Influence of sensory neuropeptides on human cutaneous wound healing process

BACKGROUND

Close interactions exist between primary sensory neurons of the peripheral nervous system (PNS) and skin cells. The PNS may be implicated in the modulation of different skin functions as wound healing.

OBJECTIVE

Study the influence of sensory neurons in human cutaneous wound healing.

METHODS

We incubated injured human skin explants either with rat primary sensory neurons from dorsal root ganglia (DRG) or different neuropeptides (vasoactive intestinal peptide or VIP, calcitonin gene-related peptide or CGRP, substance P or SP) at various concentrations. Then we evaluated their effects on the proliferative and extracellular matrix (ECM) remodeling phases, dermal fibroblasts adhesion and differentiation into myofibroblasts.

RESULTS

Thus, DRG and all studied neuromediators increased fibroblasts and keratinocytes proliferation and act on the expression ratio between collagen type I and type III in favor of collagen I, particularly between the 3rd and 7th day of culture. Furthermore, the enzymatic activities of matrix metalloprotesases (MMP-2 and MMP-9) were increased in the first days of wound healing process. Finally, the adhesion of human dermal fibroblasts and their differentiation into myofibroblasts were promoted after incubation with neuromediators. Interestingly, the most potent concentrations for each tested molecules, were the lowest concentrations, corresponding to physiological concentrations.

CONCLUSION

Sensory neurons and their derived-neuropeptides are able to promote skin wound healing.

Lipid parameters, lipid lowering drugs and the risk of venous thromboembolism

BACKGROUND

Besides their effects on atherogenesis, lipids and lipoproteins could contribute to the development of venous thromboembolism (VTE). This association has been investigated in a few studies with conflicting results.

METHODS

Plasma levels of total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein A-I and apolipoprotein B were measured in 467 patients with a first unprovoked VTE event diagnosed between May 2000 and December 2004 and in 467 age and sex matched controls. The association between these parameters and VTE was determined in non-users of lipid lowering drugs (LLD), in statin users and in fibrate users in a quartile-based analysis. We repeated this stratified analysis within each stratum of men and women.

RESULTS

The median age of patients was 73 years [interquartile range 58-80], 41.5% were men. Among the 934 patients of the study, 100 were treated with statin, 91 with fibrate and 743 were not receiving LLD. Among non users of LLD, high levels of apolipoprotein B were associated with VTE (OR 1.82, 95% CI 1.19-2.79) after adjustment for age and body mass index. Elevated LDL-cholesterol levels were associated with VTE only in men (OR 2.32, 95% CI 1.07-5.01). High levels of LDL/HDL-cholesterol and apolipoprotein B/apolipoprotein A-I ratios were associated with VTE (OR 2.76, 95% CI 1.69-4.50 and OR 1.86, 95% CI 1.16-2.97 respectively) but this effect was mainly observed in men. There was no association between lipid parameters and VTE in statin users and in fibrate users.

CONCLUSION

Our results are in line with the new concept of a global cardiovascular disease combining atherosclerosis and VTE.

The reproducibility of Stewart parameters for acid-base diagnosis using two central laboratory analyzers

BACKGROUND

Acid-base derangements can be interpreted using the Stewart-Fencl approach, which includes calculation of the apparent strong ion difference (SID(app)), the effective SID (SID(eff)), and the strong ion gap (SIG). These calculations require the measurement of several variables. We hypothesized that the SID and SIG calculated by different analyzers would not be reproducible because of variability in the measured values.

METHODS

In this prospective observational study conducted in a biochemistry laboratory, we analyzed 179 routine blood samples from consecutive patients over a 3-mo period using two automated blood chemistry analyzers, the LX20 (Beckman) and the Modular (Roche). Measured and calculated parameters from the two analyzers were compared.

RESULTS

Although the correlation between measured values was satisfactory, there were large differences in the limits of agreement for calculated values (SID(app): 9.6 mEq/L, SID(eff): 6.4 mEq/L, and SIG: 11.7 mEq/L) and a weak correlation (SID(app): r(2) = 0.54 and SIG: r(2) = 0.12) between the analyzers.

CONCLUSIONS

The results of the Stewart-Fencl approach for interpretation of acid-base status can vary according to the analyzer used. These differences may have important clinical and research implications..

