PubMed Health⌕ Search

Biomedical subjects

S Tas

Publications and source records attributed to S Tas.

At least 19 recordsLinked to original sources
PubMed2005

The suppression of spinal F-waves by propofol does not predict immobility to painful stimuli in humans.

BACKGROUND: The immobilizing effects of volatile anaesthetics are primarily mediated at the spinal level. A suppression of recurrent spinal responses (F-waves), which reflect spinal excitability, has been shown for propofol. We have assessed the concentration-dependent F-wave suppression by propofol and related it to the logistic regression curve for suppression of movement to noxious stimuli and the effect on the bispectral index (BIS). The predictive power of drug effects on F-waves and BIS for movement responses to noxious stimuli was tested. METHODS: In 24 patients anaesthesia was induced and maintained with propofol infused by a target controlled infusion pump at stepwise increasing and decreasing plasma concentrations between 0.5 and 4.5 mg litre(-1). The F-waves of the abductor hallucis muscle were recorded at a frequency of 0.2 Hz. BIS values were recorded continuously. Calculated propofol concentrations and F-wave amplitude and persistence were analyzed in terms of a pharmacokinetic-pharmacodynamic (PK/PD) model with a simple sigmoid concentration-response function. Motor responses to tetanic electrical stimulation (50 Hz, 60 mA, 5 s, volar forearm) were tested and the EC(50tetanus) was calculated using logistic regression. RESULTS: For slowly increasing propofol concentrations, computer fits of the PK/PD model for the suppression by propofol yielded a median EC50 of 1.26 (0.4-2.3) and 1.9 (1.0-2.8) mg litre(-1) for the F-wave amplitude and persistence, respectively. These values are far lower than the calculated EC(50) for noxious electrical stimulation of 3.75 mg litre(-1). This difference results in a poor prediction probability of movement to noxious stimuli of 0.59 for the F-wave amplitude. CONCLUSIONS: F-waves are almost completely suppressed at subclinical propofol concentrations and they are therefore not suitable for prediction of motor responses to noxious stimuli under propofol mono-anaesthesia.

Adult↗
PubMed2003

Management of drug rash with eosinophilia and systemic symptoms (DRESS syndrome): an update.

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a rather distinct severe adverse drug reaction characterised by skin rash, fever, lymph node enlargement and internal organ involvement. Our aim was to review the available data regarding the management of this probably underrecognised subset of drug reaction. So far, the only undisputed way to treat severe hypersensitivity reactions is prompt withdrawal of the offending drug. The use of systemic corticosteroids remains controversial. The benefit of therapies aimed at accelerating the elimination of the causative drug deserves further studies. In the absence of a well-established therapy, primary and secondary prevention have a key role in the management of DRESS syndrome.

Anti-Inflammatory Agents↗
PubMed2000

Multiple primary neoplasms at a single institution: differences between synchronous and metachronous neoplasms.

During the 10-year period (1987-1996) of our study, 26,255 patients with cancer were admitted to our clinic and, of these, 271 (1%) patients had multiple primary malignant tumors. Ninety-two (34%) patients had synchronous tumors (synchronous group), and 179 (66%) patients had metachronous tumors (metachronous group). The mean age at first diagnosis was higher in the former group. The ratio of men to women was 1.36 in the synchronous group and 0.74 in the metachronous group (p = 0.018). Smokers and drinkers were more common in the synchronous group. Breast cancer and lung cancer were most prevalent, and associations between head/neck and lung cancer and between breast and breast cancer were the most frequent associations in both the synchronous and the metachronous group. The frequency of aerodigestive tumors was higher and that of mesenchymal tumors was lower in the synchronous group than in the metachronous group. Localization in the medial region and in the head/neck was more frequent in the synchronous group than in the case of metachronous secondary tumors.

Age Factors↗
PubMed2000

[Primary and isolated cutaneous lymphomatoid granulomatosis following heart-lung transplantation].

