E-cigarettes and health risks: more to the flavor than just the name.

The growing interest in regulating flavored E-liquids must incorporate understanding of the "flavoring profile" of each E-liquid-which flavorings (flavoring chemicals) are present and at what concentrations not just focusing on the flavor on the label. We investigated the flavoring profile of 10 different flavored E-liquids. We assessed bronchial epithelial cell viability and apoptosis, phagocytosis of bacteria and apoptotic cells by macrophages after exposure to E-cigarette vapor extract (EVE). We validated our data in normal human bronchial epithelial cells (NHBE) and alveolar macrophages (AM) from healthy donors. We also assessed cytokine release and validated in the saliva from E-cigarette users. Increased necrosis/apoptosis (16.1-64.5% apoptosis) in 16HBE cells was flavor dependent, and NHBEs showed an increased susceptibility to flavors. In THP-1 differentiated macrophages phagocytosis was also flavor dependent, with AM also showing increased susceptibility to flavors. Further, Banana and Chocolate were shown to reduce surface expression of phagocytic target recognition receptors on alveolar macrophages. Banana and Chocolate increased IL-8 secretion by NHBE, whereas all 4 flavors reduced AM IL-1ß secretion, which was also reduced in the saliva of E-cigarette users compared with healthy controls. Flavorant profiles of E-liquids varied from simple 2 compound mixtures to complex mixtures containing over a dozen flavorants. E-liquids with high benzene content, complex flavoring profiles, high chemical concentration had the greatest impacts. The Flavorant profile of E-liquids is key to disruption of the airway status quo by increasing bronchial epithelial cell apoptosis, causing alveolar macrophage phagocytic dysfunction, and altering airway cytokines.

The cost of dominance: suppressing subordinate reproduction affects the reproductive success of dominant female banded mongooses.

Social species show considerable variation in the extent to which dominant females suppress subordinate reproduction. Much of this variation may be influenced by the cost of active suppression to dominants, who may be selected to balance the need to maximize the resources available for their own offspring against the costs of interfering with subordinate reproduction. To date, the cost of reproductive suppression has received little attention, despite its potential to influence the outcome of conflict over the distribution of reproduction in social species. Here, we investigate possible costs of reproductive suppression in banded mongooses, where dominant females evict subordinates from their groups, thereby inducing subordinate abortion. We show that evicting subordinate females is associated with substantial costs to dominant females: pups born to females who evicted subordinates while pregnant were lighter than those born after undisturbed gestations; pups whose dependent period was disrupted by an eviction attained a lower weight at independence; and the proportion of a litter that survived to independence was reduced if there was an eviction during the dependent period. To our knowledge, this is the first empirical study indicating a possible cost to dominants in attempting to suppress subordinate breeding, and we argue that much of the variation in reproductive skew both within and between social species may be influenced by adaptive variation in the effort invested in suppression by dominants.

Reproductive competition and the evolution of extreme birth synchrony in a cooperative mammal.

Reproductive events in animal societies often show a high degree of temporal clustering, but the evolutionary causes of this synchronization are poorly understood. Here, we suggest that selection to avoid the negative effects of competition with other females has given rise to a remarkable degree of birth synchrony in the communal-breeding banded mongoose (Mungos mungo). Within banded mongoose groups, births are highly synchronous, with 64 per cent of females giving birth on exactly the same night. Our results indicate that this extreme synchrony arises because offspring suffer an increased risk of infanticide if their mother gives birth before other females, but suffer in competition with older littermates if their mother gives birth after them. These findings highlight the important influence that reproductive competition can have for the evolution of reproductive synchrony.

Intrasexual competition and sexual selection in cooperative mammals.

