Interdigital Webs Research Articles

Evaluation of the effects of repeated disinfection on medical exam gloves: Part 1. Changes in physical integrity

COVID-19 has created shortages of personal protective equipment. In resource-constrained situations, limited cycles of disinfection and extended use of gloves is recommended by the U.S. Centers for Disease Control and Prevention to conserve supplies. However, these guidelines are based on limited evidence. In this study, serial cycles of hand hygiene were performed on gloved hands using an ethanol-based hand rub (six and 10 cycles), 0.1% sodium hypochlorite (bleach) solution (10 cycles), or soap and water (10 cycles) on latex and nitrile medical exam gloves from the United States and India. A modified water-leak test evaluated glove integrity after repeated applications of these disinfecting agents. When aggregated, dilute bleach demonstrated the lowest difference between treatment and control arms: −2.5 percentage points (95% CI: −5.3 to 0.3) for nitrile, 0.6 percentage points (95% CI: −2.6 to 3.8) for non-powdered latex. For U.S.-purchased gloves tested with six and 10 applications of ethanol-based hand rub, the mean difference in failure risk between treatment and control gloves was within the prespecified non-inferiority margin of five percentage points or less, though some findings were inconclusive since outside the margin. The aggregated difference in failure risk between treatment and control was 3.5 percentage points (0.6 to 6.4) for soap and water, and 2.3 percentage points (−0.5 to 5.0) and 5.0 percentage points (1.8 to 8.2) for 10 and 6 applications of ethanol-based hand rub, respectively. Most leaks occurred in the interdigital webs (35%) and on the fingers (34%). This indicates that some combinations of glove types and disinfection methods may allow for extended use. Ten applications of dilute bleach solution had the least impact on glove integrity. However, the majority of glove and exposure combinations were inconclusive. Additional testing of specific glove and disinfectant combinations may inform future strategies to guide extended use during glove shortages. Additional considerations, not evaluated here, include duration of use, disinfectant chemical permeation, and the effects of hand temperature, movement, and manipulation of instruments on glove integrity.

The essentials of developmental apoptosis.

Apoptotic cells are commonly observed in a broad range of tissues during mammalian embryonic and fetal development. Specific requirements and functions of programmed cell death were inferred from early observations. These inferences did not hold up to functional proof for a requirement of apoptosis for normal tissue development in all cases. In this review, we summarize how the appraisal of the importance of developmental apoptosis has changed over the years, in particular with detailed functional assessment, such as by using gene-targeted mice lacking essential initiators or mediators of apoptosis. In recent years, the essentials of developmental apoptosis have emerged. We hypothesize that apoptosis is predominantly required to balance cell proliferation. The two interdependent processes—cell proliferation and apoptosis—together more powerfully regulate tissue growth than does each process alone. We proposed that this ensures that tissues and cell populations attain the appropriate size that allows fusion in the body midline and retain the size of cavities once formed. In addition, a limited number of tissues, albeit not all previously proposed, rely on apoptosis for remodeling, chiefly aortic arch remodeling, elimination of supernumerary neurons, removal of vaginal septa, and removal of interdigital webs in the formation of hands and feet.

Comparison of whole embryonic development in the duck (Anas platyrhynchos) and goose (Anser cygnoides) with the chicken (Gallus gallus)

Embryos from aquatic birds are the primary models for the study of flipper development. While some staging of early embryogenesis in duck have been studied, characterization of the stages of the entire embryonic development period in water birds has not been described. This study aimed to establish a comparison of complete morphological development staging for ducks (Anas platyrhynchos) and geese (Anser cygnoides) with the embryonic staging system by Hamburger and Hamilton (HH) for the chicken (Gallus gallus). Our results show that morphological development in the chicken, duck, and goose are similar in the early stages. The major differences occurred after stage 27 of embryonic development, where the beak shape in ducks and geese was wider and longer than in chickens. In addition, the second and third interdigital webs of the hind limb of the chicken were found to be degraded from stage 31, and eventually vanished at stage 35; however, they were retained in ducks and geese. Rapid physical development occurred in the mid-to-late stages in ducks and geese. To our best knowledge, this is the first description of complete embryonic development for the duck and goose. Establishment of an embryonic staging system for duck and goose provides new models for the study of waterfowl development.

