Design and implementation of a Thomson parabola for fluence dependent energy-loss measurements at the Neutralized Drift Compression eXperiment

The interaction of ion beams with matter includes the investigation of the basic principles of ion stopping in heated materials. An unsolved question is the effect of different, especially higher, ion beam fluences on ion stopping in solid targets. This is relevant in applications such as in fusion sciences. To address this question, a Thomson parabola was built for the Neutralized Drift Compression eXperiment (NDCX-II) for ion energy-loss measurements at different ion beam fluences. The linear induction accelerator NDCX-II delivers 2 ns short, intense ion pulses, up to several tens of nC/pulse, or 10¹⁰-10¹¹ ions, with a peak kinetic energy of ∼1.1 MeV and a minimal spot size of 2 mm FWHM. For this particular accelerator, the energy determination with conventional beam diagnostics, for example, time of flight measurements, is imprecise due to the non-trivial longitudinal phase space of the beam. In contrast, a Thomson parabola is well suited to reliably determine the beam energy distribution. The Thomson parabola differentiates charged particles by energy and charge-to-mass ratio, through deflection of charged particles by electric and magnetic fields. During first proof-of-principle experiments, we achieved to reproduce the average initial helium beam energy as predicted by computer simulations with a deviation of only 1.4%. Successful energy-loss measurements with 1 μm thick silicon nitride foils show the suitability of the accelerator for such experiments. The initial ion energy was determined during a primary measurement without a target, while a second measurement, incorporating the target, was used to determine the transmitted energy. The energy-loss was then determined as the difference between the two energies.

Development and testing of a pulsed helium ion source for probing materials and warm dense matter studies

The neutralized drift compression experiment was designed and commissioned as a pulsed, linear induction accelerator to drive thin targets to warm dense matter (WDM) states with peak temperatures of ∼1 eV using intense, short pulses (∼1 ns) of 1.2 MeV lithium ions. At that kinetic energy, heating a thin target foil near the Bragg peak energy using He(+) ions leads to more uniform energy deposition of the target material than Li(+) ions. Experiments show that a higher current density of helium ions can be delivered from a plasma source compared to Li(+) ions from a hot plate type ion source. He(+) beam pulses as high as 200 mA at the peak and 4 μs long were measured from a multi-aperture 7-cm-diameter emission area. Within ±5% variation, the uniform beam area is approximately 6 cm across. The accelerated and compressed pulsed ion beams can be used for materials studies and isochoric heating of target materials for high energy density physics experiments and WDM studies.

Droplet evolution in expanding flow of warm dense matter

We propose a simple, self-consistent kinetic model for the evolution of a mixture of droplets and vapor expanding adiabatically in vacuum after rapid, almost isochoric heating. We study the evolution of the two-phase fluid at intermediate times between the molecular and the hydrodynamic scales, focusing on out-of-equilibrium and surface effects. We use the van der Waals equation of state as a test bed to implement our model and study the phenomenology of the upcoming second neutralized drift compression experiment (NDCX-II) at Lawrence Berkeley National Laboratory (LBNL) that uses ion beams for target heating. We find an approximate expression for the temperature difference between the droplets and the expanding gas and we check it with numerical calculations. The formula provides a useful criterion to distinguish the thermalized and nonthermalized regimes of expansion. In the thermalized case, the liquid fraction grows in a proportion that we estimate analytically, whereas, in case of too rapid expansion, a strict limit for the evaporation of droplets is derived. The range of experimental situations is discussed.

Contact gunshot wound of the head: diagnosis after surgical debridement of the wound

A case of homicidal contact gunshot wound of the head is described. The victim survived approximately 1 day and one-half following the shooting, during which time the bullet was recovered during surgery, the injuries were 'well-documented', and surgical debridement of the wound destroyed any visible evidence of gunshot residue on the scalp or underlying bone. Autopsy revealed a skull fragment with soot deposition within the depths of the injured brain, allowing an accurate determination of range-of-fire. The case reiterates the importance of performing autopsies on all homicides.

