Compensatory renal hypertrophy in the absence of androgen binding.

As a direct test for a role of androgens, compensatory renal hypertrophy was studied in normal male mice, in androgen-insensitive Tfm/Y mice, and in sibling normal female mice. Fifteen days after unilateral nephrectomy, although the kidneys of the normal male mice were larger, relative increases in renal weight were similar in all groups (33-43%). The magnitude of the increase and the contents of protein, RNA, and DNA were the same in the Tfm/Y mice and the female mice. Androgens are not essential to compensatory renal hypertrophy, but they promote larger mice with larger kidneys.

Soluble proteins in the human atherosclerotic plaque. With spectral reference to immunoglobulins, C3-complement component, alpha 1-antitrypsin and alpha 2-macroglobulin.

A number of soluble proteins contained in human aortic intimal tissue was extracted into buffered saline (pH 7.4) and identified and quantitated by immunoelectrophoresis and immunodiffusion. The proteins included IgA, IgG, IgM, B1C (C3), alpha 1-antitrypsin, alpha 2-macroglobulin, fibrinogen, albumin, LDL, HDL, alpha 1-acid glycoprotein, beta 2-glycoprotein, transferrin and ceruloplasmin. The concentration of soluble proteins was significantly higher in the atherosclerotic intima than in the normal intima. The diseased intima also contained a small amount of tissue-bound IgG, IgA and B1C which was extractable with citrate buffer at pH 3.2. The vascular band IgG, and B1C were shown by enzymatic and immunohistochemical studies to be closely associated with the collagenous tissue of the plaque. The Ig contained in the atherosclerotic plaque may be derived in part from the biosynthesis of Ig by the artery, since the incorporation of 14C-labeled leucine into IgG by the atheromatous plaque was demonstrable by radioimmunoelectrophoresis. In contrast to the diseased artery, the normal artery did not synthesize IgG and did not contain vascular bound IgG or complement. However, the normal artery was capable of fixing IgG and B1C eluted from the diseased artery. The present studies suggested that the IgG contained and synthesized by the plaque might represent an immune response to an endogenous or exogenous antigen closely associated with plaque collagen. IgG and B1C either alone or in the form of an immune complex also may play an important role in phagocytosis in the plaque and thereby influence the course of atherosclerosis. The proteolytic inhibitors, alpha 1-antitrypsin and alpha 2-macroglobulin, found in relatively high concentrations in the plaque, could enhance fibrosis of the lesion because of thier known inhibitory effects on collagenase and elastase.

Effects of anticalcifying and antifibrobrotic drugs on pre-established atherosclerosis in the rabbit.

The effects of the anticalcifying drug, ethane-hydroxydiphosphonate (EHDP) and the inhibitors of collagen biosynthesis, colchicine, penicillamine and azetidine were studied in the rabbit with pre-established atherosclerosis. The drugs were administered with a cholesterol-free diet (regression diet) for 8 weeks following the induction of atherosclerosis by feeding a hypercholesterolemic diet containing 2% cholesterol and 8% peanut oil for 8 weeks. The extent and severity of aortic atherosclerosis, as revealed by the morphological and biochemical findings, increased significantly during the regression period. In rabbits treated with EHDP (5 mg/kg/day) the aorta had fewer gross lesions and contained significantly less cholesterol, collagen and elastin than did the aorta of the rabbits fed the regression diet alone. These changes were associated with a significant reduction in aortic calcium caused by EHDP. The aortic content of cholesterol, collagen and elastin in the EHDP-treated rabbits, although less than that of the rabbits fed the regression diet alone, was about the same as that of the rabbits fed a high cholesterol diet for 8 weeks. Both colchicine (0.2 mg/kg/day) and penicillamine (100 mg/kg/day) had a selective action on the induced plaques in that they suppressed the fibrous proliferation in the lesions without preventing lipid and calcium accumulation in the lesions. Neither colchicine nor penicillamine reduced the extent of aortic atherosclerosis as determined by gross examination of the vessel. Azetidine had no significant effect on the pre-established atherosclerotic lesions. The lipid, fibrous protein and calcium content of the aorta of the azetidine-treated animals was not significantly different from that of the untreated animals. The biochemical findings in the aorta were consistent with the microscopic changes.