High-resolution MR lymphangiography for planning lymphaticovenous anastomosis treatment: a single-centre experience.

This article illustrates the feasibility of MR lymphangiography (MRL) for imaging lymphatic vessels in patients with lymphedema, its accuracy in distinguishing lymphatic vessels from veins, and its utility for planning Lymphaticovenous anastomosis (LVA) treatment. We prospectively enrolled 30 patients (24 women, range 18-70, 17 cases of lower limb lymphedema, 6 cases of primary lymphedema). All the patients underwent MRL, using a 1.5T MR unit (Signa Twin Speed Hdxt; GE), after the subcutaneous injection of gadobenate dimeglumine (Gd-BOPTA) with a little dose of lidocaine into the interdigital webs of the dorsal foot or hand. Lymphatic vessels identified for the LVA at MRL were histologically confirmed after surgery. Enhancement of lymphatic vessels and veins at different times after injection of contrast medium and their diameters were measured. A total of 79 lymphatic vessels were clearly identified in 29 patients at MRL; their morphology was tortuous in 22 patients and rectilinear in 7, whereas, the adjacent veins were straight with focal bulging only at the level of venous valve; the enhancement kinetic of the two different structures were different (p<0.05) but the mean diameter of affected lymphatic vessels was similar to the adjacent veins (p>0.05). Thirty-four out of 38 specimens of presumed lymphatic vessels at MRL, collected during surgery, resulted positive at the immunoistochemical marker d2-40, with a significant association (Chi-square=40.421, DF=1, p<0.05, contingency coefficent 0.644). One patient had an early complication 1month after treatment. MRL is easy and safe to use and combines extensive information on the anatomy and functionality of lymphatic vessels and veins in a single process; therefore, it could be useful in LVA treatment planning and evaluating possible super-microsurgical treatment complications in patients with lymphedema.

Role of Atg5-dependent cell death in the embryonic development of Bax/Bak double-knockout mice.

Programmed cell death, which is required for the development and homeostasis of metazoans, includes mechanisms such as apoptosis, autophagic cell death, and necrotic (or type III) death. Members of the Bcl2 family regulate apoptosis, among which Bax and Bak act as a mitochondrial gateway. Although embryonic fibroblasts from Bax/Bak double-knockout (DKO) mice are resistant to apoptosis, we previously demonstrated that these cells die through an autophagy-dependent mechanism in response to various types of cellular stressors. To determine the physiological role of autophagy-dependent cell death, we generated Atg5/Bax/Bak triple-knockout (TKO) mice, in which autophagy is greatly suppressed compared with DKO mice. Embryonic fibroblasts and thymocytes from TKO mice underwent autophagy much less frequently, and their viability was much higher than DKO cells in the presence of certain cellular stressors, providing genetic evidence that DKO cells undergo Atg5-dependent death. Compared with wild-type embryos, the loss of interdigital webs was significantly delayed in DKO embryos and was even further delayed in TKO embryos. Brain malformation is a distinct feature observed in DKO embryos on the 129 genetic background, but not in those on a B6 background, whereas such malformations appeared in TKO embryos even on a B6 background. Taken together, our data suggest that Atg5-dependent cell death contributes to the embryonic development of DKO mice, implying that autophagy compensates for the deficiency in apoptosis.

Single-Stage Separation of 3- and 4-Finger Incomplete Simple Syndactyly With Contiguous Gull Wing Flaps: A Technique to Minimize or Avoid Skin Grafting

Staged separation of 3- and 4-finger syndactyly is commonly performed owing to concerns about vascular supply to the central digit and availability of flap skin. We performed single-stage separation of patients with incomplete syndactyly of multiple digits with adjacent contiguous dorsal gullwing flaps and avoided skin grafts in the majority of cases. Seventy-four webs of 31 patients with more than 2-finger incomplete syndactyly were included. Median age at surgical separation was 12 months (range, 5-123 months). All cases were incomplete syndactyly that did not extend to the fingernail level, with no bonyinvolvement. A dorsal gullwing flap was used for all cases, which reconstructed the interdigital webs and partly covered the lateral side of the proximal phalanx. The technique relies on perfusion of the flap through the dorsal metacarpal artery perforator to aid flap mobility and double radial and ulnar z-plasties on each side of the flap to aid flap advancement. Skin grafts were needed if there were any remaining skin defects. In 30 of 31 cases, a single-stage procedure was accomplished. One case was staged owing to abnormal digital arterial anatomy found on exploration. No skin graft was required in 21 out of 31 patients (67.7%). Median postoperative follow-up was 12 months (range, 6-36 months). All finger web depths were normal or slightly deepened. One-stage separation for 3- and 4-finger syndactyly with a dorsal gullwing flap is feasible and safe as long as at least 1 proper digital artery is preserved in each finger. The need for skin grafting is minimized. Therapeutic IV.