Sudden death due to undiagnosed Wilms' tumor in an adult

Sudden unexpected deaths due to natural causes constitute a large number of cases encountered by the forensic pathologist. In a majority of such cases, heart disease is responsible for sudden death. Rare disease entities resulting in sudden death are occasionally encountered and may not fit the classic epidemiological profile. We present a case of sudden death due to a previously undiagnosed Wilms' tumor (WT) in an adult. The pathology of WT is discussed, as is the topic of sudden death due to previously unrecognized malignancy.

Deaths and injuries from house fires

BACKGROUND

We sought to define the factors associated with house fires and related injuries by analyzing the data from population-based surveillance.

METHODS

For 1991 through 1997, we linked the following data for Dallas: records from the fire department of all house fires (excluding fires in apartments and mobile homes), records of patients transported by ambulance, hospital admissions, and reports from the medical examiner of fatal injuries.

RESULTS

There were 223 injuries (91 fatal and 132 nonfatal) from 7190 house fires, for a rate of 5.2 injured persons per 100,000 population per year. Rates of injury related to house fires were highest among blacks (relative risk, 2.8; 95 percent confidence interval, 2.1 to 3.6) and in people 65 years of age or older (relative risk, 2.6; 95 percent confidence interval, 1.9 to 3.5). Census tracts with low median incomes had the highest rates of injury related to house fires (relative risk as compared with census tracts with high median incomes, 8.1; 95 percent confidence interval, 2.5 to 32.0). The rate of injuries was higher for fires that began in bedrooms or living areas (relative risk, 3.7); that were started by heating equipment, smoking, or children playing with fire (relative risk, 2.6); or that occurred in houses built before 1980 (relative risk, 6.6). Injuries occurred more often in houses without functioning smoke detectors (relative risk, 1.5; 95 percent confidence interval, 1.0 to 2.4). The prevalence of functioning smoke detectors was lowest in houses in the census tracts with the lowest median incomes (P<0.001).

CONCLUSIONS

Rates of injuries related to house fires are highest in elderly, minority, and low-income populations and in houses without functioning smoke detectors. Efforts to prevent injuries and deaths from house fires should target these populations.

Death due to microvascular occlusion in sickle-cell trait following physical exertion

The heterozygous condition characterized by the presence of hemoglobin AS (sickle-cell trait) occurs in approximately 8% of the American black population. Unlike the homozygous state (sickle-cell disease), sickle-cell trait is not widely recognized as a cause of life-threatening illness or death despite over 30 case reports describing fatal or serious complications of exercise in young black males with this condition. These reports identify heat stress, dehydration, viral illness, and poor physical conditioning as factors which may contribute to exertional rhabdomyolysis and sudden death, suggesting multifactorial etiology. However, since sickling is known to occur postmortem, it remains controversial as to whether the pathogenesis of these exercise related deaths involves microvascular obstruction by sickled erythrocytes. We describe three young black individuals with no significant past medical history who died following physical exertion. In all three cases, postmortem hemoglobin electrophoresis demonstrated hemoglobin AS. In none of the cases was the body temperature found to be elevated. These cases serve to remind the forensic community that, in the proper setting, sickle-cell trait must be viewed as a potentially fatal disorder.

