Histological Changes In Skin Research Articles

Activation of ER Stress and Autophagy Induced by TDP-43 A315T as Pathogenic Mechanism and the Corresponding Histological Changes in Skin as Potential Biomarker for ALS with the Mutation.

TAR DNA binding protein 43 (TDP-43) A315T mutation (TDP-43A315T) has been found in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) as a disease causing mutation with enhanced protein aggregation, formation of protease-resistant fragments, and neurotoxicity. However, the molecular mechanisms for its pathogenic effects are largely unknown. In this study, we demonstrate that TDP-43A315T enhanced neuronal toxicity via activating endoplasmic reticulum (ER) stress-mediated apoptosis in SH-SY5Y cells. Moreover, autophagy was activated by overexpression of TDP-43A315T in a self-defensive manner to decrease neuronal toxicity. Inhibition of autophagy attenuates TDP-43A315T induced neuronal cell death. Furthermore, the expression levels of TDP-43, ER chaperone 78 kDa glucose-regulated protein (GRP-78), and autophagy marker microtubule-associated protein 1A/1B-light chain 3 (LC3) in the skin tissues from ALS patients with TDP-43A315T mutation were markedly higher than those from the healthy control. Thus, our findings provide new molecular evidence for TDP-43A315T neuropathology. In addition, the pathological change in the skin tissues of the patients with TDP-43A315T mutation can be used as a quick diagnostic biomarker.

TRASER: acute phase vascular and follicular changes.

A TRASER (Total Reflection Amplification of Spontaneous Emission of Radiation) is a novel device that utilizes the energy from a flashlamp to induce the spontaneous emission of photons from a fluorescent medium. This study was designed to observe clinical and histological changes of skin treated with two different fluorescent media selected for their peak emissions tuned for vascular and hair follicle targets. A purpuric clinical response for the vascular target was assessed with a TRASER using the fluorescent medium Pyrromethene 556 producing a narrow spectrum peaking at 544 nm. Using a 12 mm spot and pulse duration of 1 ms, treatment pulses with fluences of 6.0-9.5 J/cm2 were given along the forearm of subject with photo type II skin. Follicular structures were targeted with the dye cell switched to Sulforhodamine 640 Chloride, producing a narrow peak at 654 nm. Using a 12 mm spot, single 20 ms pulses with fluencies from 14.0 to 20.0 J/cm2 were delivered with 5 °C contact cooling to the shaved chest of a subject with photo type II skin with brown hair. Clinical observations were photographed and assessed by two physicians. A 4 mm punch skin biopsy was taken at approximately 60 and 30 minutes respectively for both the vascular and hair regions. The paraffin embedded H&E stained vertical sections were analyzed by a dermatopathologist. A characteristic threshold purpuric response was noted at 7.2 J/cm2 . The histological changes consistently showed intravascular thrombosis of the small sub-dermal plexus of capillaries down to larger vessels approaching the subcutaneous fat. There were no extravasated red blood cells. Clinical hair follicle target changes of perifollicular edema and transient erythema, similar to those described with standard hair removal lasers, were noted. Histologically these were shown to be limited to the target structures. This is the first demonstration of clinical and histological acute phase changes associated with use of a TRASER with wavelengths optimized for vascular and follicular targets. The findings of this observational study support the notion that the TRASER can be used as an effective vascular and hair removal device.

Postmortem Autolytic Changes in Oral Mucosa: Histological Review

Following death various changes occur in the human body known as postmortem changes. These postmortem changes begin at molecular level which can be noted microscopically and finally grossly. Postmortem interval (PMI) is the time elapsed since death. Estimation of time since death is still a difficult task even for an experienced forensic pathologist. Gross changes within human body which occur following death during the postmortem interval have been routinely used to estimate the time of death considering different conditions. However, histological changes of skin and oral mucosa which occur during the postmortem interval have occasionally been used to estimate the time of death under different conditions.

