Microvascular anastomotic arterial coupling: A systematic review.

INTRODUCTION: There are several reasons microsurgeons may not use a coupler device in arterial anastomosis: may be thick-walled, non-pliable due to atherosclerotic calcification or present vessel geometrical discrepancies. This review summarises the current applications, efficacy and troubleshooting of microvascular coupler devices in arterial end-to-end anastomosis. METHODS: A systematic review of the literature was performed in November 2020 across 4 electronic databases and in accordance with the PRISMA guidelines. All studies comprised the data synthesis that reported the use of a microvascular coupler device for arterial end-to-end anastomosis. Data were extracted and collected in three groups of standardised variables: study, anastomosis-related and technical characteristics. RESULTS: Out of the 7,690 articles identified, 20 were included in the final data synthesis. Included studies involved a total of 1639 patients, who underwent 670 arterial and 1,124 venous anastomoses. Out of all arterial anastomoses, 351 were performed in free tissue transfers in head and neck, 117 in breast, 4 in upper extremity and 5 in lower extremity reconstruction, whereas the remaining were not specified. The total arterial coupler anastomosis success rate reported was 92.1% (617/670). Fifty-three (8%) arterial anastomoses were reported to result in either troubleshooting events or intra- or post-operative failures, most being reported in extremity reconstructions. CONCLUSIONS: Arterial coupling is not widespread with predominant use in head and neck and chest reconstructions, and total reported efficacy of 92.1%. Microsurgeons are reluctant to routinely use current widespread coupler devices as a result of inherent arterial characteristics. This study delivered collective recommendations, 'do's and don'ts' of microvascular arterial coupling.

Pemphigus vulgaris possibly associated with application of a tissue expander in a patient with Crohn's disease and primary sclerosing cholangitis.

Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by suprabasal acantholysis and formation of blisters and erosions due to generation of IgG autoantibodies directed against desmosomal proteins. Tissue expanders are devices that, through controlled mechanical overstretch, are capable of generating new skin that is used to cover wounds or extended surgical defects. We report the case of a 13-year-old girl suffering from Crohn's disease (CD) and primary sclerosing cholangitis (PSC) who developed PV after application of a tissue expander for surgical removal of a giant congenital melanocytic nevus (GCMN). To the best of our knowledge, the case presented here is the first report of PV possibly associated with the application of a tissue expander and also the first report of coexistence of PV with either PSC or with PSC and CD in the same patient. Triggering or acute exacerbation of PV may be considered a possible side-effect of tissue expander application, especially in patients with a genetic predisposition for pemphigus and/or other autoimmune diseases. In view of the increasing use of tissue expanders in clinical practice, physicians should be aware of this rare side-effect in order to promptly diagnose it.

Ethnic differences in pre-adipocyte intracellular lipid accumulation and alkaline phosphatase activity.

Alkaline phosphatase (ALP) increases lipid accumulation in human pre-adipocytes. This study was performed to assess whether ethnic differences in the prevalence of obesity in African and European females are related to differences in pre-adipocyte lipid accretion and ALP activity. Pre-adipocytes were isolated from 13 black and 14 white females. Adipogenesis was quantified using the lipid dye, Oil red O, whilst ALP activity was assayed in cell extracts on day zero and 12days after initiating adipogenesis. Lipid levels (OD units/mg protein) were lower in pre-adipocytes from white than black females on day 0 (0.36±0.05 versus 0.44±0.03, respectively; p<0.0005) and day 12 (1.18±0.14 versus 1.80±0.22, respectively; p<0.0005), as was ALP activity (mU/mg protein) on day zero (36.5±5.8 versus 136.4±10.9, respectively; p<0.0005) and day 12 (127±16 versus 278±27, respectively; p<0.0005). Treatment of pre-adipocytes with histidine, an ALP inhibitor, blocked lipid accumulation. Thus, lipid uptake is higher in pre-adipocytes isolated from black compared to white females which parallels the obesity prevalence rates in these population groups. The reason for higher fat accumulation in pre-adipocytes isolated from black females may be related to higher ALP activity.

