[The development of a finger joint phantom for the optical simulation of early inflammatory rheumatic changes]. / Entwicklung eines Fingergelenkphantoms zur optischen Simulation früher entzündlich-rheumatischer Veränderungen.

In the field of rheumatology, conventional diagnostic methods permit the detection only of advanced stages of the disease, which is at odds with the current clinical demand for the early diagnosis of inflammatory rheumatic diseases. Prompted by current needs, we developed a finger joint phantom that enables the optical and geometrical simulation of an early stage of rheumatoid arthritis (RA). The results presented here form the experimental basis for an evaluation of new RA diagnostic systems based on near infrared light. The early stage of RA is characterised mainly by a vigorous proliferation of the synovial membrane and clouding of the synovial fluid. Using a double-integrating-sphere technique, the absorption and scattering coefficients (mua, mus') are experimentally determined for healthy and pathologically altered synovial fluid and capsule tissue. Using a variable mixture of Intralipid Indian ink and water as a scattering/absorption medium, the optical properties of skin, synovial fluid or capsule can be selected individually. Since the optical and geometrical properties of bone tissue remain constant in early-stage RA, a solid material is used for its simulation. Using the finger joint phantom described herein, the optical properties of joint regions can be adjusted specifically, enabling an evaluation of their effects on an optical signal--for example, during fluorography--and the investigation of these effects for diagnostically useful information. The experimental foundation for the development of a new optical system for the early diagnosis of RA has now been laid.

Long-term evaluation of prosthetic mitral valves in sheep.

We have developed an in vivo model for chronic evaluation of prosthetic heart valves using juvenile domestic sheep. This report summarizes the results of a study conducted to assess a new bileaflet prosthetic valve. Nine juvenile sheep underwent mitral valve replacement using standard cardiopulmonary bypass techniques including mild hemodilution, systemic hypothermia, and cold fibrillatory arrest. The average time on cardiopulmonary bypass was 57 min. There were no surgical or anesthetic complications. Two (22%) early deaths occurred due to prosthetic annular size disproportion (1) and preexisting pneumonitis (1); postmortem examination of both implanted devices revealed normal function. The remaining seven animals (78%) remained clinically well and underwent left and right heart catheterization, angiography, and sacrifice after the 150th postoperative day. Left ventriculograms demonstrated normal valve function in all cases. The average mitral transvalvular gradient, as determined by simultaneous pulmonary capillary wedge and left ventricular and diastolic pressure, was 5.4 mm Hg. Thus we have developed a new in vivo model that provides a successful model for chronic evaluation of prosthetic valves using a sheep model. There are several features contributing to the success of our model. First, to decrease the possibility of bacteremia and seeding of the prosthesis, a single incision is used and intraoperative monitoring lines minimized. Second, we use a short cardiopulmonary bypass run (range 52-62 min), with no period of ischemia. Third, fresh sheep blood is transfused immediately following bypass to prevent anemia. Fourth, gastric decompression is used to prevent ruminal bloating, with the resulting vena caval compression that decreases blood return while on bypass.

Natural history of atherosclerosis and hyperlipidemia in heterozygous WHHL (WHHL-Hh) rabbits. II. Morphologic evaluation of spontaneously occurring aortic and coronary lesions.

This study evaluated the morphologic appearance of spontaneous aortic and coronary atherosclerotic lesions in 21 of the 28, 3-year old, heterozygous Watanabe heritable hyperlipidemic (WHHL-Hh) rabbits whose lipid profiles were presented in part I of this report. In situ perfusion fixation of the arteries showed 100% of the aortas involved with one or another type of intimal lesion. In male rabbits (n = 13), the abdominal aortas had more severe fibrosis and more diffuse intima thickening than the thoracic aortas, (p < 0.001). In female rabbits (n = 8), fatty streaks and fibrous lesions were more predominant in the thoracic than in the abdominal aorta (p < 0.05). Fatty aortic plaques in the female were more commonly found in the abdominal than in the thoracic aorta, but this finding was not statistically significant. In contrast, fatty aortic plaques were not found in the male aortas; however, larger areas of diffuse intimal thickening with fatty deposits were more common in the abdominal aortas of the males (p < 0.01). Annular arteriosclerotic lesions, exclusive to the thoracic aorta, occurred in three of 21 rabbits. Histologically, the aortas demonstrated subintimal fibrosis, fragmentation of the lamina elastica interna, focal medial degeneration, and cholesterol clefts. The coronary arteries were involved in 85% of the males and in 86% of the females. Lesions were more common in the left than in the right coronary artery and primarily consisted of mild nonobstructing intimal hyperplasia with fibrosis. Based on these observations, we consider older WHHL-Hh rabbits excellent models for studying atherosclerosis. Because of their genetic and age-related lesions, WHHL-Hh rabbits may be superior to the cholesterol-fed rabbit model with respect to comparability with human atherosclerotic lesions.

