Management of human bite injuries of the hand.

On the basis of experience at the Ottawa Civic Hospital over the past 10 years, a classification of and protocol for the management of human bite injuries of the hand are presented. Early exploration of such wounds under local anesthesia improves the outcome by facilitating adequate cleansing of the wound and enabling deep structures to be visualized. In this way the risk of major sepsis and of the disability so frequently associated with these innocent-looking injuries can be reduced.     

Management of open tibial fractures

A prospective study was undertaken to accurately classify open tibial fractures and to evaluate the benefit of muscle flaps in the management of these injuries. From 191 open tibial fractures, 59 type III and 14 type IV open fractures were identified and managed prospectively. Fractures managed with open-wound techniques have a much higher complication rate than those closed with flaps. Results with flap coverage are affected by the biologic phase of the wound. The best results are seen in the acute flap coverage group and are thought to be secondary to removal of devitalized tissue with provision of a vascularized soft-tissue envelope prior to wound colonization. Flap coverage of the colonized subacute wound is subject to invasive infection with additional tissue loss. The subacute wound should be managed with open-wound technique until the parameters of a chronic localized wound are established, at which time flap coverage is again indicated. Microvascular free flaps are the preferred cover for type IV wounds because the local tissues are too ischemic and devitalized for transfer. With meticulous wound care and adherence to the enumerated surgical procedures, limb salvage may be achieved in most injuries.     

Management of early human bites of the hand: a prospective randomized study

A prospective, randomized study was undertaken to determine if mechanical care of early human bites alone is sufficient therapy in the compliant patient or if prophylactic antibiotics (oral versus parenteral) are indicated. Beginning in June of 1985, patients presenting with human bites of the hand were entered into the study if (1) the bite was less than 24 hours old, (2) the patient was free of infection, (3) the bite did not penetrate the joint capsule, and (4) there was no injury to tendon. Forty-eight patients were ultimately segregated into one of three study groups after standardized ER mechanical wound care. Fifteen patients received an oral placebo, with 7 developing infection (46.7 percent). Sixteen patients received an oral antibiotic, and 17 patients received parenteral antibiotics. No infections were found in either of these latter groups. The results statistically substantiate that mechanical wound care alone is insufficient therapy. Oral antibiotics appear to be equal to intravenous antibiotics for prophylaxis. From a cost-benefit standpoint, vigorous cleaning, debridement, and coverage with a broad-spectrum oral antibiotic are adequate care for an uncomplicated bite in the compliant patient.     

Evidence of predation in Early Cretaceous unionoid bivalves from freshwater sediments in the Cameros Basin,Spain

Here, we present evidence of possible vertebrate predation on freshwater bivalves from the Lower Cretaceous strata of the Cameros Basin (Spain). The described collection contains the largest number of vertebrate‐inflicted shell injuries in freshwater bivalve shells yet reported in the Mesozoic continental record. Several types of shell damage on fossil shells of Protopleurobema numantina (Bivalvia: Unionoida) are described and their respective modes of formation interpreted in the context of morphological attributes of the shell injuries and the inferred tooth morphology of predators that could have inflicted such injuries. Detailed study of these bite marks shows similarities with the well‐documented injuries in the shells of marine molluscs, namely ammonoids, that have likewise been attributed to reptilian predators. The most parsimonious interpretation suggests crocodiles as the vertebrates interacting with the bivalves in the Cameros Basin. □Barremian–Aptian; bite marks; freshwater bivalves; predation; reptile; Unionoida.     

Defaming Rover: Error-Based Latent Rhetoric in the Medical Literature on Dog Bites

This article examines the accuracy and rhetoric of reports by human health care professionals concerning dog bite injuries published in the peer-reviewed medical literature, with respect to nonclinical issues, such as dog behavior. A qualitative content analysis examined 156 publications between 1966 and 2015 identified by terms such as “dog bite” or “dangerous dogs.” The analysis revealed misinformation about human–canine interactions, the significance of breed and breed characteristics, and the frequency of dog bite–related injuries. Misinformation included clear-cut factual errors, misinterpretations, omissions, emotionally loaded language, and exaggerations based on misunderstood or inaccurate statistics or reliance on the interpretation by third parties of other authors’ meaning. These errors clustered within one or more rhetorical devices including generalization, catastrophization, demonization, and negative differentiation. By constructing the issue as a social problem, these distortions and errors, and the rhetorical devices supporting them, mischaracterize dogs and overstate the actual risk of dog bites.     