20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol-fortified ginseng extract attenuates the development of atopic dermatitis-like symptoms in NC/Nga mice

Ethnopharmacological relevanceGinseng and ginsenosides are frequently used in the treatment of chronic inflammatory diseases. Recently, 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol (GPD), the main metabolite of ginsenosides, was reported to have both anti-allergic and anti-pruritic effects. The immunomodulatory effects of GPD-fortified ginseng extract (GFGE) on atopic dermatitis (AD)-like symptoms in mice were investigated. This study was designed to investigate the preventive effect of GFGE on AD-like symptoms. Materials and methodsThe effects of orally administered GFGE on Dermatophagoides farinae body extract (DFE)-induced AD-like symptoms in NC/Nga mice were assessed by analyzing dermatitis score, ear thickness, scratching time, skin histological changes, and serum level of macrophage-derived chemokine (MDC). In addition, splenocytes were isolated from the mice and stimulated with anti-CD3 and anti-CD28 monoclonal antibodies to produce cytokines. ResultsOral administration of GFGE significantly attenuated DFE-induced increases in dermatitis score, ear thickness, scratching time, and severity of skin lesions in NC/Nga mice. GFGE treatment also reduced level of MDC in serum, infiltration of eosinophils and mast cells in skin, and production of cytokines in splenocytes. ConclusionsThese results suggest that GFGE might ameliorate DFE-induced AD-like symptoms and be an alternative therapeutic agent for the prevention of AD.

SKIN CHANGES AND PECULIARITIES IN PATIENTS WITH METABOLIC SYNDROME

Approximately 20-25 % of the World’s adult population aged 40 - 75 years have metabolic syndrome (MS). MS is one of the most widespread risk factors for: diabetes mellitus, cardiovascular disorders and skin disorders MS, due to the oxidative stress, supports a chronic inflammatory reaction in the skin and in the other parts of the body. During oxidative stress the net amount of reactive oxygen species (ROS) exceeds the antioxidant capacity of the body causing lipid peroxidation, protein oxidation and oxidative DNA damage. The role of oxidative stress in pathogenesis of early skin changes in patients with MS is not clearly defined. The aim of our study was to compare visual skin changes between patients with MS and without it, and to reveal early histological manifestations of MS in the skin. The study was conducted at the Clinic of Aesthetic Dermatology, Riga, Latvia. 50 patients aged 45-55 were enrolled. The research consisted of a clinical examination, biochemical testing and Punch biopsies. Tissue samples were stained with haematoxylin-eosin, Masson’s Trichrome and also immunohistochemically stainining with antibodies to CD34, CD117, CD20, CD8 and bcl-2. CD1a positive Langerhans cells were evaluated in 3 fields of vision. Data was analyzed with Microsoft Excel 2010 software. Gender ratio was women: men= 1.6:1. Histological changes in the skin of patients with MS were: hyperkeratosis, acanthosis, dermal fibrosis, elastosis and mild thickening of the stratum spinosum. Infiltrates around blood vessels were composed of T lymphocytes (CD3+). More significant expression and accumulation of apoptotic protein Bcl2 in skin of patients with MS in comparison to patients without MS was noted. Initial skin histological changes in MS are dermal elastosis, thickening of stratum spinosum and acanthosis. Mild T lymphocytic infiltration around capillaries possibly reflects the inflammatory component of MS. Increased accumulation of bcl2 anti-apoptotic protein in epidermis was more significantly expressed in patients with MS.

