The endocycle restores tissue tension in the Drosophila abdomen post wound repair.

Polyploidy frequently arises in response to injury, aging, and disease. Despite its prevalence, major gaps exist in our understanding of how polyploid cells alter tissue function. In the adult Drosophila epithelium, wound healing is dependent on the generation of multinucleated polyploid cells resulting in a permanent change in the epithelial architecture. Here, we study how the wound-induced polyploid cells affect tissue function by altering epithelial mechanics. The mechanosensor nonmuscle myosin II is activated and upregulated in wound-induced polyploid cells and persists after healing completes. Polyploidy enhances relative epithelial tension, which is dependent on the endocycle and not cell fusion post injury. Remarkably, the enhanced epithelial tension mimics the relative tension of the lateral muscle fibers, which are permanently severed by the injury. As a result, we found that the wound-induced polyploid cells remodel the epithelium to maintain fly abdominal movements, which may help compensate for lost tissue tension.

Fabricated or induced illness in twins associated with insertion of trocar needles into their bodies.

Fabricated and/or induced illness (previously known as Munchausen syndrome by proxy) is a form of child abuse in which the perpetrator induces, exaggerates or fabricates illness in his/her child. Two-month-old twins were referred to the paediatric surgery centre with trocar needles lodged in different organs. A radiograph undertaken in one of them because of acute respiratory distress demonstrated needles in the heart and diaphragm which were removed surgically. The second twin, referred one week after his brother, had a needle deep in his liver and it was decided not to operate owing to the possibility of haemorrhage but, sadly, he died unexpectedly and the autopsy concluded that it was owing to sudden infant death syndrome. Because of a number of admissions to different units in the same hospital, there was a delay in the eventual diagnosis. Recurrent admissions to different hospital units should raise the suspicion of fabricated and/or induced illness.

Prevalence of occupational injuries and knowledge of availability and utilization of post exposure prophylaxis among health care workers in Singida District Council, Singida Region, Tanzania.

BACKGROUND: Infection with Human Immunodeficiency Virus is a serious public health problem that threatens the lives of many people including health care workers. Health care workers are frequently exposed to occupational hazards throughout their careers. Health care workers are at risk of being infected by the virus when caring for patients in health care facilities. Utilization of HIV Post-exposure Prophylaxis (HIV PEP) is very vital once an individual is exposed. AIM: The aim of this study is to determine the prevalence of occupational exposure, knowledge of, availability and utilization of post exposure prophylaxis among health care workers in Singida District Council, Tanzania. METHODS: A descriptive cross sectional study was conducted from April to May 2013. Health care workers actively treating patients were enrolled from 18 heath facilities in Singida District Council. Data were collected using a self-administered questionnaire, and analysed using Stata version 12. RESULTS: Out of 239 participants, slightly more than half, 124 (52%) had inadequate overall knowledge of HIV PEP. Of the 239, 121(50.6%) participants experienced occupational exposure. Two leading types of exposure were blood splash 57(47.1%) and needle stick injuries 45 (37.2%),respectively. Among the 121 exposed participants, 83(68.6%) reported the exposure incident, 91(75.2%) had an HIV test, 32 (26.4%), started HIV PEP after testing, 28 (23.1%), completed HIV PEP, and 65 (53.7%) had a follow-up HIV test. About two thirds (159/239), of participants reported that HIV PEP services were available at the time the study was conducted, and 49 (20.5%), reported daily access to HIV PEP service. CONCLUSION: The prevalence of occupational exposure among health care workers is high with low utilization of HIV PEP. The majority of healthcare workers had inadequate knowledge of HIV PEP. The findings highlight the need to improve the level of knowledge of HIV PEP and utilization of PEP among this at-high-risk-group in Singida.

In Vivo Mouse Intervertebral Disc Degeneration Model Based on a New Histological Classification.

Although human intervertebral disc degeneration can lead to several spinal diseases, its pathogenesis remains unclear. This study aimed to create a new histological classification applicable to an in vivo mouse intervertebral disc degeneration model induced by needle puncture. One hundred six mice were operated and the L4/5 intervertebral disc was punctured with a 35- or 33-gauge needle. Micro-computed tomography scanning was performed, and the punctured region was confirmed. Evaluation was performed by using magnetic resonance imaging and histology by employing our classification scoring system. Our histological classification scores correlated well with the findings of magnetic resonance imaging and could detect degenerative progression, irrespective of the punctured region. However, the magnetic resonance imaging analysis revealed that there was no significant degenerative intervertebral disc change between the ventrally punctured and non-punctured control groups. To induce significant degeneration in the lumbar intervertebral discs, the central or dorsal region should be punctured instead of the ventral region.