Arrachement du scrotum par morsure humaine: présentation d’un cas et revue de la littérature

Human bites of male external genitalia are rare. We report a case of scrotal wound caused by human bite during a sexual dispute. Lesion was recent wound caused by tearing off the summit of scrotal skin without any testicular injury. The wound was successfully treated by antibiotics, surgical debridement and suture. The patient was immunized against tetanus.     

Early rotation of a cross-lip flap to repair a defect caused by a human bite.

A case is presented of loss of half of the lower lip from a human bite. An Estlander flap was used on the fifth day for reconstruction, with no infection and a good result. This shows the advantage of a "delayed primary closure" in some of these badly contaminated wounds.     

The epidemiology of dog bite injuries in Switzerland – characteristics of victims,biting dogs and circumstances

Abstract

Dogs are a potential source of several health hazards for humans. Public attention has recently focussed on dog bites, and different prevention strategies have been suggested. As few data on dog bite epidemiology are available, a prospective study was conducted in family practices (FP) and emergency departments (ED) in Switzerland. The objectives of this study were to estimate the incidence of dog bites receiving medical treatment and to identify possible risk factors. An annual dog bite incidence rate of 180/100 000 population was estimated. The highest incidence rates were found in children, young adults and dog owners. While head and neck injuries were most common (37% of FP and 45% of ED cases) amongst children and these tended to have more severe sequelae, adults' injuries most commonly involved the extremities. Victim–dog interactions prior to the incident often were observed in children, particularly in infants (82% of 0–4-year-old cases) and in family dog bites (88%). Biting dogs were most commonly medium or large in size, male, and aged < 5 years. The three most popular breeds (Shepherd, Retriever Dogs and Swiss Mountain Breeds) also were the three most common biters. However, Shepherd dogs and Rottweilers were more common among biting dogs. No difference in bite risk was found between pure-bred and cross-bred dogs. Results of this study suggest that dog bites are a common event in the community. A multifactorial approach to dog bite prevention is recommended.     

A Pilot Study to Evaluate an Elementary School-Based Dog Bite Prevention Program

ABSTRACT

The primary objective of this program evaluation was to determine if a school-based education program is an effective means of informing elementary school-aged children enrolled in second through fourth grades about dog bite safety—the awareness of proper behavior when in the company of dogs to prevent bites, injuries, or fatalities. The pilot program, featuring written materials and a video, was developed to teach dog bite safety, and questionnaires were designed to assess the program. Students (n=486) from seven schools from Montgomery and Prince George's Counties in Maryland, USA participated. Pre- and post-program questionnaires assessed students' interactions, encounters, and relationships with dogs, as well as use of program materials, and changes in understanding about dog behavior, body language, and bite avoidance. The program results appeared to be highly effective in helping children understand how to prevent or avoid potentially threatening situations involving dogs. The program was most effective at teaching children that: (1) neighborhood and family dogs are most likely to cause dog bite-related injuries, (2) they should never run away from a dog, and (3) they should never touch a dog that is sleeping or eating. For most groups, there was also an increased level of recognition of canine body language. Almost half of the participants indicated that they had been bitten in the past, and over 80% knew the attacking dog. Finally, the findings suggest that an age-appropriate dog bite safety program delivered in an elementary school setting can be effective in producing awareness about preventing dog bite-related injuries. Future investigations should concentrate on monitoring actual changes in child behavior.     

