Subdural haemorrhage sustained in a baby-rocker? A biomechanical approach to causation

An unconscious 8 weeks old infant was admitted to hospital and found to have bilateral, subdural and retinal haemorrhages. He died the following day. The explanation for the subdural haemorrhage put forward by his carers was that the infant had been in a baby-rocker and that the carers had seen the rocker being rocked vigorously by their 14 months old daughter on two separate occasions. This paper describes the biomechanics of an infant model in the particular baby-rocker used and determines the maximum forces generated, comparing them with the 'forces' thought to be compatible with the causation of subdural haemorrhage.

The potential and limitations of utilising head impact injury models to assess the likelihood of significant head injury in infants after a fall

The use of engineering principles in assessing head injury scenarios is of increasing significance in investigations into suspected child abuse. A fall scenario is often given as the history for a head injury to an infant. This paper addresses the basic engineering principles and factors to be considered when calculating the severity of a head impact after free-fall. The application of head injury models (HIMs) to ascertain the forces involved in childhood head injuries from impact is also discussed. Previous studies including Duhaime et al. [J. Neurosurg. 66 (1987) 409] and Nokes et al. [Forensic Sci. Int. 79 (1995) 85] have utilised HIMs for this purpose: this paper reviews those models most widely documented.The HIM currently considered the 'state-of-the-art' is the head injury criterion (HIC) and it is suggested that this model should be utilised for assessing head impact injury in child abuse cases where appropriate.

Growth and pubertal milestones during adolescence in offspring prenatally exposed to cigarettes and marihuana

Weight, height, head circumference, and pubertal milestones were examined in one hundred fifty-two 13- to 16-year-old adolescents for whom prenatal exposure to marihuana and cigarettes had been ascertained. The subjects were from a low-risk, predominantly middle-class sample participating in an ongoing, longitudinal study and whose growth has been monitored since birth. The weight of the 13- to 16-year-old children of heavy cigarette smokers, after statistical adjustment, did not differ from control subjects but they had a significantly higher Ponderal Index (PI). These observations continued those noted when these subjects were 9 to 12 years of age. Among the male offspring of cigarette smokers, pubertal milestones occurred at an earlier age than among male adolescents born to nonsmokers. Active smoking by the offspring did not moderate these findings. Maternal marihuana use was not associated with any growth measurement or the timing of pubertal milestones.

A biomechanical reconstruction of a wound caused by a glass shard--a case report

During the course of a criminal trial, an investigating pathologist is commonly asked how much force was required to produce an injury. This subjective opinion is based on the pathologist's previous experience of dealing with wounds inflicted with similar weapons. However, in the case of stab wounds inflicted by broken glass, it is unlikely that two glass fragments would be physically similar. In the case studied, two theories were examined: that a wound resulted from a thrown glass fragment or that it had been caused as a stab injury by the glass held in the bare hand. The investigation involved quantifying the energy required for human tissue penetration, comparison of sharpness, a biomechanical analysis of throwing actions and testing of the hypothesis that if the glass shard were used as a stabbing implement it would result in a cut to the hand.The investigation utilised a scientific methodology that reduced the need for speculative (though informed) opinion from the pathologist by producing quantitative results.

Lung cancer in a nonsmoking underground uranium miner

Working in mines is associated with acute and chronic occupational disorders. Most of the uranium mining in the United States took place in the Four Corners region of the Southwest (Arizona, Colorado, New Mexico, and Utah) and on Native American lands. Although the uranium industry collapsed in the late 1980s, the industry employed several thousand individuals who continue to be at increased risk for developing lung cancers. We present the case of a 72-year-old Navajo male who worked for 17 years as an underground uranium miner and who developed lung cancer 22 years after leaving the industry. His total occupational exposure to radon progeny was estimated at 506 working level months. The miner was a life-long nonsmoker and had no other significant occupational or environmental exposures. On the chest X-ray taken at admission into the hospital, a right lower lung zone infiltrate was detected. The patient was treated for community-acquired pneumonia and developed respiratory failure requiring mechanical ventilation. Respiratory failure worsened and the patient died 19 days after presenting. On autopsy, a 2.5 cm squamous cell carcinoma of the right lung arising from the lower lobe bronchus, a right broncho-esophageal fistula, and a right lower lung abscess were found. Malignant respiratory disease in uranium miners may be from several occupational exposures; for example, radon decay products, silica, and possibly diesel exhaust are respiratory carcinogens that were commonly encountered. In response to a growing number of affected uranium miners, the Radiation Exposure Compensation Act (RECA) was passed by the U.S. Congress in 1990 to make partial restitution to individuals harmed by radiation exposure resulting from underground uranium mining and above-ground nuclear tests in Nevada.