Comparison between VY flap and rhomboid flap in the treatment of pilonidal sinus

Objective The present work was designed to compare a VY flap and a rhombiod flap in the treatment of pilonidal sinus. Background The pilonidal sinus is a tract that usually contains hair. It occurs under the skin between the buttocks (the natal cleft) a short distance above the anus. The sinus track traverses in a vertical direction between the buttocks. Rarely, a pilonidal sinus occurs in other sites of the body such as the axilla, groin, interdigital webs, or the feet. The exact cause is not clear. There are various theories. For example, one theory states that the problem may develop from a minor congenital or hereditary abnormality in the skin of the natal cleft, in which the hair grows into the skin rather than outwards. Materials and methods We studied 30 patients aged 19-47 years (average, 30 ± 10 years) presenting to the outpatient clinic of El-Menoufia university hospital and El-Helal insurance hospital at Shebin El-Kom with pilonidal sinus from December 2012 and May 2013. The patients were followed up until July 2013. A total of 15 patients (50%) were treated with a VY flap and 15 (50%) were treated with a dufourmentel flap. Results The outcome was successful in 14 of 15 patients who received a VY flap and 15 of 15 patients who received a dufourmentel flap. The operative time is shorter in the VY method than the dufourmentel method (P Conclusion Recovery following treatment with a dufourmentel flap is better than with the other method.

Cellular senescence occurred widespread to multiple selective sites in the fetal tissues and organs of mice.

Cellular senescence protects multicellular organisms from tissue overgrowth including cancer, and contributes to tissue ageing. With stable cell cycle arrests, cellular senescence has been mostly studied in the adult tissues of mammals. In the present study, we report widespread cellular senescence within certain time windows of late-phase normal development of mouse embryos. Using in situ senescence-associated β-galactosidase (SA-β-gal) staining, we showed SA-β-gal activity in selected cell populations of the brain, stomach, interdigital webs, tail, ear, limbs and nasal mouth area on gestation day 14.5 of the mouse embryos. On day 18.5 of gestation, selected cells in the intestines and bone developmental areas showed SA-β-gal activity. The chondrocytes in ossification zones were significantly marked by the activities of SA-β-gal, p21, p15 and Hp1Y, suggesting activation of the cell cycle checkpoint by the p53 and Rb pathways, and development of senescence-associated heterochromatic foci. Throughout gestation days 14.5-18.5, the trophoblast cells in the labyrinth layer of the placentas also showed strong activities of SA-β-gal, p53 and p21. Increased expressions of p19, p16 and Rb of the p16/Rb pathway, and reduced expressions of Ki67 were also observed in the placentas. Taken together, the present findings suggest that cellular senescence represents an essential mechanism at multiple sites including the fetal bone forming zones and placenta during mammalian embryonic development, playing potential roles in the full embryonic development of tissue growth and organ formation.

Diagnosis of Inguinal Lymph Node Metastases Using Contrast Enhanced High Resolution MR Lymphangiography

Inguinal lymph nodes can be the first or the only clinical signs of tumor metastases. The aim of the study was to evaluate the role of contrast-enhanced high-resolution magnetic resonance (MR) lymphangiography in diagnosis of inguinal lymph node metastases. The study enrolled 26 patients with inguinal lymph node metastases. Contrast-enhanced lymphangiography was performed using a 3.0T MR unit after intracutaneous injection of gadobenate dimeglumine into the interdigital webs of the dorsal foot. Images of inguinal lymph nodes were acquired before and after contrast injection. All patients exhibited edema in the subcutaneous layer with significant dilatation of lymphatic collectors in the affected lower limbs on MR images. Before contrast injection, the outline and structure of the affected nodes were unclear on T2 weighted images. Structural changes became evident on postinjection T1-weighted images. Nodal involvement on contrast enhanced MR lymphangiograms was characterized as: 1) heterogeneous structure with partial or marginal enhancement of the node indicating partial occupation by tumor; 2) homogeneous structure of the node without contrast enhancement, indicating total occupation with metastasis, with increase or no change in size; and 3) heterogeneous structure with punctiform nodal enhancement indicating diffuse growth of tumor within the node. Further examinations confirmed the diagnoses of inguinal lymph node metastases of either regional or distal tumors. Contrast-enhanced high-resolution MR lymphangiography was a sensitive modality in the diagnosis of malignant peripheral lymphedema and the identification of inguinal lymph node metastasis in patients with various tumor origins.

