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The authors have developed and tested stackable microchannel cooled laser bar diode pump packages suitable for direct pumping of slab lasers at high duty factor. A stack of 41 diode packages gives a pump array of 13.5 cm/sup 2/ and produces a peak power of 4000 W and an average power of 1000 W for an average irradiance of 75 W/cm/sup 2/. A high average power, total internal reflection face pumped Nd:YAG laser using 80 diode packages has been constructed. Preliminary testing of the slab laser using a 20% subset of diode packages arranged to pump a 4 mm*4 mm*80 mm volume of the slab has been completed. Seventy watts average power is obtained at 2.5 kHz pulse repetition rates and 100 mu s pulse widths. >

With approximately 99% of the electrical energy supplied to the National Ignition Facility (NIF) appearing as heat in the amplifiers, thermal recovery of the NIF system is a major consideration in the design process. The NIF shot rate is one shot every 8 hours, with a goal of 4 hours between shots. This necessitates that thermal recovery take place in no more than 7 hours, with a goal of 3 hours for the accelerated shot rate. Residual optical distortions, which restrict the shot rate, are grouped into two discrete categories: (1) distortions associated with residual temperature gradients in the laser slabs, and (2) distortions associated with buoyantly driven convective currents in the amplifier cavity and beam-tube regions. Thermal recovery of the amplifiers is achieved by cooling the flashlamps and blastshields with a turbulent gas flow. The cooled blastshields then serve as a cold boundary to radiatively extract the residual heat deposited in the slabs and edge claddings. Advanced concepts, such as the use of slightly chilled gas to accelerate some aspects of recovery, are addressed. To quantify recovery rates of the amplifiers, experiments and numerical models are used to measure and calculate the temperatures and optical distortions in NIF-like amplifier elements. The calculation results are benchmarked against AMLAB temperature measurements, thus allowing a quantitative prediction of NIF thermal recovery. These results indicate that the NIF requirement of 7 hour thermal recovery can be achieved with chilled temperature cooling gas.

We report on the progress in developing and building the Mercury laser system as the first in a series of a new generation of diode- pumped solid-state Inertial Confinement Fusion (ICF) lasers at Lawrence Livermore National Laboratory (LLNL). Mercury will be the first integrated demonstration of a scalable laser architecture compatible with advanced high energy density (HED) physics applications. Primary performance goals include 10% efficiencies at 10 Hz and a 1-10 ns pulse with 1 omega energies of 100 J and with 2 omega/3 omega frequency conversion.

High average power Nd:YAG lasers are increasingly interesting for industrial applications such as drilling and machining. Diode pumping of this solid state medium offers longer services intervals, reduced thermal optical distortions, higher system efficiency and more compact packaging than lamp pumping. The zigzag slab geometry is well suited for applications where the average power exceeds a few hundred watts and a good beam quality is desired, particularly if the laser pumping level is to be varied. We present the status of our latest upgrade to our (originally 300 watt 1 ) diode pumped slab laser. In what follows we first describe the diode pump source. We then discuss the zigzag slab laser design and its present performance.

The development and operation of a kilowatt scale KD(asterisk)P second harmonic generator is described. The design utilizes a simple and compact two-plate alternating-Z configuration with a transverse thermal gradient. The calculated single pulse conversion efficiency is between 50 and 75 percent for beams whose divergence is up to 15 times the diffraction limit. Offline subaperture tests demonstrated that the effect of induced thermal gradients on conversion efficiency was less than 5 percent for optical loads expected for kilowatt operation. Full aperture tests with a 300 watt average power Nd:glass zigzag slab laser gave conversions of 35 percent.

