Trichloroacetic Acid Concentration Research Articles

An assessment of the efficacy and safety of cross technique with 100% TCA in the management of ice pick acne scars

Background:Chemical reconstruction of skin scars (CROSS) is a technique using high concentrations of trichloroacetic acid (TCA) focally on atrophic acne scars to induce inflammation followed by collagenisation. This can lead to reduction in the appearance of scars and cosmetic improvement.Aims:The aim of this pilot study is to investigate the safety of the CROSS technique, using 100% TCA, for atrophic ice pick acne scars.Settings and Design:Open prospective study.Material and Methods:Twelve patients with predominant atrophic ice pick post acne scars were treated with the CROSS technique, using 100% TCA, applied with a wooden toothpick, at two weekly intervals for four sittings. Efficacy was assessed on the basis of the physician’s clinical assessment, photographic evaluation at each sitting and patient’s feedback after the fourth treatment, and at the three-month and six-month follow-up period, after the last treatment.Results:More than 70% improvement was seen in eight out of ten patients evaluated and good results (50 – 70% improvement) were observed in the remaining two patients. No significant side effects were noted. Transient hypopigmentation and hyperpigmentation was observed in one patient each. Physician’s findings were in conformity with the patient’s assessment. Three months after the last treatment, one patient noted a decrease in improvement with no further improvement even at the six-month follow-up period.Conclusion:The CROSS technique with 100% TCA is a safe, efficacious, cost-effective and minimally invasive technique for the management of ice pick acne scars that are otherwise generally difficult to treat. In few patients the improvement may not be sustained, probably due to inadequate or delayed collagenisation.

Bayesian Analysis of a Physiologically Based Pharmacokinetic Model for Perchloroethylene in Humans

Perchloroethylene (PCE) is a widely distributed pollutant in the environment, and is the primary chemical used in dry cleaning. PCE-induced liver cancer was observed in mice, and central nervous system (CNS) effects were reported in dry-cleaning workers. To support reconstruction of human PCE exposures, including the potential for CNS effects, an existing physiologically based pharmacokinetic (PBPK) model for PCE in the human (Covington et al., 2007) was modified by adding a brain compartment. A Bayesian approach, using Markov chain Monte Carlo (MCMC) analysis, was employed to re-estimate the parameters in the modified model by combining information from prior distributions for the model parameters and experimental data. Experimental data were obtained from five different human pharmacokinetic studies of PCE inhalation exposures ranging from 150 ppm to as low as 0.495 ppm. The data include alveolar or exhaled breath concentrations of PCE, blood concentrations of PCE and trichloroacetic acid (TCA), and urinary excretion of TCA. The PBPK model was used to predict target tissue dosimetry of PCE and its key metabolite, TCA, during and after the inhalation exposures. Posterior analysis was performed to see whether convergence criteria for each parameter were satisfied and whether the model with posterior distributions may be used to make accurate predictions of human kinetic data. With posteriors, the trend of percent of PCE metabolized in the liver at low concentrations was predicted under different exposure conditions. The 95th percentile for the fraction PCE metabolized at a concentration of 1 ppb was estimated to be 1.89%.

Dose Response and Optical Properties of Dyed Poly Vinyl Alcohol-Trichloroacetic Acid Polymeric Blends Irradiated with Gamma-Rays

