Dermal angiopathy in hemodialysis patients: the effect of time

We studied skin biopsies from 14 patients after 6 months to 18 years on hemodialysis (HD) to discern any effect of duration of treatment on skin and dermal capillaries. Patients selected for biopsy were without evidence of other diseases known to affect vasculature such as diabetes mellitus. Pathological changes compared with duration of HD were: capillary wall thickening, endothelial proliferation and new capillary formation, lipid content, and epidermal atrophy. Severity of morphologic changes were graded from 0 to 4+ by a pathologist who had no knowledge of HD duration. The earliest change observed was reduplication of the capillary basement membrane. Narrowing of capillary lumina due to endothelial cell proliferation and new capillary formation were noted after five years of HD; lipid droplets were noted in capillaries by five years; and epidermal atrophy by 10 years. Progressive severity of each finding was associated with length of time on HD. Neither amyloid nor Ca++ deposits were observed in any specimens. By clinical observation, easy bruisability and increased skin fragility were worse the longer the patient was on HD. Capillary occlusion inducing tissue ischemia could be a cause of the atrophic skin changes noted. However, no patient manifested dermal necrosis. While pathogenesis of the capillary changes in uremic skin is unknown, the changes have been shown to stabilize following successful kidney transplantation.

Colonic histiocytic neoplasm mimicking malignant histiocytosis and presenting as intussusception

It is now apparent that distinction between the so-called malignant histiocytosis and lymphoma can be made using panels of established immunohistochemical markers and/or genotypic analysis. Many, if not all, of the previously diagnosed cases of malignant histiocytosis have been shown to be of lymphoid, rather than histiocytic, lineage. We report a rare case of colonic histiocytic neoplasm accompanied by a lymphoreticular dissemination that mimicked that of malignant histiocytosis. In addition, barium studies and computed axial tomography confirmed an intussusception that subsequently developed. The histiocytic nature of the neoplastic cells was supported by immunohistochemical, ultrastructural, and cytochemical studies. To our knowledge our case may represent the fifth documented case of a histiocytic malignancy reported in the literature. The relationship among the various cases will be discussed as well as the significance of the focal S-100 immunoreactivity observed in the present case.

Adenocarcinoma arising within a colonic diverticulum: report of two cases and review of the literature

The first reported cases of colonic carcinoma arising within a diverticulum are documented. Although colonic diverticulitis and cancer are common diseases in patients over 60 years of age, cancer arising within a diverticulum is rare. Only close histopathologic scrutiny can differentiate inflammatory changes from neoplasia. Because colonic diverticula are characteristically thin-walled, cancers arising within diverticula may easily penetrate the serosa and first be diagnosed at an advanced stage despite their small size.

Composite adenocarcinoma and carcinoid tumor of urinary bladder

We present a unique case of primary mixed adenocarcinoma of the urinary bladder consisting of signet-ring cells, glands, and mucinous lakes intimately associated with carcinoid elements. Neuroendocrine differentiation was substantiated with immunohistochemical and ultrastructural studies. The literature on primary carcinoid tumor of the bladder is reviewed.

The effects of dimethyl sulfoxide on aortic prostacyclin production and serum thromboxane and plasma fibrinogen levels in rabbits fed a normal versus a cholesterol-enriched diet

Through an unknown mechanism, dimethyl sulfoxide (DMSO) retards atherogenesis in cholesterol-fed rabbits (CFR). We studied the effects on the development of lesions and prostacyclin (PGI2) production in the thoracic aorta and total serum lipid and cholesterol content of the abdominal aortic serum thromboxane (TXB2) and plasma fibrinogen levels in rabbits fed control versus atherogenic diets, with and without DMSO. Without DMSO, PGI2 production was significantly higher in CFR versus control animals (8.65 +/- 1.0 vs 6.38 +/- 0.3 ng/15 min [p less than 0.02]). DMSO did not influence PGI2 production in any of the groups but significantly reduced the number of atheromatous lesions in CFR (78% +/- 9% vs 8% +/- 4% [p less than 0.001]). With DMSO, CFR had a significant reduction in total lipid levels (422 +/- 5 vs 300 +/- 21 mg/gm dry wt [p less than 0.01]) and cholesterol levels (74 +/- 12.8 vs 31.8 +/- 6.4 mg/gm dry wt [p less than 0.01]) compared with control animals. Fibrinogen levels were significantly lower in CFR versus control animals (0.83 +/- 0.07 vs 2.42 +/- 0.13 mg/ml [p less than 0.01]). TXB2 was lower in DMSO plus control versus control animals alone. In conclusion, DMSO does not appear to act through changes in PGI2 or fibrinogen activity. Its effect in lowering TXB2 in CFR suggests an action on platelet function.