BACKGROUND: Lymphomatoid granulomatosis is an Epstein-Barr virus-associated B-cell lymphoproliferative disease. It is angiocentric and angiodestructive and involves the lungs, central nervous system and skin. Exclusive cutaneous involvement is rare and may be associated with a better outcome. Contrarily to the extra-cutaneous forms of lymphomatoid granulomatosis, it is difficult or impossible to detect Epstein-Barr virus DNA sequences in primary and isolated cutaneous lymphomatoid granulomatosis. CASE REPORT: A 54-year-old woman developed erythemato-violaceous lesions on both legs 3 years after a heart-lung transplantation. The diagnosis of erythema multiforme and of drug-induced vasculitis were first made. Because of fever and of the rapid extension of the lesions, the patient was hospitalized. The histologic examination of the first lesions showed a perivascular infiltrate, without epidermotropism, composed of histiocytes, lymphocytes and plasma cells. Immunohistochemistry revealed the presence of a predominantly T-cell infiltrate with some large B cells. Subsequent biopsies were diagnosed as high grade B-cell lymphoma. Polymerase chain reaction analysis as well as in situ hybridation study showed the presence of Epstein-Barr virus load in the lesions. There was however no serologic evidence of viral reactivation. Extensive systemic evaluation revealed no visceral or bone marrow involvement. Despite antiviral treatment and CHOP polychemotherapy, the patient died 3 months after her admission. DISCUSSION: This observation of lymphomatoid granulomatosis is particular because of its exclusive cutaneous involvement associated with a fulminant evolution to high grade B lymphoma. The presence of a context of iatrogenic immunosuppression underlies the role of altered immune cellular functions in the initiation and/or progression of lymphomatoid granulomatosis and strengthens the role of a viral agent in its pathogenesis. We suggest that the presence of Epstein-Barr virus, which is generally not associated with the isolated cutaneous forms of lymphomatoid granulomatosis, may have played a role in this fulminant evolution to high grade B lymphoma.

Diagnosis, Differential↗
PubMed2000

[Vacation souvenirs: inoculation pathologies (cutaneous larva migrans, cutaneous leishmaniases, Lyme disease, rickettsioses)].

Residents of western countries travel more and more to (sub)tropical areas for holidays or work. During their stay they come in contact with insects and parasites susceptible to induce skin disorders that can manifest during their stay or after returning. This dermatosis account for approximatively 10% of referral to outpatient tropical clinics. The aim of this paper is to provide family physicians not familiar with these pathologies some practical guidelines to help them to identify and treat some tropical dermatosis: cutaneous larva migrans, cutaneous leishmaniasis, Lyme disease, rickettsiosis. Cutaneous larva migrans is the most frequent serpiginous itching eruption observed in travellers. It is cause by transepidermal penetration of animal hookworms (ancylostomas) through contact with soil infested with cat and dog feces. Effective treatments include topical thiabendazole or oral albendazole or ivermectine. Persons visiting mediterranean countries can acquire cutaneous leishmanisis that has many clinical presentations; the most typical is "bouton d'Orient", which manifests as painless ulceration resistant to antibiotic treatment. Treatment with intralesionel pentavalent antimony or pentamidine injection are effective. Lyme disease is an endemic infection in certain areas of North America and Europe, caused by the spirochete borrelia and transmitted through tick bite. It manifest as non-itching large persistent migrant erythema. If untreated this infection may expose to chronic debilitating rheumatologic, cardiac and neurological complications. Rickettsiosis, especially boutonneuse fever, are a potentially fatal multisystemic infectious diseases transmitted through the bite of a dog tick. Diagnosis must be evoked in the presence of a brutal fever syndrome, a painless eschar and widespread eruption associate to systemic symptoms. This infection must be recognized clinically in order to begin rapidly treatment with cyclines.

Animals↗
PubMed1999

Drug rash with eosinophilia and systemic symptoms (DRESS syndrome).

A variety of different drugs has been associated with a rather distinct clinical illness characterised by skin rash, fever and single or multiple organ involvement, which starts within 8 weeks after the initiation of the therapy. There is no consensus in the denomination of this apparently distinct clinical entity so that the acronym DRESS (drug rash with eosinophilia and systemic symptoms) has been recently proposed to focus thinking on this particular and probably under-recognised subset of drug reaction. The aim of this review is to point to the new perspectives regarding the diagnosis, the physiopathology and the management of DRESS syndrome.