A comparative morphological study of human germ cells in vitro or in situ within seminiferous tubules

For many infertile couples, intracytoplasmic germ cell/spermatozoon injection into unfertilized eggs may be their only hope for producing their own biological children. Thus far, success with injection of pre-spermatozoan germ cells such as round spermatids has not been as great as that of spermatozoon injection. This could be due in part to the difficulty of identifying younger (less mature) male germ cells in testicular biopsy dispersions. To improve the identification of various types of live, dispersed, human testicular cells in vitro, a comparative study of the morphological characteristics of human spermatogenic germ cells in vitro or in situ within seminiferous tubules was conducted. Live human testicular tissue was obtained from an organ-donating, brain-dead person with a high density of various germ cells. A cell suspension was obtained by enzymatic digestion, and cells were cultured for 3 days in an excessive volume (100-fold medium:cells; v:v) of HEPES-TC 199 medium at 5 degrees C and observed live with Nomarski optics (interference-contrast microscopy). For comparative purposes, testes from ten men obtained at autopsy were fixed, embedded in epoxy resin, sectioned at 20 microm, and observed unstained by Nomarski optics. This approach allowed comparison of morphological characteristics of individual germ cells seen in vitro or in situ in the human testis. In both live and fixed preparations from control men with varied daily sperm production rates, Sertoli cells have oval to pear-shaped nuclei with indented nuclear envelopes and large nucleoli, which makes their appearance distinctly different from germ cells. The size, shape, and chromatin pattern of nuclei, and the presence of meiotic metaphase figures, acrosomic vesicles/structures, tails, and/or mitochondria in the middle piece of germ cells are characteristically seen in live cells in vitro and in those cells observed in the fixed seminiferous tubules. Hence, this comparative approach allows verification of the identity of individual germ cells seen in vitro and provides a checklist of distinguishing characteristics of live human germ cells, to be used by scientists and technical staff in infertility clinics when selecting specific germ cells from a testicular aspirate or enzymatically digested biopsy.

Familial filicide and filicide classification

Filicide is the killing of a child by his or her parent. Despite the disturbing nature of these crimes, a study of filicide classification can provide insight into their causes. Furthermore, a study of filicide classification provides information essential to accurate death certification. We report a rare case of familial filicide in which twin sisters both attempted to kill their respective children. We then suggest a detailed classification of filicide subtypes that provides a framework of motives and precipitating factors leading to filicide. We identify 16 subtypes of filicide, each of which is sufficiently characteristic to warrant a separate category. We describe in some detail the characteristic features of these subtypes. A knowledge of filicide subtypes contributes to interpretation of difficult cases. Furthermore, to protect potential child homicide victims, it is necessary to know how and why they are killed. Epidemiologic studies using filicide subtypes as their basis could provide information leading to strategies for prevention.

Death due to thrombotic thrombocytopenic purpura in pregnancy: case report with review of thrombotic microangiopathies of pregnancy

Maternal death during pregnancy, although uncommon, may result from a broad range of conditions. In this paper, a case of thrombotic thrombocytopenic purpura diagnosed by postmortem examination is presented. Thrombotic thrombocytopenic purpura is one of a subset of diseases that result in the formation of microthrombi within the vasculature, either as a primary or secondary manifestation. Other conditions included in the differential diagnosis during pregnancy are hemolytic uremic syndrome, systemic lupus erythematosus, preeclampsia-eclampsia and the HELLP syndrome, acute fatty liver of pregnancy, antiphospholipid antibody syndrome, and disseminated intravascular coagulation. The histologic manifestations of these diseases can be similar and in most cases do not provide adequate information to accurately differentiate these diseases in the postmortem period. This paper addresses the need for clinical history (i.e., symptomatology, trimester of onset) and antemortem laboratory testing in addition to a thorough autopsy to accurately differentiate among the conditions named previously. In the absence of an adequate clinical history and antemortem laboratory testing, the more general diagnosis of "thrombotic microangiopathy of pregnancy" is acceptable.

Death due to a ruptured berry aneurysm in a 3.5-year-old child

Berry aneurysms in childhood are rare and have certain characteristics that distinguish them from their adult counterparts. A case of death caused by a ruptured berry aneurysm in a child is presented, and the topic is reviewed.