Problem statement: The effects of gamma irradiation on optical properties of cresol-red dyed Poly Vinyl Alcohol (PVA) blended with Trichloroacetic Acid (TCA) for possible use in dosimetry and measurement of radiation dose in gamma rays have been studied using both Raman spectroscopy and UV-Visible spectrophotometer method. Approach: The dosimeters are composed of Poly Vinyl Alcohol (PVA), Trichloroacetic Acid (TCA) at various concentrations are 20, 25, 30 and 35%, and acid-base indicator cresol-red dyed. Results: The dosimeters were irradiated to doses up 12 kGy using 60Co gamma ray source at a constant dose rate. The polymeric films undergo color change from purple to yellow due to radiation-induced acid formation. The molecular vibrational spectra were measured using Raman spectroscopy, resulting in a decrease of the Raman intensity inelastic scattering of C-Cl molecular stretching from TCA with increasing dose. The absorption spectra were measured using UV-visible spectrophotometer in the wavelength range 350-700 nm, resulting in a decrease of the absorbance at 575 nm band peak with increasing dose. The dose sensitivity D0 increases with increasing TCA concentration for both scattering and absorption methods. The optical absorption studies show that the direct and indirect optical energy band gaps and optical activation energies are dependent on dose and TCA concentration. Conclusion: The shift in the optical band gap Eg values towards lower energy with radiation dose leads to a shift of the optical activation energy DeltaE value towards the lower energy region with increasing dose. The optical band gap (Eg) and the absorption edge decrease with increasing dose attributed to the structural disorder of polymer blends due to dehydrochlorination of trichloroacetic acid with increasing dose. The energy width of the tail of localized state in the forbidden band gap was evaluated using the Urbach-edges method. It was found that the activation energy (DeltaE) is less dependent of radiation dose but strongly dependent on concentration of blends.

Direct electrochemistry and electrocatalysis of hemoglobin on gold nanoparticle decorated carbon ionic liquid electrode

In this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM]EtOSO(3)) as modifier and further gold nanoparticles were in situ electrodeposited on the surface of CILE. The fabricated Au/CILE was used as a new platform for the immobilization of hemoglobin (Hb) with the help of a Nafion film. Electrochemical experimental results indicated that direct electron transfer of Hb was realized on the surface of Au/CILE with a pair of well-defined quasi-reversible redox peaks appeared. The formal peak potential (E(0)') was obtained as -0.210 V (vs. SCE) in pH 7.0 phosphate buffer solution (PBS), which was the characteristic of Hb heme Fe(III)/Fe(II) redox couple. The fabricated Nafion/Hb/Au/CILE showed excellent electrocatalytic activity to the reduction of trichloroacetic acid (TCA) and the reduction peak current was in proportional to TCA concentration in the range from 0.2 to 18.0 mmol/L with the detection limit as 0.16 mmol/L (S/N=3). The proposed electrode showed good stability and reproducibility, and it had the potential application as a new third-generation electrochemical biosensor.

TCAA degradation in ultraviolet (UV) irradiation/hydrogen peroxide (H2O2)/micro-aeration (MCA) combination process

The photochemical degradation of trichloroacetic acid (TCAA) employing ultraviolet (UV) irradiation/hydrogen peroxide (H 2 O 2 )/micro-aeration (MCA) combination process was investigated by varying operational parameters. Relatively slow TCAA degradation was observed during direct UV radiation and H 2 O 2 oxidation, while TCAA cannot be removed by MCA alone. UV/H 2 O 2 /MCA combination process proved to be more effective than UV/H 2 O 2 . With the initial concentration of 55.7 μg I -1 , more than 93.4% of TCAA can be removed within 180 min under UV radiation intensity of 1,048.7 μW cm -2 , H 2 0 2 dosage of 30 mg I -1 and MCA flow rate of 25 I min -1 in neutral conditions. Removal rate of TCAA was sensitive to UV radiation intensity, H 2 O 2 dose and solution pH, but appeared to be slightly influenced by initial TCAA concentration. There was a higher correlation between pseudo-first rate constant k and UV intensity and H 2 O 2 dosage, implying that higher removal capacity can be achieved by improvement of both factors. The newly found trichloroacetamide (TCAcAm), the potential TCAA, was more frangible than TCAA, indicating that TCAA hardly regenerates by hydrolysis of TCAcAm. Finally, a preliminary cost analysis revealed that the UV/H 2 O 2 /MCA process was more cost-effective than the UV/H 2 O 2 process in removal of TCAA from drinking water.