BID, BIM, and PUMA are essential for activation of the BAX- and BAK-dependent cell death program.

Although the proteins BAX and BAK are required for initiation of apoptosis at the mitochondria, how BAX and BAK are activated remains unsettled. We provide in vivo evidence demonstrating an essential role of the proteins BID, BIM, and PUMA in activating BAX and BAK. Bid, Bim, and Puma triple-knockout mice showed the same developmental defects that are associated with deficiency of Bax and Bak, including persistent interdigital webs and imperforate vaginas. Genetic deletion of Bid, Bim, and Puma prevented the homo-oligomerization of BAX and BAK, and thereby cytochrome c-mediated activation of caspases in response to diverse death signals in neurons and T lymphocytes, despite the presence of other BH3-only molecules. Thus, many forms of apoptosis require direct activation of BAX and BAK at the mitochondria by a member of the BID, BIM, or PUMA family of proteins.

Diagnosis of peripheral lymph circulation disorders with contrast MR lymphangiography

To evaluate anatomical and functional images of contrast MR lymphangiography in the diagnosis of limb lymphatic circulation disorders. 30 patients with limb lymphedema were enrolled in the study. There were 27 patients of primary lymphedema and 3 of secondary lymphedema. Contrast enhanced lymphangiography was performed with 3.0 T MR Unit after intracutaneous injection of gadobenate dimeglumine into the interdigital webs of the dorsal foot and hand. The kinetics of enhanced lymph flow within the lymphatics were calculated using the formula: Speed (cm) = total length of visualized lymph vessel (cm)/ inspection time (minutes) and by comparing dynamic nodal enhancement and time-signal intensity curves between edematous and contralateral limbs. Morphological abnormalities of the lymphatic system were also evaluated. Following injection of the contrast agent enhanced lymphatic channels were consistently visualized in all clinical lymphedematous limbs and five contralateral limbs of unilateral lymphedema cases. The speed of enhanced flow within the lymphatics of lymphedematous limbs ranged from 0.30 to 1.48 cm/min. The contrast enhancement in inguinal nodes of edematous limbs was significantly lower than that of contralateral limbs (P < 0.01). Dynamic measurement of contrast enhancement showed a remarkable lowering of peak time (P < 0.01) and peak enhancement (P < 0.01) and a delay in outflow in inguinal nodes of affected limbs compared with that of control limbs. Post-contrast MR imaging also depicted varied distribution patterns of lymphatics and abnormal lymph flow pathways within lymph nodes in the limbs with lymphatic circulation disorders. Contrast MR lymphangiography with gadobenate dimeglumine was able to visualize the precise anatomy of lymphatic vessels and lymph nodes in lymphedematous limbs. It also provided comprehensive information about the functional status of lymph flow transportation in lymphatics and lymph nodes.

ADAMTS Metalloproteases Generate Active Versican Fragments that Regulate Interdigital Web Regression

We show that combinatorial mouse alleles for the secreted metalloproteases Adamts5, Adamts20 (bt), and Adamts9 result in fully penetrant soft-tissue syndactyly. Interdigital webs in Adamts5(-/-);bt/bt mice had reduced apoptosis and decreased cleavage of the proteoglycan versican; however, the BMP-FGF axis, which regulates interdigital apoptosis was unaffected. BMP4 induced apoptosis, but without concomitant versican proteolysis. Haploinsufficiency of either Vcan or Fbln1, a cofactor for versican processing by ADAMTS5, led to highly penetrant syndactyly in bt mice, suggesting that cleaved versican was essential for web regression. The local application of an aminoterminal versican fragment corresponding to ADAMTS-processed versican, induced cell death in Adamts5(-/-);bt/bt webs. Thus, ADAMTS proteases cooperatively maintain versican proteolysis above a required threshold to create a permissive environment for apoptosis. The data highlight the developmental significance of proteolytic action on the ECM, not only as a clearance mechanism, but also as a means to generate bioactive versican fragments.