Familial thoracic aortic aneurysms and dissections

Rupture of thoracic aortic aneurysms and/or dissections is not rare, occurring in approximately 0.6% of all medicolegal autopsies. Most forensic pathologists are aware of the association between thoracic aortic aneurysms/dissections and trauma, atherosclerosis, inflammation and Marfan syndrome. In this report, we discuss a familial form of thoracic aortic dilatation and/or dissection that is distinct from Marfan syndrome. In addition, we review the topic of thoracic aortic aneurysm and dissection and encourage family notification by forensic pathologists when familial forms of aortic disease are suspected at autopsy.

Immersion technique for brain removal in perinatal autopsies

Perinatal autopsies present forensic patholgists with a variety of challenges, not the least of which involves the removal and examination of very small and sometimes fragile organs. Removal of the immature brain can be particularly troublesome. Even if great care is taken during brain removal, one is often left with no more than a semifluid amorphous mass of softened tissue by the time the brain is ready to be fixed in formalin. We describe a method of perinatal brain removal which helps to preserve brain shape and integrity. By removing the brain while the head (and body) is totally immersed in water, we find that the brain is easier to remove and less apt to destruction. Subsequent fixation in formalin results in well-preserved, intact specimens, allowing for optimal examination and sectioning.

Sudden death due to obstruction of coronary artery ostium by aortic valve papillary fibroelastoma

Papillary fibroelastomas are rare endocardial growths that most commonly occur on the cardiac valves. Whether papillary fibroelastomas represent true neoplasms, hamartomas, or degenerative changes is debatable. Whatever their origin, papillary fibroelastomas have a characteristic gross and microscopic appearance, are usually solitary, and are almost always incidental findings at autopsy or during cardiac surgery. We report a case of sudden death caused by occlusion of the right coronary artery ostium by a papillary fibroelastoma of the aortic valve. We discuss the gross and microscopic features, differential diagnosis, and etiology and pathogenesis of this rare and interesting cardiac lesion.

A suicide disguised as a homicide: return to Thor Bridge

Suicides staged as homicides are uncommon. We present a case of a self-inflicted gunshot wound of the chest disguised by the victim as a homicide, using a method described by Sir Arthur Conan Doyle in his Sherlock Holmes story, "The Problem of Thor Bridge."

Fatal anaphylaxis due to fire ant stings

Imported fire ants (Solenopsis invicta and Solenopsis richteri) are the source of a potentially lethal environmental hazard in the southeastern United States. Because of their resistance to natural and chemical control, fire ants can overwhelm their environment, causing destruction of land and animals. Fire ants can also cause a variety of health problems in humans, ranging from simple stings to anaphylaxis and death. We present a case of a 30-year-old woman who died of anaphylaxis following multiple fire ant stings. At autopsy, multiple skin lesions characteristic of those produced by fire ant stings were present on her arm. Postmortem blood samples were positive for imported fire ant venom-specific IgE antibodies (5654 ng/ml) and tryptase (12 ng/ml). Deaths caused by imported fire ant stings are rare but are likely to become more common as the fire ant population expands. In this report, we review deaths due to fire ant stings, discuss postmortem laboratory findings, and stress the importance of recognizing the characteristic skin lesions produced by fire ants.

Ethnic differences in testicular structure and spermatogenic potential may predispose testes of Asian men to a heightened sensitivity to steroidal contraceptives