In most animals, the sex that invests least in its offspring competes more intensely for access to the opposite sex and shows greater development of secondary sexual characters than the sex that invests most. However, in some mammals where females are the primary care-givers, females compete more frequently or intensely with each other than males. A possible explanation is that, in these species, the resources necessary for successful female reproduction are heavily concentrated and intrasexual competition for breeding opportunities is more intense among females than among males. Intrasexual competition between females is likely to be particularly intense in cooperative breeders where a single female monopolizes reproduction in each group. Here, we use data from a twelve-year study of wild meerkats (Suricata suricatta), where females show high levels of reproductive skew, to show that females gain greater benefits from acquiring dominant status than males and traits that increase competitive ability exert a stronger influence on their breeding success. Females that acquire dominant status also develop a suite of morphological, physiological and behavioural characteristics that help them to control other group members. Our results show that sex differences in parental investment are not the only mechanism capable of generating sex differences in reproductive competition and emphasize the extent to which competition for breeding opportunities between females can affect the evolution of sex differences and the operation of sexual selection.

Increased production of TGF-beta and apoptosis of T lymphocytes isolated from peripheral blood in COPD.

Chronic obstructive pulmonary disease (COPD) is associated with inflammation of airway epithelium, including an increase in the number of intraepithelial T cells. Increased apoptosis of these T cells has been reported in the airways in COPD, and although this process is critical for clearing excess activated T cells, excessive rates of apoptosis may result in unbalanced cellular homeostasis, defective clearance of apoptotic material by monocytes/macrophages, secondary necrosis, and prolongation of the inflammatory response. Lymphocytes are known to traffic between the airway and the peripheral circulation, thus we hypothesized that in COPD, circulating T cells may show an increased propensity to undergo apoptosis. We analyzed phytohemagglutinin (PHA)-stimulated peripheral blood T cells from COPD patients and controls for apoptosis using flow cytometry and staining with annexin V and 7-aminoactinomycin D. As several pathways are involved in induction of apoptosis of T cells, including transforming growth factor (TGF)-beta/TGF receptor (TGFR), TNF-alpha/TNFR1, and Fas/Fas ligand, these mediators were also investigated in peripheral blood samples from these subject groups. Significantly increased apoptosis of PHA-stimulated T cells was observed in COPD (annexin positive 75.0 +/- 14.7% SD vs. control 50.2 +/- 21.8% SD, P = 0.006), along with upregulation of TNF-alpha/TNFR1, Fas, and TGFR. Monocyte production of TGF-beta was also increased. In conclusion we have demonstrated the novel finding of increased apoptosis of stimulated T cells in COPD and have also shown that the increased T-cell death may be associated with upregulation of apoptotic pathways, TGF-beta, TNF-alpha, and Fas in the peripheral blood in COPD.

Biological effects of embedded depleted uranium (DU): summary of armed forces radiobiology research institute research.

The Persian Gulf War resulted in injuries of US Coalition personnel by fragments of depleted uranium (DU). Fragments not immediately threatening the health of the individuals were allowed to remain in place, based on long-standing treatment protocols designed for other kinds of metal shrapnel injuries. However, questions were soon raised as to whether this approach is appropriate for a metal with the unique radiological and toxicological properties of DU. The Armed Forces Radiobiology Research Institute (AFRRI) is investigating health effects of embedded fragments of DU to determine whether current surgical fragment removal policies remain appropriate for this metal. These studies employ rodents implanted with DU pellets as well as cultured human cells exposed to DU compounds. Results indicate uranium from implanted DU fragments distributed to tissues far-removed from implantation sites, including bone, kidney, muscle, and liver. Despite levels of uranium in the kidney that were nephrotoxic after acute exposure, no histological or functional kidney toxicity was observed. However, results suggest the need for further studies of long-term health impact, since DU was found to be mutagenic, and it transformed human osteoblast cells to a tumorigenic phenotype. It also altered neurophysiological parameters in rat hippocampus, crossed the placental barrier, and entered fetal tissue. This report summarizes AFRRI's depleted uranium research to date.

Detection of depleted uranium in biological samples from Gulf War veterans.