Increased canine pancreatic acinar cell damage after organophosphate and acetylcholine or cholecystokinin.

Sublethal doses of organophosphate anticholinesterases cause acute pancreatitis in dogs within 2 h. In vitro studies using canine pancreatic fragments have also demonstrated that the peak of amylase release in response to acetylcholine is shifted far to the left after incubation with the organophosphates echothiophate (10(-4) M) or tetraisopropyl pyrophosphoramide (iso-OMPA) (10(-3) M), indicating an increased sensitivity of response. The present in vitro study examined whether there was also an increased susceptibility to acinar cell damage at the electron microscopic level after acetylcholine or cholecystokinin. Minced pieces of whole fresh canine pancreas 2-3 mm in size were placed in buffered Eagle's solution and gassed with 100% O2. After pretreatment 1 h with echothiophate or iso-OMPA, they were then incubated with acetylcholine (10(-5) M). Other tissues preincubated with echothiophate were stimulated with cholecystokinin (10(-9) M). These are submaximal doses for untreated canine pancreatic fragments. After acetylcholine and echothiophate or acetylcholine and iso-OMPA, there was extensive acinar damage with the appearance of large vacuoles and lakes, and interstitial edema. There was evidence of intense supramaximal stimulation and lateral exocytosis. Similar destructive changes were seen after echothiophate and cholecystokinin. In control sections from tissues stimulated with acetylcholine (10(-5) M) or cholecystokinin (10(-9) M, there were lumenal exocytotic patterns typical of submaximal stimulation. Other controls, organophosphate alone and unstimulated basal conditions, showed only minor changes. It is concluded that the increased sensitivity to acetylcholine after organophosphate incubation correlates with an increased susceptibility to acinar ultrastructural damage from acetylcholine and cholecystokinin.

Multiple ex vivo organ preservation with warm whole blood.

To determine the feasibility of en bloc removal of the heart, lungs, liver, kidneys, and pancreas for preservation with warm blood autoperfusion, organs from 34 dogs were preserved ex vivo for periods of between 3 and 22 hours. The lungs were ventilated with a Bird Mark 7 respirator, and the heart served as the pump to perfuse all organs of the multiple organ block. In the first group of 28 animals, surgical and pharmacologic techniques were developed to permit management of the ex vivo model. The last six experiments were conducted in a standardized fashion for a period of 6 hours and evaluated on the basis of hemodynamic, biochemical, and pathologic measurements. In this group the pH level remained stable and blood gas levels remained within normal limits for inspired oxygen of 0.2. Serum and urine electrolyte levels were easily maintained within normal limits. Serum enzyme values were elevated initially after operation, and this increase persisted throughout the preservation period in most animals. Continuing refinements in surgical technique, pharmacologic management, and chamber development resulted in a dramatic reduction of the edema and organ damage seen on pathologic studies of the initial experiments. The presence of focal lymphatic congestion, however, was noted even in the animals in group II and may have been related to ligation of major lymphatic channels or to endothelial loss. These changes could contribute to the development of the pathologic changes seen in irreversible shock. Preservation of the multiple organ block by warm autoperfusion is an important step in understanding the physiology of organ preservation and has potential for permitting prolonged organ preservation. Studies are continuing to further analyze this model and prolong the time of preservation. Final assessment of the model will be transplantation of the preserved organs and evaluation of function after implantation.

Effects of insecticide, diazinon, on pancreas of dog, cat and guinea pig.