[Catch me if you can: endoscopic remove of a needle from the jejunum]. / Catch me if you can: Endoskopische Bergung einer Sicherheitsnadel aus dem tiefen Dünndarm.

INTRODUCTION: The ingestion of foreign bodies is a frequently observed problem in daily clinical practice. In order to avoid complications such as perforation, endoscopic removal of potentially penetrating foreign bodies should be attempted quickly. The use of various endoscopic techniques has been reported for this purpose. However, extraction of foreign bodies from the mid gastrointestinal tract has rarely been reported. CASE REPORT: We present the case of a patient who had swallowed a safety needle which could safely be removed from the jejunum by means of double-balloon enteroscopy (DBE). The combination of a thin p-type enteroscope with a thick t-type overtube was used in order to improve the manoeuvrability of the endoscope. The needle was pulled into the overtube which served as a protective shield during the retrieval of the endoscope. CONCLUSION: Our case report describes the potential of removing foreign bodies from the deep small bowel by pulling them into the overtube of a double-balloon enteroscope. If the suspicion of foreign body impaction in the small bowel is made, it may be advisable to primarily choose a balloon enteroscopy system. Through this, quick and deep insertion can be combined with a safe removal of the foreign body.

The CXCR1/2 ligand NAP-2 promotes directed intravascular leukocyte migration through platelet thrombi.

Thrombosis promotes leukocyte infiltration into inflamed tissues, leading to organ injury in a broad range of diseases; however, the mechanisms by which thrombi guide leukocytes to sites of vascular injury remain ill-defined. Using mouse models of endothelial injury (traumatic or ischemia reperfusion), we demonstrate a distinct process of leukocyte recruitment, termed "directed intravascular migration," specifically mediated by platelet thrombi. Single adherent platelets and platelet aggregates stimulated leukocyte shape change at sites of endothelial injury; however, only thrombi were capable of inducing directed intravascular leukocyte migration. Leukocyte recruitment and migration induced by platelet thrombi occurred most prominently in veins but could also occur in arteries following ischemia-reperfusion injury. In vitro studies demonstrated a major role for platelet-derived NAP-2 (CXCL-7) and its CXCR1/2 receptor in regulating leukocyte polarization and motility. In vivo studies demonstrated the presence of an NAP-2 chemotactic gradient within the thrombus body. Pharmacologic blockade of CXCR1/2 as well as genetic deletion of NAP-2 markedly reduced leukocyte shape change and intrathrombus migration. These studies define a distinct process of leukocyte migration that is initiated by homotypic adhesive interactions between platelets, leading to the development of an NAP-2 chemotactic gradient within the thrombus body that guides leukocytes to sites of vascular injury.

Needle puncture injury causes acute and long-term mechanical deficiency in a mouse model of intervertebral disc degeneration.

Low back pain is a significant socioeconomic burden and intervertebral disc degeneration has been implicated as a cause. A reliable animal model of disc degeneration is necessary to evaluate therapeutics, and functional metrics are essential to quantify their benefit. To this end, needle puncture injuries were created in the caudal intervertebral discs of mice to induce disc degeneration. Compression, torsion, and creep mechanics were assessed both immediately and after eight weeks to distinguish between the effects of injury and the subsequent reparative or degenerative response. Two needle sizes (29 and 26 gauge) were used to determine injury size-dependence. Compressive stiffness (62%), torsional stiffness (60%), and early damping stiffness (84%) decreased immediately after injury with the large needle (26G). These mechanical properties did not change over time despite structural and compositional changes. At 8 weeks following large needle injury, disc height decreased (37%), nucleus pulposus (NP) glycosaminoglycan content decreased (41%), and NP collagen content increased (45%). The small needle size had no significant effect on mechanics and did not initiate degenerative changes in structure and composition. Thus, the injection of therapeutics into the NP with a minimal needle size may limit damage due to the needle insertion. These findings, along with the wide commercial availability of mouse-specific biological probes, indicate that the mouse caudal disc model can be a powerful tool for investigating disc degeneration and therapy.

Detailed finite element modelling of deep needle insertions into a soft tissue phantom using a cohesive approach.