Evaluation of the Histologic Changes in the Fat-Grafted Facial Skin: Clinical Trial

Fat grafting is increasingly common in plastic surgery procedures. The discovery of stem cells in fat tissue has given a new direction to the use of fat as a therapeutic tool for other patient conditions. Only one experimental study in rats shows dermal changes after application of lipofilling. For this reason, the authors conducted this study to evaluate skin changes in patients after application of the technique. This study aimed to observe histologic changes in the skin of patients undergoing fat grafting. Fat grafting was performed in the preauricular region on one side of patients undergoing face-lifts at the Jalisco Reconstructive Surgery Institute, Guadalajara, Mexico. Preauricular skin was used in this procedure as a withdrawal study and control condition. Hematoxylin-eosin and Masson staining was performed to assess dermal and epidermal thickness, vascularity, and collagen behavior. No inferential statistics were registered with the Wilcoxon test. The study investigated 16 patients to observe statistically significant differences in dermal thickness, the presence of immature collagen (neoformation), and arteries. No difference in epidermal thickness was observed. The study showed a regenerative effect with fat grafting that included an increased thickness of the dermis, collagen neoformation, and the presence of increased vascularity in local skin subjected to treatment. 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 .

T-2 toxin induced skin inflammation and cutaneous injury in mice

T-2 toxin is one of the most toxic among several trichothecenes involved in both human and animal poisoning cases. We investigated the biochemical and histological alterations behind inflammation and cutaneous injury caused by T-2 toxin. Swiss albino mice were exposed to T-2 toxin topically at doses of 0.5, 1 and 2 LD50 (2.97, 5.94 and 11.88mg/kg respectively) and observed till 3, 24 and 72h. Topical application of T-2 toxin resulted in skin oxidative stress in terms of increased reactive oxygen species generation, lipid peroxidation and neutrophil mediated myeloperoxidase activity. The histological alterations include degenerative changes like vacuolation, ballooning of basal keratinocytes and infiltration of inflammatory cells in dermis. The mRNA levels of skin pro-inflammatory cytokines TNF-α, IL-6, and IL-1β showed significant up regulation. Anti-inflammatory cytokines IL-10 showed significant up regulation at 24h whereas IL-4 showed down regulation for all the doses and time points. Gelatin zymography and immunoblot analysis of matrix metalloproteinases (MMP)-9 and 2 indicated MMP activation and their role in degenerative skin histological changes. Time dependent increase in inducible nitric oxide synthase levels was seen. Immunoblot analysis revealed significant increase in the levels of phosphorylated p38 mitogen activated protein kinase (MAPK). Flow cytometry analysis of propidium iodide stained epidermal cells showed increase in sub-G1 population at all the doses and time points indicating apoptosis. In summary, T-2 toxin induced skin inflammation and cutaneous injury is mediated through oxidative stress, activation of myeloperoxidase, MMP activity, increase in inflammatory cytokines, activation of p38 MAPK and apoptosis of epidermal cells leading to degenerative skin histological changes.

Effect of light exposure on metalloporphyrin-treated newborn mice

Neonatal hyperbilirubinemia arises from increased bilirubin production and decreased bilirubin elimination. Although phototherapy safely and effectively reduces bilirubin levels, recent evidence shows that it has adverse effects. Therefore, alternative treatments are warranted. Metalloporphyrins, competitive inhibitors of heme oxygenase (HO), the rate-limiting enzyme in bilirubin production, effectively reduce bilirubin formation; however, many are photoreactive. Here, we investigated possible photosensitizing effects of chromium mesoporphyrin (CrMP) and zinc deuteroporphyrin bis-glycol (ZnBG). Administration of CrMP or ZnBG to 3-d-old mouse pups (3.75-30.0 μmol/kg intraperitoneally) and exposure to cool white (F20T12CW) and blue (TL20W/52) fluorescent lights (+L) for 3 h, resulted in a dose-dependent mortality (50% lethal dose (LD50) = 21.5 and 19.5 μmol/kg, respectively). In contrast to ZnBG, there was no significant difference in survival between the CrMP+L and CrMP groups. Following 30 μmol/kg ZnBG+L, we found significant weight loss, decreased liver antioxidant capacities, and increased aspartate aminotransaminase levels. At 6-d post-light exposure, ZnBG+L-treated pups showed gross and histologic skin changes at doses >7.5 μmol/kg. No lethality was observed following treatment with 30 μmol ZnBG/kg plus exposure to blue light-emitting diodes. Phototoxicity of ZnBG was dependent on light source, emission spectrum, and irradiance. Low doses of ZnBG (<3.75 μmol/kg) retained maximal HO inhibitory potency without photosensitizing effects, and therefore are potentially useful in treating neonatal hyperbilirubinemia.