There is absolutely nothing like preaching to the choir. Those who would keep alive the controversy regarding the Kennedy-Connally shooting will neither read nor hear what they do not wish to believe. It is because I have not wished to be involved in a useless (and thankless) task that I have written nothing for publication regarding the Kennedy assassination. Lattimer's article,1closely following publication of the interviews with Humes, Boswell, and Finck,2,3has provided me with an engine to make some amplifying and other comments. See also pp 1507, 1525, 1540, and 1544. The Firearm The 6.5-mm, Mannlicher-Carcano firearm used was not a "rifle" and it was not "high-velocity" or "high-powered." The velocity of the bullets at the time they struck Kennedy cannot be precisely predicted. The muzzle velocity varies depending on a number of factors that cannot be absolutely determined. Also, the distance traveled by the bullets

The interpretation of the range of fire of gunshot wounds requires coordination of information and observations from the autopsy surgeon, scene investigator, and laboratory analyst. Opinions based on incomplete information often lead to misinterpretation of the wound. The effects of interposed targets such as clothing, windows, and body parts are discussed. Case examples are given for interposed targets that cause confusing patterns and even lead to misidentification of the points of entrance and exit of the projectile in the body. The splitting of tissue in areas of bony prominence can be mistaken for evidence of discharge of a firearm at close range.

Perhaps it began with Watergate: the precipitating of confidence into the abyss of disbelief. Tolerance of citizens for the small errors of their government was shattered by their realization of major deceit on the part of their highest elected official. The mood of the people affected even the medicolegal officials, both elected and appointed. Citizens and the media alike now deemed it necessary and appropriate to question the determination and decisions, the rulings and resolutions of the many questions relating to death investigation.

A new approach to quantification of spermatogenesis has been applied to human testes to investigate germinal cell attrition during spermiogenesis and to derive an appropriate time divisor for the determination of daily sperm production from numbers of homogenization-resistant spermatids in unfixed human testes. Glutaraldehyde fixation of testes from 10 men rendered nuclei of even the most immature germinal cells resistant to homogenization. Prevention of dissolution of cell nuclei during homogenization permitted enumeration of the entire constellation of germinal cell nuclei by phase-contrast microscopy. Thus, investigation of attrition during spermatogenesis became possible. Since daily sperm production per gram of parenchyma (DSP/g) was similar (P>0.05) when based on enumeration of round spermatids (5.5 X 10’), maturation-phase spermatids (5.8 X 106), and all spermatids (5.9 X 106), no attrition was detected during human spermiogenesis. Agreement (P>0.05) between these three estimates and DSP/g based on histometric analysis of round spermatids in the same testes (5.9 X 106) validated the new technique for quantifying spermatogenesis. The number of homogenization-resistant spermatids in unfixed tissue was only 37% of the number of maturation-phase spermatids in homogenates of fixed, contralateral testes. Thus, previous estimates of DSP/g in humans from homogenates of unfixed testis are low and should be approximated by multiplying published data by the reciprocal of 0.37 (i.e., 2.7). When the corrected time divisor of 2.9 days (7.9-day time divisor for maturation-phase spermatids multiplied by the correction factor of 0.37) was employed to convert numbers of homogenization-resistant spermatids from unfixed testes to DSP, a value of 5.6 X 106 was obtained for these 10 men. No difference (P>0.05) was found among the five estimates of DSP/g.

Loss of potential sperm production during postprophase of meiosis was evaluated to determine if reduced daily sperm production in older men could be explained by an enhanced percentage of germ cell degeneration during this period of spermatogenesis. Evaluations were based on enumerating germ cells in homogenates of fixed testes using phase-contrast cytometry from 37 young adult (20-48 yr) and 34 older adult (50-85 yr) men. The time period in which germ cells degenerate was assessed in 10 men by comparing potential daily sperm production based on secondary spermatocytes with that based on primary spermatocytes or with daily sperm production based on spermatids. There was a significant (P less than 0.01) decline in sperm production potential based on primary spermatocytes and on spermatids in the older adult men such that the percentage of loss of potential production during postprophase was similar between the two age groups. Sperm production estimates based on primary spermatocytes and secondary spermatocytes were similar (P greater than 0.05); however, estimates based on secondary spermatocytes were significantly higher than those based on spermatids. Degeneration during postprophase of meiosis in humans appears to occur during or near the second meiotic division. Age-related reduced sperm production was significantly correlated with elevated levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Age-related decline in sperm production could not be explained by enhanced germ cell degeneration during postprophase but may result from reduced germ cell numbers prior to pachytene primary spermatocytes.