Detailed finite element modelling of needle insertions into soft tissue phantoms encounters difficulties of large deformations, high friction, contact loading and material failure. This paper demonstrates the use of cohesive elements in high-resolution finite element models to overcome some of the issues associated with these factors. Experiments are presented enabling extraction of the strain energy release rate during crack formation. Using data from these experiments, cohesive elements are calibrated and then implemented in models for validation of the needle insertion process. Successful modelling enables direct comparison of finite element and experimental force-displacement plots and energy distributions. Regions of crack creation, relaxation, cutting and full penetration are identified. By closing the loop between experiments and detailed finite element modelling, a methodology is established which will enable design modifications of a soft tissue probe that steers through complex mechanical interactions with the surrounding material.

Endoneurial pathology of the needlestick-nerve-injury model of Complex Regional Pain Syndrome, including rats with and without pain behaviors.

Current rodent models of neuropathic pain produce pain hypersensitivity in almost all lesioned animals and not all identified experimental effects are pain specific. 18G needlestick-nerve-injury (NNI) to one tibial nerve of outbred Sprague-Dawley rats models the phenotype of Complex Regional Pain Syndrome (CRPS), a post-traumatic neuropathic pain syndrome, leaving roughly half of NNI rats with hyperalgesia. We compared endoneurial data from these divergent endophenotypes searching for pathological changes specifically associated with pain-behaviors. Tibial, sural, and common sciatic nerves from 12 NNI rats plus 10 nerves from sham-operated controls were removed 14 days post-surgery for morphometric analysis. PGP9.5(+) unmyelinated-fibers were quantitated in plantar hindpaw skin. Distal tibial nerves of NNI rats had endoneurial edema, 30% fewer axons, twice as many mast cells, and thicker blood-vessel walls than uninjured tibial nerves. However the only significant difference between nerves from hyperalgesic versus non-hyperalgesic NNI rats was greater endoneurial edema in hyperalgesic rats (p < 0.01). We also discovered significant axonal losses in uninjured ipsilateral sural nerves of NNI rats, demonstrating spread of neuropathy to nearby nerves formerly thought spared. Tibial and sural nerves contralateral to NNI had significant changes in endoneurial blood-vessels. Similar pathological changes have been identified in CRPS-I patients. The current findings suggest that severity of endoneurial vasculopathy and inflammation may correlate better with neuropathic pain behaviors than degree of axonal loss. Spread of pathological changes to nearby ipsilateral and contralateral nerves might potentially contribute to extraterritorial pain in CRPS.

Intraneural injections and regional anesthesia: the known and the unknown.

Peripheral nerve injury is a rare complication of regional anesthesia. Intraneural injections were once considered harbingers of neural injury with practitioners focusing on their avoidance. With ultrasound guidance, it is now possible to visualize the difference between perineural (outside the nerve), intraneural (below the epineurium), and intrafascicular (within the perineurium) injections and to determine their association with postoperative neurological complications. We also now have a better understanding of the multifactorial nature of neurologic injury based on the nerve anatomy, site of needle insertion, bevel type, location of the needle tip, pressure achieved during injection, and underlying patient factors. Using ultrasound guidance during nerve blocks has revealed that not all intraneural injections result in injury, and its use will continue to provide insight into the mechanism of anesthetic-related nerve injury.

Histomorphology and vascular lesions in dorsal rat skin used as injection sites for a subcutaneous toxicity study.

Subcutaneous injection of pharmaceutical compounds into the dorsal skin of rats is common in preclinical and nonclinical studies. However, no detailed histologic description of this anatomic location has been published to date. Following the observation of vascular lesions in the dorsum of rats in a thirteen-week toxicity study, a complementary study was performed on untreated Sprague-Dawley rats to evaluate the normal histology of the skin and subcutis, the potential effect of chronic subcutaneous injection on the morphology of the skin and its vasculature, and the spontaneous vascular pathology in the areas used as injection sites in the principal study. This study showed that saline injection did not fundamentally alter the morphology of the injection sites used for the principal study. Skin thickness was greater in males than in females. Although acellular intimal thickening occurred spontaneously in the dorsal skin of untreated males and females, only males had a spontaneous incidence of intimal hyperplasia. No site predilection for intimal lesions was apparent for either sex. Saline injection, or the physical trauma of injection, may induce intimal hyperplasia; males appear more likely to develop the lesion than do females. It is possible that acellular intimal thickening can progress to intimal hyperplasia under appropriate conditions.

Structural injury to the human sciatic nerve after intraneural needle insertion.

