Comparison of the endothelial surface and subjacent elastic lamina of anterior descending coronary arteries at the location of atheromatous lesions with internal thoracic arteries of the same subjects: a scanning electron microscopic study.

Aim: Current theories fail to explain the localisation of atheromatous lesions or their variable incidence in different arteries of the same subject. The objective of this study was to compare by scanning electron microscopy (SEM) the endothelial surface and the subjacent elastic lamina of human coronary arteries at the location of areas showing infiltration by lipid and cells, with the same components of internal thoracic arteries of the same subjects.

Methods: The endothelial surface and the subjacent elastic lamina of localised atheromatous areas of 146 anterior descending coronary arteries were compared with the same structural components of the internal thoracic arteries of the same subjects, using SEM, transverse paraffin sections and freeze-fracture.

Diffusion of gamma globulin into the arterial wall identifies localized entry of lipid and cells in atherosclerosis.

Background: The localization of atheromatous lesions in vulnerable arteries and their relatively rare occurrence in other arteries of the same subject cannot be explained by current theories of the aetiology of atherosclerosis.

Objective: To determine whether abnormal diffusion of gamma globulin into the arterial wall from the lumen will identify defects of barrier function allowing localized entry of lipid and cells in atherosclerosis.

Methods: Paraffin sections of left anterior descending coronary arteries and corresponding internal thoracic arteries from 80 human subjects aged 1-65 years were stained for gamma globulin by the immunoperoxidase technique.

The initiation of intimal thickening in human arteries.

To obtain more detailed information about the relationship of intimal thickening to defects in the elastin structure of the arterial wall, the internal elastic lamina and subsequent elastin formation in the intima was studied by very oblique sectioning of paraffin sections of the arterial wall, and by scanning electron microscopy of formic acid digested preparations. Comparison was made in the same subject between the internal thoracic artery (a vessel showing only slight intimal thickening) and the anterior descending coronary (which usually develops advanced intimal thickening). There was no evidence of penetration of the normal fenestrations of the internal elastic lamina by medial smooth muscle cells.

A comparison of coronary arteries from Japanese and NZ subjects.

This paper describes a comparison of the anterior descending branch of the left coronary artery from 198 Japanese subjects of ages less than 60 yrs, with 301 New Zealand individuals of similar ages. The object of the study was to determine whether there were structural differences present which could be partially responsible for the low incidence of atherosclerosis in Japanese as well as the known low blood lipid levels. It was found that the internal elastic lamina of Japanese coronary arteries was less well formed at birth than that of NZ subjects.

Primary plexogenic pulmonary hypertension shows imperfect formation of the internal elastic lamina of the pulmonary arteries.

Lung tissue from subjects dying from primary plexogenic pulmonary hypertension (PPH) has shown defects of elastin formation of the lung arteries. Lung vessels from 5 cases of PPH were compared with those of 9 age-matched normal subjects, and 24 individuals having secondary pulmonary hypertension (2 degrees PH). PPH cases and those with 2 degrees PH due to congenital heart disease with left-to-right shunts (2 degrees PH, LRS), showed active proliferation of medial smooth muscle cells (SMC) through defects of the internal elastic lamina (IEL) into the arterial lumen to form typical plexiform lesions.

The importance of a substantial elastic lamina subjacent to the endothelium in limiting the progression of atherosclerotic changes.

This study examines the hypothesis that progressive intimal thickening and atherosclerosis in the larger pulsatile arteries arise from failure to maintain, subjacent to the endothelial cells, a substantial elastin membrane, a component which has been shown to be of special structural significance. The internal thoracic arteries of 293 subjects of all ages up to 60 years were compared histologically with the anterior descending coronary arteries of the same individuals by light- and electronmicroscopy and immunoperoxidase staining for macromolecules. The internal thoracic arteries usually developed a new robust reduplicated internal elastic lamina at an early age, no further intimal thickening, and no significant entry of lipid or cells to the intima.

Comparison of intimal thickening of Chinese and New Zealand coronary arteries.

Coronary arteries from forensic autopsies on 170 Chinese subjects aged 0 to 60 years were compared with those of 301 New Zealand individuals of corresponding ages to explore the reasons for the lower incidence of coronary artery disease in Chinese people. Intimal thickening progressed more rapidly in Chinese subjects up to the age of 30 years, but more slowly in the older age groups. The most striking difference was the much reduced lipid content of the intima and the better formed luminal surface of Chinese arteries of older subjects.

Clinical characteristics of patients in the persistent vegetative state.

Little is known concerning the specific clinical characteristics of patients in persistent vegetative states (PVS). Fifty-one patients from four nursing homes, approximately 3% of the total patients, were identified as being in a PVS. The mean age of the patients was 64.

Patients in a persistent vegetative state attitudes and reactions of family members.