Naphthyl ketones: a new class of Janus kinase 3 inhibitors

Potent inhibition of Janus kinase 3 was found for a series of naphthyl(beta-aminoethyl)ketones (e.g. 7, pIC50 = 7.1+/-0.3). Further studies indicated that these compounds fragment in less than 1 h by retro-Michael reaction in the Jak3 in vitro ELISA assay procedure. The breakdown product of 7, 2-naphthylvinyl ketone (22, pIC50 = 6.8+/-0.3) showed very similar inhibitory activity to 7. Compounds 7 (in neutral buffer) and 22 will be useful pharmacological tools for the investigation of the Janus tyrosine kinase Jak3.

The multisystem adverse effects of NSAID therapy

The clinical utility of nonsteroidal anti-inflammatory drugs (NSAIDs) to manage pain and inflammation is limited by adverse side effects. Although effective analgesic and anti-inflammatory agents, NSAIDs are associated with side effects that are a consequence of nonspecific inhibition of both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). The primary adverse events associated with NSAID therapy are upper gastrointestinal (GI) ulceration, perforation, or bleeding, all of which involve mucosal damage of varying severity and can be asymptomatic and occur with little warning. Clinicians who prescribe NSAIDs should be able to identify patients who are at risk of an NSAID-induced GI adverse event and to detect and manage the event should one occur. The use of COX-2-specific inhibitors to manage pain and inflammation may minimize the risks of NSAID-associated toxicities.

Dynamics of stab wounds: force required for penetration of various cadaveric human tissues

It is often said that once the skin has been penetrated no further force is required to produce penetration of underlying tissues. This experimental study has used technology which was not available to earlier investigators to examine this issue in detail. The results confirm the importance of skin penetration but indicate that the penetration of other tissues may also require significant force.

Biomechanics of judicial hanging: a case report

A prisoner in Washington State in the United States of America appealed against sentence of death by hanging on the grounds that it was 'cruel and unusual' and hence contravened the Eighth Amendment of the US Constitution. The man weighed 184 kg (406 lb) and it was suggested that the 'drop' proposed to effect judicial hanging might result in decapitation. This hypothesis was tested by applying simple biodynamic principles to the available data from past hangings. It was concluded that decapitation was a significant possibility.

Safety knowledge of users and non-users of the lap belt on two-point motorized belt systems

A field study of 1146 drivers and passengers of vehicles equipped with motorized passive belts was conducted in shopping malls and other locations in the states of Arizona and Indiana. The Indiana data was collected the summer of 1994 and the Arizona data the summer of 1995. Shoulder belt use by drivers and passengers was 93.4% in Indiana and 87.8% in Arizona. Lap belt use was 65% in Indiana and 69.9% in Arizona. Over 99% of drivers in both states knew that a manually fastened lap belt was provided along with the motorized shoulder belt. Most drivers agreed that they are supposed to wear the lap belt (96.3% in Indiana and 94.3% in Arizona) and said that the vehicle they were driving provided a warning signal when the lap belt was not fastened (75.7% in Indiana and 79.4% in Arizona). Most drivers were also aware of warning labels telling them to use their lap belt (63.9% in Indiana and 68.2% in Arizona).

The still video camera: a suitable and convenient method of demonstrating post mortem findings

The post mortem demonstration continues to play an important role in medical education at both undergraduate and postgraduate levels. However, for a variety of reasons its format needs to be adaptable in order to maximize the educational benefit and increasingly to comply with legislation. We have developed a method of demonstration based upon a still video camera system which we have found is acceptable to our students and overcomes some of the problems associated with other formats. In this paper we describe the system itself, compare it with other systems, discuss its potential applications and present the results of a questionnaire-based survey of the first groups of medical students to be taught in this way. These results confirm that the technique is popular with students and that it appears to be a useful teaching modality worthy of further development.