Anatomic and functional evaluation of the lymphatics and lymph nodes in diagnosis of lymphatic circulation disorders with contrast magnetic resonance lymphangiography

Owing to its structural and anatomic characteristics, imaging of the lymphatic system has been difficult. The conventional diagnostic method of radionuclide-based imaging has the disadvantage of poor resolution. Recent work has shown that magnetic resonance imaging (MRI) can depict lymphatic channels in patients with lymphedema. This study evaluated the anatomic and functional images of contrast MR lymphangiography in the diagnosis of limb lymphatic circulation disorders. The study enrolled 27 patients with primary lymphedema. Four patients had bilateral disease, and 23 had unilateral disease. Contrast-enhanced lymphangiography was performed with a 3.0-T MR unit after the intracutaneous injection of gadobenate dimeglumine into the interdigital webs of the dorsal foot. The kinetics of enhanced lymph flow within the lymphatic system were calculated using the formula [speed in cm = total length of visualized lymph vessel in cm/inspection time in minutes] and by comparing dynamic nodal enhancement and time-signal intensity curves between edematous and contralateral limbs. Morphologic abnormalities of the lymphatic system were also evaluated. Examination of the MRIs after injection of the contrast agent showed enhanced lymphatic channels consistently visualized in all clinical lymphedematous limbs and in five contralateral limbs of unilateral lymphedema patients. The speed of flow within the lymphatics of lymphedematous limbs was 0.3 to 1.48 cm/min. Contrast enhancement in inguinal nodes of edematous limbs was significantly less than that of contralateral limbs (P < .01). Dynamic measurement of contrast enhancement showed a remarkable lowering of peak time (P < .01) and peak enhancement (P < .01), and a delay in outflow in inguinal nodes of affected limbs compared with that of control limbs. Postcontrast MRI also depicted varied distribution patterns of lymphatics and abnormal lymph flow pathways within lymph nodes in the limbs with lymphatic circulation disorders. Contrast MR lymphangiography with gadobenate dimeglumine is capable of visualizing the precise anatomy of lymphatic vessels and lymph nodes in lymphedematous limbs. It also provides information concerning the functional status of lymph flow transport in the lymphatic vessels and lymph nodes of these limbs.

Eritrasma interdigital: datos clínicos, epidemiológicos y microbiológicos

BackgroundErythrasma is a superficial infection caused by Corynebacterium minutissimum and affects the major skin folds and the interdigital regions of the feet. It is characterized by erythematous, brown, scaly patches and maceration, and exhibits coral-red fluorescence under Wood light. ObjectiveThe aim of this study was to determine the frequency of erythrasma in patients with interdigital lesions. MethodsAn open, prospective, longitudinal, observational study was performed in a hospital in Mexico City between March and December, 2006. All patients with interdigital lesions were examined with a Wood lamp and direct examination was performed with 20 % potassium hydroxide. Cultures were done in Sabouraud dextrose agar and brain heart infusion agar, and smears were analyzed. General characteristics and concomitant diseases were recorded. ResultsWe examined 73 patients, of whom 24 (32.8%) were diagnosed with erythrasma based on coral-red fluorescence under Wood light and identification of corynebacteria by Gram staining. The disease was more common in women (83.33 %) and the mean age of the patients was 43.5 years. The main clinical findings were scaling and maceration, and the fourth interdigital web was the most commonly affected. Corynebacterium could not be isolated in any of the cases. Mycology was positive in 15 cases (62.5 %) and the following microorganisms were isolated: Candida (16.6 %), dermatophytes (12.5 %), and Trichosporon (4.1 %). ConclusionsInterdigital erythrasma is a common condition and can be easily confused with interdigital tinea. It persists if not treated appropriately. Rapid diagnosis is easily obtained by examination with a Wood lamp, while culture is difficult and unnecessary for diagnosis. The coexistence of erythrasma with dermatophytes and Candida should be considered when the interdigital webs are affected.

