be performed in patients with this delicate condition.

Congenital Abnormalities↗
PubMed1998

Retinal detachment after cataract extraction in myopic eyes.

PURPOSE: To determine the incidence of retinal detachment (RD) after cataract extraction in people 40 years of age or older with axial myopia (i.e., axial length > or = 25.5 mm). SETTING: Fifteen Danish eye clinics. METHODS: Two hundred forty-five eyes had cataract extraction performed at 15 eye clinics; 237 eyes had extracapsular cataract extraction (ECCE) and 8 eyes, intracapsular cataract extraction (ICCE). Postoperative data were reported by the practicing ophthalmologists. Mean follow-up was 27 months (range 14 to 32 months). RESULTS: Five RDs occurred in the 245 eyes (2.0%). Excluding the ICCE cases and the two cases of combined cornea transplantation and ECCE, RD occurred in 4 of the 235 eyes that had ECCE (1.7%). The incidence after ECCE with posterior chamber lens implantation was 1.4%. Complete postoperative status was reported on 158 eyes. Forty-eight eyes (30.4%) had a neodymium:YAG capsulotomy and 3 (6.0%) developed an RD 1, 3.5, and 21 months after the capsulotomy. CONCLUSION: The RD incidence after ECCE with posterior chamber lens implantation was low but higher than that in unselected populations. The incidence increased after laser capsulotomy.

Adult↗
PubMed1998

Modulation of UV-light-induced skin inflammation by D-alpha-tocopherol and L-ascorbic acid: a clinical study using solar simulated radiation.

OBJECTIVE: In this clinical trial we studied whether oral supplementation with D-alpha-tocopherol (alpha-Toc), L-ascorbic acid (Asc), or alpha-Toc combined with Asc influenced the solar simulated radiation (SSR) induced skin inflammation in healthy volunteers. METHODS: We investigated the following groups in a prospective, randomized and placebo controlled study: Group (1) alpha-Toc 2 g/day, group (2) Asc 3 g/day, group (3) alpha-Toc 2 g/day combined with Asc 3 g/day, and group (4) placebo. Before and 50 days after supplementation we analyzed alpha-Toc and Asc concentrations in keratinocytes. The dose response curve of UV erythema was determined by reflectance spectrophotometry and the minimal erythema dose (MED) by visual grading before and after supplementation. RESULTS: 50 days after supplementation alpha-Toc keratinocyte levels were increased in groups (1) and (3), Asc concentrations were elevated in groups (2) and (3), and the a/gamma-Toc ratio increased in groups (1) and (3). The dose response curve of UVR induced erythema showed a significant flattening and the MED increased from 103 +/- 29 mJ/cm2 (before supplementation) to 183 +/- 35 mJ/cm2 (after supplementation) in group (3), while there were no significant changes in groups (1) and (2) after vitamin supplementation. CONCLUSION: Alpha-Toc and Asc act synergistically in suppression of the sunburn reaction.

Administration, Oral↗
PubMed1998

Molecular-cytogenetic characterization of the Vicia faba genome--heterochromatin differentiation, replication patterns and sequence localization.

A comprehensive survey of the molecular-cytogenetic features of the Vicia faba chromosome complement (2n = 12) is given. It includes previous as well as new original data. Various Giemsa, restriction endonuclease and fluorochrome banding patterns, azacytidine-mediated segment extension, replication patterns, lateral A/T asymmetry and sequence localization data for tandemly arranged simple sequence repeats, dispersed repeats and coding sequences as well as histone acetylation patterns are considered. This allows not only to distinguish and characterize telomeres, subtelomeres, centromeres and the NOR, but also the structure of the 5S rRNA gene loci and two main types of interstitial heterochromatin. Additionally, it offers physical landmarks within euchromatic areas. Thus, the field bean genome, exemplified by the reconstructed karyotype ACB, belongs to the cytogenetically best investigated plant genomes.

Chromosome Banding↗
PubMed1998

Congenital ectopia lentis. A Danish national survey.