Ethnic differences in the prevalence of nonmalignant respiratory disease among uranium miners

OBJECTIVES

This study (1) investigates the relationship of nonmalignant respiratory disease to underground uranium mining and to cigarette smoking in Native American, Hispanic, and non-Hispanic White miners in the Southwest and (2) evaluates the criteria for compensation of ethnic minorities.

METHODS

Risk for mining-related lung disease was analyzed by stratified analysis, multiple linear regression, and logistic regression with data on 1359 miners.

RESULTS

Uranium mining is more strongly associated with obstructive lung disease and radiographic pnuemoconiosis in Native Americans than in Hispanics and non-Hispanic Whites. Obstructive lung disease in Hispanic and non-Hispanic White miners is mostly related to cigarette smoking. Current compensation criteria excluded 24% of Native Americans who, by ethnic-specific standards, had restrictive lung disease and 4.8% who had obstructive lung disease. Native Americans have the highest prevalence of radiographic pneumoconiosis, but are less likely to meet spirometry criteria for compensation.

CONCLUSIONS

Native American miners have more nonmalignant respiratory disease from underground uranium mining, and less disease from smoking, than the other groups, but are less likely to receive compensation for mining-related disease.

Oronasal distribution of ventilation at different ages

The route of breathing, oral or nasal, is a determinant of the doses of inhaled pollutants delivered to target sites in the upper and lower respiratory tracts. We measured partitioning of ventilation, using a divided oronasal mask during a submaximal exercise test, in 37 male and female subjects who ranged in age from 7 to 72 y. The following four patterns of breathing were evident during exercise: (1) nasal only (13.5%), nasal shifting to oronasal (40.5%), oronasal only (40.5%), and oral only (5.4%). Children (i.e., 7-16 y of age) displayed more variability than adults with respect to their patterns of ventilation with exercise. Young adults (i.e., 17-30 y of age) who initially breathed nasally with exercise switched to oral ventilation at a lower percentage of the previously measured maximum ventilation (10.8%) than older subjects (31.8%). The partitioning of ventilation between the nasal and oral routes follows complex patterns that cannot be predicted readily by the age, gender, or nasal airway resistance of the subject.

Detecting homicide in hospital

The Beverly Allitt case and the subsequent inquiry have focused attention on the detection of covert hospital homicide. Effective investigation can only take place if there is prompt recognition of circumstances that justify suspicion about a death and immediate action is taken to retrieve potentially vital evidence. The hospital itself must take responsibility for the detection of covert homicide. Confidence that such deaths will be uncovered by 'routine' investigation through the existing coroner system, including postmortem examination, is misplaced.

The use of personal health information in the coroner's inquiry

A pathologist appointed by the coroner may feel that his or her role is to review the medical notes, perform a post-mortem, examination and then interpret the findings in the light of clinical information and any other information received from the coroner, and include in the clinico-pathological summary a cause of death. We believe that such an approach is not in accordance with the legal position relating to coroners' inquests. The coroner has no automatic right to see the medical notes (and neither does the coroner's pathologist); where there is, or may be, dispute as to the circumstances leading to death, the proper way for information in the medical record to be presented at the coroner's inquest is for the maker of any note to give oral evidence. Where the cause of death requires interpretation of the clinical history or knowledge of any circumstantial evidence, a pathologist should refrain from giving a cause of death; such a task is for the court, having heard all the evidence-medical or not-relating to the death.

A randomized, double-blind comparison of donor tolerance of 400 mL, 200 mL, and sham red cell donation

BACKGROUND

Volume replacement could allow the safe collection of twice the normal amount of red cells in a standard donation. Studies in small numbers of donors have shown that a temporary decrease in red cell mass is well tolerated when donors give twice the usual amount (170-225 mL) of red cells in a standard 405- to 495-mL donation. Sham-donation control groups have not been included in previous studies of increased red cell donation, and perceptions of donation effects could have been biased.