The organophosphate insecticide Diazinon has been reported to cause acute pancreatitis in dogs. Based on histochemical examination of the acinar tissue, it was suggested that pancreatic tissue-fixed butyrylcholinesterase (BuChE) is the target enzyme of organophosphate toxicity. To further evaluate this theory, we exposed dogs, cats, and guinea pigs to a single sublethal dose of the organophosphate insecticide Diazinon (75 mg/kg). In cats, which lack pancreatic BuChE, no pathological changes occurred after two, three, and six hours, whereas in the guinea pigs as in dogs, both having abundant pancreatic BuChE, vacuolization of the acinar cells, interstitial edema and vasculitis indicate acute edematous pancreatitis as early as two hours. Atropine pretreatment (0.2 mg/kg) gave complete protection against pancreatitis. It was concluded that inhibition of pancreatic BuChe leads to cholinergic hyperstimulation of the acinar cell, which results in acute pancreatitis, and that pancreatic BuChE is essential for dogs and guinea pigs to downregulate cholinergic excitation. The insecticide pancreatitis model is considered a simple, non-invasive, reproducible, and cheap and useful method to evaluate early changes and methods of treatment in acute pancreatitis. Pancreatitis in humans has also been reported after accidental insecticide exposure.

Cytotoxic effect of anti-Mr 67,000 protein immunotoxins on human tumors in a nude mouse model.

We have studied the potential use of immunotoxins (ITs) for therapeutic treatment of human tumors in an experimental model of human neoplasia. We tested intact ricin IT for its antitumor activity against established tumors. CEM, a human T-cell leukemia line expressing an Mr 67,000 cell surface antigen, and Daudi, a human B-cell lymphoma line which does not express the antigen, were found to be consistently tumorigenic in nude mice. ITs were synthesized using T101, a high-affinity monoclonal antibody reacting with the Mr 67,000 protein determinant and intact ricin. We have shown for the first time that established CEM solid tumors in nude mice will regress following intratumoral injection of T101-ricin IT, while Daudi tumors will not. Selective activity of T101-ricin is dependent on systemic i.v. administration of lactose and local intratumoral injection of the T101-ricin IT with lactose. Intact ricin ITs require the presence of lactose to block native ricin binding and render them antigen specific when linked to monoclonal antibody. Killing of target was cell specific since (a) nonspecific (irrelevant) ITs did not cause the regression of CEM tumors, and (b) injection of large amounts of free T101 antibody prior to T101-ricin IT blocked antitumor activity. Selectivity was not absolute, since regression occurred in one of six animals given irrelevant IT, and blocking was observed in two of four mice. Intratumoral IT treatment with 1 or 2 micrograms of T101-ricin IT plus lactose was not harmful to mice in contrast to intratumoral ricin treatment, which killed all treated tumor-bearing mice at a dose of 0.3 micrograms. Without i.v. injection of lactose, intratumoral injection of T101-ricin IT was also effective in eliminating established tumors. However, this treatment did not result in the selective elimination of tumor, since Daudi tumors also regressed following T101-ricin IT treatment. IT, made with ricin A chain only (T101-A chain IT), was also tested against established CEM tumors. We found that high dosages of T101-A chain IT did not destroy CEM tumors when injected intratumorally, even in the presence of activating agents such as NH4Cl or the carboxylic ionophore X-537 A. In contrast, in vitro experiments demonstrated that T101-A chain IT plus activating agents had potent and selective cytotoxic effect against CEM cells. We conclude that ITs are specifically toxic to established tumors. Although selectivity is not absolute, ITs exhibit potential as a new class of antitumor reagents.

Percutaneous transluminal angioplasty of the aorta. Light and electron microscopic observations in normal and atherosclerotic rabbits.

Histological changes which developed after percutaneous transluminal angioplasty in normal and atherosclerotic rabbit aortas were correlated with balloon size and inflation time. In normal rabbits, progressive changes were observed in the intima and media with increasing balloon size and inflation time. The atherosclerotic aortas exhibited unpredictable fragility, with limited correlation between histological changes, balloon size, and inflation time, attributable mainly to the distribution and thickness of plaques. In atherosclerotic vessels, the mechanism of angioplasty consisted of plaque dehiscence and fracture, followed by overstretching of the plaque-free wall segments. No plaque compression was observed.

Hyperplasia of pancreatic duct epithelium produced by exposure to sodium deoxycholate.