The number of Leydig cells in the adult human testis declines as a function of increasing age, but whether these cells disappear by transforming into another cell type or by undergoing death and dissolution has not been resolved. This question was addressed in 30 men between 20 and 76 years of age who were known as a group to have experienced significant age-related loss of Leydig cells. If the loss of Leydig cells resulted from transformation into another cell type, other testicular interstitial cells in these men should have increased with age. Testes obtained at autopsy were perfused with glutaraldehyde less than 15 h after sudden death due to trauma or heart attack. Numbers of other interstitial cells were determined by quantitative histometric estimation of the proportion of testicular parenchyma occupied by other interstitial cell nuclei of measured average volume. Other interstitial cell nuclei declined significantly with advancing age (rho = -0.41, P less than 0.05). Mean number of other interstitial cell nuclei per individual was significantly reduced in the 15 men 50 yr old or older compared to the 15 younger men (460 +/- 34 million vs. 609 +/- 43 million; P less than 0.05). There was no tendency for individuals with reduced numbers of Leydig cells to have increased numbers of other interstitial cells. These findings argued against the persistence of Leydig cells in aged testes as dedifferentiated mesenchymal elements. Instead, light and electron microscopic observation of testes from these men revealed evidence of Leydig cell degeneration and dissolution.

Enumeration of homogenization-resistant spermatids in testicular homogenates provided a rapid and precise means of characterizing human spermatogenesis in quantitative terms. This technique was applied to simulated biopsy specimens as small as 10 mg of testicular parenchyma and yielded values for daily sperm production per gram of testicular parenchyma (DSP/gm) that were highly correlated with over-all DSP/gm values for paired testes (r = +0.86) and DSP/pair of testes (r = +0.93). In 12 autopsy cases representing a 100-fold range of sperm production rates, the average difference between DSP/gm values obtained from simulated biopsy specimens and from entire testes was not significantly different from zero (P < 0.05). The small amount of testicular parenchyma required for this determination indicated that both DSP data and routine histologic observations can be collected from the material included in a conventional testicular biopsy. Various measurements related to testicular size were positively but weakly correlated with DSP/testis (values for r ranged from +0.45 to +0.66). Hence, testicular size was a relatively poor index of sperm production in this study.

Germ cell degeneration during spermatocytogenesis and meiosis was investigated to explain the age-related decline in daily sperm production (DSP). Numbers of Types A-dark, A-pale, and B-spermatogonia, potential daily sperm production per g parenchyma (PDSP) based on type B-spermatogonia, early primary spermatocytes, and late primary spermatocytes, and DSP per g based on early spermatids were determined in 15 men aged 20 to 48 yr (mean +/- SEM, 33 +/- 2 yr) and 15 men aged 52 to 90 yr (65 +/- 3 yr). Testes obtained within 15 h of death (largely due to trauma or heart failure) were perfused vascularly with glutaraldehyde. The number of each cell type per g parenchyma was calculated as the product of the percentage of nuclei in the parenchyma times a correction factor for section thickness and nuclear diameter divided by the volume of a single nucleus of that cell type. Paired testicular weight was lower (p less than 0.01) in older men (33 +/- 3 g) than in the younger men (49 +/- 3 g). Younger and older men had similar numbers of A-dark, A-pale, and B-spermatogonia per g parenchyma. PDSP based on late primary spermatocytes and DSP based on early spermatids were lower (p less than 0.01) in older men than in younger men. In younger men, PDSP was similar (p greater than 0.05) between B-spermatogonia and late primary spermatocytes, whereas DSP measured at the spermatid level was abruptly lower than that estimated from younger cell types. Older men showed reduction in PDSP between early and late primary spermatocytes, with further reduction occurring in DSP at the spermatid level.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related changes in daily sperm production (DSP) and testicular weights were investigated in paired testes from 89 men aged 21-50 years and 43 men aged 51-80 years. For both DSP/testis and DSP/g parenchyma, remarkably large standard deviations exceeded 50% of mean values. However, DSP/g and DSP/testis for both right and left testes were approximately 30% higher in the younger than in the older group (P less than 0.01) and were negatively correlated with age (P less than 0.01) when data from both groups were pooled. Weights of whole testes and of testicular parenchyma were similar in both age groups and were not significantly correlated with age. However, testicular tunic weights were 29% higher in the older group (P less than 0.001) and were positively correlated with age (P less than 0.001). Both testicular tunic weight and the % of total testis occupied by tunic were negatively correlated with DSP/g (P less than 0.01); these correlations were weakened by removing the effect of age. Although total testicular weight and testicular parenchymal weight did not change with age, these values were about 10% lower on the left than on the right (P less than 0.001). In addition to its increase with age, testicular tunic weight was about 8% greater for right than for left testes in all men (P less than 0.001). Although the average size of the testis varied from right to left, DSP/g was similar in paired testes (P = 0.15), and the correlation between right and left DSP/g was high (rho = +0.89, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The human Sertoli cell population was characterized in 14 men by histometric analysis and by direct counts of nuclei in testicular homogenates. Testes obtained at autopsy were perfused with glutaraldehyde and embedded in Epon. Nucleolar and nuclear volumes were determined by the formula of a sphere given the diameter of the nucleoli or average diameter of nuclei measured at the height and width. Nuclear volume was also estimated by adding volumes of nuclear profiles in 0.5-micron serial sections. Sertoli cell number/g was calculated by the product of the percentage nucleoli or nuclei in the parenchyma, parenchymal volume, and histologic correction factor divided by the volume of a single nucleolus or nucleus. Also, Sertoli cell nuclei were counted directly in homogenates of fixed parenchyma. Number of Sertoli cells/g was similar (P greater than 0.05) whether determined by serial sections or in homogenates, but the estimate based on the nucleolar method was higher (P less than 0.01) and the nuclear measurement method was lower (P less than 0.01) than that for serial sections. A group of 37 men aged 20 to 48 yr had significantly (P less than 0.01) more Sertoli cells than did 34 men aged 50 to 85 yr. It is concluded that: 1) the homogenate method is valid for quantification of the Sertoli cell population, 2) Sertoli cells are evenly distributed in different regions of the testis, 3) the average human Sertoli cell supports relatively few germ cells, 4) the human Sertoli cell population declines with age, and 5) there is a significant relationship between sperm production rates and number of Sertoli cells.