BACKGROUND: Recent clinical reports suggest that intraneural needle placement may not always lead to neurologic injury. To explain the absence of neurologic complications in these reports, we studied the risk and extent of nerve injury after intentional needle-nerve placement in a cryopreserved human sciatic nerve. METHODS: The sciatic nerve was dissected from a cryopreserved cadaver through partial exposure. Needles were inserted through the nerve, using blunt-tip (30 degrees beveled) (group A) and sharp-tip (15 degrees beveled) (group D) needles. Five needle insertions were made for each needle type. Subsequently, transverse nerve sections at 10 needle trajectories were processed. Nerve samples were stained with hematoxylin-eosin, Masson trichromic, and immunohistochemical stains. In each section, the following variables were quantified: total number of fascicles and vessels in the immediate vicinity of the needle trajectories and the number of injured fascicles and vessels. RESULTS: A total of 520 fascicles were quantified, of which 134 were in contact with the needle trajectories. The numbers of fascicles and vessels per section were 65 +/- 8 and 14 +/- 7, respectively. A mean of 16 +/- 5 fascicles were found in contact with the needle trajectory (group A: 17+/- 3, group D: 15 +/- 6). Of these, 4 fascicles (3.2%) and 1 intraneural vessel were found damaged in group D. No fascicular or vascular injuries were found in group A. CONCLUSIONS: Our findings suggest that intraneural needle insertion may more commonly result in interfascicular rather than intrafascicular needle placement.

Developing consistently reproducible intervertebral disc degeneration at rat caudal spine by using needle puncture.

OBJECT: The goal in this study was to develop a convenient, less-invasive animal model to monitor progression of intervertebral disc (IVD) degeneration for future testing of new treatments for disc degeneration. METHODS: Level 5/6 and 7/8 IVDs of rat caudal spine were stabbed laterally with 18- or 21-gauge hypodermic needles to a depth of 5 mm from the subcutaneous surface with the aid of fluoroscopy. In vivo MR imaging studies were performed at 4, 8, and 12 weeks postsurgery to monitor progression of IVD degeneration. Histological analysis including H & E and safranin O staining, and immunohistochemical studies of collagen type II and bone morphogenetic protein receptor type II (BMPRII) were assessed at 12 weeks postsurgery. RESULTS: The 18- and 21-gauge needle-stabbed discs illustrated decreases in both the T2 density and MR imaging index starting at 4 weeks, with no evidence of spontaneous recovery by 12 weeks. Histological staining demonstrated a decreased nucleus pulposus (NP) area, and the NP-anulus fibrosus border became unclear during the progression of disc degeneration. Similar patterns of degenerative signs were also shown in both safranin O- and collagen type II-stained sections. The BMPRII immunohistochemical analysis of stabbed discs demonstrated an increase in BMPRII expression in the remaining NP cells and became stronger in anulus fibrosus with the severity of disc degeneration. CONCLUSIONS: After introducing an 18- or 21-gauge needle into the NP area of discs in the rat tail, the stabbed disc showed signs of degeneration in terms of MR imaging and histological outcome measurements. Changes in BMPRII expression in this animal model provide an insight for the effectiveness of delivering BMPs into the region responsible for chondrogenesis for disc repair. This convenient, less-invasive, reproducible, and cost-effective model may be a useful choice for testing novel treatments for disc degeneration.

Needle puncture injury affects intervertebral disc mechanics and biology in an organ culture model.

STUDY DESIGN: A bovine intervertebral disc organ culture model was used to study the effect of needle puncture injury on short-term disc mechanics and biology. OBJECTIVE: To test the hypothesis that significant changes in intervertebral disc structure, mechanics, and cellular response would be present within 1 week of needle puncture injury with a large-gauge needle but not with a small-gauge needle. SUMMARY OF BACKGROUND DATA: Defects in anulus fibrosus induced by needle puncture injury can compromise mechanical integrity of the disc and lead to degeneration in animal models. The immediate and short-term mechanical and biologic response to anulus injury through needle puncture in a large animal model is not known. METHODS: Bovine caudal intervertebral discs were harvested, punctured posterolaterally using 25G and 14G needles, and placed in organ culture for 6 days. Discs underwent a daily dynamic compression loading protocol for 5 days from 0.2 to 1 MPa at 1 Hz for 1 hour. Disc structure and function were assessed with measurements of dynamic modulus, creep, height loss, water content, proteoglycan loss to the culture medium, cell viability, and histology. RESULTS: Needle puncture injury caused a rapid decrease in dynamic modulus and increase in creep during 1-hour loading, although no changes were detected in water content, disc height, or proteoglycan lost to the media. Cell viability was maintained except for localized cell death at the needle insertion site. An increase in cell number and possible remodeling response was seen in the insertion site in the nucleus pulposus. CONCLUSION: Relatively minor disruption in the disc from needle puncture injury had immediate and progressive mechanical and biologic consequences with important implications for the use of discography, and repair-regeneration techniques. Results also suggest diagnostic techniques sensitive to mechanical changes in the disc may be important for early detection of degenerative changes in response to anulus injury.