Determination hematotoxic and hepatotoxic effects of trichloroacetic acid at sublethal dosage in rats

The present study was designed to understand the effects of sublethal concentration of trichloroacetic acid (TCA) on hematological constituents [Red Blood Corpuscles (RBC) White Blood Corpuscles (WBC), Mean Cell Volume (MCV), Mean Corpuscular Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC), Platelet (PLT) counts, Hemoglobin (HB) and Hematocrite (HCT) levels] and liver damage biomarker [cholesterol (CHL), protein (PRT) and bilirubin (BIL)] in rats at subchronic period under laboratory conditions. 2000 ppm dosage of TCA was administered orally to 6 male rats ad libitum during the tests for 52 days consecutively. Results showed that TCA caused a significant increase in the serum BIL whereas decrease in PRT and CHL. With regards to hematological constituents, while RBC, MCV, MCH, MCHC, HB and HCT level decreased significantly, PLT counts increased in rats treated with 2000ppm of TCA exposure. The observations presented led us to conclude that TCA administration of subchronic at sublethal dosage induced the liver damage and possessed hematotoxic in rat. These data, along with the determined changes suggest that TCA produce substantial systemic organ toxicity in rats during the period of a 52-day subchronic exposure.

VALIDATION OF A NEW PHYTOTOXICITY TEST (PHYTOTOXKIT) AGAINST AN ESTABLISHED FOUR-WEEK GROWING TEST WITH PRE-GROWN PLANT PLUGS

The aim of the studies was to correlate results of a fast extract-based toxicity test with results of an established growing test with mostly pre-grown plants. A standard white peat was contaminated with four levels of TCA (trichloroacetic acid), a known toxic substance. A range was composed of five levels of TCA, including zero, 0.0013, 0.013, 0.13, and 1.3 g/L of peat. Part of the material was entered in Phytotoxkit containers and covered with a filter paper. At the other side of the filter paper two dicotyledonous species, garden cress (Lepidium sativum) and mustard (Sinapis alba) and one monocotyledon, Sorghum (Sorghum saccharatum) were allowed to germinate for a three day period on the extract from the substrate in a climate-controlled cabinet. The same range of amended peats was used in the standard test to grow transplanted lettuce (Lactuca sativa), Chinese cabbage (Brassica rapa subsp. pekinensis) and directly sown barley (Hordeum vulgare). For the Phytotoxkit the above ground length and root length were recorded, and for the standard test the fresh weight and dry weight of the above ground parts were recorded. Results showed a growth reduction for all levels of TCA when using the standard method. When using the Phytotoxkit only the two highest concentrations of TCA reduced growth. For screenings of product alternatives or dissolution series the Phytotoxkit is a faster and cheaper alternative

USE OF NATIVE PLANTS FOR REMEDIATION OF TRICHLOROETHYLENE: I. DECIDUOUS TREES

Phytoremediation of trichloroethylene (TCE) can be accomplished using fast-growing, deep-rooting trees. The most commonly used tree for phytoremediation of TCE has been the hybrid poplar. This study looks at native southeastern trees of the United States as alternatives to the use of hybrid poplar. The use of native trees for phytoremediation allows for simultaneous restoration of contaminated sites. A 2-mo, greenhouse-based study was conducted to determine if sycamore (Plantanus L.), eastern cottonwood (Populus deltoides), sweetgum (Liquidambar styraciflua L.), and willow (Salix sachalinensis) trees possess the ability to degrade TCE by assessing TCE metabolite formation in the plant tissue. In addition to the metabolic capabilities of each tree species, growth parameters were measured including change in height, water usage, total fresh weight of each tissue type, and calculated total leaf surface area. Willow trees had the greatest increase in height among all trees tested; however, at higher concentrations TCE inhibits growth. Sycamore trees had the highest overall leaf surface area and total biomass, which correlated with sycamore trees also having the highest average water usage over the course of the experiment. Carbon tubes used to sample transpiration gases from sycamore, sweetgum, and cottonwood trees did not contain detectable levels of TCE. Tenex sample collection tubes used to sample willow trees during TCE exposure showed average TCE concentrations of up to 0.354 ng TCE cm−2 leaf tissue. All exposed trees contained TCE in the root, stem, and leaf tissues. The concentration of TCE remaining in tissues at the conclusion of the experiment varied, with the highest levels found in the roots and the lowest levels found in the leaves. Metabolites were also observed in different tissue types of all trees tested. The highest concentrations of trichloroacetic acid were observed in the leaves of the sycamore trees and cottonwood trees. Based on the growth parameters tested and the ability to metabolize TCE, sycamore and native cottonwood species are the best candidates for phytoremediation from this study.