A lethal complication of papaverine-induced priapism

A large series of patients was treated for impotence with intracorporeal injections of papaverine and phentolamine with no major complications and no deaths reported. We report on a 45-year-old black man with advanced multiple sclerosis who died after such therapy. When the first self-administered injection of phentolamine and papaverine failed to produce an adequate erection the patient injected a second dose that resulted in priapism and death of massive pulmonary embolism.

Biochemical and histopathologic comparison between blood and saline storage of canine veins

Patency of vein grafts may be influenced by the medium in which they are stored temporarily. We compared saline solution vs blood on prostanoid production and maintenance of endothelium in canine veins after 1 hour of storage at 23 degrees C with 0.2 mg/ml of papaverine. Spontaneous and arachidonate-stimulated prostaglandin levels were measured by radioimmunoassay. Endothelial integrity was analyzed by light and electron microscopy. Prostaglandin production in blood vs that in saline solution was 1821 +/- 1264 and 1259 +/- 719 pg/cm2/min at control and 6705 +/- 3702 vs 6264 +/- 3409 pg/cm2/min, respectively, after stimulation. There were no statistically significant differences between the groups at any time point. Thromboxane levels were also indistinguishable between groups. Microscopy revealed 70% endothelial loss in blood vs 95% for saline solution. We conclude that endothelial preservation is enhanced by blood storage, that the medial layer produces substantial amounts of prostacyclin, and that additional storage solutions need to be investigated.

Cholesterol-induced atherosclerosis in the rabbit: effect of dimethyl sulfoxide on existing lesions

Earlier studies have established that the analgesic and anti-inflammatory compound, dimethyl sulfoxide (DMSO), was effective in preventing atherosclerosis in cholesterol-fed rabbits. In the present studies, the effect of DMSO on existing atherosclerotic lesions in cholesterol-fed rabbits was investigated. Rabbits were placed on an atherogenic diet containing 1% cholesterol for a period of 10 weeks. At the end of the 10-week period, the rabbits were randomly divided into two groups: one group was placed on a control diet consisting of regular rabbit chow for an additional 12-week period, whereas the remaining group was continued on the atherogenic diet. During this period half of the rabbits in each of these groups were treated with DMSO (approximately 5 g/kg) which was included in their drinking water. Food consumption and fluid intakes were monitored daily and body weights at weekly intervals. Total serum cholesterol levels were measured at periodic intervals. Lipid deposits in the eye which accompany atherosclerosis were examined before and at 12 weeks after institution of the new dietary regimens. At the end of 12 weeks, all rabbits were killed and the thoracic aortas were examined for changes in the extent of atherosclerosis. Food consumption and body weight increased in rabbits on the control diet and in those treated with DMSO. Those maintained on the atherogenic diet showed little change in food intake or body weight. Fluid intake was significantly elevated in all rabbits placed on DMSO. Serum cholesterol levels returned to normal in all rabbits on the control diet. Serum cholesterol levels remained unchanged in rabbits kept on the atherogenic diet alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroblastoma: a rare primary intrathoracic neurogenic tumor in adults

Mediastinal neuroblastomas, which are common malignancies of childhood, are extremely rare in adults. This article presents a case of mediastinal neuroblastoma in a 57-year-old man. To the authors' knowledge, this is only the second recorded case of such a tumor in an adult. The patient's clinical course is described and is compared with other cases (in children, except for one instance) cited in the literature. The authors discuss the early diagnosis and surgical management of these uncommon lesions, which tend to be quite extensive and rapidly fatal, and which should be suspected in adults who present with a mediastinal mass.

