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Biomedical subjects

D A Hawley

Publications and source records attributed to D A Hawley.

36 records · Page 2Linked to original sources
PubMed1989

Use of aquatic insects in determining submersion interval.

Although its potential is great, the use of aquatic insects in determining submersion intervals at death-scene investigations has not been exploited in the past. Aquatic environments have no known true specific indicator species, as do terrestrial habitats. However, aquatic environmental studies show that organisms may colonize a substrate dependent on factors such as size, position, exposure to current, water temperature, current speed, water depth, the presence of algal communities, or detritus. Certain aquatic insects such as the chironomid midges (Diptera, Chironomidae), and the caddisflies (Trichoptera), are capable of colonizing immersed bodies; and with the known biology of a specific species of insect for a certain geographic area, time intervals of submersion can be established.

Animals↗
PubMed1989

Concealment of the body in drug deaths.

Discovery of a concealed body often leads to the assumption that the manner of death was homicide. However, in cases where death has resulted from illicit drug use or drug abuse, the body may be concealed to protect persons involved in drug abuse or drug marketing.

Adult↗
PubMed1989

Identification of a red "fiber": chironomid larvae.

During preliminary examination of the body of a homicide victim, a peculiar red "fiber" was noticed and recovered. Initially believing this to be a carpet fiber, the item was subjected to fiber analysis. It was found to be a short coiled particle not like any known natural or synthetic fabric fiber. Subsequent examinations determined this "fiber" to be the larva of a common freshwater midge (Diptera; Chironomidae). Chironomid larvae have been observed on other bodies recovered from freshwater environments. Entomological studies of this organism have led to the conclusion that the presence of chironomid larvae indicates submersion of the body.

Adult↗
PubMed1988

Cardiac injury during valve replacement surgery.

The commonly referenced mortality of cardiac valve replacement surgery is 2 to 5%. Some of this mortality is due to therapeutic misadventure during the procedure. Therapeutic misadventure during cardiac valve replacement may result in patterned injury of the heart, so that postmortem examination can establish the nature of the surgical injury. A case of patterned myocardial injury during valve replacement surgery is presented, with a review of literature and associated cases.

Adult↗
PubMed1987

Fatal athletic injuries.

Death during athletic training or competition often brings public media attention. Recent endeavors to attract amateur athletic competitions to Marion County, Indiana prompted a review of athletic fatalities. Trauma during training, arteriosclerotic heart disease, and congenital heart defects cause most fatalities. A prospective study has been initiated to investigate and document these deaths.

Adolescent↗
PubMed1987

Tumbling abrasions. Injuries from ricocheting bullets.

Atypical entrance gunshot wounds may be produced by deflected or ricocheting bullets. One special type of atypical entrance wound involves abrasion of the skin at a site that is remote from the point of dermal penetration. These remote abrasions, termed "tumbling abrasions," are produced by bullets that tumble after impact with an intermediate target. Three cases of tumbling abrasions are presented.

Breast↗
PubMed1986

Etiology of pure tricuspid regurgitation based on anular circumference and leaflet area: analysis of 45 necropsy patients with clinical and morphologic evidence of pure tricuspid regurgitation.

Despite recent renewed interest in the detection of tricuspid valve regurgitation by echocardiographic and Doppler techniques, little morphologic information is available on dysfunctioning tricuspid valves. This report describes 45 necropsy patients with clinical and morphologic evidence of pure (no element of stenosis) tricuspid regurgitation and provides morphometric observations (anular circumference, leaflet area) of the tricuspid valve useful in determining the etiology of pure tricuspid regurgitation. Of 45 patients, 24 (53%) had pure tricuspid regurgitation resulting from an anatomically abnormal valve (prolapse in 7, papillary muscle dysfunction in 6, rheumatic disease in 5, Ebstein's anomaly in 3, infective endocarditis in 2, carcinoid tumor in 1), and 21 (47%) had an anatomically normal valve with systolic pulmonary artery hypertension (cor pulmonale in 12, mitral stenosis in 9). Anular circumference was dilated (greater than 12 cm) in patients with various causes of pulmonary hypertension, floppy valve and Ebstein's tricuspid anomaly. Leaflet area was increased in floppy valve and Ebstein's anomaly. Of the 45 patients, 24 had pulmonary systolic artery pressure measurements available for correlation with tricuspid valve morphology. Pulmonary artery pressures accurately predicted morphologically normal from abnormal valves in 16 patients (89%). Morphologic overlap occurred in six patients with pulmonary pressures of 41 to 54 mm Hg. Of these six, the additional knowledge of normal or dilated anular circumference correctly separated valves with normal and abnormal leaflets.