Superior pedicle breast reduction for hypertrophy with massive ptosis.

Breast hypertrophy, combined with massive ptosis with a suprasternal notch-to-nipple distance of more than 40 cm, remains an endeavour. Different refinements of the initial technique with free nipple grafts have been described to circumvent the problems of nipple underprojection, areolar hypopigmentation and loss of sensibility secondary to nipple grafting, as well as lacking breast projection due to scarce glandular tissue. Techniques relying on nipple areola complex transposition, rather than grafting, have been described with inferior, superomedial and medial pedicles. The aim of this study is to present the results obtained in a series of 10 patients suffering from bilateral breast hypertrophy with massive ptosis, which was defined as a distance >40 cm from the suprasternal notch-to the nipple. All breasts were managed with a superior pedicle and inverted T technique. The mean preoperative suprasternal notch-to-nipple distance was 44 ± 2 cm, and the resection weight ranged from 800 to 2490 g per breast with an average of about 1450 g in this patient population presenting with overweight or obesity. With a mean nipple areola complex (NAC) lift of 20 ± 3 cm, neither nipple nor areola necrosis was observed. One partial epidermolysis of the areola and two cases of delayed wound healing at the trifurcation point of the inverted T were conservatively managed. Only one re-operation was necessary for an important wound dehiscence of the lateral part of the horizontal scar. These results underscore the safety of the superior pedicle technique in cases of massive ptosis with transposition of the NAC of approximately 20 cm, that is, a pedicle length of about 25 cm.

Erinea formation on Quercus ilex leaves: anatomical, physiological and chemical responses of leaf trichomes against mite attack.

Structures on the surfaces of leaves, such as dense layers of non-glandular trichomes, strongly affect phylloplane mite activities. On the other hand the feeding of eriophyoid mites on leaf surfaces can cause hyperplasia of leaf trichomes (erinea formation). In many cases the hyperplasia is accompanied by the accumulation of pigments within trichome cells, causing an impressive red-brown colouration of the erineum. There is no information, however, on the structure of these pigments as well as on the chemical alterations in the phenolic content of plant trichomes in response to mite attack. Erinea formation on the abaxial surface of Quercus ilex leaves upon Aceria ilicis (Acari: Eriophyoidea) attack provides an excellent model on this topic. Differences in the structure and chemical composition of isolated trichomes derived either from healthy (normal trichomes) or mite attacked (hypertrophic trichomes) leaves were examined. Carbon investment was comparable between the two different trichome types, but the cell walls of the hypertrophic trichomes appeared thinner and did not contain microcrystalline cellulose. Observations under the fluorescence microscope showed that the emitted fluorescence was different between the two trichome types, indicating a different composition in fluorescencing phenolic compounds. The chemical analyses confirmed that hypertrophic trichomes contained higher concentrations of the feeding deterrents proanthocyanidin B3 and catechin, as well as of quercetin-3-O-glucoside, but lower concentrations of acylated flavonoid glycosides, than the normal ones. The results showed that the structural and functional changes in leaf trichomes upon mite attack may be an effort of the leaf to compensate the damage caused by the pest.

Guard cells in albino leaf patches do not respond to photosynthetically active radiation, but are sensitive to blue light, CO2 and abscisic acid.

