Presence Of Necrotic Tissue Research Articles

Influence of serum and necrotic soft tissue on the antimicrobial effects of intracanal medicaments

The purpose of this study was to investigate the influence of serum and necrotic soft tissue on the antimicrobial activity of intracanal medicaments. The medicaments tested were: calcium hydroxyde/glycerin paste, calcium hydroxide/chlorhexidine paste, calcium hydroxide/camphorated paramonochlorophenol/glycerin paste, and chlorhexidine/zinc oxide paste. Survival of Enterococcus faecalis and Candida albicans exposed to the medicaments tested in the presence or absence of serum or necrotic tissue was monitored in three in vitro experiments where samples for culturing were taken at different time periods. The overall results demonstrated that the antimicrobial activity of all intracanal medicaments tested was slowed down in the presence of necrotic tissue. Calcium hydroxide pastes in glycerin or chlorhexidine were significantly affected by serum. Of the medicaments tested in this study, the least affected was the calcium hydroxide/camphorated paramonochlorophenol/glycerin paste.

Ex Vivo Evaluation of Antibacterial Effects of Nd:YAG and Diode Lasers in Root Canals

ABSTRACTThe presence of necrotic tissue and bacteria may cause the persistence of infection in root canals. The aim of this study is to compare the antibacterial efficacy of standard irrigating procedures with 2.5% NaOCl and 17% EDTA using the laser techniques of Nd:YAG and Diode lasers on 176 extracted single-rooted teeth.Strains of Enterococcus faecalis and Candida albicans were used. After the tests were performed, the number of colony-forming units per milliliter (CFU/ml) was counted and the results were statistically analyzed.According to the data evaluated, although EDTA, Nd: YAG, and Diode lasers were effective as a bactericidal agent in contaminated root canals, NaOCl had a significantly higher antibacterial effect. The Nd:YAG and Diode lasers showed more antimicrobial effect than EDTA in the E. faecalis group while the Nd:YAG and Diode lasers and EDTA showed the same level of antimicrobial action in the C. albicans group.

Risk factors for a pressure-related deep tissue injury: a theoretical model

Pressure-related deep tissue injury is the term recommended by the United States National Pressure Ulcer Advisory Panel to describe a potentially life-threatening form of pressure ulcers, characterized by the presence of necrotic tissue under intact skin, and associated with prolonged compression of muscle tissue under bony prominences. In this study, a theoretical model was used to determine the relative contributions of the backrest inclination angle during prolonged wheelchair sitting, the muscle tissue stiffness and curvature of the ischial tuberosities (ITs) to the risk for injury in the gluteus muscles that pad the IT bones during sitting. The model is based on Hertz's theory for analysis of contact pressures between a rigid half-sphere (bone) and an elastic half-space (muscle). Hertz's theory is coupled with an injury threshold and damage law for muscle-both obtained in previous studies in rats. The simulation outputs the time-dependent bone-muscle contact pressures and the injured area in the gluteus. We calculated the full-size (asymptotic) injured area in the gluteus and the time for injury onset for different sitting angles alpha (90-150 degrees), muscle tissue long-term shear moduli G (250-1,200 Pa) and bone diameters D (8-18 mm). We then evaluated the sensitivity of model results to variations in these parameters, in order to determine how injury predictions are affected. In reclined sitting (alpha=150 degrees) the full-size injured area was approximately 2.1-fold smaller and the time for injury onset was approximately 1.3-fold longer compared with erect sitting (alpha=90 degrees). For greater G the full-size injured area was smaller but the time for injury onset was shorter, e.g., increasing G from 250 to 1200 Pa decreased the full-size injured area approximately 2.5-fold, but shortened the time for injury onset 6.2-fold. For smaller D the time for injury onset dropped, e.g., decreased approximately 1.5-fold when D decreased from 18 to 8 mm. Interestingly, the full-size injured area maximized at D of about 12 mm but decreased for smaller or larger D. The susceptibility to sitting-acquired deep tissue injury strongly depends on the geometrical and biomechanical characteristics of the bone-muscle interface, and, particularly, on the radius of curvature of the IT which mostly influenced the size of the wound, and on the muscle stiffness which dominantly affected the time for injury onset.