Inhibition of cholesterol-induced atherosclerosis in rabbits by dimethyl sulfoxide

The effect of dimethyl sulfoxide (DMSO) on cholesterol-induced atherosclerosis in the rabbit was investigated. Two groups of rabbits were studied: a Control group which received regular chow and an Experimental group which received an atherogenic diet containing 1% cholesterol. DMSO was either omitted or added to the drinking water of both groups in amounts of 2, 4, 5 and 6%. After 3 months all animals were autopsied; the thoracic aorta was examined for atheromatous lesions and the abdominal aorta assayed for total cholesterol content. As expected the thoracic aortas of all rabbits in the Control group were free of atheromatous lesions. With the exception of one rabbit in the Experimental group, all rabbits on the atherogenic diet which did not receive DMSO had extensive aortic lesions covering 82 +/- 5% of the surface area of the thoracic aorta. Aortic lesions were inhibited by about 50% in rabbits on 2% (dose, 1.5 g/kg) DMSO and virtually absent in the majority of rabbits on 4 (dose, 3.5 g/kg), 5 (dose, 5.5 g/kg) and 6% (dose, 9.1 g/kg) DMSO. The food intake of rabbits on the atherogenic diet was not suppressed by DMSO. Changes in the cholesterol content of the abdominal aortas paralleled the presence or absence of lesions in the thoracic aorta. Blood cholesterol levels were greatly elevated in all rabbits on the atherogenic diet and not lowered by DMSO. In conclusion, cholesterol induced atherosclerosis in the rabbit was inhibited by DMSO. This action of DMSO was independent of the hypercholesterolemia and not due to a suppression of food intake. DMSO may provide a useful probe for investigating the underlying mechanism(s) in the development of cholesterol induced atherosclerosis.

Pathology of the penis in long-term diabetic rats

Pathological changes in the penis of long-term diabetic rats (greater than 1 year) include epidermal atrophy and lipid droplets in erectile tissue and dermis, as well as thickening of capillary basement membranes, dilatation and microaneurysms of capillaries, and atrophy and degeneration of erectile smooth muscle. These changes are similar to those previously described as occurring in other organs, but damage to nerves and smooth muscle can best be appreciated with electron microscopy.

Whipple's disease presenting as a small-bowel obstruction

A 51-year-old white man with chronic diarrhea, generalized weakness, and a 70-lb. weight loss in 6 months developed small-bowel obstruction while undergoing investigation in the hospital. At laparotomy, an edematous, thickened mid-portion of small bowel matted between large lymph nodes, involved by characteristics of Whipple's disease, seemed to be responsible for the small-bowel obstruction.

Enhancement of experimental atherosclerosis by aspirin

The effect of aspirin on experimentally induced atherosclerosis was studied in rabbits. Rabbits were placed on an atherogenic diet containing either no aspirin or 0.2% aspirin supplement. Control rabbits were fed regular rabbit food or rabbit food supplemented with 0.2% aspirin. Ingestion of aspirin from the diets containing aspirin was equivalent to a daily dose of 100 mg/kg. As expected, 2 mo after the rabbits were placed on the atherogenic diet, extensive atheromatous lesions were observed on gross examination sporadically distributed along the walls of the aorta. The coronary arteries also exhibited atheromatous lesions on microscopic examination. Addition of aspirin to the atherogenic diet intensified the atherosclerosis as measured by proliferation of the intima of the aorta and coronary arteries and increased occurrence and distribution of atheromatous plaques. It is concluded that, under the conditions of this experiment, the addition of aspirin to an atherogenic diet greatly intensified atherogenesis.

Action of gold thioglucose on pericapillary structures in the ventromedial hypothalamus

The administration of GTG to mice leads to death of all structures in a circumscribed area of the VMH as a result of loss of blood circulation. The loss of circulation is due to damage by GTG of neural processes adjacent to some of the capillaries in this area; damage to these processes leads to abnormal capillary permeability. Pericapillary damage occurs under conditions where capillary damage and consequent necrosis are prevented. Abnormal capillary permeability appears to follow release of a vasoactive substance from the damaged neural processes. Damage to the pericapillary neural processes by GTG is insulin-dependent and is counteracted by glucocorticoids.

