Gluteal femoral subcutaneous and dermal adipose tissue in female

BACKGROUND

During the sexual maturation, gluteal femoral adipose tissue is subjected to numerous modifications, not observable in other regions, in particular in women and less in men. Other authors described this region, but they used imaging techniques having lower resolution, than MRI proposed in this study. High resolution imaging techniques might provide important and more detailed information about the anatomy of gluteal femoral region.

METHODS

This study has been performed using 7 T-magnetic resonance imaging and ultrastructural analysis in order to provide accurate description of the subcutaneous adipose tissue and dermis of gluteal femoral region. In this study specimens harvested from cadavers and form living patients have been analyzed.

RESULTS

The results showed the presence of three layers: superficial, middle, and deep, characterized by different organization of fat lobules. High resolution imaging showed the adipose papilla that originates from dermis and protrude in subcutaneous adipose tissue. Adipose papilla is characterized by a peculiar morphology with a basement, a neck and a head and these elements represent the functional subunits of adipose papilla. Moreover, ultrastructural study evidenced the relationship between adipocytes and sweat glands, regulated by lipid vesicles.

CONCLUSIONS

This study provides important information about subcutaneous and dermal fat anatomy of gluteal femoral region, improving the past knowledge, and move toward a better understanding of the cellulite physiopathology.

A pilot study on the efficacy of a seaweed mud application in the treatment of cellulite

BACKGROUND

Cellulite represents a common multi-factorial condition that affects nearly all women and is now recognized as a clinical condition associated with systemic factors and negative psychological effects. Several noninvasive and minimally invasive treatments were developed during the last few years, but limited evidence supports many of them due to lack of evidence, insufficient participants, and potential adverse effects.

METHODS

This study aimed to evaluate the efficacy of a seaweed mud application in improving both the structure and function of tissues affected by cellulite. Sixty women with cellulite underwent 4-week applications of seaweed mud on the buttocks and thighs. The following assessments were performed at baseline and after the last treatment: photographic, clinical, and anthropometric evaluation; tests for elasticity and hydration; ultrasonography of cellulite nodules; and cellulite biopsies in the trochanteric region. Patient satisfaction was assessed using a 5-point Likert-scale questionnaire.

RESULTS

The treatment resulted in a significant improvement in the severity of cellulite severity between the initial assessment and the 4-week follow-up, with enhanced structure, elasticity, and hydration of the affected tissues. Microscopic analysis of the cellulite biopsies revealed a significant restoration of dermal organization with induced collagen synthesis and reduced inflammation, edema, and lipid deposition following the 4-week seaweed mud applications. Additionally, the treatment led to a remarkable improvement in comfort and satisfaction as well as a reduction in body circumferences.

CONCLUSIONS

The cosmetic application of seaweed mud has proven to be a safe, non-invasive treatment for improving the tissue alterations characteristic of cellulite.

The Biological and Molecular Action of Ozone and Its Derivatives: State-of-the-Art, Enhanced Scenarios, and Quality Insights

The ultimate objective of this review is to encourage a multi-disciplinary and integrated methodological approach that, starting from the recognition of some current uncertainties, helps to deepen the molecular bases of ozone treatment effects on human and animal well-being and to optimize their performance in terms of reproducibility of results, quality, and safety. In fact, the common therapeutic treatments are normally documented by healthcare professionals' prescriptions. The same applies to medicinal gases (whose uses are based on their pharmacological effects) that are intended for patients for treatment, diagnostic, or preventive purposes and that have been produced and inspected in accordance with good manufacturing practices and pharmacopoeia monographs. On the contrary, it is the responsibility of healthcare professionals, who thoughtfully choose to use ozone as a medicinal product, to achieve the following objectives: (i) to understand the molecular basis of the mechanism of action; (ii) to adjust the treatment according to the clinical responses obtained in accordance with the principles of precision medicine and personalized therapy; (iii) to ensure all quality standards.