Stem cell renewal and contraction of the tunica media caused by a damaged blood vessel following a thick needle stab.

A marked difference in the healing process of the inferior vena cava in rats following a stab with a 17-G (1.48 mm phi) ultrahard zirconium ceramic (Zr) needle and with a common stainless steel (St) needle (also 1.48 mm phi was observed. This was investigated in vivo by histological imaging and biochemical micro-autoradiographic imaging using [2-(14)C]-thymidine as a biomarker in vivo. On the first day after the stab with either, the Zr or the St injection needle, the tunica adventitia showed the most pronounced damage, as evidenced by a large puncture wound characterized by blood congestion, but with few inflammatory cells being observed. A marked contraction of the tunica media was observed. The depth of the injury reached the tunica layer, but amounted to less than 1/3 of the needle diameter. Loose fragments of the endothelial lining were detected, together with scattered red corpuscles. The survival rate of the experimental animals amounted to less than 40% on the 3rd day after the stab by either the Zr or St needle, due to the large needle diameter. In addition, histological imaging of the wound area in the endothelial layer and tunica media showed considerable congestion and inflammation, which limited the evaluation of the regeneration status of the inferior vena cava of the surviving animals. Results were obtained from a few animals that displayed satisfactory recovery status. On the 3rd day after the stab by either the Zr or St injection needle, a relatively large proportion of the hemostatic clots became incorporated into the collagenous tissue, i.e. the tunica adventitia. A marked contraction of the tunica media was also observed, similar to that on the 1st day, following the needle injury. In the case of the endothelium (tunica intima), the injury caused by the Zr needle was reinfiltrated by adult stem cells 3 days after the stab, but the tunica media, composed of endothelial cells, still contained relatively contracted collagenous material. In addition, several interesting cell colonies were observed in the medial layer at the short distance from the boundary of the damaged tissue. It was assumed that these colonies produced medial tissue composed of collagenous supporting tissue or smooth muscle cells. In the experiment using the St needle, the incorporation of [2-(14)C]-thymidine into the nucleus of the stem cells was observed in the small capillaries of the tunica media, but not in the support cells of the latter.

Injury caused by self-inoculation with a vaccine of a Freund's complete adjuvant nature (Gudair) used for control of ovine paratuberculosis.

OBJECTIVE: To document the occurrence and consequences of accidental self-inoculation of vaccinators (producers, farm employees, contractors) with the recently registered Gudair vaccine for the control of ovine paratuberculosis in Australia. DESIGN AND PROCEDURE: A survey of the first 50 primary producers permitted to use the vaccine in sheep and a description of six cases of accidental self-inoculation for which medical attention was sought, and which occurred after the vaccine became widely available. RESULTS: The survey recorded that, of 37 respondents vaccinating 155,523 sheep, there were 21 incidents of exposure to the vaccine, an overall rate of one incident per 7406 vaccinations. In five of these incidents there was only superficial skin contact with vaccine; in 16 there was needle penetration without vaccine injection. There were no reports of self-inoculation with vaccine. Six cases of self-inoculation with Gudair vaccine that required medical intervention are described. Of these five were in males and one in a female; four involved injection of vaccine into the leg and single cases involved a foot or hand. Most cases required surgical removal of the injected vaccine to allow wound repair; three required extensive surgery and open drainage. Even with surgery recovery took as long as 9 months. Possible risk factors for self-inoculation and the resulting outcome are discussed. CONCLUSIONS: Gudair ovine paratuberculosis vaccine can cause prolonged granulomatous inflammation if inadvertently injected into human tissue. After.self-inoculation, early surgical debridement of the damaged tissue and drainage to remove the vaccine material are advised to avoid progression to extensive necrosis.

Dangers of dermatologic surgery: protect your feet.

Dermatologists frequently utilize scalpels, which are reported to be to culprit in around seven percent of the 385,000 sharps-related injuries sustained by healthcare personnel a year. Injuries from sharp devices are associated with the occupational transmission of more than 20 pathogens. Dropped scalpels may penetrate unprotected lower extremity skin, and there is no published data regarding what a shoe's actual degree of protection is against the danger of falling sharps. The purpose of this study was to evaluate and determine which types of shoes will protect their wearers. Although every shoe decreased falling sharp's degree of penetration into the feet, shoes cannot be relied on to prevent injury. More than half of the shoes allowed the scalpel blade to pass through the shoes and penetrate into the meat.