Guided visualization and suggestibility: effect of perceived authority on recall of autobiographical memories.

The purpose of this study was to investigate a possible component process in the formation of childhood pseudomemories in adults. Participants recounted a childhood event, the details of which came from hearing others tell it (a know event) rather than from their personal experience (a remember event). Then participants were placed in 1 of 4 possible conditions: They completed a guided visualization task led by an expert, a guided visualization task led by a nonexpert, a visual search task, or a verbal list-learning task. For the guided visualization task, participants listened to a middle-aged man on audiotape, who asked them to imagine details about their know event. Half believed the person on the tape was a well-known and esteemed psychologist (an expert), and half were led to believe that he was someone who had gone back to school to study communications (a nonexpert). As predicted, guided visualization led participants to rate their know event closer to a remember event. Planned comparisons demonstrated that the effect was significantly greater for the expert versus nonexpert conditions. Results were applied to the process of false memory formation and the use of visualization procedures in psychotherapy.

When knowing becomes remembering: individual differences in susceptibility to suggestion.

In two experiments, the authors explored factors that might influence a person's tendency to make source-monitoring errors about autobiographical memories. In the first experiment, undergraduates retrieved a memory from childhood (a) that was known about but not remembered, (b) that was remembered, or (c) for which they were unsure of their memory's source. After writing down the memory, experimental groups listened to a guided visualization tape and answered questions about the event--interventions designed to help them focus on details of their memory. Controls also retrieved and wrote down a memory; however, instead of visualizing the memory, they were instructed to conduct a visual search task. Results indicated that guided visualization led participants to rate known memories closer to remembered events. A second experiment examined individual difference variables that might be related to this know-to-remember shift. Results indicated that extraversion, external locus of control, a memory that conveyed fear, and overall affective content predicted this rating. The applicability of these findings to the psychotherapy process is discussed.

The circumplexity of Leary's Interpersonal Circle: a multidimensional scaling perspective.

To investigate the circulant structure of the 16 scales comprising the Interpersonal Checklist (ICL; Laforge & Suczek, 1955), intercorrelation matrices for mate and female undergraduate ICL scores were subjected to multidimentional scaling analysis. Results showed the following: (a) while the 16 ICL scales fall in a rough circular array, measurement gaps exist in the friendly-dominant and hostile-submissive quadrants; (b) sixteenths A-B-P and L-M-N were misarranged; (c) stress coefficients for a three-dimensional solution were in an acceptable range. Implications of these findings for future research and anchoring of the ICL to Kiesler's (1983) "1982 Interpersonal Circle" are discussed.

Assessing variability in circumplex models of personality.

This paper describes a new methodology for assessing variability in circumplex models of personality. Leary's (1957) method for assessing such variability within his system of interpersonal diagnosis is discussed and critiqued. The authors then propose a new methodology, which is (a) consistent with assumptions underlying circumplex orderings of variables, and (b) generalizable to other circumplex models of personality and/or interpersonal communications.

Relationship status: Scales for assessing the vitality of late adolescents' relationships with their parents.

Three criteria for assessing relationship status were proposed: self-disclosure despite the risk of parental disapproval; openness to critical feedback from parents; constructive confrontation when angry with parents. These concepts were operationalized as narratives of nine interpersonal dilemmas, to which late adolescents responded by indicating "What would you do if you were in this situation?" Reliable example-anchored scales were constructed from the responses of one sample of college students and then cross-validated with two other samples. Social class had a significant but small effect on the relationship status scores; but age and sex of adolescent and sex of parent did not. The patterns of correlations of the Relationship Status Scales among themselves and with the Parent-Child Relations Questionnaire, the College Self-Expression Scale, the Fear of Negative Evaluation Scale, and Hogan's Empathy Scale were interpreted as evidence of construct validity.

