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Biomedical subjects

A Simon

Publications and source records attributed to A Simon.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Immunocytochemical localization of dopamine D1 receptors in the retina of mammals.

Dopamine is one of the major neurotransmitters in the retina. It is released from amacrine and interplexiform cells into both inner (IPL) and outer (OPL) plexiform layers. Several dopaminergic actions are known to occur through D1 receptors (D1R) but the precise location of these receptors has not been established. An antibody that recognizes the intracytoplasmic C-terminal of the rat D1R was used to detect D1R, immunohistochemically, in rats (Wistar and RCS), mouse, hamster, and macaque monkey retinas. The OPL was heavily stained in each species, consistent with the known actions of dopamine on horizontal cells. Three to five bands were observed in the IPL, depending on species. Three were in the a sublayer, the outermost of which was close to the amacrine cell layer, and may represent the massive dopamine input to the AII rod-amacrine cells. As observed in mice, where bipolar cells are D1-immunoreactive, the band located in sublayer 3 of the IPL may contain cone-bipolar cell terminals. A band of D1R-immunoreactivity in the b sublayer of the IPL contains ON-bipolar cell terminals and a second site of interaction between dopaminergic cells and the AII amacrine cells. This sublayer was absent from the RCS rat retina, suggesting a severe impairment of the rod-driven pathway following rod degeneration in these mutant rats. Cells in the ganglion cell layer exhibited relatively heavy staining, and may be ganglion cells or displaced amacrine cells. Some extrasynaptic localizations of D1R in the retina are suggested.

Animals↗
PubMedDate not supplied

[Surveillance of nosocomial infections: prospective study in a pediatric intensive care unit. Background, patients and methods].

UNLABELLED: BACKGROUND, PATIENTS AND METHODS: From November 1997 through May 1998, the incidence of nosocomial infections was studied prospectively in a 10-bed multidisciplinary pediatric intensive care unit in Germany. A standardized surveillance [SEKI] system based on the National Nosocomial Infection Surveillance [NNIS] System of the Centers for Disease Control and Prevention [CDC] was used. The CDC definitions for nosocomial infections were adapted to the current practice of pediatric intensive care in Germany. Infection rates were calculated as infections per 100 patients, per 1000 patient-days, and per 1000 device-days (central venous catheters, urinary-catheters, and mechanical ventilation). RESULTS: Fifteen nosocomial infections were recorded in 201 patients during 1035 patient-days. The overall nosocomial infection rates were 7.5/100 patients and 14.5/1000 patient-days. Device-associated nosocomial infection rates for urinary-catheters and mechanical ventilation were 7.2/1000 utilization-days and thus below the 75th percentile of the last NNIS report. Central line infection rates were 10.7/1000 utilization days and therefore above the 75th percentile of the NNIS data (10.2/1000). The median length-of-stay was 5.1 days. CONCLUSIONS: Surveillance data are indispensable for internal and external quality control, and prospective surveillance of nosocomial infections should become an essential component of hospital infection control programs in pediatric intensive care in Germany. The standardized calculation of (device utilization ratios and) device-specific infection rates yields results which can be compared with national and international surveillance data. SEKI meets the criteria of a practice oriented, prospective and standardized surveillance system. Considerable efforts for collecting and interpreting the required data should be balanced against the benefit of prevention of nosocomial infections in this population of critically ill persons.

Catheterization, Central Venous↗
PubMedDate not supplied

Characterization of digital dermatoglyphic features in Salazar Valley: comparison with other Basque valleys.

Digital dermatoglyphics of a sample from the Basque Valley of Salazar, situated in the West of the Pyrenees, were analysed. The results showed bimanual differences in both sexes, and also sexual differences for both hands. The comparative study with other Basque valleys showed that, in spite of their supposed common origin, the geographic barriers and the isolation have generated a genetic/dermatoglyphic and linguistic differentiation.

Analysis of Variance↗
PubMedDate not supplied

Enhanced constriction of the peripheral large artery in response to acute induction of a low-flow state in human hypercholesterolemia.