STUDY DESIGN AND METHODS

In the study reported here, 17 male and 13 female volunteers were randomly assigned to make a sham donation, 1-unit donation, or 2-unit donation on an automated blood cell separator. Donor tolerance was assessed by ambulatory heart rate monitoring and by a poststudy interview. Hemoglobin, hematocrit, ferritin, serum iron, total iron-binding capacity, red cell 2,3 DPG, and serum erythropoietin were measured before and after donation for comparison of the erythropoietic responses in the three study groups.

RESULTS

Red cells collected totaled 206 +/- 10 mL in the 1-unit group and 414 +/- 21 mL in the 2-unit group. Changes in heart rate, systolic blood pressure, and diastolic blood pressure with donation and changes in heart rate recorded by ambulatory monitoring did not differ for the experimental groups. Postdonation changes from baseline values were evaluated on Days 2, 7, and 14. Changes in hemoglobin were significantly different between groups (p < 0.017) in all postdonation tests. There were differences between groups in erythropoietin response, red cell 2,3 DPG, ferritin levels, and hemoglobin synthesis. Hemoglobin synthesis and mean changes in 2,3 DPG, erythropoietin, ferritin, and postdonation hemoglobin were greater in the 2-unit group than in the 1-unit group.

CONCLUSION

Donor tolerance of red cell donations of 414 +/- 21 mL, a volume of red cells twice that in a standard 450-mL blood donation, does not differ from donor tolerance of standard or sham donations. Physiologic adjustments and the hematopoietic response to reduced red cell mass were greater in the 2-unit group, but the donation of 1 unit or 2 units did not cause detectable symptoms of reduced oxygen-carrying capacity.

Information on death certificates: cause for concern?

AIMS

To assess the frequency with which the cause of death on death certificates included the relevant details requested of certifying doctors, especially in deaths due to malignant disease, but also including certain other deaths where specific information would be expected to be included.

METHODS

Consecutive series of certificates attributing death to malignancy, pneumonia, an acute cerebrovascular event, and renal failure were inspected and compared with the categories identified in the International Classification of Disease. Review of clinical notes and of laboratory data was used to determine the number of cases in which detailed histological diagnoses were available.

RESULTS

A histological diagnosis was available in 79.1% of cases of deaths due to malignancy, but was recorded on only 23.6% of certificates. Haematologists performed best (69.6%) and general surgeons worst (2.8%). The sites of primary tumours were recorded in detail in only 23 of 89 cases of tumours of the large bowel (22/36), lung (1/35) and stomach (0/18). In cases of pneumonia the causative organism was recorded in only 4 of 330. In cases of an acute cerebrovascular event one of 70 was recorded as being due to haemorrhage. A distinction between cerebral or precerebral arterial occlusion (embolism/thrombosis) and cerebral haemorrhage was not recorded in any of the other cases. In cases of renal failure a cause was not recorded in 75 of 95.

CONCLUSIONS

Despite consistent encouragement to record all relevant details on death certificates this study shows that doctors fail to do so in most cases. Such a failure diminishes information available to the Office of Population Censuses and Surveys, affecting mortality statistics and gives further cause for concern about standards of certification. Means by which the standard of certification might be improved are discussed, including screening of certificates by a medically qualified person prior to registration.

Cardiopulmonary manifestations of hantavirus pulmonary syndrome

OBJECTIVE

To describe the clinical characteristics of a group of patients infected with the newly recognized hantavirus in the Southwestern United States.

DESIGN

Case series.

SETTING

Tertiary referral center.

PATIENTS

All patients with confirmed hantavirus infection admitted to the University of New Mexico Hospital between May 1, 1993 and January 1, 1994.

INTERVENTIONS

Records of patients with hantavirus infection were reviewed to collect all pertinent clinical data.