Glycoprotein reutilization in regenerating microvilli after renal ischemia in rats.

Renal ischemia causes a reversible loss of microvillar membrane (MVM) of the proximal tubule cell and of MVM enzyme specific activities (S.A.). We sought to determine if recovery of the MVM glycoprotein was accomplished through de novo synthesis or recycling. Renal ischemia (25 min) was induced in rats by occlusion of the left renal artery, followed by 15 min or 4 hrs of reflow of blood. Radiolabelled fucose was injected into rats before or after ischemia and was used as a marker for new glycoprotein synthesis or recycling of prelabelled glycoprotein. Ischemia, followed by 15 min of reflow, caused a 49% reduction in protein associated with the isolated MVM fraction of the ischemic kidney. There was also a decrease in newly fucosylated glycoprotein in both homogenate and MVM fraction measured as S.A. or total amount of labeled glycoprotein. Pre-labelled glycoproteins had no change in S.A. in homogenates or MVM fractions of ischemic or contralateral kidneys. However, the total amount of labeled glycoprotein in the ischemic MVM fraction was reduced. At 4 hrs of reflow, protein content of the MVM fraction was back to normal. Pre-labelled glycoproteins of the ischemic homogenate and MVM fraction were also back to normal with no significant dilution of glycoprotein S.A. by newly synthesized protein, indicating that glycoprotein recycling occurs to a large extent in the ischemic kidney.

Aggravation of atherosclerosis by hypertension in a subhuman primate model with coarctation of the aorta.

The interrelationships between hypertension and atherosclerosis were investigated in a subhuman primate model (cynomolgus monkey) with hypertension produced by surgically coarcting the miathoracic aorta. The hypertensive coarcted monkey fed a low cholesterol diet for 6 months did not develop complicating atherosclerosis but did develop focal intimal lesions as well as marked thickening of the musculoelastic media of both the large and small arteries. Fibrocellular thickening of the intima and media occurred in the vessels proximal to the coarctation but not distal to the coarctation suggesting that a high level of blood pressure with resulting increase in arterial wall tension is responsible for these changes. The hypertensive coarcted monkey fed a hypercholesterolemic diet (2% cholesterol and 10% butter) for 6 months developed severe coronary atherosclerotic disease with fibrous plaque formation. The disease produced over 65% luminal narrowing of the major coronary arteries and their extramural and intramural branches. In contrast the noncoarcted normotensive animal fed the same diet developed mild atherosclerosis of only the major coronary arteries which caused an average luminal narrowing of 12%. Aggravation of atherosclerosis by hypertension also appeared to occur in the other arteries above the coarctation particularly the cerebral arteries. When the hypertensive coarcted monkey with preestablished coronary atherosclerosis was treated with a low cholesterol diet and a combination of antihypertensive drugs (hydrochlorothiazide, hydralazine, and reserpine), the progression of the disease was arrested. There also was evidence that treatment caused some regression of the coronary lesions which appeared to "heal" by fibrosis. The treatment of both hyperlipidemia and hypertension appeared to be more effective than the treatment of hyperlipidemia, alone.

Regeneration of the renal brush border after renal ischemia in rats.

An early change following mild renal ischemia is the loss of the renal microvilli, which then regenerate morphologically within 6 h. We studied microvillar regeneration in rats with 25 min of renal artery occlusion and subsequent reflow. At subsequent intervals the rats were injected intraperitoneally with [14C]choline and [3H]leucine; 25 min later they were killed and their renal brush border membranes isolated. At 30 min of reflow of blood there was a 77% reduction in the incorporation of [3H]leucine into microvillar protein compared with that of the opposite control kidney (P less than 0.02). The incorporation rose to normal within 60 min. At 30 min of reflow, the incorporation of [14C]choline into phospholipids increased twofold (P less than 0.005), then returned toward normal values after 2 h. The altered incorporation of tracers was not due to change in membrane turnover or substrate pools. The activities of alkaline phosphatase, gamma-glutamyl transpeptidase, and alpha-glucosidase decreased 50% following ischemia (P less than 0.02) and returned to control values within 2 h. Thus, renal damage severe enough to partly efface microvilli is repaired metabolically within several hours.