The diameter, blood velocity, and blood flow of the brachial artery were evaluated with a pulsed-Doppler apparatus before and after wrist occlusion in 16 normocholesterolemic and 27 hypercholesterolemic male subjects of similar age and body mass index. Before occlusion, no hemodynamic differences were observed between the two groups. Occlusion significantly reduced blood velocity and blood flow in the two groups (p less than 0.001), but such reductions were not different between hypercholesterolemic and normocholesterolemic groups. Occlusion decreased the arterial diameter in the hypercholesterolemic group only (p less than 0.001), and absolute diameter changes after occlusion were significantly different between the two groups (p less than 0.001). No correlation was found between the change in arterial diameter after occlusion and the baseline diameter before occlusion in the normocholesterolemic and hypercholesterolemic population overall. Absolute and percent diameter changes after occlusion were correlated with total cholesterol (r = -0.73, r = -0.72; p less than 0.001) and with low density lipoprotein (LDL) cholesterol (r = -0.68, r = -0.69; p less than 0.001) in the normocholesterolemic and hypercholesterolemic population overall, respectively. These findings indicate that the low-flow state induces a reduction in large-artery diameter in the hypercholesterolemic but not in the normocholesterolemic state and is closely related to the degree of elevation of blood cholesterol and of its LDL fraction.

Adult↗
PubMedDate not supplied

Pulsed Doppler: an evaluation of diameter, blood velocity and blood flow of the common carotid artery in patients with isolated unilateral stenosis of the internal carotid artery.

Arterial diameter, blood velocity and blood flow of both common carotid arteries were studied in 24 patients with isolated unilateral internal carotid artery stenosis, without any other significant lesion of the carotid system. The methodology used a pulsed Doppler system with two original characteristics: an adjustable range-gated system and a double transducer probe enabling both the arterial diameter and blood velocity to be evaluated. On the involved side, the diameter, the blood velocity and the blood flow were significantly reduced (p less than 0.001) in comparison with the opposite side. The degree of the internal carotid artery stenosis judged on arteriography was negatively correlated with (i) the blood flow of the common carotid artery homolateral to the stenosis (r = -0.78, p less than 0.001); and (ii) the ratio of the common carotid artery blood flow between the involved and the opposite side (r = -0.80, p less than 0.001). The proposed quantitative evaluation can be suitable for the detection and for the follow up of patients with stenosis of the internal carotid artery who do not have any other lesion of the carotid system.

Aged↗
PubMedDate not supplied

Lipiodol ultra-fluid: an antitumor agent-in vitro study.

Lipiodol Ultra-Fluid (LUF), a contrast medium for the diagnosis and treatment of hepatocellular carcinoma (HCC), is used by hepatic intra-arterial infusion. Hepatoma cells are capable of active uptake of LUF and retaining it for prolonged periods of time. These characteristics have important therapeutic potential for the targeting of anticancer drugs and have lead us to form an intratumoral diffuser. But, before in vivo studies, we have investigated in vitro LUF effects on various cell species in order to explain and refine the lipiodol chemotherapy. The antiproliferative and cytotoxic effects of LUF on HepG2 (human hepatoma cells), MCF-7 (human breast cancer cells) murine macrophages and human hepatocytes, were assessed by Trypan blue exclusion and lactico-dehydrogenase extracellular tests. We demonstrated the dose and time-dependent antiproliferative and cytotoxic activities of LUF on cells. Cytotoxicity was different according to cells species, whether or not they had cancerous characteristics and phagocytosis function: this cytotoxicity was very significant on macrophages and was greater for cancerous cells than for human hepatocytes in primary culture. We showed in vitro, for the first time, that LUF was an antiproliferative and cytotoxic agent, because of its active uptake and selective retention which lead to cellular death due to necrosis by lipoperoxidation increase.

Animals↗
PubMedDate not supplied

VIPoma of pancreas in a child.