Histological changes of skin and its relationship with wound healing in diabetic nude mice

Objective To observe the histological changes of skin and explore its relationship with wound healing in diabetic nude mice. Methods Diabetic nude mice models were established by intraperitoneal injection of 150 mg/kg STZ.Full-thickness skin of 1.8 cm in diameter was obtained from the dorsum of normal control rats(n=20) and diabetic nude mice(n=20) 4 weeks after model establishment.HE staining was used to observe the histological changes of skin,and the thickness of dermis and epidermis was measured.Picrosirius red staining was employed to analyse the relative content of collagen in dermis.The cutaneous content of glucose was determined by glucose oxidase method.The wound closure rates were calculated 3 d,5 d,7 d,14 d and 21 d after operation. Results The dermis and epidermis of diabetic nude mice were significantly thinner than those of normal controls(P0.05),and the relative content of collagen in dermis of diabetic nude mice was significantly lower than that of normal controls(P0.01).The concentration of blood glucose and cutaneous content of glucose of diabetic nude mice were significantly higher than those of normal controls(P0.01),and there was a positive correlation between cutaneous content of glucose and concentration of blood glucose(r=0.951,P0.01).The wound closure rates of diabetic nude mice 3 d,5 d,7 d,14 d and 21 d after operation were significantly lower than those in normal controls(P0.01). Conclusion There are significant histological changes of skin in diabetic nude mice induced by STZ,and these changes may be related to the accumulation of advanced glycation end products,which may lead to the impaired wound healing.

The Clinical and Histological Skin Changes After the Cupping Therapy (Al-Hijamah)

Background: Cupping Therapy (CT) has been reported as treatment for several skin conditions such as acne, post herpetic neuralgia, psoriasis, atopic dermatitis and urticaria. Although it is often considered as part of the Traditional Chinese Medicine (TCM), it has been widely practiced in the Middle East and the rest of the world for centuries. In Basra, a city in the southern part of Iraq, cupping therapy is often used by alternative medicine practitioners for treating skin disorders. However, limited is known about the clinical and histological effects of cupping therapy on the skin. Objectives: To investigate the immediate and delayed effect of CT on the skin, clinically and histologically. Material and Methods: TWe visited alternative and herbal medicine clinics that practice cupping therapy in Basra. Questionnaires were given to the patients and the alternative medicine practitioners to explore their experience with cupping therapy in terms of the presenting complaints and symptoms following therapy. The different types of application techniques and the immediate and delayed clinical changes on the skin following cupping therapy have been recorded. Ten skin biopsies were taken from male participants to investigate the histological changes in the application sites. Results: One hundred and thirty five patients were enrolled in the study. Of them, 102 (75.6%) were males and 33 (24.4 %) were females. The presenting complaints in males were back pain (29.4 %), Sciatica pain (15.7%) then headache (12.7%). In females, the presenting complaints were frozen shoulder (30.3%), back pain (18.2%), joint pain (12.1%) and gynecological causes (9.1%). Skin diseases were the presenting complaints in 4.9% of the males and 3% of the females. They included psoriasis, vitiligo, and eczema. Following cupping therapy, the immediate signs were erythema, swelling, bruising, bleeding, bullae formation and sings of cutting as results of cutting the skin for bloodletting. Patients reported discomfort ranging from slight tingling sensation to severe pain. Delayed clinical effects were scars in 6% of cases and patches of post inflammatory hyper-pigmentation with or without ring of ecchymosis in 4 % of total cases 30 days after cupping therapy. In all other cases complete healing of the skin was within three weeks. No adverse events were noted in our study. Histological changes following cutting and bloodletting were mild oedema, vacuolization and longitudinal fissure as a result of cutting in the epidermis. In the dermis, histological changes were dermal oedema and bleeding in the upper and lower parts of the dermis. No cellular infiltration was noted. Conclusion: Cupping therapy is associated with distinctive early and late clinical changes. However, it is safe procedure and most of these changes are reversible within three weeks. There were no adverse events as a result of the therapy. The efficacy of cupping therapy in treatment is beyond the scope of this study and further studies are needed.