Arterial uptake and synthesis of low density lipoproteins.

The accumulation of cholesterol in atherosclerotic lesions is associated with an increased uptake of plasma cholesterol and LDL by the arterial wall. During the regression of atherosclerosis, the uptake of these macromolecules returns to or below normal, suggesting that the retention of cholesterol in regressed lesions is due to a defect in the removal of cholesterol from the arterial wall rather than to an abnormality in vascular permeability. Although increased amounts of 125I-LDL were detected in atherosclerotic vessels, the percent distribution and fractional degradation rate of 125I-LDL appeared similar in normal and diseased vessels. The present studies in support of earlier findings in human vessels indicate that LDL in the artery is contained in a number of different cellular and extracellular pools in close association with AMPS. These lipoproteins appeared to be derived not only from the lipoproteins contained in the plasma but also from lipoproteins synthesized by the arterial wall.

Role of hypertension in ischemic heart disease and cerebral vascular disease in the cynomolgus monkey with coarctation of the aorta.

The role of hypertension in cardiovascular disease was studied in the hypertensive coarcted monkey during the feeding of an atherogenic and nonatherogenic diet. During the 15-month period of observation, half of the hypertensive coarcted monkeys developed cardiovascular disease which included heart failure, ischemic heart disease, stroke, and sudden death. There were no cardiovascular complications in the control normotensive monkeys except for one cholesterol-fed animal. The incidence of ischemic heart disease and sudden cardiac death was higher in monkeys with both hypertension and hypercholesterolemia than in those with hypertension or hypercholesterolemia alone. Postmortem studies revealed that the former monkeys had both hypertensive and atherosclerotic heart disease, whereas the monkeys with hypertension or hypercholesterolemia had either hypertensive or atherosclerotic heart disease. Hypertensive heart disease was characterized not only by hypertrophy of the left ventricle but also by focal myocardial degeneration and fibrosis and by focal thickening and narrowing of the small coronary arteries, particularly the sinus node artery and the atrioventricular node artery. The finding of transmural myocardial infarction in two monkeys with patient coronary arteries suggests a possible role of coronary artery spasm in ischemic heart disease in hypertension. The cerebral vascular complications of hypertension included hypertensive encephalopathy, transient "ischemic" attacks, and hemorrhagic stroke. The complications were associated with severe hypertension and with hypertensive vascular disease or hypertensive and atherosclerotic vascular disease of the cerebral arteries.

Occurrence of Cryptosporidium oocysts in fecal samples submitted for routine microbiological examination.

During a 7-month period, 2,252 fecal samples submitted for routine microbiological examination from 1,621 patients were screened for Cryptosporidium oocysts by the auramine staining method with Kinyoun acid-fast stain as the confirmatory stain. Cryptosporidium oocysts were detected in fecal samples from 19 (1.2%) patients, 18 of whom had gastroenteritis. Diarrheic stools from 14 of these 18 patients were negative for the usual enteropathogens but contained the oocysts in moderate to large numbers. Although Cryptosporidium oocysts were found in patients of all ages, they occurred slightly more frequently in infants and children than in the rest. Cryptosporidium species was one of the common enteropathogens identified in fecal samples submitted for routine parasitological examination during the period of the survey and was second only to Giardia species in terms of frequency. Considering cryptosporidiosis in the differential diagnosis of gastroenteritis in immunocompetent persons and including a search for Cryptosporidium oocysts in routine parasitological examinations of fecal samples appear warranted.