Severe epithelial hyperplasia was produced in a canine model by the perfusion of the main pancreatic duct with 15 mM of deoxycholate at rates as low as 1.5 ml/day in 6 to 14 days. At higher rates (5 ml/day) deoxycholate caused complete epithelial cell lysis in the duct closest to the tip of the cannula with hyperplastic changes downstream from this section. Perfusion with a buffer solution alone and cannulation alone produced none of these changes in similar duct segments. No hyperplasia was seen in the upstream cannula obstructed duct, even in the presence of severe atrophy. Long-term (81 days) perfusion with 3 mM of deoxycholate at 3 ml/day resulted in more severe hyperplasia that still appeared benign. When glycine-conjugated deoxycholate was perfused through the duct, hyperplasia but no cell lysis was seen. In vitro, deoxycholate caused epithelial cell lysis in pancreatic duct fragments at concentrations of 0.5 mM and above. The results of this study suggest that secondary bile salts or other similar surface-active cytotoxic agents present in the biliary tree or duodenum may play a more important role in the pathogenesis of pancreatic ductal epithelial hyperplasia associated with pancreatic cancer than ductal obstruction.

Metorchis conjunctus (Cobbold, 1860) infection in wolves (Canis lupus), with pancreatic involvement in two animals.

The trematode Metorchis conjunctus (Cobbold, 1860) was found in seven of 211 wolves from Saskatchewan which were examined between 1976 and 1983. The parasite caused cholangiohepatitis with periductular fibrosis in the liver of all the wolves, and chronic inflammation and fibrosis of the pancreas in two animals. The wolves with pancreatic involvement were emaciated. Five of the seven infected wolves were from one local area, and three of these were from a pack known to consume fish.

Experimental pancreatitis after surfactant exposure.

The effects of pancreatic intraductal infusions of the surface active pancreatic ductogram enhancing agent, polyoxyethylene hydrogenated castor oil, were studied in the dog. Moderately high pressure retrograde infusions of 5 per cent polyoxyethylene hydrogenated castor oil into the main pancreatic duct resulted in pancreatitis-like changes significantly greater than those seen in the saline solution control group. These changes persisted despite buffering of the agent to physiologic pH and the elimination of nonphysiologically high pressure by direct ductal perfusion. Similar inflammatory changes were associated with ductal perfusion using oleic and, to a lesser degree, ricinoleic-fatty acids at concentrations of 10(-4) molar sufficient to account for the titratable acidity of 5 per cent polyoxyethylene hydrogenated castor oil. It is postulated that residual-free fatty acids may play some role in polyoxyethylene hydrogenated castor oil related toxicity. The surface active properties of the agent may also be involved. Caution and further research are recommended prior to widespread use of the agent in endoscopic retrograde pancreatography.

Optical transforms of epidermal Langerhans' cell granules.

The internal structure of the epidermal Langerhans' cell granule (LCG) was studied with optical transforms of electron micrographs representing 3 planes of sectioning. Its "limiting membrane" exhibited linear discontinuity with a periodicity of about 11 nm similar to the structural repeats of the core (10.8 mm) in both the "outer" and the "internal leaflets". The average thickness of the nonvesicular part of the LCG was 55.7 nm. Disarray present in the optical diffractograms was incompatible with crystallinic or paracrystallinic orderliness of the periodic structures in the LCG. The structure appeared as an assembly of 4 sheets of roughly hexagonally packed particles: The stacked particles of 2 sheets in orthogonal contact forming the core (13.2 nm) were separated by an intermediate space (2.7 nm) from the single sheet of the outer layer and staggered by one-half the particle diameter on cross-sections. The validity of this model was inferred from the similarity of optical transforms of model structures.

Polioencephalomalacia in white-tailed deer (Odocoileus virginianus) in Saskatchewan.

Polioencephalomalacia similar to that in domestic ruminants was diagnosed in two wild white-tailed deer (Odocoileus virginianus) with abnormal behaviour in Saskatchewan.

Myocardial damage after repetitive direct current shock in the dog: correlation between left ventricular end-diastolic pressure and extent of myocardial necrosis.