Sirtuins and redox signaling interplay in neurogenesis, neurodegenerative diseases, and neural cell reprogramming

Since the discovery of Neural Stem Cells (NSCs) there are still mechanism to be clarified, such as the role of mitochondrial metabolism in the regulation of endogenous adult neurogenesis and its implication in neurodegeneration. Although stem cells require glycolysis to maintain their stemness, they can perform oxidative phosphorylation and it is becoming more and more evident that mitochondria are central players, not only for ATP production but also for neuronal differentiation's steps regulation, through their ability to handle cellular redox state, intracellular signaling, epigenetic state of the cell, as well as the gut microbiota-brain axis, upon dietary influences. In this scenario, the 8-oxoguanine DNA glycosylase (OGG1) repair system would link mitochondrial DNA integrity to the modulation of neural differentiation. On the other side, there is an increasing interest in NSCs generation, from induced pluripotent stem cells, as a clinical model for neurodegenerative diseases (NDs), although this methodology still presents several drawbacks, mainly related to the reprogramming process. Indeed, high levels of reactive oxygen species (ROS), associated with telomere shortening, genomic instability, and defective mitochondrial dynamics, lead to pluripotency limitation and reprogramming efficiency's reduction. Moreover, while a physiological or moderate ROS increase serves as a signaling mechanism, to activate differentiation and suppress self-renewal, excessive oxidative stress is a common feature of NDs and aging. This ROS-dependent regulatory effect might be modulated by newly identified ROS suppressors, including the NAD⁺-dependent deacetylase enzymes family called Sirtuins (SIRTs). Recently, the importance of subcellular localization of NAD synthesis has been coupled to different roles for NAD in chromatin stability, DNA repair, circadian rhythms, and longevity. SIRTs have been described as involved in the control of both telomere's chromatin state and expression of nuclear gene involved in the regulation of mitochondrial gene expression, as well as in several NDs and aging. SIRTs are ubiquitously expressed in the mammalian brain, where they play important roles. In this review we summarize the current knowledge on how SIRTs-dependent modulation of mitochondrial metabolism could impact on neurogenesis and neurodegeneration, focusing mainly on ROS function and their role in SIRTs-mediated cell reprogramming and telomere protection.

Pilot study of histology aspect of cellulite in seventy patients who differ in BMI and cellulite grading

BACKGROUND

Cellulite is a topographic alteration of the skin with unknown etiology and is characterized by the presence of a dimpled or puckered aspect, as resembling an orange peel and cottage cheese or as having mattress-like appearance.

AIM

The aim of this research was to find the different histological aspect of cellulite in sixty patients.

MATERIALS AND METHODS

A total of 60 women, mean age 48.8 ( ± 11.08) were included in the study. Among these, 11 women were in menopause (18.33%). All patients after physical examination, aesthetic, and dermatological evaluation were subjected to five cellulite biopsies with a 2.0 mm diameter and 1.5 mm in length in the trochanteric region affected by cellulite. The descriptive statistics were performed for each study predictors demographic age, height, bmi, waist, belly, hip thigh, and knee.

RESULTS

The histological analysis of the stained slides showed five different histological features were present in the most of patient.

CONCLUSION

In conclusion, the outcome of this study shows that the histological evidence does not characterize the different states of cellulite, but several different histological aspects were present in the same patient, which effectively eliminates staging and could consider cellulite as a degenerative disease.

Clinical evaluation of efficacy and tolerance of a skin reconditioning compound for anti-aging

Facial aging involves all facial structures located at different levels: bones soft tissues and skin with a reduction of the extracellular matrix. The aim of the study was to evaluate the efficacy of the injectable solution antiaging complex composed by non-reticulated hyaluronic acid (HA) and amino acids vitamins and antioxidants conveyed with mesotherapy technique in subjects with different expressions of aging. 114 patients with different expressions of aging were enrolled in this study with mean age (49±6). HA and amino acids vitamins and antioxidants complex solution Neofound (Love Cosmedical, Castagneto, Italy) was injected on the dermal plane or superficial subdermal plane. Among the various imperfections, fine roughness surface irregularities skin firmness brightness/discoloration cutaneous hydration were those with the greatest response to therapy. The clinical data showed that the medical device Neofound is effective and safe to treat various skin signs of chrono and photoaging thanks to its ability to protect tissues from oxidative stress and hydrate the skin.

The role of hyaluronic acid and amino acid against the aging of the human skin: A clinical and histological study

BACKGROUND

In esthetic medicine, different techniques have been used against the aging of the human skin especially in the facial area. Hyaluronic acid is used for improving the quantity of water and extracellular matrix molecule. The aim of this study is a clinical and histological evaluation of the effect of low-molecular-weight hyaluronic acid fragments mixed with amino acid (HAAM) on the rejuvenation the face skin treated with intradermal microinjections.