MEASUREMENTS AND MAIN RESULTS

Pulmonary disease in these patients was characterized by hypoxemia covering a wide range of severity. The cause of hypoxemia was an increased permeability (noncardiac) pulmonary edema which could be differentiated from hydrostatic (cardiac) pulmonary edema by its association with low pulmonary artery occlusion pressures and increased protein content of edema fluid. Hemodynamic measurements in severe cases showed a shock state characterized by a low cardiac index (range 1.6 to 3.0 L/min/min2), a low stroke volume index (range 10.5 to 29 mL/m2), and high systemic vascular resistance index (range 1,653 to 2,997 dyne.sec/cm5.m2). Progression to death was associated with worsening cardiac dysfunction unresponsive to treatment and causing oxygen debt and lactic acidosis.

CONCLUSIONS

The two major life-threatening pathophysiologic changes in Hantavirus Pulmonary Syndrome are increased permeability pulmonary edema, and an atypical form of septic shock caused by myocardial depression and hypovolemia.

Significance of chronic tonsillar herniation in sudden death

The Chiari I malformation is a congenital abnormality of the cerebellum strongly associated with syringomyelia and also associated with bony abnormalities of the base of the skull and the cervical spine. This review examines the case of a 25 year old man who collapsed and died following a blow to the face and was found at post mortem to have a Chiari I malformation and syringomyelia but no gross or microscopic evidence of fresh brain or spinal cord injury. The occurrence of sudden and unexpected deaths in this condition is discussed especially in the context of apparently minor coincident trauma.

Limitations of expert evidence

Doctors from diverse specialties are required, from time to time, to give evidence either in documentary form or in person to both civil and criminal courts. A joint conference of the Royal Colleges of Physicians and Pathologists was held at the Royal College of Physicians on 25 October 1994, with the intention to explore those areas where difficulties might arise for the doctor from either a medical or a legal point of view, both as an informative exercise and in order to identify subjects which might usefully be further examined.

Death certification: is correct formulation of cause of death related to seniority or experience?

We looked at a series of death certificates completed by various grades of hospital clinicians, general practitioners (GPs) and pathologists. Specific error types were defined and identified in each group. In hospital it is still the pre-registration house officer who completes most of the death certificates. Senior hospital doctors make more errors than their juniors while GPs and pathologists make fewest errors. Even amongst pathologists 11% of certificates recorded no adequate underlying cause of death, 85.7% failed to record organisms identified and 76.7% failed to record the site or histological type of tumours. This agrees with other studies that show that inaccuracies in death certificates arise from inadequate formulation of cause of death and failure to record relevant information. It reveals that little heed has been paid to the recommendation in the joint report of the Royal College of Physicians and Pathologists that senior doctors should be more involved in certification--the frequency of errors in this group suggests that it might not, in any case, lead to a great improvement. The number or errors made by GPs and pathologists suggest that even practitioners with clinical experience and regular exposure to certification frequently make errors. The reasons for this are discussed and possible solutions proposed.

Silicosis and lung cancer risk in underground uranium miners

The presence of radiographic silicosis as a risk factor for lung cancer was assessed in a case-control study conducted within a study cohort of New Mexico underground uranium miners. Chest radiographs were interpreted for the presence of silicosis for 65 lung cancer cases and 216 controls. The presence of silicosis on the chest radiograph taken closest to the start of employment or on the latest radiograph available was not associated with lung cancer risk after adjustment for cumulative exposure to radon progeny. The odds ratio associated with the presence of any type of opacity indicative of pneumoconiosis on the chest x ray closest to the start of employment was 1.33 (95% confidence interval, 0.31-5.72). For the most recent available chest x ray, the corresponding odds ratio was 1.16 (95% confidence interval, 0.35-3.84). Although the findings are limited by the relatively small number of subjects, the lack of association of silicosis with lung cancer suggests that silica exposure should not be regarded as a major uncertainty in extrapolating radon risk estimates from miners to the general population.

Sources of variability in posterior rhinomanometry

Sources of variability in nasal airway resistance measured by posterior rhinomanometry were studied in 5 subjects tested on 5 different days and 56 subjects tested on 2 different days. On each day, a questionnaire on upper airway health and nasal symptoms was completed. The mean individual difference in nasal airway resistance between the 2 test days in the group of 56 subjects was 5.3% (SD 52.7%). Between-subject variability accounted for 74.9% and 72.5% of the total variability in the group of 5 and the group of 56 subjects, respectively. For the 5 subjects, by accounting for a change in upper airway symptoms or upper respiratory tract infection that occurred over the 5 test days, there was a significant decrease in the between-subject variability. The difference in sources of variation due to a change in upper airway symptoms was not seen in the group of 56 subjects. We conclude that the largest source of variability in nasal airway resistance is due to between-subject differences.