Acute renal dysfunction after cardiac surgery with cardiopulmonary bypass is associated with plasmatic IL6 increase

BACKGROUND

Acute renal dysfunction (ARD) is common after cardiac surgery with cardiopulmonary bypass (CPB). CPB results in a sudden systemic inflammatory response. Systemic and local pro-inflammatory cytokines synthesis has been linked with sub-clinical renal injury, especially tubular lesions. Therefore, we sought to assess the systemic synthesis pro-inflammatory cytokines and its association with perioperative ARD after cardiac surgery with CPB.

METHODS

Sixty-two patients undergoing cardiac surgery with CPB were prospectively included. Four groups of patients were defined according to blood creatinine increase: no ARD (less than 25% increase), faint ARD (25-50% increase), moderate ARD (50-100% increase), severe ARD (more than 100% increase).

RESULTS

Within the 48 post-operative hours was ARD observed as no dysfunction (41.9%), faint (32.2%), moderate (16.1%), severe (9.6%). One patient had to undergo a dialysis. Pre-operative characteristics were homogenous between the four groups excepted the left ventricle ejection fraction. ARD was associated with a low urinary output with high sodium excretion fraction. Significant increase of IL-6 level occurred when patients underwent a severe ARD despite no significant differences for the CRP and TNF-alpha concentrations.

CONCLUSION

Severe acute renal dysfunction after cardiac surgery with CPB is associated with a significant increased IL-6 systemic production.

Topical imiquimod treatment of lentigo maligna: Clinical and histologic evaluation

We have treated extensive lentigo maligna in two elderly patients with Imiquimod 5% (Aldara). It was applied 3 times weekly, for 3 to 5 months. Clinical and histological remission was observed over 13 months of follow-up care. Tolerance was good. We suggest that topical imiquimod could be an interesting therapeutic alternative.

Is age-related macular degeneration associated with serum lipoprotein and lipoparticle levels?

OBJECTIVE

The etiology of age-related macular degeneration (ARMD) is poorly understood. Risk factors for cardiovascular disease have been thought to be associated with ARMD. Our purpose was to measure the concentration of atherogenic apolipoproteins (apo) and lipoparticles in serum from ARMD patients.

METHODS

We analyzed lipids, lipoparticles and apolipoproteins concentrations in 84 unrelated patients with ARMD and compared the results with those of age- and sex-matched control subjects (n=62). Serum lipid concentrations were determined enzymatically; apolipoproteins levels by kinetic nephelometry and lipoparticles by electroimmunodiffusion.

RESULTS

No difference in total cholesterol, triglycerides, phospholipids, high- and low-density lipoprotein-cholesterol (lHDL-C and LDL-C) concentrations were observed between ARMD patients and controls. Apo E and LpE non-B concentrations were found to be higher in serum from patients than in serum from controls. In contrast, Apo C-III and LpC-III non-B concentrations were lower in serum from patients than in serum from controls.

CONCLUSIONS

The main differences observed between ARMD patients and controls are in Apo E, Apo C-III, LpC-III non-B and LpE non-B concentrations. These lipoparticles belong to the HDL family, which is considered to consist of anti-atherogenic lipoproteins. These results raise the possibility that cardiovascular risk factors are not associated with ARMD. Furthermore, we can hypothesize that ARMD development is linked to perturbations of HDL metabolism.

[Epidemiologic study of urinary calculi in Western France]

OBJECTIVES

An epidemiologic study of urinary calculi (N = 1843) was conducted in Western France: distribution according to the main chemical compounds, age and sex. Comparison with the results of a study with national recruitment (N = 10,617) and a study with regional recruitment (N = 1774).

METHOD

The study involved 1843 stones characterized beforehand by morphological analysis associated with infra-red spectrophotometry (FTIR). If analysis of the composition of the stones was carried out on the totality of calculi, studies related to age and sex included only 1583 cases. Comparison of percentages was made using chi 2 test.

RESULTS

The composition in main compounds of calculi was comparable with the results of other studies; minor significant compounds presented great differences, raising the problem of interpretation of the infra-red spectra of the latter. Hence, our work was directed towards the analysis of the major compounds and we showed, like most authors, that monohydrate calcium oxalate is predominant in male (46%) as well as in females (37%). Calculi average sex-ratio was 2.19 but dehydrated calcium oxalate sex-ratio was 4.42, suggesting that this compound is found mainly in men. Conversely, for the majority of phosphate stones, the sex-ratio was lower or equal to one, indicating that they predominate in women. Infectious calculi (particularly struvite calculi) appeared slightly more frequent in our population than in other studies, whereas the number of uric acid calculi was lower. This, however, remains to be confirmed.