METHODS

Twenty women with mean age 45 range from 35 to 64 were studied, thereof 8 in menopause and 12 of childbearing age. The patients were treated with the HAAM products by mesotherapy technique; before and after 3 months of the therapeutic procedure, each patient underwent small biopsies with a circular punch biopsy.

RESULTS

The clinical results of the present study showed that the administration of the dermal filler containing fragments of hyaluronic acid between 20 and 38 monomers and amino acid via dermis injection technique produces an esthetic improvement in the faces of the treated patients, while the histological evaluation shows an increased fibroblast activity with the production of type III reticular collagen and increased number of vessels and epidermis thickness.

CONCLUSIONS

The clinical and histological assessment showed that subcutaneous HAAM infiltration has a significant impact on the dermis and clinical aspects of the face.

A New Treatment for Local Adiposity with Ascorbic Acid and Ascorbyl-Palmitate Solution: Clinical and Histological Study

Background

Localized adiposity (AL) is the accumulation of subcutaneous adipose tissue, placed in definite anatomic areas, building up an alteration of the body silhouette. The aim of the present clinical and histological study is to assess the effectiveness of an injectable solution containing sodium salt of ascorbic acid 0.24% and surfactant agent at 0.020% ascorbyl-palmitate (SAP) for treating local adiposity.

Methods

Eighty healthy female adult patients were selected, suffering from local adiposity in the abdominal region. The patients underwent a cycle of 6 sessions, with biweekly treatments, without the addition of any active ingredient. Direct infiltration of pharmacologically active SAP solutions into the adipose tissue with a long needle, very similar to the needles used for spinal anesthesia, was performed. This procedure is quick and painless (does not require any anesthesia) with moderate infiltration speed.

Results

All the patients treated showed good results with good satisfaction of the circumferential reductions. Before treatment: Waist (cm) 78.8 ± 10.6 and hip 93.6 ± 9.0 with WHR 0.84 ± 0.07. After treatment: Waist (cm) 70.8 ± 9.6 and hip 92.6 ± 8.0 with WHR 0.76 ± 0.06. Indeed, signs of adipocyte apoptosis were observed in subcutaneous skin after injection of SAP.

Conclusion

The results showed in the present study suggest that the SAP utilized induces apoptosis of adipocytes and could be of use as a safe and effective method with which to eliminate subcutaneous abdominal fat.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Vitamin D Serum Level in Elderly Patients with Alzheimer’s Disease: Preliminary Analysis from Cilento Region

Introduction:

It is estimated that 46 million people in the world live with dementia and it is estimated that this number will increase 3-fold by 2050, being a leading cause of disability worldwide and major welfare and economic problem. The aging of the general population increase these problems, especially in regions, such as Cilento (Southern Italy), where we can register higher longevity. Preserving cognitive health is one of the most important aims of the current research, also through the identification of possible preventative life-style strategies. Recent meta-analyses suggest that low serum vitamin D concentrations could be associated with Alzheimer's disease (AD) and cognitive impairment. The specific role of Vitamin D, however, is still controversial. There is a growing evidence of high rates of vitamin D deficiency in the elderly and there is still much uncertainty about the cause of AD and other forms of dementia. On the other hand, there is no definitive evidence is not conclusive and vitamin D could be involved in many other physiological and pathological mechanisms.

Objective:

Our aim is to investigate vitamin D serum levels in a small preliminary sample of AD patients from the Cilento area.

Materials and Methods:

Patients were recruited from the AD centre of the San Luca Hospital, in Vallo della Lucania (SA). We enrolled 25 consecutive patients, 13 women, and 12 men. The mean age was 78.5±8.3 years, the mean duration of the disease was 3.5±1.8 years. The average school-age of the patients was 6.1 +/- 3.5 years, the average disease age was 6.3 +/- 1.7 years, the average basal Mini-Mental Score Examination (MMSE) score was 17.6 +/- 3.6. We determined serum 25-hydroxyvitamin D (25[OH]D) in 25 consecutive AD patients.

Results:

The mean vitamin D serum level was 17.9+7.9 UI/ml, denoting a state of insufficiency. Among our 25 patients, only 3 had serum level above 30 UI/ml; most patients (17 out of 25) showed serum level among 10 and 30 UI, while in 5 patients, serum level was less than 10 UI.