Stomatal openings can be stimulated by light through two signalling pathways. The first pathway is blue light specific and involves phototropins, while the second pathway mediates a response to photosynthetically active radiation (PAR). This second pathway was studied with the use of albino Vicia faba plants and variegated leaves of Chlorophytum comosum. Treatment of V. faba with norflurazon (Nf) inhibits the synthesis of carotenoids and leads to albino leaves with guard cells that lack functional green chloroplasts. Guard cells in albino leaf patches of C. comosum, however, do contain photosynthetically active chloroplasts. Stomata in albino leaf patches of both plants did not respond to red light, although blue light could still induce stomatal opening. This shows that the response to PAR is not functioning in albino leaf patches, even though guard cells of C. comosum harbour chloroplasts. Stomata of Nf-treated plants still responded to CO2 and abscisic acid (ABA). The size of Nf-treated guard cells was increased, but impalement studies with double-barrelled microelectrodes revealed no changes in ion-transport properties at the plasma membrane of guard cells. Blue light could hyperpolarize albino guard cells by triggering outward currents with peak values of 37 pA in albino plants and 51 pA in green control cells. Because of the inhibition of carotenoid biosynthesis, Nf-treated V. faba plants contained only 4% of the ABA content found in green control plants. The ABA dose dependence of anion channel activation in guard cells was shifted in these plants, causing a reduced response to 10 microM ABA. These data show that despite the dramatic changes in physiology caused by Nf, the gross responsiveness of guard cells to blue light, CO2 and ABA remains unaltered. Stomata in albino leaf patches, however, do not respond to PAR, but require photosynthetically active mesophyll cells for this response.

The relationship between alkaline phosphatase activity and intracellular lipid accumulation in murine 3T3-L1 cells and human preadipocytes.

Alkaline phosphatase (ALP) is expressed in 3T3-L1 preadipocytes, and its activity increases during adipogenesis. The purpose of this study was to determine whether ALP activity could be used as a measure of intracellular lipid accumulation in human preadipocytes and 3T3-L1 cells and which of the factors that induce adipogenesis are responsible for stimulating ALP activity. Adipogenesis was initiated in 3T3-L1 cells by incubation with differentiation medium containing insulin, dexamethasone, and 3-isobutyl-1-methylxanthine. The effect of leaving out each of the differentiation medium components was studied. Adipogenesis was also assessed in human preadipocytes and 3T3-L1 cells in the presence of the ALP inhibitor histidine. ALP activity was measured using an automated colorimetric assay and intracellular lipid accumulation was measured using the lipid-specific dye oil red O. Removal of insulin or dexamethasone from the differentiation medium had little effect on either ALP activity or lipid accumulation in 3T3-L1 cells, while removal of IBMX blocked both. Histidine inhibited ALP activity and adipogenesis in human preadipocytes and 3T3-L1 cells. Pearson univariate correlation analysis demonstrated strong correlations between ALP activity and lipid accumulation in human preadipocytes (r=0.78, n=69) and in 3T3-L1 cells (r=0.92, n=27). These data suggest that ALP and fat storage are tightly linked during preadipocyte maturation and that the measurement of ALP activity may be a novel technique for the quantification of intracellular lipid accumulation that is more sensitive and rapid than currently used methods.

The effect of alkaline phosphatase inhibitors on intracellular lipid accumulation in preadipocytes isolated from human mammary tissue.

BACKGROUND: A previous study has demonstrated that alkaline phosphatase (AP) may play a role in the control of intracellular lipid accumulation in the rodent preadipocyte cell line, 3T3-L1. The present study investigated whether AP may have a similar function in preadipocytes isolated from human mammary gland tissue. METHODS: Preadipocyte maturation was induced in the presence or absence of the tissue non-specific AP inhibitors levamisole and histidine, and the tissue-specific AP inhibitor PheGlyGly. Cellular AP activity and adipogenesis were both assessed at 0 and 12 days post-induction of differentiation. RESULTS: After differentiation, AP activity increased 5.1 +/- 1.3-fold in the absence and 8.9 +/- 2.8-fold (P < 0.05) in the presence of levamisole. However, adipogenesis increased 1.95 +/- 0.11-fold in the absence but only 1.36 +/- 0.06-fold (P < 0.001) in the presence of levamisole. There was a 4.2 +/- 2.2-fold increase in AP activity in the absence and a 0.51 +/- 0.46-fold (P < 0.05) decrease in the presence of histidine. Adipogenesis increased 2.09 +/- 0.35-fold in the absence of histidine but only 1.22 +/- 0.30-fold (P < 0.05) in the presence of histidine. PheGlyGly had no effects. Fluorescent microscopy showed AP activity was localized to the triglyceride-containing droplets of the cell. CONCLUSION: This is the first study to show that tissue non-specific AP inhibitors can block adipogenesis in human preadipocytes.