An eleven-year-old girl had massive watery diarrhea. She was found to have pancreatic VIPoma. It responded favorably to surgical resection of the tumor. There was no tumor recurrence at 18 months of follow-up.

Biopsy, Needle↗
PubMedDate not supplied

[Real-time quantitative PCR for toxoplasmosis diagnosis].

Congenital toxoplasmosis results from foetus contamination by Toxoplasma gondii during pregnancy. It is a frequent and severe condition calling for close monitoring of mothers at risk. During the last decades, numerous advances have been made specially in the antenatal diagnosis. The congenital toxoplasmosis diagnosis relies currently on PCR test of amniotic fluid, with a sensitivity of 80%. More recently, real-time quantitative PCR has been developed to improve toxoplasmosis diagnosis. We therefore compared the diagnosis value of quantitative real-time PCR with our conventional PCR-hybridization for the diagnosis of congenital toxoplasmosis.

Amniotic Fluid↗
PubMedDate not supplied

Effect of etanercept and anakinra on inflammatory attacks in the hyper-IgD syndrome: introducing a vaccination provocation model.

BACKGROUND: Hyper-IgD and periodic fever syndrome (HIDS) is an hereditary autoinflammatory syndrome, characterised by recurrent inflammatory attacks. Treatment of HIDS is difficult, although simvastatin is beneficial and etanercept might be effective. Studying the treatment of a rare periodic syndrome is complicated by the varying frequency and severity of symptoms and low prevalence. Our aim was to develop a system of clinical observations to evaluate effectiveness of treatment-on-demand. METHODS: Seven fever episodes in three HIDS patients were monitored, with and without administration of etanercept or anakinra. We developed a clinical score, which includes 12 symptoms. In one patient, inflammatory attacks were provoked by vaccination. RESULTS AND CONCLUSIONS: At the onset of an attack, all patients reported a clinical score between 20 and 25. The score was used to quantify severity and define the end of an attack. Reproducible monitoring of inflammatory episodes was difficult, even in this pilot study. The effect of early administration of etanercept was variable. In one patient, a fever episode could be readily provoked within 12 to 24 hours by vaccination. In this patient, the IL-1ra analogue anakinra was more successful in aborting the inflammatory attack than etanercept. We propose that this vaccination model will allow evaluation of treatment-on-demand in a controlled setting.

Adult↗
PubMedDate not supplied

[Role of prostaglandins and the beta-adrenergic system in central and peripheral hyperkinesia in borderline hypertension].

The effects of short-term administration of indomethacin and propranolol were studied in two groups of patients with borderline hypertension and both central and peripheral hyperkinesia. Indomethacin and propranolol both significantly increased total peripheral resistance (respectively +32 +/- 3%, +59 +/- 7%, p less than 0.001). The increase in blood pressure after administrating propranolol was not significant (+3 +/- 2%), as opposed to what was obtained with indomethacin, (+5 +/- 2%, p less than 0.02). On the brachial artery, Indomethacin had no effect on blood flow and local resistance, on the other hand propranolol induced a decrease in blood flow in the brachial artery (-43 +/- 3%, p less than 0.001) and an elevation of local resistance (+105 +/- 18%, p less than 0.01). While central hyperkinesia depends on both prostaglandins and on the beta-adrenergic system, high muscle blood flow seems to be regulated by the beta-adrenergic system alone, without participation of prostaglandins.

Hemodynamics↗
PubMedDate not supplied

Second-trimester heterotopic pregnancy after in vitro fertilization and embryo transfer--a case report and review of the literature.

Seven cases of heterotopic pregnancies following in vitro fertilization (IVF) and embryo transfer (ET) have been seen. In these cases, concomitant intrauterine and extrauterine pregnancies were described in the first trimester. We present the first case of second-trimester heterotopic pregnancy after IVF with successful surgical treatment of the ectopic pregnancy and subsequent full-term birth of the intrauterine pregnancy. The etiologic factors, possible explanation for the relatively frequent occurrence of heterotopic pregnancies in IVF, and the diagnostic difficulties are presented.

Embryo Transfer↗