Dermabrasion with steel wool in the extensive partial burns during shock stage: A case report and review

As we all know, the burn wound induces a series of responses, which is typified by profound systemic alterations of endothelial immunological, vasoactive, and barrier function [1]. The presence of necrotic tissue not only inhibits of wound healing, but also may deepen the wound through an excessive inflammatory response [2]. Thus it is most important to remove the necrotic tissue as soon as possible. Methods to treat burn wounds have changed in recent decades. In full-thickness burns, excision of eschar is the only method. In partial thickness burns, however, there are several methods to be chosen: tangential excision, YAG laser [3], Enzymatic debridement [4] dermabrasion and so on. Increasingly, aggressive surgical approaches with early tangential excision and wound closure is being applied [5]. Customarily tangential excision of deep burn wound is performed with a roller axle graft knife followed by a skin graft. Although healthy tissue is preserved as much as possible in tangential excision, it is a technique-dependent procedure with difficult depth evaluation and plane level control. Despite the numerous and varied means of depth cover that are available, they are not yet widely in practice. So it still depends on the physician’s own experience. However, in a third of all cases the evaluation is not accurate [6].

Maggot Therapy: The Science and Implication for CAM Part I—History and Bacterial Resistance

It is now a universally acknowledged fact that maggot therapy can be used successfully to treat chronic, long-standing, infected wounds, which have previously failed to respond to conventional treatment. Such wounds are typically characterized by the presence of necrotic tissue, underlying infection and poor healing. Maggot therapy employs the use of freshly emerged, sterile larvae of the common green-bottle fly, Phaenicia (Lucilia) sericata, and is a form of artificially induced myiasis in a controlled clinical situation. In this review article, we will discuss the role of maggots and their preparation for clinical use. Maggot therapy has the following three core beneficial effects on a wound: debridement, disinfection and enhanced healing. In part I we explore our current understanding of the mechanisms underlying these effects.

Comparison of Two Chlorhexidine Rinse Protocols on the Incidence of Alveolar Osteitis following the Surgical Removal of Impacted Third Molars

Alveolar osteitis (dry socket) is the most common complication following the extraction of permanent teeth. This study was undertaken to compare the effect of two chlorhexidine rinse protocols on the incidence of alveolar osteitis in patients undergoing surgical removal of impacted mandibular third molar teeth. A prospective randomized clinical trial was conducted among 99 subjects. Patients were randomly assigned into two groups. Subjects were instructed to rinse twice daily with 15 ml of chlorhexidine rinse 30 seconds for one week before and one week after surgery (group I) or one week after surgery (group II). Postoperatively, all patients were instructed to return in one week or sooner if bothersome pain increased or persisted. Data were collected regarding abnormal healing, presence of necrotic tissue, exposed bone, and absence of clot. The results indicated group I and group II were not statistically significant different in the reduction of alveolar osteitis. To reduce alveolar osteitis after impacted third molar surgery, it was observed use of postoperative chlorhexidine rinse was adequate. The postoperative use of chlorhexidine is more feasible than both preoperative and postoperative use.

Quality indicators for prevention and management of pressure ulcers in vulnerable elders.

Pressure ulcers can lead to pain, disfigurement, and slow recovery from comorbid conditions. They interfere with activities of daily living, predispose to osteomyelitis and septicemia, and are stro...

APhA Drug Treatment Protocols: Management of Foot Ulcers in Patients with Diabetes: Rapidity of foot ulcer healing depends on many factors, including wound size, presence of necrotic tissue, infection, quality of diabetes care, degree of vascular compromise, and patient compliance

To investigate the risk factors for infection of the diabetic foot with multidrug resistant microorganisms.Amongst 102 diabetic patients with evidence of soft tissue infection of the foot who presented to our health center over a three year period, we investigated risk factors that might be predictive of multi-antibiotic resistance of the infecting organism.Of 102 patients with a diabetic foot wound, bacteria were cultured from 73, yielding a total of 104 isolates. The number of multidrug resistant isolates was 42 from 36 cases and the number of isolates other than multidrug resistant ones was 62 from 37 cases. Previous antibiotic therapy (p = 0.002) and its duration (p = 0.0001), frequency of hospitalization for the same wound (p = 0.000), duration of hospital stay (p = 0.000) and osteomyelitis (p = 0.001) were significant risk factors for infections with multidrug resistant microorganisms.In conclusion, an appropriate antibiotic should be initiated promptly, wound perfusion should be effective, duration of hospital stay should be as short as possible and optimum hygiene should be provided during wound care to prevent infections of diabetic foot wound with multidrug resistant microorganisms.