CONCLUSION

The population studied was not significantly different from the national population regarding lithiasis, except perhaps for uric acid and struvite calculi, despite specific regional differences in diet and the role of nutritional factors in lithogenesis.

Ontogeny of steroid metabolizing enzymes in rat oligodendrocytes

Rat oligodendroglial cells were isolated from newborn and developing brains and used immediately after, for quantification of steroid metabolizing activities. Oligodendrocytes (Ol) and their progenitor cells were incubated with [(14)C] testosterone, [(14)C] progesterone, [(14)C] pregnenolone or [(14)C] dehydroepiandrosterone (DHEA). Oligodendrocytes and their progenitor cells expressed different steroid metabolizing enzymes. The main activities were 5 alpha reduction of testosterone and progesterone and 3 beta hydroxy steroid dehydrogenase-isomerase which transformed pregnenolone into progesterone and DHEA into Delta 4 androstenedione. 5 alpha reductase activity increased in male and female rats in parallel with testosterone or progesterone. Contrary to this, 3 beta hydroxysteroid dehydrogenase-isomerase activity was found to be high in the young rat and to decrease when testosterone and progesterone plasma concentration increased.

Expression of alpha and beta thyroid receptors during oligodendrocyte differentiation

To determine which thyroid receptor (TR) isoforms are expressed during oligodendrocyte differentiation, we studied the expression of the mRNAs encoding two alpha (alpha 1 and alpha 2) and one beta (beta 1) TR isoforms in a bipotential oligodendrocyte-type 2-astrocyte (O-2A) progenitor cell line (CG-4) as well as in rat O-2A progenitor cells and oligodendrocytes. O-2A progenitor cells expressed only TR alpha-mRNAs, whereas oligodendrocytes and type 2-astrocytes also expressed TR beta 1-mRNAs. The differential expression of alpha 1 and beta 1 TRs suggests specific functions for both types of TRs during oligodendrocyte differentiation. We present evidence for a possible role of TR alpha 1 in the effect of thyroid hormones on the proliferation of CG-4 cells maintained as progenitor cells.

Characterization and solubilization of testosterone 17 beta-hydroxysteroid dehydrogenase in human hyperplastic prostate

17 beta-Hydroxysteroid dehydrogenase is a membrane-bound enzyme in human prostate. Solubilization of this enzyme can only be obtained in the presence of detergents. The optimal solubilization mixture contained 50 mM Tris-HCl buffer pH 9.0, 20% glycerol, 0.1 M KCl and 5 mg/ml of the non-ionic detergent N-octyl glucoside. In these conditions, the soluble fraction contained more than 90% of the enzymatic activity. A 2.5-fold increase of specific activity was obtained during solubilization under optimal conditions.

[Value of omeprazole in the treatment of collagenous colitis]

The authors report the case of a patient suffering from collagen colitis in whom the administration of omeprazole achieved the rapid and total abolition of the clinical signs and a significant reduction of the collagen band (measurements determined over 10 cryptic spaces using a graduated micrometric ocular microscope). Although the outcome of this disorder is variable, with the possibility of spontaneous recovery or, more frequently, of remission, the authors consider, in their conclusions, that omeprazole may have a beneficial effect in this disorder even though the mechanism for this has not been established.

Metabolism of androgens in human hyperplastic prostate: evidence for a differential localization of the enzymes involved in the metabolism

The subcellular distribution of 5 alpha-reductase, 17 beta-hydroxy steroid dehydrogenase, 3 alpha- and 3 beta-hydroxysteroid dehydrogenase activities was studied in human hyperplastic prostate. 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase activities are located in the nuclear envelope. 3 alpha-hydroxysteroid dehydrogenase activity was almost equally distributed between cytosol and membranes, 3 beta-hydroxysteroid dehydrogenase activity was linked to all membranes. Direct testosterone metabolism (transformation into its active metabolite 5 alpha-DHT and into androstenedione, an inactive androgen) takes place only in the nucleus whereas indirect metabolism takes place mainly in the cytoplasm. These findings add new evidence for the mechanism of action of testosterone in prostatic tissue. Testosterone diffuses into the cell, migrates toward the nucleus and is transformed at the nuclear envelope level into two metabolites, DHT and androstenedione. After transformation into its active form, the hormone enters the nucleus whereas the inactive form is released into the cytoplasm. This metabolism could be seen as a control of the amount of active hormone entering the nucleus and being able to bind the androgen receptor.