Patients in a persistent vegetative state (PVS) constituted approximately 3% of the population in four Milwaukee nursing homes. In order to understand family members' attitudes and reactions toward such patients, 33 (92%) of 36 family members of patients in PVS contacted were studied. The age of the patients ranged from 19 to 95 with a mean age of 73.

The intima of human coronary arteries.

Intimal thickness relative to that of the media (r) was measured in coronary and internal mammary arteries from 300 human subjects. Whereas this ratio remained low (less than 0.17) in the mammary arteries, coronary arteries showed progressive intimal thickening (r = 4.

A comparison of structural features of the walls of coronary arteries from 10 different species.

The intimal thickness of the coronary arteries of humans less than 20 years of age was compared with that 9 other species. It was found that humans were unique amongst the species studied in showing substantial intimal thickening at an early age. The intimal thickening was associated with defects of the internal elastic lamina (IEL), which in humans were not repaired, but which in other species were associated with an effective reduplication of the IEL.

The internal elastic lamina in normal and abnormal human arteries. A barrier to the diffusion of macromolecules from the lumen.

The distribution of albumin in the walls of normal and abnormal human arteries from surgical and autopsy material was studied to gain insight into the barriers affecting the outward diffusion of plasma macromolecules. In normal arteries there was a steep reduction in albumin concentration at the position of the internal elastic lamina (IEL), suggesting that it acts as a barrier to diffusion. In abnormal arteries such as small vessels present in inflammatory tissue, the IEL was frequently discontinuous and associated with intimal thickening.

Discontinuities in the internal elastic lamina: a comparison of coronary and internal mammary arteries.

The internal elastic lamina (iel.) of the anterior descending branch of the left coronary artery, and the internal mammary artery, were studied in 166 unselected subjects of different ages and races. The coronary artery showed substantial defects in the iel.

A comparison of coronary and internal mammary arteries and implications of the results in the etiology of arteriosclerosis.

Comparison was made between the intimal thickening of the anterior descending branch of the left coronary artery and the internal mammary artery in 352 necropsy examinations. The coronary arteries showed severe intimal thickening, progressing in severity throughout life, whereas the internal mammary showed no more than slight changes at any age. These observations, together with the variation in severity of the changes in different portions of the same vessel, and the freedom from this disease of the smaller arteries throughout the body, strongly suggest that a local or anatomic factor is the dominant influence in coronary artery disease.

The arterial wall in malignant disease.

The intimal thickening of arteries present in 95 resected specimens of carcinoma of the colon was studied, using sections from the tumour area and from adjacent normal bowel. Arteries from the tumour area showed a very significant increase in intimal thickening as compared with the controls. It is suggested that the local factor associated with the tumour area is an impaired drainage of macromolecules from the intimal compartment of the arteries due to obstruction of the lymphatic channels of the surrounding interstitial tissue by tumour cells and fibrosis.

The mechanism of intimal thickening in arteriosclerosis.

The limitations of current theories of the mechanism of intimal thickening in arteriosclerosis are briefly reviewed. The suggestion is advanced that this change is due to intimal oedema, arising from failure of the lymphatic system of the surrounding tissue to remove adequately, protein-containing fluid filtering outwards through the vascular endothelium. It is postulated that such local environmental influences account for the variability in the degree of arterial degeneration seen in different arteries, and in different portions of the same artery.

A comparison of the effects of halothane and other anaesthetic agents on hepato-cellular function in patients submitted to elective operations.

In an attempt to gather objective evidence of possible hepato-cellular toxicity of the halogenated anaesthetics halothane and methoxyflurane pre-operative and post-operative enzyme estimations were done on patients admitted for elective operations. The series of approximately 500 cases included 160 patients submitted to cholecystectomy, an operation associated with a high percentage of detectable alteration of hepatocellular function in the post-operative period. There was no significant difference between the groups of patients receiving halothane, methoxyflurane, or nitrous oxide and oxygen with analgesic supplement.

Serum arginino-succinate lyase: observations on the sensitivity and specificity of this test in the detection of minimal hepatocellular damage.

The serum argino-succinate lyase (ASAL) activity was measured in preoperative and post-operative serum samples, from approximately 500 patients submitted to elective surgery. The results were compared with the determinations of 6 other enzyme activities on the same serum specimens. Serum ASAL elevations correlated highly with increases in serum alanine aminotransferase (ALT) activity, and were nearly twice as great.

Brain damage in dogs immediately following pulsatile and non-pulsatile blood flows in extracorporeal circulation.

The brains of dogs subjected to total cardiac bypass were examined for early signs of ischaemic nerve cell changes. Diffuse nerve cell changes were found immediately following two- and three-hour non-pulsatile perfusions but not following pulsatile perfusions of the same durations. The nerve cell changes found in the brains were acute cell swelling and early ischaemic cell change.