Disease Susceptibility↗
PubMed1998

[Phototoxic contact phytodermatitis: clinical and biological aspects].

We report the case of a 39-year-old patient, gardener, who develops, during a beautiful sunny summerday, an erythemato-bullous eruption of the forearms. The diagnosis is a Contact Phototoxic Phytodermatitis (dermite des prés, dermatitis bullosa striata) with a classical presentation. This clinical observation gives us the opportunity to remind of the clinical and biological aspects of this dermatosis, whose frequency is probably underestimated, related to an often rapidly favourable evolution.

Adult↗
PubMed1996

The influence of different food components on the in vitro availability of iron, zinc and calcium from a composed meal.

The availability of iron, zinc and calcium from a composed meal was studied by an in vitro method using equilibrium dialysis after simulated gastric digestion. Four different concentrations of four influencing factors (coffee, vitamin C, wheat bran and pectin) were added to the mixed meal and their effect on the relative index of availability was studied after elemental analysis by atomic absorption spectrometry. Apart from ascorbic acid, all other factors had a negative effect on availability of minerals and trace elements. Most pronounced effect, and for all three elements, was observed for the addition of wheat bran. Zinc was the trace element, which was most sensitive to increased spiking of food constituents.

Ascorbic Acid↗
PubMed1996

Occupational hazards for the male reproductive system.

The etiology of male infertilities is largely undetermined, and our knowledge of exogenous factors affecting the male reproductive system is still limited. In particular, the role of specific environmental and occupational factors is incompletely elucidated. Various occupational (physical and chemical) agents have been shown to affect male reproductive functions in animals, but large differences in reproductive function and/or xenobiotic handling between species limit extrapolation to humans. When available, human data are often conflicting and, except in a few instances, usually refer to broad and heterogenous occupational categories or to groups of agents (e.g., solvents). It is often difficult to elucidate the role of a single agent because occupational exposure conditions are often complex and various confounding factors related to lifestyle (smoking, alcohol, and diet) or socioeconomic state may also affect sperm quality, fertility, or pregnancy outcomes. The objective of this work is to summarize the main epidemiological and, where relevant, experimental findings pertaining to agents (physical and chemical) encountered in the occupational environment that might affect the male reproductive system (sperm count, motility and morphology, libido, and fertility) and/or related pregnancy outcomes (spontaneous abortion, stillbirth, low birth weight, and birth defects and childhood malignancy in offspring). Some methodological issues related to research on the reproductive effects of toxicants are also discussed briefly.

Anesthetics↗
PubMed1995

Early decortication for postpneumonic empyema in children. Effect on pulmonary perfusion.

Early pulmonary decortication was performed on 66 of 137 children with postpneumonic empyema, while 71 received conventional treatment. The mean age of the 66 patients with decortication was 5.5 years (range 6 months-14 years). The empyema was left-sided in 34 and right-sided in 32. Decortication was performed when lung expansion was not obtained after 10-12 days of intercostal tube drainage, antibiotic therapy (guided by sensitivity tests of pleural fluid) and pleural irrigation. Scintigraphy showed loss of pulmonary perfusion on the side of empyema to be 65% +/- SD 20 (25-98)% before decortication in the 23 tested patients. In ten of them the test was repeated after surgery and showed significant (p < 0.001) diminution of the perfusion defect, from 57 +/- 6.8 (25-84)% to 4 +/- 2.6 (0-8)%. The hospital stay was significantly (p < 0.001) shorter for the surgically treated than for the classically managed patients, viz. 19.5 +/- 4 (13-36) days vs 73.6 +/- 14 (34-110) days. Early decortication thus had beneficial effects on pulmonary perfusion and hospital stay.

Adolescent↗
PubMed1994

Determinants of benzo[a]pyrene diol epoxide adducts to albumin in workers exposed to polycyclic aromatic hydrocarbons.