Acute myocardial necrosis was produced in 27 anesthetized dogs by repetitive DC 75 joule shock delivered with one electrode in the left ventricular cavity and the other on the left chest wall. A total of 1 shock/kg body weight delivered at 10 sec intervals resulted in discrete anterior wall necrosis of 7% to 31% (mean, 17.6%) of the mass of left ventricular myocardium. After some transient bradycardia, normal sinus rhythm was restored. Depression of left ventricular function 15 min after shock (rise in LVEDP from 4.0 +/- 1.5 to 17 +/- 2 mm Hg and fall in cardiac output from 2.29 +/- 0.24 to 1.82 +/- 0.12 L/min) recovered only slightly during the ensuing 2 hr. A significant correlation (r=0.85) was observed between the LVEDP at 2 hr after shock and the extent of necrosis determined histochemically and histologically at the time of sacrifice 3 hr after shock. Thus, in this form of acute myocardial damage, pump dysfunction is closely related to the area of necrosis.

Myopathy and myoglobinuria in a wild white-tailed deer.

Fatal myopathy similar to "capture myopathy" described for African game was diagnosed in a wild white-tailed deer. Clinical signs included depression, inability to rise or stand, and myoglobinuria. Values for serum creatine phosphokinase, glutamic oxaloacetic transaminase, and blood urea nitrogen were high. The deer died 42 hours after capture. At necropsy the muscles of the limbs had a waxy, "cooked" appearance and the kidneys were brown. Microscopic findings included severe degeneration and fragmentation of skeletal muscle fibers, nephrosis, centrilobular hepatic necrosis, myocardial degeneration, and anoxic neuronal degeneration.

Investigations on the suitability of mice for potency testing of FMD vaccines.

Potency testing of FMD vaccines by a three-point method was elaborated. Mice myotropic FMD virus was used as challenge virus. With this test the immunogenicity of FMD vaccines based on BHK, calf kidney or swine kidney was examined. The results are reproducible and allow quantification of the antigenic value of FMD vaccines within statistical limits.

[Microsome-associated 17beta-hydroxysteroid dehydrogenases of human placenta, ii kinetic studies and characterization of the solubilized estradiol-and testosterone-"sensitive" 17beta-HSD-Activities]. / 17BETA-Hydroxysteroid-Dehydrogenasen aus Humanplacenta-Mikrosomen, II Kinetische Untersuchungen und Charakterisierung der solubilisierten Oestradiol-bzw. Testosteron-"sensitiven" 17 beta-HSD-Aktivitäten

Detailed enzyme kinetic parameters of the reactions catalyzed by the two 17beta-hydroxysteroid dehydrogenases (17beta-HSD), which were solubilized from the microsomes of human placenta by treatment with phospholipase A, followed by enrichment and separation were determined. Both enzymes are strictly substrate specific. The most active substrate of one of the 17beta-HSD (fraction A) is estradiol-17beta, the other 17beta-HSD (fraction B) is sensitive to testosterone. Both NAD and NADP can serve as hydrogen transferring coenzymes, the latter giving about one-third of the initial rate of the former. With respect to the influence of temperature, different buffers and pH values, Michaelis constants (Km) with estradiol-17beta and testosterone as substrates, the solubilized and separated microsomal 17beta-HSD behave like those isolated from the cytoplasmic fraction. The two 17beta-HSD, after solubilization from the microsomal fraction of human placenta, enrichment and separation from each other, show only a little activity for the transfer of hydrogen between C17 of estradiol-17beta and C17 of androstenedione. On the other hand, intact microsomes and an integrated system prepared by recombination of the 17beta-enzymes by preincubation in phosphate buffer are able to catalyse very actively the transfer of hydrogen between estradiol-17beta and androstenedione. The effect of temperature and time on the recombination of the two enriched and separated microsomal enzyme activities and the determination of the pH-optimum of the hydrogen transfer reaction are described. Finally it is proposed that the hydrogen transfer between steroid hormones represents an aspect of the true reaction mechanism of steroid hormones: Steroid hormones function as hydrogen transferring coenzymes by forming part of a chain of hydrogen carriers.

Arthropathy in white-tailed deer and a moose.

Degenerative lesions were found in the skeletal system of 20 to 128 white-tailed deer (Odocoileus virginianus) examined. Similar changes were found in an aged male moose (Alces alces). Arthropathy involving the stifle joint was present in 60% (15/25) of male deer 4 years of age or older, and in 16.7% (4/25) of females in the same age range. Vertebral osteophytes were not found in any of 62 female deer, nor in male deer less than 6 years of age, but were present in 50% (7/14) of males 6 year of age or older. The possible etiology and significance of the conditions are discussed.