The timing of histologic changes in liver lacerations.

Microscopic examination was performed on 55 cases of traumatic liver lacerations incurred from fatal motor vehicle accidents. None of the deaths was due to the liver injury. In 38 of 55 cases, the decedent was pronounced dead at the scene. Microscopic examination of the liver lacerations in these 38 cases revealed no histologic changes related to the trauma. In 17 of 55 cases, the decedent was transported to the emergency room (ER) with a "survival time" (from Emergency Medical Service arrival to the time of pronouncement) of 15 minutes to 7 hours and 10 minutes. Nine of these 17 had vital signs at the scene. Five of the 17 had neutrophilic infiltration and hepatocyte necrosis at the site of the laceration. Four of these had vitals signs at the scene. Survival time of the 5 patients with a vital reaction at their liver injury ranged from 51 minutes to 7 hours and 10 minutes.

Fatal anaphylaxis to indoor native fire ant stings in an infant.

The red (Solenopsis invicta) and black (Solenopsis richteri) imported fire ants (IFA) are a common cause of venom allergy in the southeastern United States. Hypersensitivity to stings of native fire ants is less common, although anaphylaxis has been reported to various native Solenopsis species. There have been numerous reports of indoor stings caused by IFA, including in nursing homes and private residences. The following is a report of fatal anaphylaxis to a native fire ant sting in an infant that occurred indoors at a daycare facility. A 3-month-old female was left unattended on a bed. The caregiver had heard the child crying, but attributed this to colic. A short time later, the caregiver found the child apneic and covered with ants. Emergency medical services were summoned, and resuscitation attempts were unsuccessful. Postmortem examination revealed approximately 40 erythematous lesions without pustules. Examination of the respiratory system was notable for congested parenchyma and mild laryngeal edema. Laboratory studies revealed an elevated tryptase of 23.9 ng/mL and radioallergosorbent test (RAST) of 1.4% specific IgE antibody binding to Solenopsis richteri venom. RAST for specific IgE antibody binding to Solenopsis invicta venom was negative. Ants recovered from the scene were identified by an entomologist as Solenopsis xyloni, a native fire ant endemic to the southwestern United States. Native fire ants have features that distinguish them from IFA. Some native species do not build mounds, and stings may not result in pustules characteristic of IFA. There is significant cross-reactivity among the venoms of Solenopsis species, although some species' specificity exists for the Sol 2 allergen. Testing and treatment with IFA whole-body extract is likely to be to be effective for native fire ant allergy. A mixture of S. invicta and S. richteri extracts should be considered when native fire ant species are presumed to cause the primary sensitization to reduce the chance that species-specific reactivity is missed.

Suicide by firearms: a 15-year experience.

A retrospective review of 1704 cases of suicide involving firearms investigated by the Bexar County Medical Examiner's office between 1984 and 1998 was performed. The age distribution was similar in male and female victims, and the type of weapon was not associated with age. Approximately 78% of the victims used a handgun (87% of female and 76% of male victims). In 4.0% of head wound cases, the site of the entrance wound was the back of the head. Thus, this report refutes the common belief that all gunshot wounds to the back of the head represent homicides. In 1.9% of the cases, the wounds were inflicted at intermediate range. With handguns, the right temple was the most common site, but with rifles and shotguns, the most common site was the mouth.

Prothrombin gene mutation uncommon in pulmonary embolism.

BACKGROUND: Venous thrombosis followed by pulmonary embolism is one of the most common causes of sudden death among middle-aged adults. Several inherited polymorphisms are associated with heightened risk of venous thrombosis, including mutation at position 20210 of the prothrombin gene and mutation at codon 506 of the factor V gene. METHODS: We studied mutation prevalence in 67 individuals who died of pulmonary embolism and were autopsied in a medical examiner's facility over a 5-year period. Mutations were identified by polymerase chain reaction followed by allele-specific endonuclease digestion. RESULTS: Traditional risk factors for pulmonary embolism (eg, immobility, oral contraceptive use, cancer) were identified in 75%. Heterozygous mutation of the prothrombin gene was found in 3/67 (4%), and heterozygous mutation of the factor V gene was identified in 3/66 (4%). No homozygotes or compound heterozygotes were identified. The prevalence of mutation was not significantly different from that of the general population. CONCLUSIONS: Individuals who die suddenly from pulmonary embolism are not often affected by prothrombin or factor V gene mutations. Therefore, medical examiners need not routinely test for these mutations in individuals who die of pulmonary embolism.

Fatal hyperthermia in hot baths in individuals with multiple sclerosis.

The authors report the case of a 47-year-old black man with a history of multiple sclerosis who was found dead in a bathtub, head above water, with a body temperature of 105.7 F. Results of a complete autopsy and toxicologic screen were negative. Individuals with multiple sclerosis, if immersed in hot water, develop motor weakness, which may be so severe as to prevent them from getting out of the water, whether they be in a bathtub or whirlpool bath. In this case, the individual was trapped in a bathtub in which there was a continuous flow of hot water. This overwhelmed an already impaired thermoregulatory mechanism, causing hyperthermia and death.