The role of primary bone grafting in complex craniomaxillofacial trauma

The role of craniofacial surgical techniques and immediate bone grafting in the management of complex craniofacial trauma has been reviewed. Four hundred and one patients with complex facial injuries have been treated. Two hundred and forty-one primary bone and cartilage grafts have been performed in 66 patients. Complex facial injuries should be managed by direct exposure, reduction, and fixation of all fractures utilizing interfragmentary wiring. Very comminuted or absent bone is replaced by immediate bone grafting, producing a stable skeleton without the need for external fixation devices. Associated mandibular fractures are managed with rigid internal fixation utilizing A-O technique. Results of immediate bone grafting have been excellent, and complications are rare. All deformities should be corrected, whenever possible, during the initial operation. This one-stage reconstruction of even the most complex facial injuries will prevent severe postoperative traumatic deformity and disability that may be extremely difficult or impossible to correct secondarily.     

儿童毒蛇咬伤的特点与程序化救治的疗效观察

目的通过分析儿童毒蛇咬伤的特点,评价程序化综合救治方法对儿童毒蛇咬伤的疗效。方法通过观察17例毒蛇咬伤儿童的临床特点,尽早进行病情预测,同时根据毒蛇咬伤的临床病情分型予程序化综合救治。监测病情变化、伤口愈合情况及平均住院时间。结果儿童毒蛇咬伤的特点为不明种类毒蛇咬伤多,症状较成人严重,易发生并发症。经过早期程序化综合救治总有效率100%,伤口渗血、肿胀明显缓解,无1例死亡,平均留观时间4.5天。结论根据儿童毒蛇咬伤特点,早期准确预测和尽快应用程序化救治能提高毒蛇咬伤疗效。     

An index for assessing effectiveness of plant structural defences against mammal browsing

Plant structural defences against mammals play an important role in ecosystem functioning as they simultaneously mediate the fitness of both animals and plants. The efficiency of structural defences can be described by the amount of plant material an animal can remove in one bite. Quantifying bite size by direct observation is difficult requiring controlled access to both the plants of interest and the herbivores. A method called the bite size index (BSI) has been proposed using human bites to simulate the bite size of medium-sized mammalian herbivores. In this paper, we evaluated the utility of the BSI for assessing the efficacy of plant structural defences. We analysed the intra- and inter-specific variability of the BSI in an African savanna (Hluhluwe–iMfolozi, South Africa) rich in herbivores, its repeatability between recorders, how the results reflect known properties of plant structural defences and how well the index correlates with the bite size of goats and its efficacy for explaining species distribution on a fire–herbivory gradient. The BSI was readily applied to a large set (n = 55) of plant species and proved to be consistent among recorders (8 of the 9 recorders obtained similar estimates). Bite sizes of goats and human observers were strongly correlated for 14 plant species (R ² = 0.70) with divergent leaf and branch types. An analysis of BSI for 55 plant species disclosed two main contributory factors: leaf dimensions and spinescence. The BSI was significantly related to plant species distribution on a fire–herbivore gradient in an African savanna.     

Characteristics of American alligator bites on people in Florida

Human–American alligator (Alligator mississippiensis) conflict in Florida, USA, has increased since the early 1970s, along with the recovery of the American alligator population. To better understand factors contributing to the risk of people being bitten by free-ranging alligators in Florida, we evaluated the trend of alligator bites during 1971–2014 and examined characteristics associated with bites on people documented during 1948–2014. We classified 372 bites as either unprovoked or unintentionally provoked and used these in further analyses. Major injuries to victims occurred in 247 bite incidents. The estimated annual number of bites resulting in major injury to the victim increased from 3.5 to 7.0 during 1971–2014. The number of bites per Florida resident did not show a significant trend during 1971–2014. No significant change occurred in the frequency of fatal attacks during 1971–2014. Monthly frequency of bites was positively correlated with both mean maximum and mean minimum air temperatures but was not significantly correlated with testosterone concentration in adult male alligators, suggesting that bites are more likely related to feeding rates associated with seasonal fluctuations in ambient temperature than to aggression by male alligators during the breeding season. A high percentage of bites (41.8%) occurred in unnamed water bodies, which were generally small or man-made. Most (93.7%) victims were Florida residents, and 58.7% resided close to the incident site. Victims were predominantly male (81.4%), and adults were more frequently victims than were adolescents or children. Most victims (93.9%) were in the water or near the shore when bitten. Victims were more likely to sustain major injuries if the bite occurred in deeper water. Male alligators were more frequently (76.9%) responsible for bites. We found only 1 instance in which a bite was associated with defense of eggs or young by an adult female alligator. Evidence of people feeding alligators before the bite was documented in 34.7% of bite incidents. Twenty-two fatalities were attributed to alligator attacks, but we could not discern a pattern in the ages of victims. Alligators responsible for severe or fatal bites were predominantly in good condition with few deformities or injuries. Most alligator bites in Florida appeared to be attempts at feeding, although 36.8% of incidents entailed a single bite followed by immediate release, suggesting that alligators were unsure about their prey or were biting in defense. The risk of alligator bites can be reduced by educating people likely to interact with alligators and by selectively removing problem alligators in human residential areas and water bodies used regularly by people for swimming, wading, and shoreline activities. © 2019 The Wildlife Society.     

