Thomas F. McDonald

Connective Tissues in Arterial and Pulmonary Disease

I Connective Tissues in Arterial Disease.- Structure and Function of Aorta Proteoglycan.- Discussion.- Quantitation of Cells and Fibers in Histologic Sections of Arterial Walls: Advantages of Contour Tracing on a Digitizing Plate.- Discussion.- Biochemical Changes of the Arterial Wall in Atherosclerosis with Special Reference to Connective Tissue: Promising Experimental Avenues for their Prevention.- Discussion.- Biochemistry of Collagen with Special Reference to the Arterial Wall.- Discussion.- II Connective Tissues in Pulmonary Disease.- Connective Tissues and the Mechanical Behavior of Lungs.- Discussion.- Lathyrism and the Biochemistry of Elastin.- Discussion.- Proteolytic Mechanisms and Pulmonary Emphysema.- Discussion.- Histochemical Investigations of Elastin, Collastin, and Other Collagens.- Discussion.- III Holde Puchtler: An Appreciation.- A Proclamation.- Greetings.- Essentials of Histological Staining: Dr. Holde Puchtlers Contribution.

Cell turnover in ciliary epithelium compared to other slow renewing epithelia in the adult mouse

Adult albino mice received tritiated thymidine either injected subcutaneously (333 microCi) every 6 hours for up to 36 hours, or administered in their drinking water for up to 74 days (about 45 microCi/day). Tissue sections were examined with autoradiography to determine the distribution of the label. Animals receiving subcutaneous injections showed no labeled cells in the choroid plexus epithelium and only one cell of 6600 cells counted in the ciliary epithelium was labeled. Animals exposed to the isotope in their drinking water for 74 days showed considerable uptake of label in hepatocytes (15%) and cortical kidney tubules (17%), whereas ciliary and choroid epithelia showed very low uptake at 0.25% and 0.01%, respectively. The data show that the ciliary and choroid epithelia have a very slow turnover rate compared to other slow renewing tissues, and, under normal conditions, these tissues are not renewed in the animals adult life span.

Effects of water-soluble marihuana-derived material (MDM) on the rabbit ciliary body: Light and electron microscopy

The response of the ciliary processes of the rabbit eye to water-soluble marihuana-derived material (MDM) has been examined with light and electron microscopy. Following intravenous injection of MDM, the processes undergo considerable swelling within 1 hour followed by thrombus formation in the capillaries and extravasation of red cells. Later phases include the formation of cysts between the non-pigmented and pigmented cell layers of the ciliary epithelium. The ciliary process edema coincides with the initial hypertensive phase seen after intravenous MDM, while the hematogenous response coincides with the fall in intraocular pressure. Following intravitreal injection of MDM, a similar pattern of structural changes occurs that accompanies a fall in intraocular pressure that lasts for several days; because the physiological response occurs over a longer time course (14-20 hours) relative to intravenous administration where the intraocular pressure changes occur rapidly, the ciliary process swelling phase does not result in an increase in intraocular pressure. The physiologic changes in the eye caused by MDM appear to be related to the induction of a general inflammatory response in the ciliary processes, with a primary effect on the vascular system.

Prostaglandin involvement in the responses of the rabbit eye to water-soluble marihuana-derived material

Both anticoagulants (heparin and streptokinase) and non-steroidal anti-inflammatory compounds (aspirin and indomethacin) were used against a water-soluble derivative of marihuana, MDM. While the anticoagulants had no effect on the ocular effects of MDM, both aspirin and indomethacin altered the time course and effected the MDM-induced reduction of intraocular pressure. The usual initial hypertensive effect of intravenous MDM was eliminated and the later intraocular pressure fall occurred earlier as well as being inhibited by about 35 to 50%. Assay for prostaglandins revealed that intravenous MDM (3.86 micrograms) caused a marked rise in PGE2 concentration of the aqueous humor and iris-ciliary body during the first hour or two after administration of MDM, but normal values occurred at 4, 6, and 8 hours when the intraocular pressure is reduced by up to 60%. Following intravitreal MDM (0.002 microgram), however, the PGE2 levels remained unchanged over 24 hours, despite the induction of a fall in intraocular pressure between 14 and 18 hours which lasts for many hours. Prostaglandin appears to be involved in the hypertensive phase of intraocular pressure change after intravenous MDM injection; and, while the fall in intraocular pressure may contain a component partially mediated by prostaglandins, there is no evidence that intravitreal MDM induces any effect on prostaglandin levels. The involvement of prostaglandins, therefore, in the mediation of MDM-induced ocular hypotensive effects is apparently small.

Marijuana-derived material-induced changes in monkey ciliary processes differ from those in rabbit ciliary processes

The morphologic changes in ciliary processes and the associated intraocular pressure (IOP) were observed in owl and squirrel monkeys after intravitreal (IVT) and intravenous (IV) injections of water soluble marijuana-derived material (MDM). The response in monkeys differed from that reported in rabbits wherein IV injection induced severe ciliary swelling and a significant decrease in IOP. Only moderate swelling occurs in monkey processes after IV injection of relatively high dose of MDM, and this change, which includes disruption of the basal lamina of the pigment epithelium, is not associated with a change in IOP. Severe swelling occurs in the crests of monkey ciliary processes after IVT injection, which is accompanied by a fall in IOP. The difference in the response in monkey versus rabbit ciliary processes after IV injection of MDM may be due to a more compact stroma in the monkey processes.

Studies in the biochemistry of skin V. The particulate origin of adenylate kinase in the skin of neonatal rats

Abstract Evidence is presented to show that in the skin of the neonatal rat, the enzyme adenylate kinase is associated with particles. We prepared a lysosomal fraction from neonatal rat skin and then further fractionated this material by the use of a density gradient which varied from 0–16% Ficoll and 0.88–1.4 M sucrose. Three bands were isolated which had acid phosphatase, β-glucuronidase and adenylate kinase activity. Each of these fractions was then resubjected to an expanded density gradient corresponding to the range in which it had previously sedimented. When equilibrium had been reached, the particles still exhibited acid phosphatase, β-glucuronidase and adenylate kinase activity. Repeatedly washed particles retained adenylate kinase activity.

Rabbit Ciliary Process Responses to Different Routes of Water-Soluble Marihuana-Derived Material Administration

AbstractThe pharmacologic and morphologic effects of water-soluble marihuana-derived material (MDM) were examined in rabbits after different routes of administration. Subcutaneous (SC) MDM alone caused little change in intraocular pressure (IOP) yet significantly antagonized subsequent intravenous (IV) or intravitreal (IVT) MDM injections; this occurred despite the failure of SC MDM alone to induce morphological changes in the ciliary processes. Morphologic effects are usually associated with a pharmacologic response. IV MDM alone induced a large IOP fall that accompanied substantial morphologic changes; further IV MDM was ineffective in causing a change in IOP until 4 or 5 days after the initial injection. IVT MDM after IV MDM caused a fall in IOP with additional morphologic effects. IVT MDM alone caused marked pharmacologic and morphologic changes, and IV MDM after IVT MDM caused additional morphologic changes that accompanied an IOP fall. IVT injections, after a prior IVT injection, were pharmacologica...