Conclusion:

Our preliminary data showed that Vitamin D deficiency was, in our patients, independently associated with AD, even in a special population, high rate of centenarians, like Cilento people. However, our preliminary study has different limitations. The vitamin D deficiency has been evaluated through a single time-point of measurement (or in different periods of the year), that may be susceptible to bias. Even the differences in age and level of education should be taken into consideration. Nevertheless, these data in the Cilento region are original (there are no similar reports to our knowledge). However, our results confirm the necessity of other study, and this result is an important opportunity to introduce a modifiable risk fact and, consequently, a new treatment for AD.

Assessment of living conditions in wild boars by analysis of oxidative stress markers

This study demonstrated that it is possible to differentiate wild boars living in habitats with different animal densities by the measurement of oxidative stress markers. Therefore, reactive oxygen metabolites, the antioxidant barrier, i.e., the biological antioxidant potential and the antioxidative power (OXY-Adsorbent), as well as cortisol were measured in freely ranging wild boars. In two different areas of a State Forest in the Campania Region (Italy), 42 freely ranging, managed wild boars were captured with a corral trap, and blood samples were collected. The wild boars were divided by age (>1 year old and <1 year old) and sex (male and female). Animals in one area showed significantly higher values of oxidative stress parameters than those living in the other area. The annual boar censuses of areas highlighted a higher population density in the first area than in the second one, and this would explain the results obtained. Since the health or nutritional status of animals is reflected by oxidative stress, wild boars in areas with higher animal densities may live under worse conditions than animals in areas with lower densities which becomes evident by measuring oxidative stress markers. As cortisol in blood is only reflecting a short period, the measurement of oxidative stress level may be a better indicator to evaluate the living conditions of wild boars.

Molecular changes in glaucomatous trabecular meshwork. Correlations with retinal ganglion cell death and novel strategies for neuroprotection

Glaucoma is a chronic neurodegenerative disease characterized by retinal ganglion cell loss. Although significant advances in ophthalmologic knowledge and practice have been made, some glaucoma mechanisms are not yet understood, therefore, up to now there is no effective treatment able to ensure healing. Indeed, either pharmacological or surgical approaches to this disease aim in lowering intraocular pressure, which is considered the only modifiable risk factor. However, it is well known that several factors and metabolites are equally (if not more) involved in glaucoma. Oxidative stress, for instance, plays a pivotal role in both glaucoma onset and progression because it is responsible for the trabecular meshwork cell damage and, consequently, for intraocular pressure increase as well as for glaucomatous damage cascade. This review at first shows accurately the molecular-derived dysfunctions in antioxidant system and in mitochondria homeostasis which due to both oxidative stress and aging, lead to a chronic inflammation state, the trabecular meshwork damage as well as the glaucoma neurodegeneration. Therefore, the main molecular events triggered by oxidative stress up to the proapoptotic signals that promote the ganglion cell death have been highlighted. The second part of this review, instead, describes some of neuroprotective agents such as polyphenols or polyunsaturated fatty acids as possible therapeutic source against the propagation of glaucomatous damage.

Effects of mode of delivery on pro-oxidant/antioxidant balance in fetal circulation