PURPOSE: To elucidate demographic and nosologic characteristics of congenital ectopia lentis (ECL) in Denmark. METHODS: A register of affected persons was established based on information provided from medical records and files in a nation-wide retrospective study, the Danish ECL-study. RESULTS: Three hundred and ninety-six cases (197 males, 199 females) with ECL were included in the study. By January 1st, 1993, the estimated prevalence rate of ECL was 6.4/100,000. The estimated average point prevalence rate at birth 1976-85 was 0.83/10,000 live born. Only in 69% of the cases (274/396) was a nosologic classification possible, based on preexisting information about familial occurrence, systemic and ocular findings: Marfan syndrome was found in 68.2% of these (187/274), ectopia lentis et pupillae in 21.2%, simple dominant ectopia lentis in 8.0%, homocystinuria in 1.1%, sulfite oxidase deficiency and Weill-Marchesani syndrome in 0.7% each. In the remaining 31% (122/396) a nosologic diagnosis could not be established. CONCLUSION: The majority of affected persons have congenital ectopia lentis as a manifestation of a systemic disease. It is therefore essential to evaluate ECL patients systemically with a general physical examination, a metabolic screening, and an echocardiography as a minimum, in order to make a nosologic diagnosis and to prevent potentially life-threatening systemic complications.

Adolescent↗
PubMed1998

A Ty3/gypsy retrotransposon-like sequence localizes to the centromeric regions of cereal chromosomes.

A 745 bp sequence (pSau3A9) located at the centromeres of several cereal species was isolated from a sorghum BAC library by Jiang et al. (1996, Proc. Natl Acad. Sci. USA, 93, 14210-14213). We have amplified a partially homologous 809 bp sequence from barely genomic DNA by PCR and localized it to the centromeres of barley, wheat and rye chromosomes by fluorescent in situ hybridization (FISH). Sequence analysis showed this barley homolog of pSau3A9 to have high similarity to the integrase region of the polyprotein gene of Ty3/gypsy group retrotransposons. Using this integrase sequence as a probe, several clones were isolated from a lambda library constructed of genomic barley DNA. One of the lambda clones contained coding regions for all five catalytic sites characteristic of the retrotransposon polyprotein. Two direct repeats flanking the polyprotein gene are homologous to the cereal centromeric sequence described by Aragón-Alcaide et al. (1996, Chromosoma, 105, 261-268) and may represent all or part of the long-terminal repeats (LTRs). Different plasmid subclones containing various regions of the lambda clone were used in FISH to show that the entire polyprotein gene and upstream flanking sequences, including the presumed LTR, are present at barley centromeres. The preferential (or exclusive) localization of an apparently complete retroelement within the centromeric regions of several cereal species raises interesting questions about its role in karyotype evolution and centromere function.

Amino Acid Sequence↗
PubMed1998

Tubular esophageal duplication associated with esophageal stenosis, pericardial aplasia, diaphragmatic hernia, ramification anomaly of lower lobe bronchus and partial pancreas anulare.

Alimentary tract duplications are rare anomalies, which are often associated with other congenital malformations. We report on a newborn with the combination of tubular esophageal duplication, congenital esophageal stenosis, ramification anomaly of lower left lobe bronchus, complete pericardial aplasia and malrotation of the bowel with a partial pancreas anulare. The diagnoses are based on esophagogram, bronchogram, bronchoscopy, gastroscopy, explorative thoracotomy and laparotomy. The treatment was a resection of the duplication per thoracotomy, esophageal myotomy with fundoplicatio.

Abnormalities, Multiple↗
PubMed1998

The occurrence of liver growth factor in hepatoblastoma.