During the Persian Gulf War, soldiers may have inhaled, ingested, and/or experienced wound contamination by depleted uranium (DU), which is used in military projectiles and armor. DU is produced by depleting natural uranium of 234U and 235U during the uranium-enrichment process. Although the long-term effects of significant DU exposures require investigation, many veterans express fears about its impact on health. An assay by which DU exposure can be assessed would not only be a useful research tool, but the information could help mitigate the concerns of exposed individuals. In this study, urine samples from individuals enrolled in the Depleted Uranium Follow-Up Program at the Baltimore Veterans Administration Medical Center were examined for uranium content. Isotopic composition of urine uranium was determined by measuring the 235U/238U ratio, using an inductively coupled plasma mass spectrometer. Using this method, natural and depleted uranium could be readily differentiated. By demonstrating the absence of DU in soldiers who suspect exposure by inhalation or ingestion, the assay should reduce psychological stress in these individuals.

Behavioural consequences of oligodendrocyte progenitor cell transplantation into experimental demyelinating lesions in the rat spinal cord.

Glial cell transplantation has the potential to be developed into a clinical treatment for human demyelinating diseases because of its demonstrated efficacy in remyelinating experimentally demyelinated axons. As a step towards clinical application it is necessary to demonstrate that the procedure is safe and efficacious in promoting behavioural recovery. In this study we transplanted glial cell progenitors into demyelinating lesions induced by intraspinal injection of ethidium bromide in the rat. Locomotor function after transplantation was assessed using a beam-walking test that has previously been shown able to detect deficits associated with demyelination in the dorsal funiculus of the rat spinal cord. Two groups of animals with transplants were examined. In one group, spontaneous remyelination was prevented by exposure of the lesion to 40 Gy of X-irradiation; in the other, male glial cells were transplanted into nonirradiated female recipients, permitting their identification by use of a probe specific to the rat Y chromosome. Following transplantation, there was severe axon loss in a large proportion of the irradiated animals and those affected did not recover normal behavioural function. In contrast, both the small proportion of the irradiated group that sustained only mild axon loss and the nonirradiated recipients of transplants recovered normal function on our behavioural test. We conclude that glial cell transplantation is able to reverse the functional deficits associated with demyelination, provided axonal loss is minimal.

Localization of an insulin-like growth factor (IGF) binding site of bovine IGF binding protein-2 using disulfide mapping and deletion mutation analysis of the C-terminal domain.

We have investigated which region(s) of bovine insulin-like growth factor binding protein-2 (bIGFBP-2) interact with insulin-like growth factors (IGFs) using C-terminally truncated forms of bIGFBP-2. Initially to aid in mutant design, we defined the disulfide bonding pattern of bIGFBP-2 C-terminal region using enzymatic digestion. The pattern is Cys186-Cys220, Cys231-Cys242, and Cys244-Cys265. In addition, cyanogen bromide cleavage of bIGFBP-2 revealed that the N- and C-terminal cysteine-rich domains were not linked by disulfide bonds. Taking the disulfide bonding pattern into consideration, C-terminal truncation mutants were designed and expressed in COS-1 mammalian cells. Following IGF binding assays, a region between residues 222 and 236 was identified as important in IGF binding. Specifically, mutants truncated by 14, 36, and 48 residues from the C terminus bound IGFs to the same extent as wild type (WT) bIGFBP-2. Removal of 63 residues resulted in a greatly reduced (up to 80-fold) ability to bind IGF compared with WT bIGFBP-2. Interestingly this mutant lacked the IGF-II binding preference of WT bIGFBP-2. Residues 236-270 also appeared to play a role in determining IGF binding specificity as their removal resulted in mutants with higher IGF-II binding affinity.

Successful treatment of lentigo maligna and lentigo maligna melanoma with Mohs' micrographic surgery aided by rush permanent sections.