The present study was undertaken among 260 subjects [133 controls and 127 persons exposed to polycyclic aromatic hydrocarbons (PAHs) from two steel foundries and a graphite electrode producing plant in order to investigate the relationship between the benzo[a]-pyrene-diol epoxide adducts to albumin (BPDE-alb) and the intensity of exposure to PAHs. Blood samples were collected from each subject and BPDE-alb adduct determination was performed using a high-pressure liquid chromatography technique with fluorescence detection. Exposure to PAHs was assessed by measuring airborne concentration of 13 PAHs including benzo[a]pyrene (BaP) using personal air sampling and 1-hydroxypyrene excretion (1-HOP) in postshift urine. Significantly higher BPDE-alb adduct levels were observed in exposed workers compared to controls but wide interindividual variation was observed between subjects with the same level of exposure. BPDE-alb adduct level was weakly but significantly associated with the airborne concentrations of total PAHs (r = 0.35, P = 0.0001) and BaP (r = 0.30, P = 0.0001), and urinary 1-HOP excretion (r = 0.29, P = 0.0001). Alcohol and dietary habits, place of residence, and renal and hepatic status were not found to influence the concentration of BPDE-alb adducts significantly. However, for the same level of exposure to BaP, smokers had a higher probability of having an elevated BPDE-alb adduct level than non-smokers.(ABSTRACT TRUNCATED AT 250 WORDS)

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1994

Determinants of benzo(a)pyrenediol epoxide adducts to haemoglobin in workers exposed to polycyclic aromatic hydrocarbons.

OBJECTIVE: The aim was to assess the determinants of benzo(a)pyrenediol epoxide adducts to haemoglobin (BaPDE-Hb) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: This was a study of the correlations between the concentrations of PAHs in air, 1-hydroxyprene in urine, and BaPDE-Hb adduct concentration in the blood in 206 men working in steel foundries and one graphite electrode producing plant, taking into consideration confounding factors such as smoking and dietary habits. RESULTS: BaPDE-Hb adduct concentration was correlated (r = 0.26; p = 0.0002) with the airborne PAH concentration and was influenced by tobacco consumption but not by dietary habits. Benzo(a)-pyrene concentration in air, 1-hydroxypyrene concentration in urine, and duration of exposure to PAHs were not associated with the adduct concentration. CONCLUSION: Although environmental exposure to PAHs was statistically associated with BaPDE-Hb adduct concentration, differences between individual subjects in the metabolism of benzo(a)pyrene probably play an important part in determining the amount of BaPDE-Hb adducts formed.

Air↗
PubMed1993

Plasminogen activator activity and fertilizing ability of human spermatozoa.

Mature spermatozoa contain a number of proteases that are supposed to contribute to their fertilizing ability. The present study was directed at plasminogen activator (PA), a protease that belongs to the group of serine proteases and converts the zymogen plasminogen to the active broad-spectrum protease plasmin. To investigate the possible role of PA in the fertilization process, we have measured sperm-bound PA activity in 63 patients included in an in-vitro fertilization (IVF) programme and assessed their relationship to standard semen parameters and the rate of fertilization. PA activity was correlated significantly with the sperm count, as well as with sperm motility and morphology. Using logistic regression analysis, specific PA (pmol pNA 10(-6) cells min-2) was found to significantly influence the probability of fertilization. Other significantly predictive factors were motility and the percentage of spermatozoa with normal morphology. The sperm concentration (10(6) cells ml-1) did not significantly affect the outcome of IVF. We suggest that sperm-bound PA is involved in the fertilization process and may represent a potential indicator of sperm fertilizing capacity.

Female↗
PubMed1990

Separation of the DNA molecules beyond conventional size limits by gel electrophoresis with sodium dodecyl sulfate.

Electrophoretic mobility of DNA through polyacrylamide as well as agarose gels is greatly increased by sodium dodecyl sulfate (SDS). DNA molecules well beyond the conventionally separable size limits are separated readily and rapidly by gel electrophoresis with SDS in a conventional static electric field. Furthermore in optimal concentration gels DNA molecules of similar molecular sizes are separated better from one another in the presence of SDS than without it. Evidence is presented that SDS may act at least in part by altering conformation of DNA. This simple and readily available means for high resolution separation of hitherto impossible sizes of DNA molecules in polyacrylamide and agarose gels in an ordinary static electric field should find general use in molecular genetic analyses. Structural analyses of DNA-protein complexes are also facilitated by virtue of the simultaneous separation of the DNA and protein components on the same gel lane.

Chromatin↗