Tubular boundary tissue and seminiferous epithelia were evaluated stereologically in testes from 28 men aged 20 to 48 years and 28 men aged 50 to 90 years. Testes obtained at autopsy within 15 hours of death were perfused with glutaraldehyde, embedded in Epon (Ladd Research Industries, Inc., Burlington, VT), sectioned at 0.5 micron, and stained with toluidine blue. Volume densities (percentage of the testicular parenchyma) of various parameters determined by point counting and diameter measurements were used to calculate total volumes, length of tubules, and number of cells. Electron microscopy was used to determine the volume density of myoid cells in the boundary tissue. Significant (P less than 0.01) age-related reductions occurred in paired testicular weights, paired parenchymal weights, total volume of seminiferous tubules and of seminiferous epithelium, and length of tubules. The volume density and thickness of boundary tissue increased (P less than 0.01) with age. The volume of boundary tissue per man and the volume density of myoid cells in the boundary tissue did not vary with age. Although the number of myoid cells per man tended to be lower in the older group, the number of myoid cells per cross section of seminiferous tubule was increased (P less than 0.01) in older men. The age-related thickening of the boundary tissue was not due to an increase in boundary tissue but resulted from a reduction in the length of the seminiferous tubules.

Aged men, known to have high serum gonadotropin levels and reduced spermatogenic potential, were used to study the relationship between serum follicle-stimulating hormone (FSH) and germ cell degeneration. Serum hormones were measured from blood obtained at autopsy. Phase-contrast cytometry was used to enumerate germ cells in homogenates of fixed testes from 13 younger (24-51 yr) and 14 aged (69-90 yr) men. The developmental steps of spermatogenesis during which germ cells degenerate were determined by comparing potential daily sperm production based on primary spermatocytes with daily sperm production based on two different types of spermatids. During spermiogenesis, there was no significant degeneration in the younger or aged men. During postprophase of meiosis, aged men had more (p less than 0.01) germ cell degeneration, significantly lower (p less than 0.05) serum testosterone, and greater (p less than 0.01) serum FSH than did younger men. Germ cell degeneration during postprophase of meiosis was negatively correlated (p less than 0.01) to daily sperm production and significantly (p less than 0.01) related to serum concentrations of FSH. As revealed in these aged men, meiotic germ cell degeneration has a direct effect on daily sperm production and is significantly related to serum FSH concentrations.