Fate of THMs and HAAs in low TOC surface water

A total of 30 conventional surface water treatment plants (WTPs) implementing prechlorination and postchlorination simultaneously from different regions in Korea were investigated to assess formation and removal of THMs and HAA 5. All water was low in total organic carbon (TOC) ranging from 0.74 to 6.20 mg/L with an average of 1.63 mg/L. The ranges of THMs and HAA 5 levels were 4.5–84.3 μg/L and 1.5–90.8 μg/L, respectively. THMs concentration was more sensitive to water temperature than HAA 5 and the ratio of THMs in summer over winter was 2.06. The sum of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was 97% of HAA 5. The extent of formation and speciation of DBPs varied greatly by season and geography. The concentration of DCAA and TCAA of the finished water was comparable on a yearly base, but more TCAA was noticed in summer and the opposite trend was noticed in winter. This can be caused by different biodegradability in the sand filter between DCAA and TCAA that formed through prechlorination. Investigation on the removal of preformed DBPs in the GAC filter–adsorber (FA) revealed that breakthrough of THMs and HAA 5 was noticed after 3 months of operation. However, gradual improvement (>90%) in HAA 5 removal was observed again after breakthrough, which could be attributable to biodegradation. Heterotrophic plate counts confirmed active biological activity in the GAC FA.

トリクロール酢酸による化学焼灼を施行した梨状陥凹瘻の４例

Pyriform sinus fistula is a relatively rare disease that causes recurrent neck abscess. Radical treatment for this disease involves extirpation of the fistula; however, the physical and emotional stress caused by the surgery is sometimes not well tolerated by patients, especially small children. Thus, it is important to pursue the possibility of other trearment strategies. Recently, it is suggested that chemocauterization of the internal opening of the fistula is a safe and effective mode of management of pyriform sinus fistula. We reviewed four cases (two boys and two girls, aged 5 to 7 years) with pyriform sinus fistula treated with trichloroacetic acid (TCA) chemocauterization during the period from 2002 through 2007 at Nippon Medical School. By direct endoscopy, the opening of fistula in the left pyriform sinus was easily detected. There were no intraoperative or postoperative complications. In two of the four patients, it was not necessary to incise the neck to drain the abscess as they were managed with antibiotics and chemocauterization. Oral feeding was started within the first 2 days postoperatively. Only one of the four patients had a recurrent neck abscess, which was managed by extripation of neck granulation and repeated TCA chemocauterization. Our experiences suggest that TCA chemocauterization is a relatively safe, simple and useful mode of treatment for pyriform sinus fistula especially in children. The appropriate concentration of TCA, indications for using this mode of treatment and the long term prognosis remain to be determined.

Atrophic acne scar treatment using triple combination therapy: Dot peeling, subcision and fractional laser

Atrophic scars are a common complication of acne. Many modalities are proposed but each does not yield satisfactory clinical outcomes. Thus, a new combination therapy is suggested that incorporates (i) dot peeling, the focal application and tattooing of higher trichloroacetic acid concentrations; (ii) subcision, the process by which there is separation of the acne scar from the underlying skin; and (iii) fractional laser irradiation. In this pilot study, the efficacy and safety of this method was investigated for the treatment of acne scars. Ten patients received this therapy for a year. Dot peeling and subcision were performed twice 2–3 months apart and fractional laser irradiation was performed every 3–4 weeks. Outcomes were assessed using scar severity scores and patients’ subjective ratings. Acne scarring improved in all of the patients completing this study. Acne scar severity scores decreased by a mean of 55.3%. Eighty percent of the patients felt significant or marked improvement. There were no significant complications at the treatment sites. It would appear that triple combination therapy is a safe and very effective combination treatment modality for a variety of atrophic acne scars.