MR lymphangiography for the assessment of the lymphatic system in patients undergoing microsurgical reconstructions of lymphatic vessels

Objective To assess the morphology of the lymphatic system pre- and postoperatively in patients undergoing microsurgical reconstructions of the lymphatic vessels. Materials and methods 8 lower extremities in 4 consecutive patients with secondary unilateral lymphedema of the lower extremities were examined by MR lymphangiography. 18 mL of gadoteridol and 1 mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously into the dorsal aspect of each foot at the region of the four interdigital webs and medial to the first proximal phalanx. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography a 3D-spoiled gradient-echo sequence was used. For evaluation of the lymphedema a heavily T2-weighted 3D-TSE sequence was performed. Results In 2 patients the 3D-TSE sequence demonstrated a decrease of the epifascial lymphedema in the postoperative acquisitions, whereby MR lymphangiography displayed an improvement of dermal-back areas and collateral lymphatic vessels. In one patient the epifascial lymphedema of the lower extremity decreased, whereas the diameter of the lymphatic vessels showed a constant diameter of 2 mm. In one patient with a lymphocutaneous fistula at the level of the right groin, the feeding lymphatic vessels and contrast media extravasation could clearly be visualized. The 3D-TSE sequence demonstrated an epi- as well as subfascial lymphedema of the right leg. Conclusion MR lymphangiography is a safe and accurate diagnostic imaging method for the pre- and postoperative evaluation of the lymphatic circulation in patients undergoing microlymphatic surgery. Due to the minimal-invasiveness and lack of radiation, diagnostic follow-up MR lymphangiography examinations can be performed routinely and with no risk for the patient.

Interdigital Erythrasma: Clinical, Epidemiologic, and Microbiologic Findings

Background Erythrasma is a superficial infection caused by Corynebacterium minutissimum and affects the major skin folds and the interdigital regions of the feet. It is characterized by erythematous, brown, scaly patches and maceration, and exhibits coral-red fluorescence under Wood light. Objective The aim of this study was to determine the frequency of erythrasma in patients with interdigital lesions. Methods An open, prospective, longitudinal, observational study was performed in a hospital in Mexico City between March and December, 2006. All patients with interdigital lesions were examined with a Wood lamp and direct examination was performed with 20% potassium hydroxide. Cultures were done in Sabouraud dextrose agar and brain heart infusion agar, and smears were analyzed. General characteristics and concomitant diseases were recorded. Results We examined 73 patients, of whom 24 (32.8%) were diagnosed with erythrasma based on coralred fluorescence under Wood light and identification of corynebacteria by Gram staining. The disease was more common in women (83.33%) and the mean age of the patients was 43.5 years. The main clinical findings were scaling and maceration, and the fourth interdigital web was the most commonly affected. Corynebacterium could not be isolated in any of the cases. Mycology was positive in 15 cases (62.5%) and the following microorganisms were isolated: Candida (16.6%), dermatophytes (12.5%), and Trichosporon (4.1%). Conclusions Interdigital erythrasma is a common condition and can be easily confused with interdigital tinea. It persists if not treated appropriately. Rapid diagnosis is easily obtained by examination with a Wood lamp, while culture is difficult and unnecessary for diagnosis. The coexistence of erythrasma with dermatophytes and Candida should be considered when the interdigital webs are affected.

A New Amazonian Species of the Frog Genus Colostethus (Dendrobatidae) that Lays its Eggs on Undersides of Leaves

We describe adults, tadpoles, advertisement calls, and provide information on the natural history of a new Amazonian species of Colostethus from Rio Branco, Acre, Brazil. The new species is diagnosed by small size, sexual dimorphism in ventral coloration, absence of median lingual process, white throat in males, testis white in adult males, absence of dorsolateral and ventral stripes, terminal discs of digits swollen, absence of swollen Finger III, fringes and webs absent on fingers, rudimentary interdigital webs between Toes III and IV. The species also differs from other described Colostethus species in tadpole morphology and acoustics. This species is the first Colostethus known to lay its eggs on the lower surface of leaves. Clutches of C. subfolionidificans, new species, are composed of about six to eight white eggs and are attended by the male. The tadpoles develop on the lower surface of leaves until stage 25, when they are carried by the male to complete metamorphosis in pools.