Seminiferous tubular boundary tissue thickens with age. The objective was to characterize the composition of boundary tissue in 16 young adult (20 to 29 years) and 18 older adult (51 to 84 years) men. Testes were perfused with glutaraldehyde, placed in osmium, and embedded in Epon 812 (Ladd Research Industries, Burlington, VT). Paired testicular weight, length of tubules, volume of seminiferous epithelium, and daily sperm production were significantly reduced in older men. Although the thickness of boundary tissue was greater (P less than 0.01) in older men, the volume of boundary tissue per man was similar between age groups. The percentages and volumes per man of boundary tissue myoid cells, collagen, microfibrils, and other components also were similar (P greater than 0.05) between age groups. This study confirms that age-related thickening of boundary tissue occurs without the new deposition (augmentation) of collagen or other extracellular components.

Previous studies of adult men have failed to reveal a relationship between numbers of Leydig cells in the testes and rates of sperm production, perhaps because of a functional excess of these cells in younger men. Hence, a possible relationship between Leydig cell numbers and sperm production was sought in 50 older men, aged 50-90 years, in whom the Leydig cell population had been depleted by age-related attrition. When these men were sorted by increasing numbers of Leydig cells per man into two, three, or five groups, no difference could be found between or within these groups when daily sperm production per man (DSP); seminiferous tubular volume, diameter, or length; or seminiferous epithelial volume was examined. Furthermore, no significant correlation could be detected between Leydig cell numbers and DSP in these 50 men. The only relationship between numbers of Leydig cells and spermatogenesis appeared to be a threshold effect, in that men with fewer than 60 million Leydig cells (4 in this study) had drastically reduced DSP. Men with few Leydig cells tended to have larger Leydig cells, and the increased size was due to more cytoplasm instead of nucleoplasm. There were weak but significant positive correlations between total Leydig cell cytoplasm per man and DSP and between average size of a Leydig cell and DSP. These findings suggest that a relationship may exist between sperm production and the amount of cytoplasm containing testosterone-producing organelles in surviving Leydig cells of older men.

Potential daily sperm production per gram of testicular parenchyma (PDSP/g) based on pachytene plus diplotene primary spermatocytes was determined by two methods for 10 men aged 26 to 53 years and compared with published daily sperm production per gram parenchyma (DSP/g) based on round spermatid nuclei for these same men. The PDSP/g based on primary spermatocytes was similar (P greater than 0.05) whether determined by histometric analysis (10.0 +/- 1.1 X 10(6] or from homogenates of parenchyma (10.4 +/- 1.0 X 10(6]. When PDSP/g values were compared to DSP/g (5.9 +/- 0.9 X 10(6) for the histometric or 5.5 +/- 0.8 X 10(6) for the homogenate method), 44.9 +/- 6.7% loss of potential sperm production during postprophase of meiosis was detected by the histometric approach and 48.3 +/- 7.9% loss by the homogenate method. Similar results were obtained when testes of 15 additional men aged 26 to 53 years were evaluated by the homogenate method; PDSP/g was 10.6 +/- 0.6 X 10(6), DSP/g was 5.8 +/- 0.5 X 10(6), and the loss during postprophase of meiosis was 45.3 +/- 4.4%. For all 25 men, DSP/g was significantly (P less than 0.01) correlated with PDSP/g (r = + 0.70) and with the percentage loss of potential sperm production during postprophase of meiosis (r = 0.86). Over 73% of the variation in DSP/g could be attributed to variation in the percentage loss during postprophase of meiosis. Whether faulty meiotic divisions and/or degenerating secondary spermatocytes were responsible, almost half of the potential sperm production in these 25 men was lost during postprophase of meiosis.

Every firearms injury case is an opportunity for research. To exploit this opportunity, the pathologist must be aware of firearms and ammunition changes and developments. Recent developments in both firearms and ammunition are described with some of the variations in wounding patterns resulting therefrom. In addition, case documentation and better chain of custody in firearms injury cases are urged.

