Placental transfer and neonatal effects of propofol in caesarean section

Rheumatoid arthritis (RA) patients are at higher risks of bacterial infection than healthy subjects. Polymorphonuclear leukocytes (PMN) are the first line of nonspecific cellular defence against these infections. We tested the hypothesis that abnormal directed migration of PMN may be one reason for the increased infection rate of RA patients. PMN migration was investigated in 68 peripheral blood samples of 15 RA patients compared with 64 samples of healthy controls in a novel whole blood in vitro membrane filter assay. The migration of PMNs from RA patients and controls was stimulated using the bacterial chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Unstimulated PMN migration of RA patients was increased compared with healthy controls as measured by the following parameters: (a) absolute number of migrant PMNs (1954+/-87 vs. 1238 +/-58 PMN/mm2), (b) percentage of PMNs migrated into the filter (total migration index, TMI) (28.6+/-0.9 vs. 24.0+/-0.8%), (c) the distance half the migrating PMNs had covered (distribution characteristic, DC) (22.6+/-1.1 vs. 16.1+/-0.6 mm) and (d) the product of TMI and DC (neutrophil migratory activity, NMA) (669.0+/-45.0 vs. 389.0+/-18.9). fMLP stimulated PMNs of RA patients showed defective migration compared to unstimulated samples as shown by (a) a reduced number of migrant PMNs (1799+/-93 PMN/mm2), (b) lower TMI (26.1+/-0.9%), (c) unremarkable altered distribution characteristic (22.9+/-0.8 mm) and (d) significant reduced migratory activity (600.0+/-30.0). Our data suggest that the high incidence of infections in RA patients may partly be caused by defective migratory activity of PMNs to bacterial chemoattractants as demonstrated by fMLP.     

Facial rehabilitation by the application of osseointegrated craniofacial implants

The prevalence of allergic disease is low in Eastern Europe for reasons that are poorly understood. Our study aimed to investigate the levels of exposure to indoor allergens and living conditions among Estonian infants in relation to sensitization. Dust samples were collected during four winter months in 1993/94 from the homes of 197 infants participating in a prospective study of sensitization. Information about living conditions was collected through a home visit and interviewing the mothers when the children were 6 weeks old. Three dust samples were collected from each home; i.e., from the infant's mattress, bedroom floor, and living-room carpet. The levels of allergens were determined by ELISA with monoclonal antibodies. The highest allergen level in a home was regarded as the peak value. The peak geometric mean values (+/-SD) of Der p 1 and Der f 1 were 0.3 (0.07-1.4) microg/g dust, of Can f 1, 0.86 (0.23-3.12) microg/g dust, and of Fel d 1, 0.1 (0.01-0.9) microg/g dust. In 12 homes (9%), the peak value of house-dust mite (HDM) allergens exceeded 2 microg/g dust, with Der p 1 as the dominating allergen. Multivariate analyses indicated that high levels of HDM allergens were more common in apartments that were on the ground floor or first floor, that were heated with stoves, and/or that had a dampness problem. The mean allergen levels at home were similar in children sensitized to HDM (n=17, 0.29 vs 0.3 microg/ g dust), dog (n=5, 0.55 vs 1.06 microg/g dust, and cat (n=18, 0.21 vs 0.09 microg/g dust) and in children who were not sensitized to these allergens. Most of the sensitized children were exposed to relatively low allergen levels at home; i.e., below 1 microg/g dust. This level was exceeded in the homes of 4/17 mite-, 5/18 cat-, and 0/5 dog-sensitized children. The similar levels of the major indoor allergens in Estonia and in Scandinavia indicate that the large differences in atopy prevalence among children and young adults in the two regions are not due to differences in allergen exposure. No allergen threshold level for sensitization was identified.     

Diagnostic and treatment implications of nasal obstruction in snoring and obstructive sleep apnea

LEARNING OBJECTIVES: The purpose of this review is to highlight fundamental aspects of obstructive sleep apnea (OSA), and to present an overview of the medical literature that pertains to the clinical interplay between various allergy-related disorders, nasal patency, and OSA. This should enable the reader to play a more proactive role in the diagnosis, management, and prevention of OSA. DATA SOURCES: Relevant reviews, texts, and articles. The MEDLINE database was used to find related literature. CONCLUSIONS: In predisposed individuals, OSA, sleep fragmentation, and the sequelae of disturbed sleep often result from nasal obstruction. Since breathing through the nose appears to be the preferred route during sleep, nasal obstruction frequently leads to nocturnal mouth breathing, snoring, and ultimately to OSA. Allergists can thus play a vital role in assessing sleep problems in their patients with allergic rhinitis and other upper respiratory disorders, in treating these problems more aggressively, and in some instances, in preventing them.     