Objective: This study was undertaken to assess the influence of mode of delivery on the balance between pro-oxidant/antioxidant systems in fetal circulation. Materials and methods: Both umbilical arterial and venous blood samples were obtained from 37 pregnant women who delivered by spontaneous vaginal delivery (VD group) and from 29 pregnant women who delivered by elective cesarean section (CS group). Oxidative stress and antioxidant activity were evaluated by reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP), respectively. Results: The d-ROMs values of the VD group were higher than that of the CS group in both umbilical arterial and venous blood and these differences were found to be statistically significant (p < .01 and p < .01, respectively). The BAP values of only the umbilical arterial blood were found to be statistically significant (p < .01), with values from the VD group being higher than those of the CS group. In all measurements, the d-ROMs values averaged below 120 CARR U and BAP values averaged above 2200 µmol/L. The ratio of BAP/d-ROMs difference was found to be statistically significant (p < .01) only in the umbilical venous blood, with ratios in the VD group being lower than those in the CS group. Conclusions: Our statistical analyses suggest that vaginal delivery has an effect on increasing oxidative stress as a result of the stress of labor and that an elective cesarean section does not impair the mother's oxidative stress status. Furthermore, the high BAP values in all the measurements suggest that neonates just after birth have the ability to cope with oxidative stress. Rationale   In many studies, the diversity of views on the influence of mode of delivery on the redox status of neonates is likely to be caused by the use of different biomarkers to measure either the oxidative stress, the antioxidant activity, or both. Furthermore, incomplete explanation for sampling cord blood in these studies, either arterial, venous blood or both, complicates matters. To solve the above, this study was designed to assess the effects of mode of delivery on both pro-oxidants, via d-ROMs, and antioxidants, via BAP, in both umbilical arterial and venous blood samples obtained just after birth. There are no existing studies of BAP in both umbilical arterial and venous blood to which we can refer. In conclusion, our study suggests that the pro-oxidant/antioxidant balance in neonates just after birth is better than may be expected when compared to the potentials of adults (including pregnant mothers) according to interpretations of BAP/d-ROMs. This can be understood that neonates may have already been endowed with the ability to cope with oxidative stress, as informed by high BAP values in both umbilical arterial and venous blood. Vaginal delivery may have an effect on increasing oxidative stress as a result of the stress of labors (as measured by d-ROMs), and an elective cesarean section, which has better BAP/d-ROMs in umbilical venous blood than that of vaginal delivery, may not impair the mother's oxidative stress status.

Oxidative stress in chronic lymphocytic leukemia: still a matter of debate

There is a large body of evidence showing a strong correlation between carcinogenesis of several types of human tumors, including chronic lymphocytic leukemia (CLL), and oxidative stress (OS). The mechanisms by which OS may promote cancer pathogenesis have not been completely deciphered yet and, in CLL, as in other neoplasms, whether OS is a primary cause or simply a downstream effect of the disease is still an open question. It has been demonstrated that, in CLL, OS concomitantly results from increased reactive oxygen species (ROS) production, mainly ascribable to CLL cells mitochondrial activity, and impaired antioxidant defenses. Interestingly, OS evaluation in CLL patients, at diagnosis, seems to have a prognostic significance, thus getting new insights in the biological comprehension of the disease with potential therapeutic implications.

Prognostic relevance of oxidative stress measurement in chronic lymphocytic leukaemia

OBJECTIVE

To evaluate the prognostic significance of oxidative stress (OS) and antioxidant defence status measurement in patients with chronic lymphocytic leukaemia (CLL).

METHODS

d-ROMs test and BAP test were evaluated at diagnosis of 165 patients with CLL and correlated with clinical-biological features and prognosis.

RESULTS

An increased oxidative damage (d-ROMs test) and a reduced antioxidant potential (BAP test) were found in CLL patients than normal controls (P<.0001). CLL patients with higher d-ROMs values had higher number of circulating white blood cells and lymphocytes, and higher values of β₂ -microglobulin. Higher d-ROMs values were found in female (P=.0003), in patients with unmutated IgVH (P=.04), unfavourable cytogenetics (P=.002) and more advanced clinical stage (P=.002). Higher BAP test values were found in patients expressing CD49d (P=.01) and with more advanced clinical stage (P=.004). At a median follow-up of 48 months, CLL patients with d-ROMs ≥418 CARR U were found to have a shorter time to first treatment (TFT) (P=.0002), and a reduced survival (P=.006) than others. CLL patients with BAP test values ≥2155 μmol/L had a shorter TFT (P=.008) and a shorter survival (P=.003).

CONCLUSIONS

OS can affect CLL patients by concomitantly increasing reactive oxygen metabolites production and decreasing antioxidant defences.

Analytical performances of d-ROMs test and BAP test in canine plasma. Definition of the normal range in healthy Labrador dogs

An high level of ROS (Reactive Oxygen Species), due to an increased production of oxidant species and/or a decreased efficacy of antioxidant system, can lead to oxidative stress, an emerging health risk factor involved in the aging and in many diseases, including inflammatory, infectious and degenerative disorders, either in humans or in animals. In the last years some assays panels have been developed to globally evaluate the oxidative balance by means of the concomitant assessment of ROS production and antioxidant system capability. In this report, the validation trials of d-ROMs (Reactive Oxygen Metabolites- derived compounds) and BAP (Biological Antioxidant Potential) tests in canine specie are described and also the specific referral ranges are calculated in a Labrador population. The results of linearity, precision and accuracy trials show that both tests exhibit good to excellent analytical performances. The possibility of measuring oxidative stress in vivo with simple, cheap and accurate tests, d-ROMs test and BAP test, provides for the veterinarians a very suitable tool to monitor oxidative stress and to correctly choice of eventual antioxidant supplementations in diseases proven related to oxidative stress in animals and particularly in dogs. Further studies will be useful to confirm this possibility.