The efficacy of trident flap technique in releasing contracted first webspace in a burned hand

Staged separation of 3- and 4-finger syndactyly is commonly performed owing to concerns about vascular supply to the central digit and availability of flap skin. We performed single-stage separation of patients with incomplete syndactyly of multiple digits with adjacent contiguous dorsal gullwing flaps and avoided skin grafts in the majority of cases.Seventy-four webs of 31 patients with more than 2-finger incomplete syndactyly were included. Median age at surgical separation was 12 months (range, 5–123 months). All cases were incomplete syndactyly that did not extend to the fingernail level, with no bony involvement. A dorsal gullwing flap was used for all cases, which reconstructed the interdigital webs and partly covered the lateral side of the proximal phalanx. The technique relies on perfusion of the flap through the dorsal metacarpal artery perforator to aid flap mobility and double radial and ulnar z-plasties on each side of the flap to aid flap advancement. Skin grafts were needed if there were any remaining skin defects.In 30 of 31 cases, a single-stage procedure was accomplished. One case was staged owing to abnormal digital arterial anatomy found on exploration. No skin graft was required in 21 out of 31 patients (67.7%). Median postoperative follow-up was 12 months (range, 6–36 months). All finger web depths were normal or slightly deepened.One-stage separation for 3- and 4-finger syndactyly with a dorsal gullwing flap is feasible and safe as long as at least 1 proper digital artery is preserved in each finger. The need for skin grafting is minimized.Therapeutic IV.

Loss of Nidogen-1 and -2 Results in Syndactyly and Changes in Limb Development

Nidogens are two ubiquitous basement membrane proteins produced mainly by mesenchymal cells. Nidogen-mediated interactions, in particular with laminin, collagen IV, and perlecan have been considered important in the formation and maintenance of the basement membrane. However, whereas mice lacking both nidogen isoforms or carrying mutations in the high affinity nidogen-binding site upon the laminin gamma1 chain have specific basement membrane defects in certain organs, particularly in the lung, characterization of these mice has also shown that basement membrane formation per se does not need nidogens or the laminin-nidogen interaction. Limb development requires the complex interplay of numerous growth factors whose expression is dependent upon the apical ectodermal ridge. Here, we show that lack of nidogen-1 and -2 results in a specific and time-limited failure in the ectodermal basement membrane of the limb bud. The absence of this basement membrane leads to aberrant apical ectodermal ridge formation. It also causes altered distribution of growth factors, such as fibroblast growth factors and leads to a fully penetrant soft tissue syndactyly caused by the dysregulation of interdigital apoptosis. Further, in certain animals more severe changes in bone formation occur, providing evidence for the interplay between growth factors and the extracellular matrix.

Localization of Apaf1 gene expression in the early development of the mouse by means of in situ reverse transcriptase‐polymerase chain reaction

Apoptosis is an essential ubiquitous process that controls the duration of the life span of cells, thus playing a crucial role in morphogenetic, histogenetic, and phylogenetic developmental processes. Apaf1 (apoptosis protease activating factor 1) is one of the central mediators of the intrinsic apoptotic pathway and a part of the apoptosome, which activates procaspase-3 and promotes cell death. Gene knockout of Apaf1 in mice leads to late embryonic lethality with malformations such as the persistence of interdigital webs and hyperplasia of brain and retina. Therefore, Apaf1 is generally believed to play a crucial role in developmental apoptosis and have a widespread expression. However, its pattern of expression in early development remains unknown. To specify whether Apaf1 indeed plays this key role, we investigated the pattern of gene expression for Apaf1 in mouse embryos on day 7, 9, and 12 of development. Our results show, that gene expression for Apaf1 first occurs within the embryo between day 7 and 9 of development, becoming more widespread toward day 12 and then includes structures, such as yolk sac, mesenchyme, cartilage, heart anlage, otic vesicle, peridermis, and anlagen of the spinal ganglia and vertebral bodies. Our results also show that gene expression for Apaf1 is not ubiquitous in early mouse development. This finding indicates that cell death processes are independent of or less dependent on Apaf1 during this time. Of interest, an active gene expression for Apaf1 is also present in organ anlagen such as heart or intestine, in which no obvious phenotype is seen after Apaf1 deletion. This finding suggests a possible role for Apaf1 in such anlagen as a putative alternative compensatory pathway, which could be switched on in the case of defects in the mediators that are normally involved in such organs.