Adolescent↗
PubMed1983

Determination of alternate pathway complement kinetics by electron spin resonance spectroscopy.

We describe a technic that measures the kinetics of the metabolic burst of peripheral blood neutrophils (PMN) by electron spin resonance (ESR) spin trapping. Using this technic, a functional assay for the kinetics of the alternate pathway complement cascade is developed. PMN were stimulated by phagocytosis of opsonized zymosan (OpZym) to undergo the metabolic burst and the resulting free hydroxyl radicals generated during the burst were trapped using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to form a stable spin adduct. Rapid sequential measurements of the spin adduct concentration were made using a computer-controlled ESR spectrometer to follow the time course of the metabolic burst. Differences in the results obtained with OpZym and with PMN incubated with unopsonized zymosan (Zym) and serum yields information about the kinetics of opsonization. The kinetics of the alternate complement pathway opsonization in sera from normal and C8-deficient patients were compared and found not to be affected significantly by the absence of C8 complement protein.

Adult↗
PubMed1983

Cytomegalovirus encephalitis in acquired immunodeficiency syndrome.

A 38-year-old black man died from acquired immunodeficiency syndrome (AIDS) after a 15-month course. The autopsy revealed a pancolitis and a pneumonia caused by cytomegalovirus (CMV). Exceptionally, there also was a periventricular encephalitis caused by the same organism. Identification of the virus was aided by immunoperoxidase methods.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Chain initiation factor 3 crosslinks to E. coli 30S and 50S ribosomal subunits and alters the UV absorbance spectrum of 70S ribosomes.

We report a direct procedure to determine the proteins near the IF-3 binding site in purified 30S and 50S ribosomal subunits. This procedure introduces only limited numbers of cleavable crosslinks between IF-3 and its nearest neighbors. The cleavable crosslinking reagent, 2-iminothiolane, was used to crosslink IF-3 in place to both 30S and 50S subunits. Ribosomal proteins S9/S11, S12, L2, L5 and L17 were found, by this approach, to be in close proximity to the factor in purified IF-3-subunit complexes. In addition, IF-3 was shown to alter the ultraviolet absorbance spectrum of E. coli 70S ribosomes at 10 mM Mg2+. The magnitude of the observed difference spectrum at a constant IF-3/ribosome ratio of 1.0, is linearly dependent upon ribosome concentration over the range 5 nM - 55 nM. Titration experiments indicated that the observed effect is maximal at an IF-3/ribosome ratio of approximately 1.0. These results are taken to indicate a conformational change in the 70S ribosome induced by IF-3.

Escherichia coli↗
PubMed1981

Normal neutrophil function in human renal allograft recipients receiving Minnesota anti-lymphoblast globulin (MAG).

Equine anti-human lymphoblast globulin (MAG) used in combination with other immunosuppressive agents did not impair chemotaxis, phagocytosis, nitroblue tetrazolium (NBT) reduction or halogenation by peripheral blood neutrophils (PMN) from seven human recipients of cadaver renal allografts. MAG was given to the allograft recipients following transplantation, and the dosage was determined each day by quantitation of peripheral blood T and B lymphocytes. No deposition of immunoglobulin or complement on the recipient's PMN was detected by indirect immunofluorescence. Chemotaxis of PMN was determined in blind-well chambers, and phagocytosis of opsonized zymosan was quantitated by spectrophotometric measurement of solubilized formazan, and halogenation was measured by quantitating the incorporation of 125I into PMN that had phagocytosed opsonized zymosan. Chemotaxis, phagocytosis, NBT reduction, and halogenation by neutrophils from patients receiving MAG, prednisone and azathioprine were not impaired.

Adult↗
PubMed1977

Requirement of chain initiation factor 3 and ribosomal protein S1 in translation of synthetic and natural messenger RNA.

Amino acid incorporation directed by poly(A), poly(U) or R17 RNA has been examined in S1-depleted protein synthesizing systems. We observe that the translation of either synthetic or natural messenger RNA is strictly dependent on the presence of chain initiation factor 3 and ribosomal protein S1. With poly(A) or poly(U) both IF-3 and S1 stimulate amino acid incorporation at least 25-fold, and with R17 RNA the stimulation is approximately 15-fold. More than one copy of S1 per ribosome decreases amino acid incorporation directed by poly(U) or R17 RNA. Initiation complex formation with R17 RNA is also stimulated optimally by the addition of one copy of S1 per ribosome. The function of IF-3 and S1 in protein synthesis is considered.

Bacterial Proteins↗