Lycopene in association with alpha-tocopherol or tomato lipophilic extracts enhances acyl-platelet-activating factor biosynthesis in endothelial cells during oxidative stress

Lipophilic compounds contained in tomato can prevent cardiovascular diseases by modulating the atherogenic processes in vascular endothelium mediated by oxidized low-density lipoproteins (LDLs). We investigated the effects of lycopene on the metabolism of platelet-activating factor (PAF) and its much less biologically active acyl analog, acyl-PAF, known to prevent LDL oxidation. Lycopene, or lycopene in association with alpha-tocopherol, or whole tomato lipophilic extracts (containing more than 80% lycopene) were used in experiments in which endothelial cells (ECs) are known to synthesize PAF following H(2)O(2)-induced oxidative stress. The results indicated that in each case H(2)O(2)-stimulated PAF biosynthesis in ECs, which is catalyzed by acetyl-CoA acetyltransferase (AT), appeared strongly inhibited. However, acyl-PAF biosynthesis, which also occurs through the PAF-dependent transacetylase (TA), was significantly increased by lycopene only when it was in association with alpha-tocopherol or with the minor compounds present in the whole lipophilic tomato extract. These findings suggest that alpha-tocopherol or lipophilic compounds present in tomato juice potentiate the effects of lycopene on the modulation of PAF and acyl-PAF biosynthesis in ECs during oxidative stress.

Simultaneous determination of lysophospholipids by high-performance liquid chromatography with fluorescence detection

A high-performance liquid chromatography (HPLC) procedure for the separation of choline lysophospholipids including 1-acyl-lysophosphatidylcholines and 1-O-alkyl-lysophosphatidyl- cholines, like the lysoform of the platelet activating factor (2-lysoPAF), is described. The lysophospholipids are derivatized at the sn-2 position of the hydroxyl group by 7-diethylaminocoumarin-3-carbonylazide, which converts them into the corresponding carbamoyl derivatives. The derivatized compounds were well separated by reversed-phase HPLC and quantified by fluorimetric detection. This method shows a high sensitivity and allows the separation and quantification of mixtures of lysophospholipids at picomolar level. The method was applied to assay enzyme activities, like phospholipase A2 and PAF-acetylhydrolase, on single phospholipids or their mixtures.

Measurement of platelet-activating factor acetylhydrolase activity by quantitative high-performance liquid chromatography determination of coumarin-derivatized 1-O-alkyl-2-sn-lysoglyceryl-3-phosphorylcholine

A sensitive method for determining platelet-activating factor acetylhydrolase (PAF-AH) activity in human serum, using high-performance liquid chromatography (HPLC) with a fluorimetric detection, is described. The method is based on the derivatization with 7-diethylaminocoumarin-3-carbonylazide of the 2-lyso-PAF, by-product of PAF-AH activity, extracted from the reaction mixture by phase partition into organic solvents. After 3 h of derivatization, the fluorescent derivatives were analyzed by HPLC on a reversed-phase column. The mobile phase was made up with a gradient between head solvent, composed of methanol:water (80:20, v/v) containing 0.25 g/liter choline chloride, and chloroform. Fluorescence detection was at excitation wavelength of 400 nm and at emission wavelength of 480 nm. The described chromatographic procedure is able to resolve and simultaneously quantitate the fluorescent derivatives of the C:18 and C:16 2-lysoPAF. The comparison with the classical radiometric determination of PAF-AH activity demonstrates that the herein described procedure is suitable for study of enzyme kinetics and changes occurring in physiological conditions such as pregnancy.