Cholinesterase activity at the myoneural junction in human intercostal muscle was demonstrated histochemically. Activity was present in refrigerated muscle up to 157 days and for a similar time in tissues removed from bodies within 24 hours after embalming. The duration of cholinesterase activity in muscle treated with various fixatives was also investigated.

Post-mortem radiographs as well as careful inspection at autopsy of 100 consecutive traffic accident victims revealed an incidence of cervical spine injury of 24%. All but four of the 24 fractures and/or dislocations were localized to the level between the occiput and the axis. One half of the cases were not clinically suspected of having spine injuries before the detailed postmortem search. Seventeen of the 24 cervical spines were resected en bloc and the pathologic anatomy of the injuries was determined. The high incidence of cervical spine injuries and the anatomic findings at dissection have clinical implications for physicians who manage multiply traumatized patients. The need for immobilization and early radiographic evaluation of patients with cervical spine injuries is emphasized.

Age-related changes in Leydig cell number, daily sperm production, and circulating hormone levels were studied in 15 men between 20 and 48 yr of age and 15 men between 50 and 76 yr of age. Testes and blood samples were obtained at autopsy less than 15 h after death due to trauma or heart attack. Leydig cell number was determined by quantitative histometric estimation of the proportion of glutaraldehyde-perfused, decapsulated testicular parenchyma occupied by Leydig cell nuclei of measured average volume in both testes of each subject. Daily sperm production was determined by phase contrast cytometry of round spermatid nuclei in homogenates of both fixed testes from each individual. LH, FSH, PRL, and testosterone in serum from the heart or large veins were quantified by RIA. No relationship was detected between any of the testicular or hormonal values and postmortem time. The average total number of Leydig cells was reduced by 44% in the older men and was negatively correlated with age (p = -0.62) in all men. Mean serum LH was elevated more than 2-fold in the older men and was positively correlated with age (p = +0.53) in all men. Neither serum testosterone nor serum PRL changed significantly with age. Daily sperm production was more than 50% lower in older men and was negatively correlated with age (p = -0.76) in all men. Serum FSH was more than 3-fold higher in the older men and was positively correlated with age (p = +0.72) in all men. The highest FSH levels were found in men with the lowest rates of sperm production, and FSH and daily sperm production were inversely correlated even after the effects of age were removed. These findings show that the response of the human testis to aging is variable and that the predictive value of age for most testicular characteristics is weak at the level of individual men. Nevertheless, age accounts for more than a third of the variation in Leydig cell number, and it explains more than half the variation in daily sperm production. Hence, age is the largest single contributing factor yet identified in the search for explanations underlying the variation in testicular structure and function found in groups of normal men.

The accuracy of the cause and manner of death based on a medical examiner external examination of the body and review of other evidence was investigated. The authors retrospectively identified 185 such forensic cases in which an autopsy was performed subsequently at a major teaching hospital. Autopsy disclosed a change in the manner of death in only one instance. Of the 89 natural deaths, the cause of death based on external examination was erroneous in 26 (29 per cent). The majority of the errors was the result of an overdiagnosis of arteriosclerotic cardiovascular disease, hypertensive cardiovascular disease, and cancer.

The effectiveness of previously untested disaster plans was demonstrated during the aftermath of the crash of Delta Airlines Flight 191 at D/FW International Airport on Friday, August 2, 1985. These plans, in effect for years and subjected to periodic review, were as yet untried before this first disaster at D/FW International since its opening. This paper outlines the disaster plans, the actual problems encountered, the logistics of a disaster of this kind, and insights gained from the experience.

IN the past few years, iodine, usually in the form of iodides, has been implicated as an etiologic agent in certain goiters of the adult.1 2 3 4 5 6 7 So-called "congenital" goiter, or goiter of the newborn, has been the subject of many reports. Since we do not propose to review the literature concerning goiter of the newborn, the reader is directed to the paper of Bongiovanni et al.,8 which surveys much of the available literature. In some cases the thyroid gland has been sufficiently enlarged to cause airway obstruction and death by suffocation. In others the tracheal compression has been somewhat less marked . . .