Spermatogenesis in Asian men appears to be more susceptible to suppression by steroidal contraceptives administered in clinical trials than spermatogenesis in Caucasian men. The objective of this study was to determine whether ethnic differences exist in testicular structure and spermatogenic potential that might predispose Asians to a high sensitivity to steroidal contraceptives. Testes from 12 Chinese men were compared to those from 8 Hispanic men and 12 non-Hispanic Caucasian men of ages 29+/-3, 30+/-2, and 29+/-3 years, respectively. Testes were fixed by vascular perfusion with glutaraldehyde, further fixed in osmium, embedded in Epon, and evaluated by stereology using 0.5-microm sections stained with toluidine blue. Homogenates of fixed testes were evaluated for the number of Sertoli cells and the daily sperm production based on pachytene primary spermatocytes (PDSP) or spermatids with spherical nuclei (DSP). Paired parenchymal weight was less (P < 0.05) in Chinese men than in Hispanic or Caucasian men. The PDSP per gram of parenchyma was lower (P < 0.05) and the DSP per gram tended to be lower in Chinese men than in other groups. The histologic appearance, volume density, and length per man of seminiferous tubules were the same among the ethnic groups; however, the diameter of seminiferous tubules was less (P < 0.05) in Chinese than in Hispanic or Caucasian men. The PDSP per man and the DSP per man were lower (P < 0.05) in Chinese than in Hispanic or Caucasian men. The number of Sertoli cells per gram was higher (P < 0.05) in Chinese or Caucasian men than in Hispanic men, but the number of Sertoli cells per man was lower (P < 0.05) in Chinese men than in Hispanic or Caucasian men. Sertoli cell function, measured as the number of germ cells accommodated by a single Sertoli cell, was lower (P < 0.05) in Chinese men than in Caucasian men. The volume density of Leydig cell cytoplasm was greatest (P < 0.05) in Chinese men, but the number of Leydig cells was similar among the ethnic groups. Hence, smaller testes coupled with reduced Sertoli cell number and function and reduced daily sperm production could predispose Asian men to have a heightened negative response of testes to steroidal contraceptives, as compared to Caucasian men. Dampening (by exogenous androgens) of any physiological benefit to spermatogenesis that a high volume density of Leydig cell cytoplasm may bestow on the human testis (that Asian men may have evolved to require) would exacerbate ethnic differences in the spermatogenic response to hormonal contraceptives.

Jejunostomy tube failure: malnutrition caused by intraluminal antegrade jejunostomy tube migration

Complications occurring with jejunostomy feeding tubes are common and sometimes life-threatening. We describe a case of peristalsis-induced intraluminal antegrade migration of a jejunostomy tube's distal end with concomitant retrograde movement of the small bowel over the tube, which was first discovered at autopsy. This ultimately resulted in the jejunostomy feedings entering the distal ileum, therefore bypassing most of the small intestine. Subsequent malnutrition was a contributing factor in the death of the patient, who had required tube feedings after suffering severe head trauma in a motor vehicle accident 29 months earlier. The only nutritional interventions attempted before death involved various attempts at controlling diarrhea. We discuss the incidence, cause, recognition, and prevention of this rarely reported complication of a "functioning" jejunostomy feeding tube.

Frequency of unilateral and bilateral mesial temporal sclerosis in primary and secondary epilepsy: a forensic autopsy study

Controversy exists regarding the pathogenetic relationship of mesial temporal sclerosis (MTS) to epileptogenesis. Some investigators view hippocampal sclerosis as the primary cause of temporal lobe epilepsy, whereas others interpret the changes to be the result of chronic seizure activity. The present autopsy-based study attempts to clarify the etiologic relationship between mesial temporal sclerosis and epilepsy. To investigate the assumption that bilateral MTS is more likely to be the result of chronic seizure activity associated with a seizure focus outside the hippocampus, two subject groups were identified. The first group comprised 43 patients who had no extrahippocampal pathology and were classified as having primary epilepsy. The second group comprised 35 patients who, had identifiable extrahippocampal pathology and were classified as having secondary epilepsy. Fifteen of the 35 cases of secondary epilepsy also had MTS; seven of these were unilateral and eight were bilateral. Of the 43 cases with primary epilepsy, only one had MTS, and it was unilateral. Significantly more cases of primary epilepsy than secondary epilepsy had no MTS (p < 0.001), suggesting that both unilateral and bilateral forms of MTS occur with greater frequency in subjects with seizure foci outside the hippocampus. These results also suggest that unilaterality of MTS does not exclude an extrahippocampal cause.