CROSS technique: chemical reconstruction of skin scars method

Skin scars remain a therapeutic challenge to dermatologists. Over the past several decades, numerous surgical techniques have been used to improve the appearance of scarring. The objective of this study is to evaluate the efficacy of a local application of a (50%) concentration of trichloroacetic acid (TCA) for the treatment of atrophic acne scars (grade 3 in Goodman classification), as opposed to the higher (90%) TCA concentration used in previous studies, in order to reduce adverse local effects. The primary goal was the resolution of acne or chickenpox scars. Secondary goals were physician and subject assessments of scar improvement. Fifty percent TCA was applied locally to atrophic scars in five patients. Three patients had treated scars on the face and two patients had treated scars on the back. Wooden applicators were used to apply TCA locally and the treatment was repeated at 4-week intervals for a total of three sessions. Digital photographic analysis of lesions supported clinical observations. Histologic examination was performed only on two samples of patients with treated scars on the back. Clinical examination revealed cosmetic improvements in both depth and appearance of skin scars. We believe that the 50% TCA CROSS can be an effective technique for the treatment of atrophic scars.

Trichloroethylene Causes Generalized Hypersensitivity Skin Disorders Complicated by Hepatitis

Idiosyncratic generalized skin disorders complicated by hepatitis, which resemble severe drug hypersensitivities, occur sporadically in workers exposed to trichloroethylene (TCE) in China. However, it has been a matter of controversy whether the solvent itself, not its impurities or stabilizers, can cause hypersensitivity reactions or not. This study aimed to characterize the exposure of hospitalized patients and their healthy colleagues. TCE metabolites were measured in urine of 19 hospitalized patients suffering from the disorders. To assess the exposure of patients' healthy colleagues, on-site surveys were conducted in 6 factories where the disorders occurred and in 2 control factories without such occurrences despite TCE use. Urinalysis of the patients detected trichloroacetic acid (TCA) in all of them. Its average concentration in the end-of-shift urine was estimated to be 206 mg/l. On-site survey of healthy exposed workers revealed that the maximum urinary TCA concentrations and the maximum time-weighted average concentrations of personal TCE exposure were 318-1,617 mg/l and 164-2,330 mg/m(3), respectively. There was no common impurity in TCE used in the factories. These results suggested that TCE itself caused the skin hypersensitivity disorders, and that the disorders occurred in factories where TCE metabolites could be extensively accumulated, possibly due to long working hours. Since the lowest TCA concentration in the end-of-shift urine of the patients was estimated to be 72-80 mg/l, it is recommended to control TCE exposure to keep the urinary TCA concentration below 50 mg/l to reduce the disease risk.

Sci‐Fri PM: Planning‐07: A low diffusion radiochromic gel dosimeter for three‐dimensional radiation dosimetry

To develop a low diffusion radiochromic leuco crystal violet (LCV) hydrogel utilizing micelles, for three-dimensional (3-D) radiation dosimetry. Concentrations of LCV dye, Triton X-100 and trichloroacetic acid were varied to determine the optimal gel sensitivity for optical computed tomography (CT). Using a laser optical CT scanner at λ = 594 nm, diffusion rate measurements were performed on half-irradiated (6 MV x-rays) cuvette gel samples made with and without surfactant, respectively. A cylindrical 1 L gel volume was irradiated with a 12 MeV electron beam (Varian Clinac 2100C) to a dose of 30 Gy and scanned with cone- beam optical CT at λ ∼ 590 nm (Vista™, Modus Medical Devices Inc.). The most radiation sensitive gel formulation was found to be: 1 mM LCV, 4 mM Triton X-100, 30 mM trichloroacetic acid and 4% gelatin. The diffusion rates of a LCV gel without and with surfactant present were about 2 and 20 times lower than the Fricke xylenol-orange gel system, respectively. Comparison of the central axis gel attenuation coefficients normalized at depth of maximum dose (dmax ) with TG21-corrected ion chamber data, were in agreement, thus, indicating energy and dose-rate independence. Radiochromic LCV micelle gels show minimal diffusion effects and a dose response that is linear, energy and dose-rate independent. Optical CT scanned LCV micelle gels are a promising system for 3-D dose verification. Two of the authors (JB, KJ) have a licensing agreement with Modus Medical Devices Inc. concerning the commercialization of Vista™.