Rapid growth of recurrent disseminated tumor and/or metastases can occur in children after incompletely resected, non-pretreated malignant hepatoblastoma (HB). This accelerated tumor growth is observed during the first four postoperative weeks, which is the period of maximal liver regeneration. One key regulator of regeneration, the hepatocyte growth factor (HGF), may be responsible for the induction of tumor growth. We, therefore, investigated levels and sources of HGF in HB patients. With ELISA we measured elevated serum levels (> 1,000 pg/ml) of HGF in 10 of 23 HB patients in comparison with three healthy children (< 610 pg/ml). HGF values of non-pretreated children with HB ranged from 169-10,183 pg/ml (mean 889 pg/ml) while those of patients after primary chemotherapy reached 608-15,000 pg/ml (mean 4,556 pg/ml). An up to fourfold increase of HGF was detected in 10 of 12 children 24-72 hours after liver resection. With immunoenzymatic staining on cryostat sections and cytospin preparations of the tumors we could localize HGF to the fibroblasts of the mesenchymal tumor components. In contrast, its receptor (c-met) was found to be expressed on the epithelial HB cells. Our results indicate that HGF secretion is enhanced after liver resection in children with HB and thus could have a biological function for growth of HGF receptor-expressing tumor cells. The results of immunostaining further suggest that HB is able to produce HGF as its own growth factor in a local paracrine fashion.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Multiparameter analysis of clastogenic factors, pro-oxidant cytokines, and inflammatory markers in HIV-1-infected patients with asymptomatic disease, opportunistic infections, and malignancies.

HIV-1-infected patients are in chronic oxidative stress and clastogenic factors (CFs) are present in their plasma. CFs from patients with HIV are formed via superoxide anion radical and stimulate further superoxide production. The pathophysiolgic significance and the exact composition of the circulating clastogenic material in patients with HIV is unknown. Cytokines, such as tumor necrosis factor-alpha (TNF-alpha), are increased in the plasma of patients with HIV and TNF-alpha shows clastogenic activity in vitro. The aim of this clinical study was to compare levels of CF in HIV-1-positive patients with asymptomatic disease, opportunistic infections, and malignancies with those in HIV-1-negative control groups and to correlate CF activity with CD4+ T cell numbers, the cytokines (TNF-alpha, interleukin-2 [IL-2], IL-6), and the inflammatory markers (C-reactive protein [CRP], neopterin, granulocyte elastase). CFs were significantly increased in all HIV-1-positive patients and in HIV-1-negative patients with malignant tumors. HIV-1-positive patients with Kaposi's sarcoma showed the highest CF activity in their plasma (p < 0.08). CFs appear very early in HIV infection, and they correlate negatively with CD4+ T cells, which are an indicator of disease activity. The presence of CF in the plasma of HIV-infected patients is not a general response to a viral infection because these factors are not increased in HIV-1-negative patients with viral infection (zoster). CFs are not specific for the HIV-1 infection; they also occur in HIV-1-negative patients with malignant tumors. There was a tendency towards a positive correlation (p < 0.14) between CF and TNF-alpha but there was no positive correlation of CF with IL-2, IL-6, CRP, elastase, and neopterin levels. This indicates that TNF-alpha may be among the components of CF in HIV-1-infected patients. In addition, other unidentified components may contribute to the clastogenic activity of the plasma or the composition of CF may vary from patient to patient. Further clinical studies with larger sample populations are necessary to analyze the composition of CF in HIV-1-positive patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Resources for home nursing care: willingness to undertake care by persons not involved in nursing services].

In Germany the majority of people in need of nursing care are attended to at home. This is also promoted by the German nursing care insurance. Considering the increasing number of people in need of care more (people who care for them) are required. The article describes the readiness to care of a representative sample of 4806 people who are actually not involved in nursing care activities. The results show that the readiness to give nursing care is highly dependant on the care recipient. Independant from age, sex or social class, there is an strong readiness concerning care of the partner. Regarding other relatives (children, parents) or non-related persons like friends or neighbours, women show greater readiness than men to take over nursing care activities. Age and social class provoke differences, but not in such a homogenious way. All in all the readiness to provide nursing care is surprisingly high; it is to be hoped that it leads to realisation, in case of need.

Adolescent↗