Postmortem State Research Articles

DEVELOPMENT OF A MODEL SYSTEM USING GLYCERINATED MUSCLE FOR THE STUDY OF PHYSICAL PROPERTIES

A model system which duplicates in some of its properties the chemical and physical states of non-glycerinated muscle in its various postmortem states, has been developed using glycerinated muscle at different states of contraction. The state of the muscle was related to sarcomere length, extractable actomyosin, and binding of 1-fluoro-2, 4-dinitrobezene (FDNB) to myofibrillar proteins. It was established that FDNB binding was a more accurate measure of actomyosin formation in situ than was actomyosin extractability. FDNB binding was presumably related to thin and thick filament overlap, even after the Z disc was removed, whereas extraction of actomyosin was not. Results of extensibility with the glycerinated muscle could be predicted based on the model and matched that found with non-glycerinated muscle as described in the literature. The model system offers the following advantages over non-glycerinated muscle: stability, convenience, maintenance of a “pre-rigor” condition indefinitely, and a “pre-rigor” muscle that is not contractile.

Neurotransmitter-related enzymes and indices of hypoxia in senile dementia and other abiotrophies.

Fifty-six brains from middle-aged and elderly normal as well as demented subjects and patients with provisional clinical diagnosis of other neurological and psychiatric diseases were assessed histologically. On this basis the specimens were classified into 14 diagnostic groups. A survey of potential indices of specific neurons has been carried out on these brains in which neurotransmitter-related enzymes, gamma-GTP (a potential index of capillaries) and specific proteins have been determined in up to 20 brain regions. In addition, the agonal state has been tentatively assessed by examining the post-mortem states of the circulatory and respiratory systems. CAT and gamma-GTP activities and the concentration of a soluble neuronal-type protein (neuronin S-5) were found to be relatively unaffected by the agonal state. When cases of senile dementia were compared to controls (matched with respect to the cause of death) the activity of CAT (the potential index of cholinergic neurons) appears to be reduced in the cerebral cortex. This is a preliminary finding, although a correlation was indicated between CAT activity and 'senile' morphological changes, the activity was markedly reduced in only 3 brains. However, despite inconsistencies in the literature (Karczmar, 1975) at least one pharmacological study on humans appears to show that the cholinergic system may be involved in age-related memory degeneration (Drachman and Leavitt, 1974). Cholinergic neurons may be abnormal in the other abiotrophies examined (Huntington's chorea, motor neuron disease and mixed vascular and senile dementia). gamma-GTP and neuronin S-5 (identical in most respects to the soluble acidic neuronal protein 14-3-2 of antigen alpha) were not reduced in senile dementia. The activities of brain decarboxylase (GAD and AAD) and the concentration of another soluble acidic brain protein (neuronin S-6) appear to be affected by the agonal state. This is remarkable because GAD and, in particular, neuronin S6, are relatively unaffected by post-mortem autolysis. As judged by the state of the extraneural systems which regulated the blood and oxygen supply to the brain it appears that terminal 'cerebral hypoxia' is responsible for the depletion of these brain constituents. This effect appears to be particularly marked in deep grey matter. In non-demented patients that die of bronchopneumonia, the areas of the cortex which are depleted in neuronin S-6 are consistent with the pattern of the 'selective vulnerability' of the cortex to hypoxia, suggesting that the terminal state can also affect the neocortex. If so, then this is particularly relevant to studies on senile dementia, for the effect of the terminal bronchopneumonia that so often occurs in these patients (and in patients with other abiotrophies) may be exacerbated by a terminal reduction in cerebral blood flow...

Letter to the Editor

The article, Anesthetic Risks in Sickle Cell Trait, is disconcerting because its conclusions are unjustified and its implications unwarranted. For example, due to the paucity of preoperative information one might conclude that the patients were doubly heterozyous for a hemoglobinopathy such as sickle thalassemia. The presence of generalized sickling at postmortem exam in the five patients reported does not constitute proof that intravascular sickling was pathogenic in the patient's death, for it is obvious that red cells from a patient with sickle trait will assume the sickled shape in the acidotic and hypoxic postmortem state.

Coronary Artery Disease in Younger Men

ABSTRACT To the Editor.— We think that the incidence of coronary arteriosclerosis as reported in casualties of the Vietnam war by McNamara and his colleagues (216:1185, 1971) as compared to earlier reports from our studies of casualties from the Korean conflict (158:912, 1955) probably reflects a meaningful downward trend. The most recent study utilized postmortem coronary angiography and dissection of coronary arteries in order to demonstrate atherosclerotic plaques and coronary artery narrowing. The earlier study was accomplished solely through the routine anatomical cross-sectioning and longitudinal dissection of the coronary vessels. Both methods of study are reliable but include certain unavoidable artifacts inherent to the postmortem state of the heart.Coronary arteries from Korean conflict battle casualties have been studied by the cross-section and longitudinal methods (Fig 1 through 3). These illustrations have not been in eluded in any of our previous reports. The degree of luminal narrowing is extensive

Comparison of inner ear fluids in the antemortem and postmortem state of the cat.

Comparison of inner ear fluids in the antemortem and postmortem state of the cat.