Relationships between the concentrations of trichloroacetic acid-soluble copper and caeruloplasmin in the serum of cattle from areas with different soil concentrations of molybdenum

The concentrations of trichloroacetic acid (tca)-soluble copper and caeruloplasmin were determined in 345 serum samples taken from cattle in March 1998 by eight Scottish Agricultural College veterinary disease surveillance centres...

Induction of PDGF-B in TCA-treated epidermal keratinocytes

Trichloroacetic acid (TCA) is one of the most widely used peeling agents, and induces full necrosis of the whole epidermis, followed by reconstitution of the epidermis and the matrix of the papillary dermis. The cytotoxic effects of TCA, such as suppressing proliferation of keratinocytes and fibroblasts and protein synthesis by fibroblasts, have already been reported. However, the entire biological mechanism responsible for TCA peeling has yet to be determined. Hypothetical activation effects of TCA treatment on epidermal cells to induce production of growth factors and cytokines are examined, and are compared with its cytotoxic effects in terms of time course and applied TCA concentrations. After various periods of incubation with TCA, viability of Pam212 murine keratinocytes was investigated with MTT assay and dye exclusion assay, and production of growth factors and cytokines with reverse transcription-polymerase chain reaction (RT-PCR). Changes in platelet-derived growth factor (PDGF)-B mRNA expression and protein production in the human skin specimens after TCA application were then examined by RT-PCR and immunohistochemistry, respectively. Incubation with TCA showed cytotoxicity and induced death of Pam212 cells, depending on the incubation period and the TCA concentration. In addition, expressions of PDGF-B, tumor growth factor (TGF)-alpha, TGF- beta1 and vascular endothelial growth factor, which are the growth factors reportedly secreted from keratinocytes during wound healing, were all detected in Pam212 cells after short-term treatment with TCA. Expressions of inflammatory cytokines such as interleukin (IL)-1 and IL-10 were also induced. In TCA-treated NIH-3T3 fibroblasts, in contrast, observed was upregulation of only keratinocyte growth factor, which is reportedly secreted from fibroblasts, as well as the similar cytotoxic effect. In human skin, PDGF-B mRNA expression became significantly upregulated after TCA application, and then immediately downregulated. Immunoreactive PDGF-B in the cytoplasm of keratinocytes became detectable throughout the epidermis after TCA application, reached maximum after the peak of mRNA expression, and then declined significantly over 24 h when the epidermis became completely necrotic. The TCA-treated epidermis acts as a major source of growth factors, including PDGF-B, before undergoing full necrosis. This effect might contribute to a promotion of re-epithelialization and dermal regeneration without wound contraction and scarring.

Toxicokinetics of Inhaled Trichloroethylene and Tetrachloroethylene in Humans at 1 ppm: Empirical Results and Comparisons with Previous Studies

Trichloroethylene (TRI) and tetrachloroethylene (TETRA) are solvents that have been widely used in a variety of industries, and both are widespread environmental contaminants. In order to provide a better basis for understanding their toxicokinetics at environmental exposures, seven human volunteers were exposed by inhalation to 1 ppm of TRI or TETRA for 6 h, with biological samples collected for analysis during exposure and up to 6-days postexposure. Concentrations of TRI, TETRA, free trichloroethanol (TCOH), total TCOH (free TCOH plus glucuronidated TCOH), and trichloroacetic acid (TCA) were determined in blood and urine; TRI and TETRA concentrations were measured in alveolar breath. Toxicokinetic time courses and empirical analyses of classical toxicokinetic parameters were compared with those reported in previous human volunteer studies, most of which involved exposures that were at least 10-fold higher. Qualitatively, TRI and TETRA toxicokinetics were consistent with previous human studies. Quantitatively, alveolar retention and clearance by exhalation were similar to those found previously but blood and urine data suggest a number of possible toxicokinetic differences. For TRI, data from the current study support lower apparent blood-air partition coefficients, greater apparent metabolic clearance, less TCA production, and greater glucuronidation of TCOH as compared to previous studies. For TETRA, the current data suggest TCA formation that is similar or slightly lower than that of previous studies. Variability and uncertainty in empirical estimates of total TETRA metabolism are substantial, with confidence intervals among different studies substantially overlapping. Relative contributions to observed differences from concentration-dependent toxicokinetics and interindividual and interoccasion variability remain to be determined.