Efficacy of Marigold Extract-Loaded Formulations Against UV-induced Oxidative Stress

The present study investigated the potential use of topical formulations containing marigold extract (ME) (Calendula officinalis extract) against ultraviolet (UV)B irradiation-induced skin damage. The physical and functional stabilities, as well as the skin penetration capacity, of the different topical formulations developed were evaluated. In addition, the in vivo capacity to prevent/treat the UVB irradiation-induced skin damage, in hairless mice, of the formulation with better skin penetration capacity was investigated. All of the formulations were physically and functionally stable. The gel formulation [Formulation 3 (F3)] was the most effective for the topical delivery of ME, which was detected as 0.21 μg/cm(2) of narcissin and as 0.07 μg/cm(2) of the rutin in the viable epidermis. This formulation was able to maintain glutathione reduced levels close to those of nonirradiated animals, but did not affect the gelatinase-9 and myeloperoxidase activities increased by exposure to UVB irradiation. In addition, F3 reduced the histological skin changes induced by UVB irradiation that appear as modifications of collagen fibrils. Therefore, the photoprotective effect in hairless mice achieved with the topical application of ME in gel formulation is most likely associated with a possible improvement in the collagen synthesis in the subepidermal connective tissue.

Molecular characterization of 11 Italian patients with Darier Disease

Darier disease (DD) is an autosomal dominant genodermatosis characterized by multiple warty papules coalescing in seborrheic areas and specific histological skin changes. Heterozygous mutations in ATP2A2, encoding the sarco-endoplasmic reticulum calcium pumping ATPase type 2, are identified as the molecular basis of DD. In this study, molecular features in a large cohort of Italian patients are reported. Molecular data were collected along with the main clinical features. Genomic DNA was used for direct sequencing of ATP2A2. The effect of selected mutations was predicted by in silico analysis or investigated by gene expression studies. 10 different ATP2A2 mutations were identified. Three mutations (c.2300A>G, c.2794G>A, c.569delAins34) have been previously described, while 7, including 2 missense (c.545G>A and c.2116G>A), 2 nonsense (c.1372G>T and c.1675C>T), 1 small deletion (c.142delA), 1 duplication (c.2935_2949dup15) and 1 splice-site mutation (c.2742-1G>A), were novel. Collected data added new variants to the ATP2A2 repertoire and confirmed that ATP2A2 mutations are scattered over the entire gene and, in most cases, private.

Role of Il-17 Varies at Different Periods After Hematopoietic Stem Cell Transplantation: Protection From Acute Graft-Versus-Host Disease and Exacerbation of Chronic Graft-Versus-Host Disease.