Evidence of intraspecific agonistic interactions in Smilodon populator (Carnivora,Felidae)

The saber-toothed cat Smilodon is a characteristic genus of the Pleistocene faunas of the American continent. Smilodon belongs to an extinct clade of felids that had hypertrophied blade-like upper canines. Because the length of the canines is so extreme, the killing bite of Smilodon is a hotly debated topic in vertebrate paleontology. Some authors have proposed that saber-toothed cats had a weak bite and their canines were fragile, not useful for attacking prey or penetrating bones. The aim of the present contribution is to describe two new specimens of Smilodon populator that have injuries on their skulls. Although it cannot be ruled out that the injuries were caused by a potential prey kicking the skull, the size, shape and general features of the injuries suggest that they were inflicted by the upper canines of another Smilodon individual during agonistic interactions.     

Regeneration of articular cartilage in healer and non-healer mice

Mammals rarely regenerate their lost or injured tissues into adulthood. MRL/MpJ mouse strain initially identified to heal full-thickness ear wounds now represents a classical example of mammalian wound regeneration since it can heal a spectrum of injuries such as skin and cardiac wounds, nerve injuries and knee articular cartilage lesions. In addition to MRL/MpJ, a few other mouse strains such as LG/J (a parent of MRL/MpJ) and LGXSM-6 (arising from an intercross between LG/J and SM/J mouse strains) have now been recognized to possess regenerative/healing abilities for articular cartilage and ear wound injuries that are similar, if not superior, to MRL/MpJ mice. While some mechanisms underlying regenerative potential have been begun to emerge, a complete set of biological processes and pathways still needs to be elucidated. Using a panel of healer and non-healer mouse strains, our recent work has provided some insights into the genes that could potentially be associated with healing potential. Future mechanistic studies can help seek the Holy Grail of regenerative medicine. This review highlights the regenerative capacity of selected mouse strains for articular cartilage, in particular, and lessons from other body tissues, in general.     

Flow cytometric sorting and analysis of human epidermal stem cell candidates

ESC (epidermal stem cells) play a central role in the regeneration of human epidermis. These cells are also responsible for wound healing and neoplasm formation. Efficient isolation of ESC allows their use in medicine and pharmacy as well as in basic science. Cultured keratinocytes and ESC may be used as biological dressing in burn injuries, chronic wounds and hereditary disorders. Therefore, the isolation and characterization of ESC have been goals in biomedical science. Here, we present a flow cytometric method for the isolation and analysis of human ESC candidates. The strategy presented for the isolation of ESC combines previously proposed enzymatic digestion and FACS‐sorting of the obtained cell suspension that utilizes morphological features, integrin‐β1 expression and Rh123 (Rhodamine 123) accumulation of the cells. We also performed a flow cytometric analysis of sorted cells using a cell tracer.     