The implantable cardioverter-defibrillator. A potential hazard for autopsy pathologists

The implantable cardioverter-defibrillator (ICD) is an implantable electronic device that has been proven to be safe and effective in treating various malignant tachyarrhythmias in susceptible individuals. As the use of ICDs becomes more widespread, more individuals with the implanted devices will be encountered at autopsy. Manipulation of an activated ICD can result in electrical shock. To avoid injury, pathologists must be properly prepared to deal with bodies containing activated ICDs. These devices can also provide valuable information that may be helpful in determining the cause and mechanism of death. Herein, we present information regarding the appropriate guidelines and safeguards for pathologists confronted with an activated ICD.

Cardiac perforation due to Wallstent embolization: a fatal complication of the transjugular intrahepatic portosystemic shunt procedure

The transjugular intrahepatic portosystemic shunt procedure is an effective intervention for patients with bleeding esophageal varices. Potential complications are numerous but rarely serious. A case of hemopericardium, cardiac tamponade, and death caused by perforation of the right atrium and aorta by a stent after embolization from the liver during stent placement is reported.

Heterotopic transplantation as a model to study the regulation of spermatogenesis; some histomorphological considerations about sperm decline in man

A novel animal model (syngeneic neonatal testicular graft transplanted under the skin of the outer ear in adult inbred Fischer rats that had been castrated, hypophysectomised, and/or subjected to hormonal replacement therapy) was developed to study regulation of spermatogenesis and Sertoli cell number. Given that Sertoli cell number and testicular size are important in determining spermatozoan production rates, this model was first used to study Sertoli cell proliferation, testicular size, and establishment of germ cells. The specific objectives were to determine the developmental pattern of Sertoli cell numbers in transplanted testes and the effect of number of testes transplanted, sex of hosts, pituitary hormonal removal, and replacement on Sertoli cell number, hormonal status of the host, and establishment of germ cells. A few tubules had complete spermatogenesis at 90 days posttransplantation, indicating that Sertoli cells in some of these tubules were functional. Leydig cell structure appeared to be normal, but the density of these interstitial cells was greater than that in testes of intact rats. Although the weight of the seminal vesicles and prostate were maintained in the castrated host with transplants, both serum FSH and LH concentrations were higher than intact control rats. Leukocytic infiltration of testes was not observed in intact rats or in rats receiving neonatal testes. Although transplanted testes showed a delay in reaching the plateau value for Sertoli cell number per testis and although the value reached was lower than in intact testes, the developmental pattern of Sertoli cell proliferation (early division of cells followed by stabilized number of cells) in transplanted testes was similar to that in intact rats. Hypophysectomy reduced the growth of testicular grafts, and hormonal replacement via retransplantation to pituitary intact hosts enhances Sertoli cell proliferation and testicular growth. When two on four testes were transplanted into castrated males or ovariectomized female hosts for 65 days, there was no difference in the graft weights or Sertoli cell numbers between sexes of hosts. Four transplanted testes per rat produced more total testicular parenchyma and a greater number of Sertoli cells per testis than did two testes regardless of sex of the host. Transplantation of six or eight testes produced more total Sertoli cells/host than that found in testes of intact rats. Using hormonal therapy in hypophysectomized hosts, the testicular parenchymal weight was greater for pituitary-intact hosts and FSH-LH combination than the control media. There was no statistically significant difference among the media control, LH, FSH, and GH. This testicular transplant model has shown that the period of Sertoli cell proliferation can be delayed by hypophysectomy, that Sertoli cell number can be influenced by endogenous and exogenous hormones, and that a major component in regulation of testicular size is at the level of the testis. Hence, this model should facilitate study of experimental endocrine manipulation control and potential experimental intervention to increase Sertoli cell number, testicular size, and spermatogenesis. Regarding human sperm count decline in recent years, there appears to be no significant decline in Sertoli cell number or spermatogenic potential in a group of North American men. However, there was a significant decline in volume/man of Leydig cells and volume/man of Leydig cell cytoplasm.