AbstractAbstract 3741Th17 is a newly identified T cell lineage that secretes the proinflammatory cytokine IL-17. Th17 cells have been shown to play a crucial role in mediating autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), arthritis, and colitis. Anti-IL-17 therapy for some autoimmune diseases in clinical settings has been started and promising results have been reported. However the role of IL-17 on developing acute and chronic GVHD in hematopoietic stem cell transplantation (HSCT) is not yet fully understood. Interaction between IL-17 and IL-17 receptor is complicated because IL-17 is produced in various kinds of immune cells other than CD4+ T-cells, and IL-17 receptors express on not only immune cells but also various epithelial cells, including lung and intestine, both of which are target organs of GVHD. To explore the role of host derived or donor derived IL-17 separately in acute GVHD, lethally irradiated wild type (WT) or IL-17 knockout (KO) Balb/c (H-2d) were given WT or IL-17 KO C57BL/6 (H-2b) bone marrow (BM) cells with WT splenocytes to induce acute GVHD. Infused cell number of WT splenocytes in this study induced acute GVHD, but not lethal in IL-17 WT host mice. In contrast, IL-17 KO host mice receiving WT BM plus WT splenocytes developed severe acute gut GVHD and finally half of them died (p<0.05). To exclude the possibility that alloreactivity of host IL-17 KO derived dentritic cells (DCs) could be much more than that of WT DCs, mixed leukocyte reaction (MLR) was performed using stimulators from WT or IL-17 KO DCs and responders from WT CD4+ T-cells. No significant differences were observed between WT DCs and IL-17 KO DCs in thymidine uptake and percentage of responder cells producing IFN-g or TNF-a. Taken together, host-derived IL-17 has a protective effect against acute GVHD. Moreover similar results were observed when IL-17 KO Balb/c mice were given BM cells from another strain B10.D2 plus splenocytes shown in the figure below (p<0.05). Next, we compared the development of chronic GVHD between the lethally irradiated WT Balb/c mice given IL-17 KO C57BL/6 BM cells or WT BM cells with low dose WT splenocytes to induce sublethal acute GVHD and chronic GVHD subsequently. After day 60 the mice receiving WT BM cells plus WT splenocytes experienced weight loss accompanied by skin histological changes (p<0.05, shown in the figure below), while mice receiving IL-17 KO BM plus WT splenocytes showed minimal signs of GVHD as well as mice receiving IL-17 KO BM or WT BM alone. Increased number of donor-BM derived IL-17 producing cells was observed in the mice showing chronic GVHD compared to BM control (p<0.05). Moreover, a significant increase of T-cell proliferation was observed by adding rIL-17 into MLR culture (p<0.05). These results suggest that donor BM derived IL-17 producing cells involved in the pathogenesis of chronic GVHD by exacerbating the alloimmune response in part. In conclusion IL-17, especially from host-derived, has a protective effect against acute GVHD. On the contrary, donor BM derived IL-17 exacerbates chronic GVHD. Neutralizing IL-17 would be a potent strategy only for preventing chronic GVHD, not for acute GVHD. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Darier disease, multiple bone cysts, and aniridia due to double de novo heterozygous mutations in ATP2A2 and PAX6

Darier disease (DD) is an autosomal dominant genodermatosis caused by mutations in ATP2A2 and characterized by multiple warty papules coalescing in seborrheic areas and specific histological skin changes. Rare patients are described with variable bone involvement, but this association has never been sufficiently emphasized. Aniridia is a developmental disorder of the eye due to heterozygous mutations in PAX6. DD and aniridia are Mendelian traits mapping on independent loci and have never been reported in association. Here, we describe a 14-year-old girl showing the unique combination of DD, multiple bone cysts, and bilateral aniridia. Molecular investigations demonstrated that such a complex phenotype is due to double de novo heterozygous mutations in ATP2A2 and PAX6. Review of the literature indicates that, in DD, bone cysts are true developmental abnormalities of the skeleton. This finding suggests a role for ATP2A2 in bone biology. More systematic studies are expected in order to estimate the true prevalence of bone cysts in DD and the relationship between skeletal changes and ATP2A2 perturbation.

Effects of blood glucose fluctuation on skin biophysical properties, structure and antioxidant status in an animal model