When an Insect Dies

I am sure I need not explain that although most of his work may be with living insects, the insect pathologist is perhaps more concerned with the mechanisms of death than are his colleagues in most of the other entomological disciplines. He not only studies the normal, healthy insect, and the diseased or abnormal insect, but he must also be intimately familiar with the dying and dead insect. When an insect dies in the pathologist's laboratory, it usually is not considered merely one of a number that may have died in an experiment, and to be swept away to the refuse container. More often than not the insect has been watchfully followed through the agonies of its disease and death, and then carefully and minutely studied in its postmortem state. Thus the pathologist comes close to the concern felt by the poet who wrote of the katydid when she “folds in death her feeble wings beneath the autumn sun.”

CLINICOPATHOLOGICAL STUDIES ON THE ANEURYSM OF THE ABDOMINAL AORTA.

The aneurysm of the abdominal aorta (AAA) accounts for 75.8% of all the diseases of the abdominal aorta, which were operated upon in the department of surgery of Professor KIMOTO. AAA is different in its shape and location, and the most predominant one occupies from below the ramifications of the renal arteries to the bifurcation of the abdominal aosta. This typical AAA accounts for 96.8% of all AAA and was studied clinicopathologically in this thesis, beginning with its relation to the normal abdominal aorta and referring lastly to its therapy and prognosis.1. An aortometry was performed on the translumbar aortograms and normal aortae of autopsy cases. The circumferences of the abdominal aorta differ greatly between that intravital and this postmortem state at the ramification of celiac artery, but scarcely below the ramifications of the renal arteries, indicating that this latter suffers an irreversible distension. As is well known, the distal portion of the abdominal aorta belongs to the ‘transitional type of artery (ROTTER and ROTTMANN)’ and reveals earlier and stronger arteriosclerotic changes.2. An intravital YOUNG's modulus (IYM) was defined on the basis of the reversible intravital distension of the aorta at the ramification of the celiac artery. IYM (Y) is given by: Y=PLL'/2π(L-L'), where P is mean blood pressure, L is intravital and L' is postmortem circumference of the aorta. IYM varies between the value of the YOUNG's modulus of the elastic fibers and that of the smooth muscles, and reveals a characteristic pattern in relation to age. This pattern can be divided into three phases, namely the first phase being up to the second decade of age, the second phase ranging from the third decade of age to the sixth decape of age in man and the fifth decade of age in woman, and lastly the third phase being the age thereafter. In the second phase the value of IYM approaches to that of the YOUNG's modulus of the smooth muscles, and in other phases it approaches to the value of the YOUNG's modulus of the elastic fibers. On the whole, the value of IYM of man is nearer than that of woman to the value of the YOUNG's modulus of the smooth muscles.3. The histometrical results of the study of histological constitution of the normal abdominal aortae are as follows.a. The thickness of media increases until the fourth decade of age in man and the sixth decade of age in woman, and decreases there-after. Accordingly it is thicker in woman than in man in and after the sixth decade of age.b. The number of the elastic fibers scarcely differs according to sex and age, but greatly decreases in the more distal portion of the aorta. The elastic fibers begin to become exhausted and splitted in and after the third decade of age. There changes are severe in the more distal portion of the aorta.c. The percentage of the collagen fibers in the media is high during the first two decades and in and after the fifth decade of age. In the third and fourth decade the percentage of the smooth muscles is also relatively high.4. The above-mentioned facts substantiate the high value of IYM in its first and third phase. On the other hand, in the second phase of IYM it is expected that the active tension of the smooth muscles is considerably strong to resist the blood pressure. This tension decreases as the smooth muscles become exhausted and collagenated, resulting medial thinness and extention.5. From the foregoing results, it is considered that the distal portion of the abdominal aorta is apt to suffer arteriosclerotic infirmity especially in man after the fifth decade of age, being one of the major causes from which AAA arises.6. Typical AAA can be divided into four different types, each of which has characteristic aortogram and clinicopathological findings. They can be summarized as the following table.

THE EFFECT OF ACUTE PULMONARY EDEMA UPON LUNG COMPLIANCE

Thirty-eight puppies were paired according to weight and one of each pair was infused intravenously with normal saline and levarterenol in order to produce acute pulmonary edema. The lungs were immediately excised and the relationship of gas volume to airway pressure was examined in either the natural or gas-free postmortem state. The edematous lungs consistently opened at lower pressures than did the nonedematous lungs. After opening had occurred, the rise in airway pressure for a given increase in gas volume was often, but not invariably, greater in the edematous lung. The effect of change in pulmonary vascular volume was studied in eight excised adult dog lungs. In the absence of pulmonary edema, an increase in vascular volume [SEE FIG. 5. IN SOURCE PDF] caused a slight increase in airway pressure. In the same lungs, massive pulmonary edema increased airway pressure independent of vascular pressure. [SEE FIG 4 IN SOURCE PDF] These findings suggest that changes in the bronchial mucus-alveolar lining layer complex, parenchyma, and vascular volume all contribute to the changes in compliance seen in acute pulmonary edema. The change in the bronchial mucus-alveolar lining layer complex is of such a nature as to increase compliance, whereas the changes in the parenchyma and pulmonary blood volume decrease compliance.