BACKGROUND: Lentigo maligna (LM) is a pigmented neoplasm on sun-exposed skin of elderly patients. LM slowly increases in size and may become lentigo maligna melanoma (LMM), a potentially fatal malignancy. Complete excision is the treatment of choice. Mohs' micrographic surgery (MMS) with frozen and permanent sections may be used for complete eradication of the lesion, while sparing as much normal tissue as possible. The authors studied the efficacy of MMS for the treatment of LM and LMM. METHODS: Between 1985 and 1992, 45 patients with LM (26) and LMM (19) were treated with MMS. The authors' technique was to use examination of frozen sections and rush permanent sections (prepared and read within 24 hours). Positive frozen sections warranted further excision. For negative or equivocal frozen sections, surgery was interrupted until the examination of permanent sections was performed. RESULTS: All 45 patients were free of local disease and evidence of metastases at an average of 29.2 months (range, 4-81 months) after therapy. CONCLUSIONS: MMS aided by rush permanent sections yielded a prolonged disease free survival for all 45 patients with LM or LMM. Because the MMS technique minimizes the removal of normal tissue, and the local cure rate in this study was superior to that reported for conventional surgery, the authors recommend this technique for the treatment of LM and LMM.

Facial characteristics in children with Down's syndrome and spectacle fitting.

Significant refractive error is very common among children with Down's syndrome so the requirement for spectacles for this group is high. The aim of this study was to measure the facial characteristics of children with Down's syndrome and to compare them with two previous studies which have aided the design of children's spectacle frames. The study was carried out in two schools in South Wales, measuring 20 children between the ages of 3.6 and 14.4 years. The results show that between the ages of 7 and 14 years, facial characteristics of children with Down's syndrome do not change with age and rarely coincide with those of other children, either of a similar age or younger. Thus children with Down's syndrome cannot be fitted satisfactorily with conventional children's frames, and it would be desirable for a specially designed range of frames to be made available.

Atypical melanocytic nevi. Clinical and histopathologic predictors of residual tumor at reexcision.

BACKGROUND: The appropriate method for surgical management of melanocytic lesions with disordered architecture and melanocytic atypia (formerly dysplastic nevi) has been controversial. Physicians often reexcise these lesions after primary removal because of their potential relation to malignant melanoma. The outcomes of these reexcisions and the original biopsy specimens have not been previously examined. OBJECTIVE: The purpose of this study was to examine reexcision specimens and their respective original specimens to determine whether there were any characteristics predictive of the presence of residual nevus cells (RNCs) on reexcision. METHODS: One hundred eighty-nine reexcision specimens of atypical melanocytic lesions were evaluated for this study. The original specimens were examined for specific histopathologic features without knowledge of the findings on reexcision. Clinical characteristics were also examined. RESULTS: Of the 189 reexcision specimens, 47 (24.9%) contained RNCs. The proportion of specimens with RNC on reexcision was significantly greater if the original lesion was removed by punch biopsy rather than by shave or elliptical excision (38.3% vs 22.0% vs 10.5%, respectively; p < 0.03). Lesions located on the chest had a higher likelihood of RNCs than those on the back or leg (52.2% vs 21.7%; p = 0.009; 52.2% vs 9.7%, p < 0.002, respectively). Mean age was greater in those with RNCs at reexcision than those without (43.6 vs 37.9 years, respectively; p < 0.0001). The proportion of specimens with RNCs at reexcision was greater in those that had both lateral margins involved than in those that had nevus cells in either one or neither of the lateral margins in the original biopsy specimens (39.7% vs 24.0% vs 7.8%, respectively; p = 0.0005). One of the 189 reexcision specimens (0.5%) contained melanoma, although the original histopathologic diagnosis was an atypical melanocytic nevus. CONCLUSION: We identified several clinical and histopathologic factors that are strongly associated with the presence of RNCs on reexcision.

Twenty percent of biopsy specimens from sun-exposed skin of normal young adults demonstrate positive immunofluorescence.