Nondestructive assessment of leaf chemistry and physiology through spectral reflectance measurements may be misleading when changes in trichome density co-occur.

Reflectance indices are frequently used for the nondestructive assessment of leaf chemistry, especially pigment content, in environmental or developmental studies. Since reflectance spectra are influenced by trichome density, and trichome density displays a considerable phenotypic plasticity, we asked whether this structural parameter could be a source of variation in the values of the most commonly used indices. Trichome density was manipulated in detached leaves of three species having either peltate (Olea europaea and Elaeagnus angustifolius) or tubular (Populus alba) trichomes by successive removal of hairs. After each dehairing step, trichome density was determined by light or scanning electron microscopy and reflectance spectra were obtained with a diode-array spectrometer. Although species-specific differences were evident, most of the indices were considerably affected even at low trichome densities. In general, the less-affected indices were those using wavebands within the visible spectral region. The index that could be safely used even at very high hair densities in all species was the red edge index (lambda(RE)) for chlorophyll. The results indicate that changes in reflectance indices should be interpreted cautiously when concurrent changes in trichome density are suspected. In this case, the red edge for chlorophyll content may be the index of choice.

Development and structure of drought-tolerant leaves of the Mediterranean shrub Capparis spinosa L.

Capparis spinosa (caper), a winter-deciduous perennial shrub, is a consistent floristic element of Mediterranean ecosystems, growing from May to October, i.e. entirely during the prolonged summer drought. The internal architecture of young and fully expanded leaves was studied, along with certain physiological characteristics. Capparis spinosa possesses thick, amphistomatic and homobaric leaves with a multilayered mesophyll. The latter possesses an increased number of photosynthesizing cells per unit leaf surface, a large surface area of mesophyll cells facing intercellular spaces (Smes) and a low percentage of intercellular space per tissue volume. Smes and chlorophyll content attain their maximum values synchronously, slightly before full leaf expansion. Nitrogen investment is also completed before full leaf expansion. The structural features, in combination with the water status, could contribute to enhanced rates of transpiration and photosynthesis under field water shortage conditions.

Exposed red (anthocyanic) leaves of Quercus coccifera display shade characteristics.

Young leaves in some plants are transiently red due to the presence of anthocyanins, which disappear upon maturation. We investigated the hypothesis that light attenuation by anthocyanins may lead to a shade acclimation of the photosynthetic machinery in red leaves. We took advantage of the intra-species variation in anthocyanin levels of young, exposed leaves of Quercus coccifera. Thus, photosynthetic and photoprotective characteristics were compared in young green and red leaves of the same age, sampled from the corresponding phenotypes occupying the same habitat. Red leaves displayed several shade attributes like thinner laminae, lower Chl a/b ratios and lower levels of the xanthophyll cycle components and ß-carotene. In addition, although both leaf kinds had the same area based levels of chlorophylls, these pigments were excluded from the sub-epidermic anthocyanic cell layers, leading to a further reduction of effective mesophyll thickness and an increase in chlorophyll density. Accordingly, red leaves had higher absolute chlorophyll fluorescence signals. In spite of these apparent shade characters, red leaves were less prone to photoinhibition under mild laboratory conditions and displayed slightly but significantly higher PS II photochemical efficiencies at pre-dawn in the field. No differences in all the above measured parameters were found in mature green leaves of the two phenotypes. The results confirm the light acclimation hypothesis and are also compatible with a photoprotective function of anthocyanins.