Pulsed Lavage in Wound Cleansing

Wound cleansing is an essential component of wound management used to facilitate the wound healing process.1,2 Several methods are available for use by the physical therapist to achieve wound cleansing.1–4 This update reviews the research examining the effects of pulsed lavage in wound cleansing and comparisons with more traditional methods of wound cleansing. Normal wound healing is characterized by 3 overlapping phases: inflammatory, proliferative or fibroplastic, and remodeling.5,6 Vascular and cellular responses to trauma occurring during the inflammatory phase remove infectious microorganisms, foreign materials, and necrotic tissue from the wound's surface. During the proliferative phase, tissue granulation and reepithelialization occur.5,6 Collagen fibers are deposited in the dermis of the skin during the remodeling phase to strengthen the healing wound. If the body's inflammatory response is inadequate to overcome surface microorganisms, a wound is predisposed to infection, delaying wound angiogenesis and granulation.7 In the 1950s, Liedberg et al8 showed that when bacterial concentrations of streptococci, pseudomonas, or staphylococci were greater than 100,000 organisms per gram in tissues, skin grafts on rabbits were destroyed. In 1969, Robson and Heggers9 summarized military and civilian studies examining the critical level of bacterial burden necessary to produce wound sepsis and failure to heal. They concluded that wound healing is possible only when bacterial counts are maintained at a concentration of 100,000 organisms per gram or less. Impediments to healing are not limited to the presence of microorganisms on the wound's surface. Winter,10 for example, suggested that the presence of eschar or scab in a dry wound delays wound epithelialization and contraction. Likewise, Constantine and Bolton11 surmised that the presence of necrotic tissue or eschar, within the wound or at the wound's margin, impedes wound contraction and closure. Elek …

Histological comparison of postoperative wound care regimens for laser resurfacing in a porcine model.

The use of short-pulsed CO2 lasers for skin resurfacing is routinely performed, but few studies have examined postsurgical care. To determine which postoperative treatments are most beneficial in promoting optimal healing after laser resurfacing. Four pigs received laser resurfacing. The laser sites were randomly left untreated or treated with petroleum-based ointment or dressed with 1 of the following occlusive dressings: hydrocolloid, hydrogel or foam. Biopsies were taken from each treatment group on Days 2, 3, 4, 5, 8, 12, and 19. All samples were stained with hematoxylin and eosin. Each histological slide was evaluated by a blinded investigator. Differences were observed between treatment groups in the amount of cellular infiltrate, presence of necrotic tissue, progression of the epidermal sheet, maturation of the epidermis, presence of rete ridges, and appearance of new collagen. Postoperative treatments after laser resurfacing vary in their ability to influence the quality of healing.

Debridement of Wounds

In order for a wound to heal quickly the wound bed needs to be free from debris such as devitalized tissue (slough or necrotic tissue). The presence of necrotic tissue prolongs the inflammatory phase of healing and serves as a focus for infection (Benbow, 1998). This dead tissue must, therefore, be removed, a process known as debridement.

Injury by electrical forces: Pathophysiology, Manifestations, and therapy

The pathogenesis and pathophysiologic features of electrical injury are more complex than once thought. The relative contributions of thermal and pure electrical damage depend on the duration of electric current passage, the orientation of the cells in the current path, their location, and other factors. If the contact time is brief, nonthermal mechanisms of cell damage will be most important and the damage is relatively restricted to the cell membrane. When contact time is much longer, however, heat damage predominates and the whole cell is affected directly. These parameters also determine the anatomic tissue distribution of injury. Damage by Joule heating is not known to be dependent on cell size, whereas larger cells are more vulnerable to membrane breakdown by electroporation. Cells do survive transient plasma membrane rupture under appropriate circumstances or if therapy is instituted quickly. If membrane permeabilization is the primary cellular pathologic condition, then injured tissue may be salvageable and the challenge for the future is to identify a technique to reseal the damaged membranes promptly. Present standards of care for electrical injury require a fully staffed and well-equipped intensive care unit, available operating suites, and the availability of the full range of medical specialists. Major teaching hospitals with burn centers may be the ideal setting for the treatment of an electrical trauma victim. After the initial resuscitation, efforts are directed primarily towards preventing additional tissue loss mediated through the compartment syndrome, compressive neuropathies, or the presence of necrotic tissue. Renal and cardiac failure caused by the release of intracellular muscle contents into the circulation must be prevented. Attention can then be directed towards maximizing tissue salvage and preventing late skeletal and neuromuscular complications. Reconstructive procedures that transfer healthy tissue from a distance are necessary to optimize the functional value of the remaining tissue. Finally, unless the patient is rehabilitated psychologically, the real benefit from other sophisticated care will not be fully realized. These goals are important throughout the acute care of the patient. In the future, new guidelines for treating electrical trauma will be based on a clearer understanding of the relevant pathophysiologic features. These strategies will rely on improved diagnostic imaging and on reversing the fundamental problem of cell membrane damage. Moreover, complex biochemical and organ system pathophysiologic interactions will require careful management. If successful, research efforts presently underway should improve the prognosis of victims after electrical trauma.