Distribution of organosilicon polymers in augmentation mammaplasties at autopsy

Silicone-containing breast implants have been used since 1963 for cosmetic augmentation and breast reconstruction. Currently, there is intense debate regarding the extent and mechanism of migration of silicone from the area of implant. The current study compares tissue distribution of organosilicon polymers between women with and without silicone breast implants to determine the extent of silicone migration from breast implants. Samples were collected at autopsy from 15 individuals with bilateral breast implants with no known history of chest trauma and from 14 age- and sex-matched controls. Capsule, breast, axillary lymph nodes, abdominal fat, liver, lung, and spleen were collected for analysis of organosilicon polymers by atomic absorption spectrometry and for examination by light microscopy. Blood was collected for analysis of rheumatoid factor and antinuclear antibodies. Silicone was observed microscopically in at least one capsule section from all implant cases and in at least one lymph node in 8 of 15 implant cases. Silicone was not observed in lymph nodes from control cases. Organosilicon polymers were extracted from tissue using heptane, and the silicon content of the extract was quantitated by atomic absorption spectrometry. Silicon was detected in all capsules; statistically significant increases of organosilicon polymers were measured in axillary lymph nodes, breast, and abdominal fat from individuals with silicone breast implants when compared with the nonimplant group. Measurable amounts of organosilicon polymers were found in tissues from the nonimplant group. Suitable blood specimens were analyzed for the presence of rheumatoid factor and antinuclear antibodies. All nine implant cases tested were negative for the presence of antinuclear antibodies. Three implant cases which were tested for rheumatoid factor also were negative. We conclude that organosilicon polymers routinely migrate from the site of breast implantation to regional tissues near the implant site. Tissues from nonimplant cases often contained measurable amounts of organosilicon polymers, and tissue distribution was variable within any single individual: this is consistent with the wide-spread use and form of organosilicon polymers.

Cellular characterization of adipose tissue from various body sites of women

Adipose tissue is the primary site of estrogen biosynthesis in postmenopausal women. The two main histologic components of adipose tissue are mature adipocytes and fibroblasts. Aromatase P450 expressed in the fibroblast component of adipose tissue is responsible for catalyzing conversion of C19 steroids to estrogens. We previously have demonstrated that in women, aromatase expression in adipose tissue of various body sites increases with age and that aromatase expression in the hip is markedly higher than in the abdomen. To determine whether this age- and regional-dependent variation in aromatase expression is caused by an alteration in the ratio of fibroblasts to mature adipocytes, we collected sc adipose tissue samples from 19 women (age range: 21-93 yr) at the time of autopsy. Using a computerized image analysis system, we determined by morphometry the proportions of adipocytes, fibroblasts, and vascular endothelial cells within histologic sections of adipose tissue from midabdomen, both breasts, and both hips. The percentage of each cell component at each body site was expressed as the mean of triplicate replicates. Statistical analysis of our results did not indicate any correlation between advancing age and fibroblast to adipocyte ratios in the breast, abdomen, or hip. Fibroblast to adipocyte ratios were found to be significantly higher in the breast and abdomen compared with the hip ( P < 0.05). No statistical differences were found between the breast and abdomen. These findings suggest that the increase in aromatase expression with advancing age and the higher aromatase expression in the hip compared with the abdomen in women may be caused by alterations in specific signal transduction mechanisms rather than a simple increase in local adipose fibroblast numbers.

Sudden unexpected death in patients with Dandy-Walker malformation

An uncommon but well-recognized occurrence in patients with Dandy-Walker malformation is sudden unexpected death. The mechanism of demise has not been established. We report three patients with Dandy-Walker malformation that experienced sudden unexpected death without uncal or tonsillar herniation, the mechanism usually proposed for demise in such situations. Our findings suggest the possibility of vascular compromise as the cause of the sudden unexpected death in these patients. Early and effective relief of the pressure in the posterior fossa may prevent the occurrence of this catastrophic complication.