Intermittent blood-glucose fluctuation (BGF) can accelerate diabetes and its complications, but it is still unknown whether BGF can damage the skin of patients with diabetes. To investigate the effects of repetitive fluctuation in blood glucose concentration on the biophysical properties, structure and antioxidant capacity of diabetic mouse skin. Mice with alloxan-induced diabetes were injected with glucose three times daily to induce repetitive BGF. Six weeks later, skin elasticity and skin hydration were measured to evaluate skin water-holding capacity and contraction function. The histological changes of skin were also studied, using haematoxylin and eosin. In addition, we compared levels of blood sugar and advanced glycation end products (AGEs), the activities of superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) and hydroxyproline in the skin of normal mice and diabetic mice with or without BGF. The diabetic mice with BGF displayed an 18.6% increase in blood sugar level, an 11.3% increase in AGEs content and a 13.1% increase in MDA content compared with the diabetic mice (P < 0.01). There was a greater reduction in skin elasticity, skin hydration, hydroxyproline content and SOD activity in the diabetic mice with BGF (P < 0.01). Histological examination showed that BGF enhanced skin lesions in diabetic mice. Repetitive fluctuation in blood-glucose concentration produced a marked detrimental effect on skin structure and function in diabetic mice. The deleterious effects of BGF on skin appeared to due at least partly to the oxidative stress.

Preclinical investigation to compare different gadolinium-based contrast agents regarding their propensity to release gadolinium in vivo and to trigger nephrogenic systemic fibrosis-like lesions

Recent reports suggest that nephrogenic systemic fibrosis (NSF) is associated with the administration of gadolinium (Gd)-based contrast agents (GBCAs) and in particular with the stability of the Gd-complex. The aim of this investigation was to compare GBCAs and their potential to trigger NSF. Forty-two healthy male rats received repeated intravenous injections of six different GBCAs at high doses to simulate the exposure seen in patients with severe renal dysfunction. Histopathological and immunohistochemical analysis of the skin was performed, and the concentrations of Gd, zinc and copper were measured in several tissues by inductive coupled plasma atomic emission spectroscopy. Macroscopic and histological skin changes similar to those seen in NSF patients were only observed in rats receiving Omniscan. In addition, very high concentrations of Gd were observed in the animals treated with Omniscan, and, to a lesser extent, in animals treated with OptiMARK. Significantly lower levels of Gd were found after the treatment with ionic linear agents and even less after the treatment with macrocyclic agents. The data in this investigation strongly suggest that the stability of the Gd-complex is a key factor for the development of NSF-like symptoms in this experimental setting.

Histologic evidence of new collagen formation using a Q‐switched Nd:YAG laser in periorbital rhytids

Objectives: Non‐ablative laser treatment has been used for improving dermal toning. Laser application to dermis causes new collagen formation in terms of wound healing. We aimed to study mainly histological changes in skin after the use of a Q‐switched Nd:YAG laser in non‐ablative treatment of wrinkles. Methods: The laser was adjusted to a fluency of 7 J/cm2 with a spot size of 3 mm and a pulse rate of 10 Hz to treat periorbital wrinkled areas. None of the patients had received filling materials, botulinum toxin injections or any dermabrasion procedures. All laser sessions were held every 15 days for a total of six sessions and all patients were photographed before treatment and then 2 months after the last treatment. Histological examinations were performed before laser treatment and 1 month after the final treatment. Results: Four of eight individuals showed clinical improvement. The histological proportion of collagen fibers was measured by using the Samba method. An increase in the mean optical densities (MOD) of collagen fibers compared with baselines was statistically significant in all patients (p<0.05). Conclusion: The 1064‐nm Q‐switched Nd:YAG lasers appear to be safe and efficient for non‐ablative remodeling of periorbital wrinkles.

Acute Toxicity and Sublethal Effects of Nitrite on Selected Hematological Parameters and Tissues in Dark‐banded Rockfish, Sebastes inermis

