PubMed Health⌕ Search

Biomedical subjects

D Hirsch

Publications and source records attributed to D Hirsch.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Detection of enhanced monohydroxyeicosatetraenoic acid and F2-isoprostane levels in human plasma samples after extracorporeal photoimmunotherapy.

To investigate the involvement of reactive oxygen species in extracorporeal photoimmunotherapy (photopheresis), we have introduced two highly sensitive and specific techniques for the detection and quantitative measurement of oxygenated nonenzymatically formed arachidonic acid isomers [mono-hydroxyeicosatetraenoic acids (HETEs) and F2-isoprostanes] by gas chromatography-mass spectrometry/negative ion chemical ionization (GC-MS/NICI) in plasma samples of patients suffering from cutaneous T-cell lymphoma and progressive systemic scleroderma II. The analysis of HETEs involved hydrogenation, solid phase extraction on a C18 cartridge, formation of pentafluorobenzyl bromide and trimethylsilyl ether derivatives. In the case of F2-isoprostanes, the analytical procedure was similar to that of HETEs except that the hydrogenation step was omitted. In the plasma of healthy volunteers picomole amounts of 2-, 5-, 8-12-, 15-HETEs, 8-iso-PGF(2alpha) and 9alpha,11alpha-PGF(2alpha) were quantified by using 12-hydroxy-heptadecatrienoic acid and PGF(2alpha)-d4 as internal standards of HETEs and isoprostanes, respectively. Analysis of plasma samples obtained from patients before and after extracorporeal photoimmunotherapy revealed characteristic increases in both, HETE and isoprostane levels. The enhancement of indicators of lipid peroxidation is in correspondence with a moderate loss of alpha-tocopherol, the most important lipid-soluble antioxidant in human plasma. Thus, our data confirm the involvement of lipid peroxidation in extracorporeal photoimmunotherapy.

Arachidonic Acid↗
PubMedDate not supplied

Detection of monohydroxyeicosatetraenoic acids and F2-isoprostanes in microdialysis samples of human UV-irradiated skin by gas chromatography-mass spectrometry.

UV irradiation of the human skin leads to induction of oxidative stress and inflammation mediated by reactive oxygen radicals, lipid peroxidation, liberation of arachidonic acid from membrane phospholipids and formation of prostaglandins and leucotrienes. We investigated "lipid mediators", such as F(2)-isoprostanes (8-iso-PGF(2alpha), 9alpha,11alpha-PGF(2alpha)) and monohydroxyeicosatetraenoic acids (HETEs) in the dermal interstitial fluid obtained by a cutaneous microdialysis technique. Defined areas on the volar forearm of 10 healthy volunteers were exposed to UVB irradiation (20-60 mJ/cm(2)). Microdialysis membranes were cutaneously inserted beneath the irradiated area. The probes were perfused with isotonic saline solution, and microdialysate samples were collected at 20-min intervals up to 4-5 h. Oxidized arachidonic acid derivatives (2-, 3-, 5-, 8-12- and 15-HETEs, 8-iso-PGF(2alpha) and 9alpha,11alpha-PGF(2alpha)) could be detected and quantified in microdialysates of normal skin in the picomole (HETEs) and femtomole (isoprostanes) range and after UVB irradiation using sensitive gas chromatography-mass spectrometry/negative ion chemical ionization. UVB irradiation enhanced the levels of 8-iso-PGF(2alpha) after 24 h significantly, whereas the HETE levels were slightly increased within shorter time intervals (3 h after UVB irradiation). Further investigations have to show whether these new findings are relevant to validate therapeutic strategies for topical and systemic UV prevention agents or for monitoring of specific therapeutic strategies in inflammatory skin disorders.

Adolescent↗
PubMedDate not supplied

Skin necrosis: an unusual complication of hyperphosphatemia during total parenteral nutrition therapy.

BACKGROUND: Hyperphosphatemia complicated by calcification of subcutaneous arteries and skin infarcts are very rarely reported in the absence of chronic renal failure (CRF). We describe identical lesions in an obese woman with sepsis. Hyperphosphatemia resulted from an unintended excess of phosphate in her total parenteral nutrition (TPN) formulations. She did not have CRF or hyperparathyroidism. METHODS: The patient's records during 37 weeks of hospitalization 12 years ago and, subsequently, her outpatient records were reviewed. RESULTS: During a 7-week period, the total elemental phosphorus infused daily, as divalent phosphate, ranged from 1.8 to 4.2 g, median 3.1, over triple the normal daily requirement. This excess was unintended. This occurred before the current practice of pharmacist-monitoring of TPN formulations, and possibly resulted from misinterpretation of a revised formulation sheet, newly introduced to the nursing units at the start of that period. Serum phosphorus increased to 3.02 mmol/L (normal 0.76 to 1.46 mmol/L). She developed calcification of subcutaneous arteries, which was complicated by widespread infarcts of the anatomically related skin and subcutis, apparently the result of hypoperfusion of these vessels during an episode of septic shock. The infarcts were heralded by unusual, blotchy skin discolorations. CONCLUSIONS: This report, illustrating a startling cutaneous complication associated with apparent misinterpretation of TPN formulations, demonstrates a pathogenetic relationship between hyperphosphatemia, calcification of subcutaneous arteries, and necrosis of the skin and subcutis in the absence of CRF and hyperparathyroidism and introduces a new differential diagnosis for unusual skin lesions appearing during TPN therapy.

Adult↗
PubMedDate not supplied

Efficacy and safety of trazodone versus clorazepate in the treatment of HIV-positive subjects with adjustment disorders: a pilot study.

The efficacy of trazodone and clorazepate to relieve anxiety and depressive symptoms in 21 HIV-positive subjects with adjustment disorders was determined in a 28-day single-centre, randomized, double-blind study. Subjects were evaluated using the Hospital Anxiety and Depression Scale, the Revised Symptom Checklist, the European Organization for Research and the Treatment of Cancer Quality of Life Questionnaire, and a binary criterion based on the Clinical Global Impression. The incidence of successful treatment was 80% for trazodone compared with 64% for clorazepate; the sample number was too small to establish a significant difference. Bayesian analysis revealed the probability of making a wrong decision in prescribing trazodone rather than clorazepate reduced from 35% to 18% in this small sample. Clinical evaluations using the different scales suggest some benefit from trazodone, although this was not significant. Safety of both treatments was similar. Trazodone is devoid of the risk of abuse and dependence, and may be a valuable alternative to benzodiazepines for the treatment of HIV-related adjustment disorders.

Adjustment Disorders↗
PubMedDate not supplied

[Integrated care of HIV-seropositive patients: liaison psychiatry revisited].

Psychiatric, psychologic and psychotherapeutic care of HIV patients is integrated inside a specific medical institution. The psychological representations that AIDS mobilizes pervade the intense medical relationship between internists, nurses and the HIV patients. This relationship becomes the central node for the differentiation of psychologists and psychiatrists function inside the team. We propose here three different functions: the bio-psycho-social integrated care of the patients; the "binding" of psychical representatives inside the HIV patient who is in a death process; the binding of the representatives disseminated inside the medical team by the patient.

Comprehensive Health Care↗