Inborn errors of metabolism diagnosed in sudden death cases by acylcarnitine analysis of postmortem bile

Fatty acid oxidation (FAO) disorders represent a frequently misdiagnosed group of inborn errors of metabolism. Some patients die at the first episode of fasting intolerance and, if appropriate investigations are not undertaken, often meet the criteria of sudden infant death syndrome (SIDS). To expand existing protocols for the postmortem diagnosis of FAO and other metabolic disorders, we tested the hypothesis that analysis for acylcarnitine in bile, a specimen readily available at autopsy, may be utilized for diagnostic purposes. Using electrospray/tandem mass spectrometry, we analyzed for acylcarnitine postmortem bile specimens from two infants with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency, one infant with glutaryl-CoA dehydrogenase deficiency, and 17 uninformative SIDS cases as controls. The affected cases, and none of the controls, showed marked accumulation of C10-C18 acylcarnitines or glutarylcarnitine (acyl/free carnitine ratio: 5.2, 2.7, and 1.9, respectively; controls 0.2 +/- 0.1). In one patient, all other diagnostic methods were uninformative, suggesting that bile acylcarnitine profiling could lead to identification of previously overlooked cases.

Inborn errors of metabolism diagnosed in sudden death cases by acylcarnitine analysis of postmortem bile

Fatty acid oxidation (FAO) disorders represent a frequently misdiagnosed group of inborn errors of metabolism. Some patients die at the first episode of fasting intolerance and, if appropriate investigations are not undertaken, often meet the criteria of sudden infant death syndrome (SIDS). To expand existing protocols for the postmortem diagnosis of FAO and other metabolic disorders, we tested the hypothesis that analysis for acylcarnitine in bile, a specimen readily available at autopsy, may be utilized for diagnostic purposes. Using electrospray/tandem mass spectrometry, we analyzed for acylcarnitine postmortem bile specimens from two infants with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency, one infant with glutaryl-CoA dehydrogenase deficiency, and 17 uninformative SIDS cases as controls. The affected cases, and none of the controls, showed marked accumulation of C10-C18 acylcarnitines or glutarylcarnitine (acyl/free carnitine ratio: 5.2, 2.7, and 1.9, respectively; controls 0.2 +/- 0.1). In one patient, all other diagnostic methods were uninformative, suggesting that bile acylcarnitine profiling could lead to identification of previously overlooked cases.

Pressure sores in a Christian Science sanatorium

We reviewed the Dallas County Medical Examiner's Office records of all individuals who had died in a local Christian Science Sanatorium during a 5 1/2-year period. Of 116 such patients, only 13 (11%) had pressure sores (decubitus ulcers). In 10 of these patients, the sores were described as small, superficial, and/or healing, while the other three patients had more serious ulcers. In contrast, for patients dying in nursing homes or hospitals, the incidence of pressure sores may be as high as 54-57%. It is our opinion that the difference in incidence is due to the personal and conscientious nursing care provided by Christian Science institutions.

Fine scale thermal blooming instability: a linear stability analysis

The fine-scale thermal blooming instability of a high power trans-atmospheric laser beam is shown to be affected by the laser pulse length. In this study, we calculate the asymptotic gain of a sinusoidal perturbation as a function of pulse length and perturbation wavenumber. We include the effects of viscosity, diffusion, and wind shear, and we heuristically estimate the effect of turbulence. We find that for short laser pulses, the small wavenumber perturbations are reduced due to acoustic effects. However, large wavenumber perturbations remain large and extend to a higher cutoff in wavenumber than in the long laser pulse limit. At wavenumbers higher than this cutoff, thermal diffusion causes exponential decay of the perturbations. For long laser pulse length wind shear and turbulence limit perturbation growth.