Histometric and Histochemical Analysis of the Effect of Trichloroacetic Acid Concentration in the Chemical Reconstruction of Skin Scars Method

Atrophic scars can be induced by various causes, including severely inflamed acne, chicken pox, and trauma. Many treatment modalities are used for reconstructing and improving the appearance of scars with various treatment results. A recent report shows the clinical efficacy of the chemical reconstruction of skin scars (CROSS) method, which consists of the focal application of trichloroacetic acid (TCA) in a higher concentration. Histometric analysis of the CROSS method, however, has not yet been established. In this study, five hairless mice were used to evaluate the effect of the CROSS method and to analyze the difference between the CROSS method and simple TCA application. Similar histologic changes were observed in the two methods, including epidermal and dermal rejuvenation with new collagen deposition. These changes, however, were more prominent in the CROSS method-treated areas, particularly when 100% TCA was used. The results of this study suggest that treatment of atrophic scars using the CROSS method is more effective than simple application of TCA in activating fibroblasts in the dermis and increasing the amount of collagen.

Histometric and Histochemical Analysis of the Effect of Trichloroacetic Acid Concentration in the Chemical Reconstruction of Skin Scars Method

BACKGROUND Atrophic scars can be induced by various causes, including severely inflamed acne, chicken pox, and trauma. Many treatment modalities are used for reconstructing and improving the appearance of scars with various treatment results. OBJECTIVE A recent report shows the clinical efficacy of the chemical reconstruction of skin scars (CROSS) method, which consists of the focal application of trichloroacetic acid (TCA) in a higher concentration. Histometric analysis of the CROSS method, however, has not yet been established. METHODS In this study, five hairless mice were used to evaluate the effect of the CROSS method and to analyze the difference between the CROSS method and simple TCA application. RESULTS Similar histologic changes were observed in the two methods, including epidermal and dermal rejuvenation with new collagen deposition. These changes, however, were more prominent in the CROSS method–treated areas, particularly when 100% TCA was used. CONCLUSION The results of this study suggest that treatment of atrophic scars using the CROSS method is more effective than simple application of TCA in activating fibroblasts in the dermis and increasing the amount of collagen.

Screening of inhibitors of porcine dipeptidyl peptidase IV activity in aqueous extracts from marine organisms

Dipeptidyl peptidase IV (DPPIV, EC 3.4.14.5) hydrolyses biologically active peptides that control critical functions. For example, action of glucagons-like peptide I, an hormone that plays multiple roles in metabolic homeostasis and a potential agent for the treatment of type 2 diabetes mellitus is diminished by its susceptibility to DPPIV activity. The goal of this work was to the search for DPPIV inhibitory activity in the Caribbean marine fauna. The screening was done in aqueous crude extracts of species belonging to phyla Cnidaria, Mollusca, Annelida, Echinodermata, Poriphera, Chordata, Chlorophycota and Chlorophyta collected on the Northern coast of Havana (Cuba). An inhibitory activity was found in extracts of three species belonging to phyla Poriphera and Cnidaria: the sponge Xetospongia muta and the sea anemones Bunodosoma granulifera and Bartholomea annulata. The crude extracts from these species were treated with 2.5% final concentration of trichloroacetic acid (TCA) or with heat (60 °C, 10 min). Both treatments increased inhibitory activity in X. muta but failed in B. granulifera and B. annulata extracts. Preliminary characterization indicated that in each case the effect on DPPIV activity is dose-dependent, the inhibition is slow and the molecule responsible for DPPIV inhibition has a low molecular weight. The present contribution shows that the detected species are promising sources of DPPIV natural inhibitors with potential therapeutic applications