Assessment of heart rate as a predictor of ventilation

The rate of ventilation and route of breathing (i.e., nasal versus oronasal) are potential determinants of pollutant doses to target sites in the lung. However, the lack of accurate methods for ambulatory measurement of ventilation has hindered estimation of exposure and dose in freely ranging individuals, complicating the interpretation of the relationships among exposure, dose, and response in epidemiological studies. The goal of this project was to develop and validate a method of monitoring ventilation for large-scale epidemiologic investigations. We estimated ventilation for individual subjects from ambulatory heart rate monitoring, using the relationship between ventilation and heart rate that had been obtained during exercise testing. Fifty-eight subjects participated in the study, which included healthy adults and children, and subjects with lung and heart disease. Subjects performed cycle exercise and tasks involving lifting and vacuuming. Work loads of progressive and variable order were used in the testing. Conventional methods were used to measure heart rate and total ventilation, and a sampling mask was developed to measure the partitioning of breathing between oral and nasal routes. The minute ventilation-heart rate relation was evaluated under steady-state and varying work loads. In a second phase, subjects wore wristwatch monitors that recorded their heart rates, minute by minute, throughout the day. Subjects recorded activities, locations, and levels of exertion. Two 16-hour monitoring periods were obtained from each subject. The laboratory findings documented considerable intersubject variability in the minute ventilation-heart rate relation with a two- to five-fold range in the coefficients describing the change in ventilation relative to heart rate. This variation implies that individual testing is required to derive accurate predictive equations. Minute ventilation-heart rate regressions for the maximal progressive exercise test and for the test with a nonprogressive submaximal work load sequence were comparable, indicating that varying the sequence of work loads does not substantially affect the minute ventilation-to-heart rate ratio. During upper body work (e.g., lifting), the minute ventilation-to-heart rate ratio was one-third greater than during lower body exercise. Diverse patterns of partitioning breathing between oral and nasal routes were observed with increasing oral ventilation in most subjects as work load increased. In the field, heart rate and activity patterns were monitored successfully in adults and children with low rates of instrument failure and noncompliance.(ABSTRACT TRUNCATED AT 400 WORDS)

Rapid death due to group A streptococcal infections. Necrotizing fasciitis and acute bacterial myositis

Soft tissue infections due to the group A Streptococcus are difficult to diagnose and rapidly fatal. They may present to the forensic pathologist as an "obscure autopsy". Death may occur within or outside the hospital and with or without a history of fulminant infection or predisposing factors. It is important for the pathologist to exclude this condition through awareness of its existence and by appropriate dissection with retention of materials for microbiological and histological examination.

Survey of hypnotic drug use in nursing homes

The prescribing patterns for hypnotic medications were surveyed in 765 patients of three skilled-nursing facilities and two intermediate-care facilities. Seven per cent of the patients received a hypnotic routinely; an additional 3 per cent had as-needed orders for a hypnotic medication. Temazepam, flurazepam, and triazolam were, in descending order, the three most commonly prescribed hypnotics and accounted for 79 per cent of the hypnotic prescriptions. The average duration of use for triazolam, temazepam, and flurazepam was 11 weeks, 24 weeks, and 82 weeks, respectively. Seventy-six per cent of the flurazepam prescriptions were given seven days a week; 31 per cent of these prescriptions were for 30 mg doses. Medications that were not hypnotics but did have sedative side-effects were prescribed with bedtime orders for 11 per cent of the patients. The three most commonly prescribed drugs in this class were diphenhydramine, thioridazine, and haloperidol. Possible explanations for the lower frequency of hypnotic use observed in this study as compared to the frequencies reported in the literature are discussed, as are possible hazards of high-dose and long-term use of hypnotics.