The human capsaicin model of allodynia and hyperalgesia: sources of variability and methods for reduction

The paper deals with the hydrodynamics of artificial heart valves (AHVs) used in clinical practice. It reviews and analyzes the studies of AHV hydrodynamics, as well as the hydrodynamic beds which stimulate physiological flow through the valve. Photochronic imaging (PCI) is proposed for examination of AHV hydrodynamic characteristics under model physiological flow. The hydrodynamics of different AHVs was tested on the beds simulating blood flow through AHVs by employing PCI. PCI involved preparation of model photochronic solution that simulates blood, colour labels by using laser radiation. In the model photochronic solution, 10(-6)-10(-9)-sec laser radiation gave rise to linear colour labels whose movement was recorded by a speed camera in the flow behind the valve. The profiles of speed behind the valves, the dimensions of congestive areas, the positions of flow detachment and regurgitation flow were calculated by a speed shooting in different periods of valvular performance. PCI defined congestive areas behind the valves, the areas of closed circulations, the sizes of reversing flow areas and examined the time course of flow behind the valves as a whole. The paper is of interest for AHV designers and cardiac surgeons who apply various AHVs.     

Tumor-suppressor p53: implications for tumor development and prognosis

The p53 protein plays a central role in modulating cellular responses to cytotoxic stresses by contributing to both cell-cycle arrest and programmed cell death. Loss of p53 function during tumorigenesis can lead to inappropriate cell growth, increased cell survival, and genetic instability. p53 gene mutations occur in approximately half of all malignancies from a wide range of human tumors. In some tumor types, these p53 mutations are associated with poor prognosis and treatment failure. Based on these insights, new approaches are being developed to prevent, diagnose, and treat cancer.     

Pharmacokinetic and pharmacodynamic evaluation of the potential drug interaction between venlafaxine and ethanol

Venlafaxine is a new antidepressant with a unique mode of action. Because many patients taking antidepressant therapy may self-medicate with ethanol, this study was undertaken to assess the possible pharmacokinetic and pharmacodynamic interactions between venlafaxine and ethanol. This randomized, double-blind, placebo-controlled, two-period crossover study was conducted with 16 healthy men. Multiple doses of venlafaxine (50 mg every 8 hours) or placebo were administered for 7 days. On days 5 and 7 a single dose of 0.5 g/kg of ethanol or a placebo solution was administered in a randomized fashion. Pharmacokinetic data indicated that ethanol administration did not affect the disposition of venlafaxine or O-desmethylvenlafaxine. Similarly, venlafaxine administration did not affect the pharmacokinetic disposition of ethanol. Ethanol produced its expected effects on the eight psychometric tests administered. Venlafaxine produced small effects on the results of the Digit Symbol Substitution Test, the Divided Attention Reaction Time, and the Profile of Mood States. No pharmacodynamic interaction was detected between venlafaxine and ethanol.     

Reflection measurement during retinal laser coagulation in patients. Development of an automatically controlled dosimeter

PURPOSE: Retinal laser coagulation has limited reproducibility, because every laser exposition is unpredictably affected by pigmentation and media opacities. This can lead to complications. A feedback-controlled dosimeter would make retinal laser treatment a safer, more reproducible and faster procedure. METHOD: A reflectometer was developed that allows monitoring of the reflection of laser light during standard photocoagulation. Hundreds of coagulations in rabbit eyes and about 12,000 coagulations in patients undergoing routine laser treatment were recorded. RESULTS: The results of the first reflectance measurements in humans are presented along with extensive animal studies. A typical reflectance history was found for different lesion intensities. The degree of retinal whitening correlates with reflectance characteristics. These characteristics allow an early prediction of lesion intensity. Motion during laser exposure affects each coagulation in a fashion similar to spot size and exposure time. CONCLUSION: Reflectometry is the currently most effective means of monitoring lesion development. An automatic dosimeter for retinal photocoagulation seems feasible.     

Relaxant effect of levcromakalim in isolated human small subcutaneous arteries

The effect of levcromakalim, an ATP-sensitive K+ channel opener, on isolated subcutaneous arteries from mammary tissues obtained from female patients undergoing reconstructive breast surgery was investigated. The small arteries were preserved in the University of Wisconsin (UW) solution. The contractile responses to K+ and 9,11-dideoxy-11a,9a-epoxy-methano-prostaglandin F2 alpha (U46619) and the relexant responses to levcromakalim and to the endothelium-dependent vasodilator, methacholine, in these arteries remained fully intact after preservation in UW solution for at least 5 days. The pD2 value and maximal relaxation obtained from the concentration-response curve of levcromakalim (n = 7) were 5.78 +/- 0.23 and 81 +/- 6%, respectively. The vasodilator effect of levcromakalim was significantly antagonised by the ATP-sensitive K+ channel blocker, glibenclamide (1 and 3 microM). In conclusion, isolated human arteries contain ATP-sensitive K+ channels, which can be modulated by K+ channel openers and blockers. Subcutaneous small arteries, as used in our experiments, appear to be very suitable for pharmacological experiments.