Abstract Acute toxicity and sublethal effects of nitrite in dark‐banded rockfish, Sebastes inermis (83.3 ± 7.2 g), were studied under static conditions for a period of 96 h. The acute toxicity of nitrite evaluated for the 96‐h lethal concentration (LC50) was 700 mg/L. The sublethal effects on selected hematological parameters of S. inermis, such as total erythrocyte count (TEC), hemoglobin, plasma glucose, and serum protein content, were measured after 0, 6, 12, 24, 48, 72, and 96 h of exposure to 0, 50, 100, 200, 400, and 700 mg/L of nitrite. Sublethal nitrite caused progressive reduction in the TEC, hemoglobin, and serum protein content in fish depending on the nitrite concentration and exposure period. The 96‐h exposure resulted in a 14–42% reduction in TEC and 25–33% reduction in hemoglobin content for 100–700 mg/L of nitrite compared to the control. A dose‐related reduction in plasma glucose (25.7–34.2%) was observed for concentrations of 200–700 mg/L of nitrite during 48 h of exposure, followed by an increase through 96 h. A significant reduction in serum protein (7.3–12.6%) was observed for 200–700 mg/L of nitrite after 96 h of exposure. Abnormal histological changes in skin, gill, liver, and kidney tissue were observed in fish exposed to 700 mg/L of nitrite after 96 h of exposure compared to the control. Although no mortality of S. inermis occurred at 500 mg/L of nitrite, all hematological parameters adversely responded to a nitrite dose of 200 mg/L for 96 h. These results showed that although acute toxicity concentration of nitrite in S. inermis is higher than 700 mg/L, sublethal concentrations of nitrite also negatively affect hematological parameters.

Molecular, cellular and histological changes in skin from a larval to an adult phenotype during bony fish metamorphosis

Developmental models for skin exist in terrestrial and amphibious vertebrates but there is a lack of information in aquatic vertebrates. We have analysed skin epidermal development of a bony fish (teleost), the most successful group of extant vertebrates. A specific epidermal type I keratin cDNA (hhKer1), which may be a bony-fish-specific adaptation associated with the divergence of skin development (scale formation) compared with other vertebrates, has been cloned and characterized. The expression of hhKer1 and collagen 1alpha1 in skin taken together with the presence or absence of keratin bundle-like structures have made it possible to distinguish between larval and adult epidermal cells during skin development. The use of a flatfish with a well-defined larval to juvenile transition as a model of skin development has revealed that epidermal larval basal cells differentiate directly to epidermal adult basal cells at the climax of metamorphosis. Moreover, hhKer1 expression is downregulated at the climax of metamorphosis and is inversely correlated with increasing thyroxin levels. We suggest that, whereas early mechanisms of skin development between aquatic and terrestrial vertebrates are conserved, later mechanisms diverge.

Modulation of Cutaneous Aging With Calorie Restriction in Fischer 344 Rats

To examine whether histological changes in skin owing to intrinsic aging in a laboratory rodent model are modulated by caloric restriction (CR). The abdominal skin from colony-raised ad libitum-fed Fischer 344 rats and age-matched rats subjected to CR was studied in the light microscope using histological morphometric methods. Animals 4, 12, and 24 months or older were used in this study. We studied the skin to obtain (1) quantitative data on the depth of the epidermis, dermis, and fat layer, the epidermal cellular density, the percentage fraction of dermal collagen, elastic fibers, pilosebaceous units, and capillaries, and the fibroblast density; and (2) qualitative assessment of histological staining for dermal glycosaminoglycans. We analyzed data by means of general linear model 2-way analysis of variance to obtain significance for the effects of age, diet, and age-diet interaction. The ad libitum-fed rats showed age-related increase in the depth of the epidermis, dermis, and fat layer. Calorie restriction prevented these changes, but epidermal nuclear density appeared to be stimulated. A trend toward increased values for collagen and elastic fibers, fibroblasts, and capillaries in skin samples from CR rats was observed. Pilosebaceous units were not modified. Moderately reduced staining for the dermal glycosaminoglycans in the skin of CR rats was noticed. Histomorphological changes resulting from intrinsic aging affected some of the studied variables in the rat skin, and these changes were delayed or prevented by CR. Some stimulatory effects, such as increased densities of fibroblasts and capillary profiles and higher values of connective tissue fibers resulting from CR, were also observed. Cutaneous morphological changes due to natural aging in this rat model seem to be modified by physiological or metabolic alterations imposed by CR.