Outer-membrane porins from gram-negative bacteria stimulate platelet-activating-factor biosynthesis by cultured human endothelial cells

Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gram-negative bacteria. The effect of porins on the biosynthesis of platelet-activating factor (PAF) by cultured human umbilical-cord-vein-derived endothelial cells (HUVEC) was investigated. The results demonstrate that porins were able to induce a dose-dependent synthesis of PAF in HUVEC. PAF, synthesized after stimulation with porins, was mainly cell associated and the synthesis peaked at 15 min, decreasing rapidly thereafter. Experiments with radiolabeled precursors demonstrated that PAF, a 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, was synthesized via the remodeling pathway involving the acetylation of 1-O-alkyl-2-lyso-sn-glyceryl-3-phosphorylcholine (2-lysoPAF) generated from 1-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase-A2 activity. The activation of phospholipase A2 in HUVEC stimulated by porins was detected by observing the mobilization of [14C]arachidonic acid. In addition, the activity of acetyl-CoA:1-alkyl-sn-glycero-3-phosphorylcholine 2-O-acetyltransferase was transiently increased in porin-stimulated HUVEC and, after incubation with [3H]CoASAc or [3H]acetate, the [3H]acetyl group was incorporated into newly synthesized PAF. Porins, by forming transmembrane channels, induced a sustained influx of extracellular 45Ca2+ into the cytosol. The activation of PAF synthesis by porins depended on this influx rather than on intracellular calcium mobilization, since PAF synthesis did not occur in the absence of extracellular Ca2+.

tRNA fluorescent labeling at 3' end inducing an aminoacyl-tRNA-like behavior

A fluorescent tRNA derivative labeled at 3'-O position of the ultimate adenosine residue by reaction, under mild conditions, of tRNA with isatoic anhydride [3,1-benzoxazine-2,4(1H)-dione] was obtained. The labeling selectivity was determined by several criteria: digestion with RNase, followed by HPLC of the digest, produces only one labeled nucleoside, identified as 3'-O-anthraniloyladenosine; the ratio of the absorbance at 260 nm to 332 nm also suggests a 1:1 molar ratio between the nucleic acid and the fluorophore; finally, the incapacity of the labeled tRNA to be charged by the specific aminoacyltransferase further demonstrates the engagement of the 3'-O position. Although the 3'-O-anthraniloyl-labeled tRNA does not seem to be functionally active, as far as the aminoacyl charging activity is concerned, surprisingly we found that it is able to form the ternary complex with elongation factor Tu (EF-Tu) and GTP with an affinity consistently higher than uncharged tRNA. From fluorescence anisotropy measurements the ternary complex dissociation constant was estimated as 73 nM for Escherichia coli and 140 nM for yeast anthraniloyl-tRNA(Phe). These results may be interpreted in terms of the particular structure of the anthraniloyl group that makes the labeled tRNA similar to an aminoacyl-tRNA.

Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells

Porins, a family of hydrophobic proteins located in the outer membrane of the cell wall of gram-negative bacteria and lipopolysaccharide (LPS), were shown to stimulate the synthesis of platelet activating factor (PAF), a phospholipid mediator of inflammation and endotoxic shock, by cultured human glomerular mesangial cells (MC). The synthesis of PAF induced by porins was rapid (peak at 20 min) and independent either from contamination by LPS or from generation of an endotoxin-induced cytokine such as tumor necrosis factor (TNF) since it was not prevented by cycloheximide, an inhibitor of protein synthesis or anti-TNF blocking antibodies. LPS also stimulated PAF synthesis by MC. However, the kinetic of PAF synthesis induced by LPS was biphasic with an early and transient peak at 10 minutes and a second and sustained peak at three to six hours. This second peak required an intact protein synthesis and was prevented by anti-TNF antibodies, suggesting the dependency on LPS-induced synthesis of TNF. Experiments with labeled precursors demonstrated that in MC, either after stimulation with porins or LPS, PAF was synthesized via the remodeling pathway that involves acetylation of 1-0-alkyl-sn-glyceryl-3-phosphorylcholine (2-lyso-PAF) generated from 1-0-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins and LPS, indeed, induced PLA2-dependent mobilization of [14C]-arachidonic acid that was inhibited by p-bromodiphenacylbromide (PBDB). PBDB, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase.(ABSTRACT TRUNCATED AT 250 WORDS)

Salmonella typhimurium porins stimulate platelet-activating factor synthesis by human polymorphonuclear neutrophils