In most instances of death from gunshot wounds, the forensic pathologist is readily able to determine whether or not a particular gunshot wound was inflicted at contact, intermediate, or distant range. In some instances, however, such a determination is virtually impossible. Most difficulty occurs in differentiating a contact wound from a distant wound. A contact wound is apparent when soot is present on the outside of the skin, if there is a muzzle imprint, or if there is tearing of the skin caused by the effects of gas. However, determination of whether a wound is contact or distant can be a problem when (1) the body is decomposed; (2) the deceased has survived days or weeks after the initial wound; (3) the wound is a contact wound and there are multiple layers of clothing that filter out the soot and powder; and (4) the edges of the wound have dried in contact wounds with small caliber weapons.

Gases produced during structural fires were studied as to their potential toxicities. Carbon monoxide was the only gas measured in concentrations considered to be lethal within a short period of time. No correlations were found between gases produced and materials burning. However, significant correlations were discovered between gases produced and the physical aspects of the fire (intensity, burning rate, and the like). The organic compounds identified within the gases gave insight as to another potential health hazard not yet considered. These organic compounds are the products of free radical reactions and as free radicals their potential as toxics is enormous.

From 1971 through 1980, 1115 deaths were ascribed by the Dallas County Medical Examiner's Office to poisoning of some type. An analysis of these deaths, with emphasis on the substances involved, is the purpose of this study. Relatively few agents or groups of agents accounted for 87% of these deaths: carbon monoxide, barbiturates, propoxyphene, narcotics, tricyclic antidepressants, ethyl alcohol, and inhalants (gases and solvents). Twenty-five percent of the deaths were classified as mixed intoxications, resulting from combinations of agents. Two major trends were observed: in the second five-year period, barbiturate-induced deaths decreased considerably (58%) and deaths from tricyclic antidepressants increased more than four times as compared with the first five-year period. Yearly statistics have been compiled for deaths from each agent.

Previous studies have implicated drugs as a significant factor in intoxicated motor vehicle drivers [1,2]. Little has yet been published on the incidence and role of drugs in motor vehicle crash fatalities, however. A comprehensive study by the Midwest Research Institute on specimens from victims of motor vehicle crashes procured from a number of geographic locations has indicated an incidence of positive drug findings of 13.09% in the urine of fatally injured drivers [3]. In only about 4% were drugs detected in the blood of victims, however.

A 16-year-old pregnant female presented to a hospital emergency room with vaginal bleeding and uterine cramping. She underwent a hysterotomy and curettage and, during the procedure, her pulse dropped from 130 to 30 beats/minute, her pO2 fell to 10 mm of mercury, and she could not be resuscitated. At autopsy, she was found to have massive pulmonary embolization of syncytiotrophoblast from a hydatidiform mole of the uterus. This is the sixth reported case of trophoblastic embolization from a hydratidiform mole ending in death. This fatal termination may occur after a period of respiratory symptoms and may occur regardless of the mode of treatment.

The spread of AIDS and its association with a retrovirus, commonly called T-lymphotropic virus type III (HIV) has produced great concern among those involved in transplantation about the possibility for transmission of this disease through tissue and organ transplant. Isolation of the virus from conjunctiva and tears further heightened this concern for corneal transplants. This review of medical examiner (ME) cases, a population in which high numbers of transplant corneas are retrieved, has revealed positive serologic tests for HIV in serum from 5 cases in 205 screens. These represent potential donors based on other standard medical criteria available at the time of collection. This tissue was also submitted for viral culture, and virus was recovered from the corneal tissue in McCarey-Kaufman (MK) media. These findings and case reviews are discussed.

Determination of the distance from muzzle to victim from the appearance of a gunshot wound in the skin is often of great importance. Such information may be necessary to confirm or disprove an account of the circumstances surrounding a death due to firearms. Contact wounds generally can be recognized by the presence of soot and powder in and around the wound as well as searing of the skin from the flame. When the contact wound overlays bone, tearing of the skin or muzzle imprints may be present. Intermediate range gunshot wounds are characterized by powder tattooing (stippling) of the skin around the wound of entrance. Soot may or may not be present. While soot can usually be wiped away, powder tattooing cannot. When the muzzle-to-target distance increases so that powder tattooing no longer occurs, the gunshot wound is called a distant wound and range determinations can no longer be made.