Fifty normal healthy adults, aged 18 to 41 years, without a history of systemic diseases, dermatoses, or photosensitivity and who were not receiving medication were studied. Paired 3-mm punch biopsy specimens were obtained from the sun-exposed and the non-sun-exposed skin. The data from the study revealed a bright continuous band of immunofluorescence (IF) along the dermoepidermal junction in 10 (20%) of 50 sun-exposed skin biopsy specimens, as compared with none from non-sun-exposed skin biopsy specimens with the use of polyvalent antisera. Fractionated monospecific immunoglobulin demonstrated a bright continuous band of IF composed of IgG alone in one patient, IgA alone in two patients, IgG and IgA in combination in two patients, and the combination of IgG, IgM, and IgA in five patients. There was a statistically significant increase in positive IF in men (seven of 15) vs women (three of 35). This information suggests that in the examination of a patient suspected of having lesions of cutaneous lupus erythematosus, positive IF from sun-exposed skin is nonspecific and adds little information to the clinical and histopathologic findings.

Cutaneous leukocytoclastic vasculitis. Serial histopathologic evaluation demonstrates the dynamic nature of the infiltrate.

Data from experimentally induced cutaneous vasculitis have suggested that the inflammatory infiltrate is dynamic. In contrast, data from humans with cutaneous vasculitis have suggested that two distinct patterns of cellular infiltrate exist, a mononuclear-predominant and a neutrophilic-predominant type. There are little data regarding the temporal evolution of spontaneously occurring cutaneous vasculitis in humans. A patient with a cutaneous leukocytoclastic vasculitis manifest as palpable purpura had four lesions encircled on the day of presentation. Biopsies of these lesions were obtained sequentially at 0, 24, 48, and 120 hours. The histopathologic specimens were graded without knowledge of the timing of the biopsy. The character of the infiltrate progressively changed from a neutrophilic-predominant to a mononuclear-predominant infiltrate supporting the theory of a dynamic process in cutaneous vasculitis. The previous reports that suggest that there are two distinct inflammatory cell types may be the result of performing the biopsy at one point in time during this transitory process.

Possible ultraviolet A-induced lentigines: a side effect of chronic tanning salon usage.

A patient who developed lentigines after prolonged ultraviolet A (UVA) exposure in a tanning booth is described. The patient had no exposure to psoralens or furocoumarins. Histologic examination of a representative lentigo revealed melanocytic hyperplasia and cytologic atypia. Increased nevocytic activity with histologic dysplasia was present in several junctional nevi excised during the period of UVA exposure. Several studies have revealed significant effects of UVA on melanocytes. Patients should be cautioned to avoid tanning bed use in view of these potentially deleterious effects.

Immunoperoxidase technique on paraffin sections fails to demonstrate immunoglobulin deposition in cutaneous lesions from patients with dermatomyositis.

Nine formalin-fixed paraffin sections of skin biopsy specimens of patients with clinically and histologically proven dermatomyositis were studied using the avidin-biotin immunoperoxidase technique. No evidence of dermoepidermal junction or perivascular IgG, IgA, or IgM deposits were noted. These findings may be related to loss of antigenicity during the fixation process or to the small amount of immunoglobulin deposit previously reported in dermatomyositis. The negative findings demonstrate an inability to use this technique to find immunoglobulin deposition retrospectively in dermatomyositis.

Cutaneous leukocytoclastic vasculitis: correlation of histopathological changes with clinical severity and course.

We have examined 61 histopathologic specimens from 54 patients with cutaneous leukocytoclastic vasculitis (LV). They were examined without knowledge of clinical disease for the following characteristics: vessel wall inflammation, erythrocyte extravasation, depth of infiltrate, leukocytoclasis, fibrinoid necrosis, epidermal necrosis and fibrin thrombi. Independent of the histopathological study, the following clinical observations were recorded: type of lesion, severity and the presence and type of systemic disease. The severity score was based on the extent of cutaneous disease, the presence of systemic disease and the difficulty of disease control. The clinical and histological features were then compared using an analysis of variance. Statistically significant results included (1) the relation of clinical severity to vessel wall inflammation, leukocytoclasis, overall histologic severity; and (2) the mildness of histological changes in patients with urticarial lesions. Thus, we have demonstrated that the severity of histopathologic changes seen on skin biopsy is (1) predictive of clinical severity, (2) may correlate with the type of skin lesion observed, but (3) does not correlate with the presence or absence of internal vasculitic involvement.