Porins, a family of hydrophobic proteins located in the outer membrane of cell-wall of Gram-negative bacteria, were shown to stimulate the synthesis and release of platelet-activating factor (PAF), a 1-O-alkyl-2-acetyl-sn-glycerol-3-phosphorylcholine mediator of inflammation and endotoxic shock produced by polymorphonuclear neutrophils. PAF synthesis was independent either from contamination by LPS or generation of TNF. Experiments with labeled precursors demonstrated that PAF was synthesized via the remodeling pathway that involves acetylation of 1-O-alkyl-sn-glyceryl-3-phosphorylcholine generated from 1-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins, indeed, induced a sustained PLA2-dependent mobilization of [14C]arachidonic acid that was inhibited by p-bromodiphenacylbromide. p-Bromodiphenacylbromide, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase. The addition of 2-lyso-PAF restored PAF synthesis. The activity of acetyl CoA:2-lyso-PAF acetyltransferase was transiently increased in porin-stimulated PMN and the [3H]acetyl group was incorporated in the synthetized PAF after cell preincubation with [3H]acetyl CoA. The activation of PAF synthesis by porins as well as its release were dependent on extracellular Ca2+. Porins by forming trans-membrane channels determined a sustained influx of 45Ca2+ into the cytosol. As shown by inhibitors of Ca(2+)-calmodulin complexes, calmodulin mediated the Ca(2+)-dependent activation of enzymes involved in PAF synthesis.

Salmonella typhimurium porins stimulate platelet-activating factor synthesis by human polymorphonuclear neutrophils

Porins, a family of hydrophobic proteins located in the outer membrane of cell-wall of Gram-negative bacteria, were shown to stimulate the synthesis and release of platelet-activating factor (PAF), a 1-O-alkyl-2-acetyl-sn-glycerol-3-phosphorylcholine mediator of inflammation and endotoxic shock produced by polymorphonuclear neutrophils. PAF synthesis was independent either from contamination by LPS or generation of TNF. Experiments with labeled precursors demonstrated that PAF was synthesized via the remodeling pathway that involves acetylation of 1-O-alkyl-sn-glyceryl-3-phosphorylcholine generated from 1-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins, indeed, induced a sustained PLA2-dependent mobilization of [14C]arachidonic acid that was inhibited by p-bromodiphenacylbromide. p-Bromodiphenacylbromide, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase. The addition of 2-lyso-PAF restored PAF synthesis. The activity of acetyl CoA:2-lyso-PAF acetyltransferase was transiently increased in porin-stimulated PMN and the [3H]acetyl group was incorporated in the synthetized PAF after cell preincubation with [3H]acetyl CoA. The activation of PAF synthesis by porins as well as its release were dependent on extracellular Ca2+. Porins by forming trans-membrane channels determined a sustained influx of 45Ca2+ into the cytosol. As shown by inhibitors of Ca(2+)-calmodulin complexes, calmodulin mediated the Ca(2+)-dependent activation of enzymes involved in PAF synthesis.

Platelet-activating factor biosynthesis by cultured mesangial cells is modulated by proteinase inhibitors

Rat mesangial cells stimulated with calcium ionophore A23187 and phagocytosis were shown to produce platelet-activating factor (PAF), a mediator of inflammation and endotoxic shock. In the study presented here, the cultured human mesangial but not epithelial cells synthetized PAF not only in response to calcium ionophore A23187 and phagocytosis of immunoglobulin G-coated latex beads, but also after stimulation with cytokines such as tumor necrosis factor-alpha and interleukin-1 beta. PAF synthetized after stimulation with A23187 and to a lesser extent with phagocytosis was partially released. In contrast, PAF synthesized by stimulation with tumor necrosis factor-alpha and interleukin-1 beta remained cell associated. Experiments with labeled precursors demonstrated that PAF was synthetized via the remodeling pathway that involves the activation of phospholipase A2 and of an acetyl-coenzymeA:2-lyso-PAF acetyltransferase. Synthetic inhibitors of serine proteases as well as plasma alpha 1-proteinase inhibitor inhibited the activation of phospholipase A2 detected as release of (14C) arachidonic acid and the activation of acetyl-CoA:2-lyso-PAF acetyltransferase at concentrations 100-fold lower than those present in plasma. This raises the question about the ability of mesangial cells to synthetize PAF in vivo. However, the inhibitory effect of plasma alpha 1-proteinase inhibitor may be abrogated by oxidative inactivation due to a concomitant stimulation of mesangial cell respiratory burst or in zones of close contact among cells or matrix, which have been shown to exclude antiproteinases.