Accelerated Wound Closure In Vitro by Fibroblasts from a Subgroup of Cleft Lip/Palate Patients: Role of Transforming Growth Factor-α

In a fraction of patients surgically treated for cleft lip/palate, excessive scarring disturbs maxillary growth and dento-alveolar development. Since certain genes are involved in craniofacial morphogenesis as well as tissue repair, a primary defect causing cleft lip/palate could lead to altered wound healing. We performed in vitro wound healing assays with primary lip fibroblasts from 16 cleft lip/palate patients. Nine foreskin fibroblast strains were included for comparison. Cells were grown to confluency and scratch wounds were applied; wound closure was monitored morphometrically over time. Wound closure rate showed highly significant differences between fibroblast strains. Statistically, fibroblast strains from the 25 individuals could be divided into three migratory groups, namely “fast”, “intermediate”, and “slow”. Most cleft lip/palate fibroblasts were distributed between the “fast” (5 strains) and the “intermediate” group (10 strains). These phenotypes were stable over different cell passages from the same individual. Expression of genes involved in cleft lip/palate and wound repair was determined by quantitative PCR. Transforming growth factor-α mRNA was significantly up-regulated in the “fast” group. 5 ng/ml transforming growth factor-α added to the culture medium increased the wound closure rate of cleft lip/palate strains from the “intermediate” migratory group to the level of the “fast”, but had no effect on the latter group. Conversely, antibody to transforming growth factor-α or a specific inhibitor of its receptor most effectively reduced the wound closure rate of “fast” cleft lip/palate strains. Thus, fibroblasts from a distinct subgroup of cleft lip/palate patients exhibit an increased migration rate into wounds in vitro, which is linked to higher transforming growth factor-α expression and attenuated by interfering with its signaling.     

Incisal bite force direction in humans and the functional significance of mammalian mandibular translation

Incisal bite force direction was recorded and analyzed in ten human subjects using a specially designed force transducer. In all ten subjects the maxillary incisal bite force was vertically and anteriorly directed both during static biting and during biting associated with simultaneous mandibular translation and rotation. Since the resultant muscle force could not have been equal and opposite to the mandibular bite force, the mandibular condyles must have been loaded. These data demonstrate that the mandible acts as a lever during incisal biting and that there is no consistent relationship between incisal bite force direction and object size. In some individuals the bite force direction was more vertical during biting on a large transducer (30 mm high), while in other subjects it was more vertical during biting on a small transducer (10 mm high).     

Evidence for infanticide in bottlenose dolphins of the western North Atlantic

Nine bottlenose dolphin (Tursiops truncatus) calves that stranded in Virginia in 1996 and 1997 died of severe blunt-force trauma. Injuries were concentrated on the head and chest and multiple rib fractures, lung lacerations, and soft tissue contusions were prominent. Skeletal and/or soft tissue trauma occurred bilaterally in all of the calves. One had a bite wound across the left mandible that exhibited deep punctures consistent with the tooth placement in an adult bottlenose dolphin. The lesions were not compatible with predation, boat strike, fisheries interactions, rough-surf injury, or blast injury. However, they were similar to traumatic injuries described in stranded bottlenose dolphin calves and harbor porpoises (Phocoena phocoena) in Great Britain attributed to violent dolphin interactions. The evidence suggests that violent dolphin behavior was the cause of the trauma in the nine calves reported here and that infanticide occurs in bottlenose dolphins of the western North Atlantic.     

Amplification of Oral Streptococcal DNA from Human Incisors and Bite Marks

Challenges to the evidentiary value of morphometric determinations have led to a requirement for scientifically substantiated approaches to the forensic analysis of bite marks. Human teeth support genotypically distinctive populations of bacteria that could be exploited for forensic purposes. This study explored the feasibility of directly amplifying bacterial DNA from bite marks for comparison with that from teeth. Samples from self-inflicted experimental bite marks (n = 24) and human incisors were amplified by PCR using primers specific for streptococcal 16S ribosomal DNA. Amplicon profiles (resolved by denaturing gradient gel electrophoresis) from bite mark samples aligned significantly more closely with profiles generated from the teeth responsible than with those from other teeth. Streptococcal amplicons were generated from dental samples applied to excised porcine skin for up to 48 h. These findings indicate that streptococcal DNA can be amplified directly from bite marks, and have potential application in bite mark analysis.