Root resorption beneath the main hyalinized zone.

A previous investigation on the initial phase of root resorption associated with orthodontic overcompression of local areas of the periodontal ligament (PDL), indicated that a differentiation should be made between two stages: (1) the very first resorption occurring in the periphery of the main necrotic zone; and (2) the root resorption occurring on that part of the root surface situated beneath the main bulk of necrotic tissue (Brudvik and Rygh, 1993a). The aim of the present investigation was to study the latter stage. Attention was focused on: (1) the possible association between the presence of necrotic tissue and root resorption; and (2) the cells that invaded and removed the necrotic tissue, as well as the cells that started to remove/resorb the cementum. Mesial movement of the upper first molars (rats) and lower first molars (mice) was performed by a fixed orthodontic appliance. The results indicate an association between the root resorption, and the presence and active removal of the hyalinized tissue. Root resorption beneath the main hyalinized zone occurred in areas where invading cells were observed close to the root surface. The majority of the cells involved in removal of the necrotic tissue and resorption of the root surface were multi-nucleated and TRAP-positive. It is hypothesized that multi-nucleated TRAP-positive cells when reaching the subjacent contaminated and damaged root surface after having removed necrotic PM tissue, continued to remove the cementum surface.

Fluoride Susceptibility of Tomato Plants as Affected by Magnesium Nutrition1

Abstract Tomato plants (Lycopersicon esculentum Mill. cv. Bonny Best) grown in sand culture and provided with a complete nutrient solution or solutions containing sub- or supraoptimal Mg concentrations were fumigated with hydrogen fluoride (HF) at 5.0 or 9.7 μg F/m3 for 7 days. The severity of HF-induced chlorosis on apical and medial leaves was enhanced in Mg-deficient plants and suppressed in plants grown at the highest level of Mg. Foliar accumulation of fluoride (F) from exposure to the highest HF concentration was inhibited in plants provided the lowest and highest Mg levels. The presence of necrotic tissue probably suppressed the accumulation of F in Mg-deficient plants; however, it was not a factor in plants given supraoptimal Mg. The interactive effects of HF and Mg on foliar injury and F accumulation revealed that Mg-deficient plants were more susceptible and plants given excess Mg were more tolerant to HF than plants cultured on complete nutrient medium.

The infection of strawberry and raspberry fruits by Botrytis cinerea Fr.

SUMMARY Botrytis cinerea occurs abundantly throughout the year as a saprophyte and facultative parasite on a wide variety of plant materials in raspberry and strawberry plantations. Despite high concentrations of airborne spores at the time of fruit development, relatively few infections have resulted from penetration of fruit surfaces following the germination of spores in drops or films of water, uninfluenced by the presence of necrotic tissues. The majority of fruit infections are initiated from mycelium growing saprophytically in contiguous plant material or from spores germinating in solutions trapped between such material and the fruit surface.Dry spores of B. cinerea on the surface of strawberry fruits do not readily germinate in a saturated atmosphere but germinate rapidly in a water film. Although ripe and unripe fruits differ markedly in susceptibility, fruit maturity induces only small differences in the rates of spore germination. Field observations suggest that water films generally do not persist on the surface of the fruit long enough for the post‐germination infection process to be completed. Such films, however, may persist much longer when trapped between floral parts, and spores germinating there are able to initiate infections almost as soon as the buds open. The process may be accelerated by the presence of necrotic tissue, for example, in flowers damaged by frost. Mycelium infecting floral parts may subsequently invade the proximal end of both strawberry and raspberry receptacles. This mycelium may remain quiescent until the fruit ripens; consequently infected fruit may escape notice during picking and marketing.Some methods of supplementing fungicidal control measures by reducing the incidence of sources of infection are suggested.

Unusual gas-forming infections.