Regeneration of jejunal mucosa during recovery from malnutrition and pancreatic insufficiency

A patient with a history of alcohol abuse, who presented with severe malnutrition, was subjected to serial jejunal biopsies during his hospitalization. The improvement in villous size and absorptive cell ultrastructure paralleled his clinical recovery. It is concluded that the caloric and trophic benefits of food, the pancreatic and vitamin replacement therapy and withdrawal of alcohol, all played an integral part in the regeneration of the jujunal mucosa.

Alcohol ingestion-induced changes in the human rectal mucosa: light and electron microscopic studies

Histologic and ultrastructural examination of specimens of rectal mucosa from 11 patients who had recently consumed excessive quantities of alcohol revealed marked pathologic changes. Goblet cells were decreased and a dense mononuclear cell infiltrate was seen on light microscopic study. Electron microscopy revealed swollen, distorted mitochondria and dilated and vesicular endoplasmic reticulum. These abnormalities disappeared after two weeks' abstinence. It is suggested that disordered organelle structure and function might contribute to the diarrhea frequently observed following excessive alcohol intake.

Heart morphological changes in rats placed in a crowded environment

A group of rats were stressed by placing them in a crowded environment. Examination of the hearts showed the following anatomic changes: (1) increased weight; (2) occlusion of capillaries by platelet thrombi; (3) endothelial swelling of capillaries; and (4) swelling and deformity of mitochondria.

Gold thioglucose obesity syndrome

Parenteral administration of gold thioglucose to mice produces an area or necrosis in the ventromedial portion of the hypothalamus. The lesion, like lesions produced by electrocautery of this area, causes hyperphagia and consequent obesity. The glucose moiety of gold thioglucose is essential for production of the lesion. Glucose analogues (2-deoxy-glucose, sodium thioglucose and phlorizin) prevent the gold thioglucose-induced lesion, and by themselves produce a transient hyperphagia. Insulin deficiency prevents the lesion. Either adrenalectomy or hypophysectomy counteracts the effect of insulin deficiency. Electron microscopic studies, in which general necrosis is avoided by administration of aspirin before gold thioglucose or by administration of subnecrotic doses of gold thioglucose, reveal that gold thioglucose primarily affects neural elements contiguous with capillaries in the ventromedial hypothalamus. The experimental observations indicate the presence of special glucoreceptor cells in the ventromedial hypothalamus that are involved in the regulation of food intake.

Stress and the induction of intravascular platelet aggregation in the heart

Intravascular aggregation of platelets similar to that found in dogs after norepinephrine infusion was demonstrated using the electron microscope in the hearts of 20 of 23 rats subjected to two forms of stress (immersion in hot water, 7 of 8 rats; repeated small electric shocks to the feet, 13 of 15 rats). Only one of 14 unstressed rats was found to have similar intravascular platelet aggregates. These findings suggest that catecholamines secreted endogenously during stress are sufficient to cause platelets to aggregate intravascularly and raise the possibility that clinical myocardial infarction occurring during severe or prolonged stress may be caused by catecholamine-induced platelet thrombi which occur at, or travel to, and occlude a coronary artery already narrowed by previous atherosclerosis.

Intravascular platelet aggregation in the heart induced by stress

Sixteen rats, stressed by immersion in ice-cold water for 25-45 min, were found to have platelet aggregates in myocardial small vessels on electron microscopic study. None of six similar nonstressed control rats had platelets in myocardial vessels. It is concluded that stress, probably via catecholamine secretion that enhances platelet stickiness, can induce intravascular platelet aggregation. It is possible that this mechanism plays a part in the relationship between stress and acute clinical myocardial infarction.

Intravascular platelet aggregation in the heart induced by norepinephrine. Microscopic studies

Aggregated platelets and occlusive platelet thrombi were found in small myocardial vessels of dogs on electron-microscope examination after prolonged infusion of norepinephrine. The etiology of the myocardial necrosis and fibrosis induced by catecholamines in experimental animals and seen in patients with pheochromocytoma and patients after norepinephrine treatment for shock may be related to this intravascular platelet-aggregating effect of catecholamines. The link between stress and acute myocardial infarction may be via catecholamine-induced intravascular platelet thrombosis. If the thrombogenic theory of atherosclerosis is valid, platelet aggregation induced by catecholamines may be the mechanism whereby arteriosclerotic heart disease is related to stress.