Gas gangrene is generally caused by the clostridial bacteria. Certain anaerobic streptococci, the diphtheria bacillus, and Actinomyces may cause a gangrenous myositis resembling clostridial gas gangrene. Although gas infection is usually a disease of the battlefield, it may occur whenever necrotic tissue is present. In World War I, Pettit reported the development of gas gangrene in 221 (5 per cent) of 4,377 patients, with a resulting fatality of 27.6 per cent. During the Korean War, among 4,900 battle casualties reported by Howard and Inui, only 4 cases of gas gangrene occurred, with no fatalities (2). Clostridium welchii (perfringens) is the most important anaerobic organism in the formation of gas gangrene. The pathogenic powers of the clostridial bacilli result from production of one or more potent exotoxins. All Clostridia produce several different toxins, but usually only one of these is paramount in the genesis and progression of the disease. It is against this specific toxin that an appropriate antiserum is prepared. Certain of these toxins are enzymes and their specific substrates have been identified. This has been an important finding, leading toward the investigation of gas gangrene. These organisms will grow and produce their toxins only under conditions of markedly reduced oxygen tension. Generally, trauma, the presence of necrotic tissue, or a foreign body is sufficient to permit germination of the gas-forming bacteria. Once the toxins are produced, they diffuse into the surrounding tissues, causing necrosis and permitting spread of the organisms into new areas of reduced oxygen tension. Clostridium welchii has been studied extensively and it is clear that the alpha toxin is the element of prime importance. At surgery, changes in the infected muscles are noted, consisting of edema, loss of contractility, and discoloration which varies from a reddening to a dark purple mottling. On squeezing the tissues, bubbles of gas can be expressed. Clostridia may exist as contaminants without producing any harmful effects. The stimulus for growth and production of the toxin is not well understood in spite of considerable study. Necrotic tissue is apparently the best catalyst for production of gas gangrene. The mere presence of Clostridia is of little significance, since they require delicately adjusted environmental conditions before they can produce the manifestations of disease. It must be strongly emphasized that clostridial infections in man are clinical and not bacteriologic entities. The spread of the disease is usually in the muscles and along the muscle planes, although other tissues may be involved. One of the 2 cases to be reported here was due to Clostridium welchii, the other to an anaerobic streptococcus. Case Reports Case I: A 54-year-old white male with myeloid leukemia showed progression of the disease in spite of treatment with Chlorambucil, transfusions, and supportive measures.

Tetanus Prophylaxis with Penicillin-Procaine G.

ConclusionsResults indicate that penicillin-procaine G in sesame oil and 2% aluminum monostearate is of significant value prophylactically in lowering the mortality of mice experimentally infected with a lethal dose of detoxified spores of Clostridium tetani. In addition to decreasing the mortality, it retards the development of symptoms and resulting deaths. Injected into the necrotic areas, it is more effective than the same unitage injected at an uninfectd site. Whether this is caused by insufficient penetration of the drug due to the presence of necrotic tissue or to interference by the calcium chloride has not been determined.

Gas Gangrene of the Uterus

Gas gangrene of the uterus is a rare condition with a high mortality rate. The literature reveals about 175 cases diagnosed mainly at autopsy. Hill in 1936 reported a detailed study of 30 cases with a mortality of 63 per cent. In 4 cases the diagnosis was established antemortem by physical examination and laboratory methods; in 16 cases the diagnosis was not suspected until autopsy. About 75 per cent of the cases were associated with abortions. The roentgen diagnosis of gas gangrene of the uterus is extremely rare. The literature yields but one example, reported by Russell and Roach in 1939. Unfortunately, these authors did not publish the film upon which they based their diagnosis. No illustration, therefore, depicting gas gangrene of the uterus could be found in the literature. The rarity of films showing gas gangrene of the uterus is dependent not on any diagnostic difficulty from the roentgenologic standpoint but rather upon failure to recognize the advantage of x-rays as a diagnostic modality over the ordinary physical examination and laboratory methods. Since gas is one of the by-products of this type of infection and since it is formed early and easily detected roentgenographically, it follows logically that the roentgenogram is the ideal diagnostic agent. Gas in the uterus may be of accidental or infectious origin; in the latter case it is caused by the entrance or introduction of gas-forming bacilli into the generative tract, where the presence of necrotic tissue provides favorable soil. As the infection spreads in the fulminating types, the involved tissue becomes gangrenous and full of gas bubbles. There are various bacilli capable of gas formation in the tissues and it may be extremely difficult to differentiate between the types. Gas gangrene and gas in the tissues are not synonymous with B. welchii infection, only a small percentage of cases being due to that organism. Gas gangrene is a general term covering infections due to one or more gas-forming anaerobes of varying degrees of virulence. The varieties most to be feared are B. welchii, B. oedematiens, and Vibrion septique. B. welchii is a heavy, encapsulated, anaerobic, non-motile, non-liquefying bacillus which is gram-positive. As pointed out above, roentgenography is the method of choice for the diagnosis of gas gangrene of the uterus. The gas bubbles are demonstrable in the roentgenogram and the extent of the involvement can be accurately determined, making early treatment possible. Guinea-pig inoculation with material from anaerobic lactose agar cultures and smears from the labia, vagina, and uterus is another diagnostic procedure. At operation gas escapes when the infected tissue is opened and the uterus appears black, friable, and extensively necrotic. From his series of cases, Hill concludes that the clinical detection of gas gangrene in the uterus is difficult and often impossible.