A method for the preparation of platelets for transmission electron microscopy.
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Biomedical subjects
Publications and source records attributed to J C Garancis.
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Synovial tissue excised from the unstable right shoulder joint of a patient with an absent rotator cuff, severe glenohumeral joint degeneration, and hydroxyapatite-containing microspherules, collagen types I, II, and III, active collagenase, and neutral protease in the joint fluid showed extensive osteochondromatosis histologically. Electronmicroscopy revealed calcific foci in microvilli which could easily escape into the adjacent joint space through areas denuded of synovial cells. Fibrocytes demonstrated intensive pinocytotic activity of unknown significance. Energy dispersive analysis showed elemental ratios consistent with hydroxyapatite. A literature review suggested some relationships between the various pathologic lesions present in this joint. Whether similar synovial changes exist in the opposite shoulder joint of this patient and in 3 other subjects with nearly identical clinical, radiographic, and joint fluid findings is not known.
Synthetic triclinic calcium pyrophosphate dihydrate crystals, uniformly labeled with 85Sr and 45Ca, were injected into the knee joints of 2 normal adult rabbits and 2 rabbits previously injected repeatedly with autologous blood. The "half clearance time" of the injected crystal mass was 20.4 and 19 days from control joints, nearly identical to previously reported values in 6 rabbits (19.1 +/- 1.4), and 28.8 and 34 days from the joints injected with blood, a significant difference (P less than 0.05). Iron stains showed hemosiderin granules in the superficial synovium in these joints. Electron microscopy showed crystals with a molar calcium/phosphorus ratio of 1.0 and particles containing iron within synovial cells. We hypothesize that the decreased clearance rate from hemosiderotic synovium is due to inhibition of one or more intracellular pyrophosphatases by iron.
Pure chick kidney glomeruli and proximal tubular fragments have been isolated by graded sieving through nylon screens. Electron micrographs revealed that, in distinct contrast to proximal epithelial cells, the glomerular epithelial and endothelial cells are essentially devoid of mitochondria. Glomeruli as well as proximal tubular fragments contain the 1 alpha- and 24R-hydroxylases of 25-hydroxycholecalciferol. The level of 1 alpha-hydroxylase activity was the same in both segments of the nephron. However, the tubular fragments contained twice the 24R-hydroxylase activity found in glomeruli. Glomerular nuclei were purified by sucrose gradient sedimentation and used to confirm the association of the 1 alpha-hydroxylase with this kidney organelle. Almost all of the glomerular 1 alpha-hydroxylase activity was found in the nuclear fraction. Two metabolites, which are produced predominantly by the nuclei, are designated N-1 and N-2. Their structural identity remains unknown. The novel presence of the 1 alpha-hydroxylase in the glomerulus may be important in defining the etiology of bone diseases in patients with glomerulonephritis and similar disorders.
Frog sciatic nerves were incubated in vitro in isotonic solutions in which the relative concentrations of sodium and potassium were varied. The cross-sectional areas of the unmyelinated axons, the Schwann cells ensheathing the axons, and the periaxonal spaces were measured, and the densities of the axoplasmic organelles were determined. It was found that the nerve fibers were relatively resistant to solutions with low sodium and high potassium concentrations. At very low sodium and high potassium concentrations, there was swelling of the Schwann cells with compression of the axons. A slight degeneration of the axoplasmic organelles was also noted. In an extremely low sodium and high potassium solution, the mesaxons of a few nerve fibers opened up; this was associated with swelling of the axons and slippage of the opposing surfaces of the axolemma and schwann cell membrane. The width of the periaxonal space remained unchanged even with extreme shrinkage or swelling of the axons. These findings indicate that the Schwann cell and axon react differently to low sodium and high potassium concentrations and that the Schwann cell appears to act as a buffer zone, protecting the axon by maintaining optimal ionic concentrations in the periaxonal space.
Exercise can induce proteinuria, hematuria and cylindruria in normal individuals. This suggests that exercise adversely affects glomerular function. In this study we examined the impact of moderate daily treadmill exercise on the glomerulonephritis (GN) of 'one-shot' bovine serum albumin (250 mg/kg i.v.) serum sickness in rabbits. We found that exercise alone increased serum creatinine concentration (Scr) but exercise plus GN did not increase Scr further. Blood urea nitrogen values were unchanged. Albuminuria and the renal histopathology findings were not different between the exercised and non-exercised groups of rabbits. Muscle cytochrome oxidase and mitochondrial protein concentrations were not increased in the exercised animals. We conclude that exercise, below the level that causes exercise adaptation in muscle enzymes, does not adversely affect this form of acute GN.
Antithrombin deficiencies may be the reason for seemingly unexplained thrombosis and graft failure. We treated seven patients who developed clotting difficulties as a result of antithrombin II and/or III deficiencies. In four, arterial thrombosis occurred after arterial reconstruction--three with occluded femoral grafts and one with runoff and digital vessel thrombosis that developed during profundoplasty. Two patients has spontaneous thrombosis of the arterial system of the vessels of the lower leg, and one developed ileofemoral phlebitis. Three patients had abnormally low levels of both antithrombin II and III, whereas two had low levels of antithrombin II only and two had low levels of antithrombin III. Of the four patients in whom this disorder occurred during vascular reconstruction, three experienced graft occlusion that resulted in below-knee amputation in two. There were no common predisposing factors. Antithrombin deficiency should be suspected when there is an unusual propensity to develop thrombus, when heparin cannot prolong coagulation time, and when measurements show reduced levels of antithrombin. Fresh frozen plasma should be given initially and long-term Coumadin therapy started. Early recognition and treatment is necessary to avoid limb loss or death.
Progressive multifocal leukoencephalopathy and malignant lymphoma of the brain were noted at postmortem examination in a 68-year-old white woman who was treated with immunosuppressive agents after renal transplantation. The two diseases are not uncommon in patients with immunodeficiency, but their occurrence in the same patient is extremely rare. This association suggests the oncogenicity of papova viruses in man. However, no papovavirus was demonstrated in the tumor by electron microscopy and immunohistochemical staining. The immunohistochemical staining of routine histology sections for the common antigen of polyomaviruses by the peroxidase anti-peroxidase technique is shown to be simple and specific for the detection of polyomaviruses in the demyelinated areas of progressive multifocal leukoencephalopathy.
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Heparin sodium-induced thrombosis is insidious and difficult to diagnose. If untreated, it results in death or major amputation. We have treated seven patients with thromboses resulting from platelet aggregation induced by heparin. Four patients had acute arterial ischemia of the lower extremity, venous gangrene developed in two, and one patient had an occluded autogenous vein femoral popliteal bypass in the immediate postoperative period. The platelet count was noticeably reduced in affected patients. White platelet thrombi were noted in four patients, three of whom had acute arterial occlusion. A white thrombus was the cause of immediate failure of a femoral popliteal graft. Electron microscopic examination of these thrombi demonstrated predominantly fibrin platelet aggregates with an occasional entrapped WBC and a rare RBC. All patients receiving heparin therapy must have platelet counts performed regularly. If thrombocytopenia is detected, platelet aggregation studies are indicated. When abnormal platelet aggregation is noted, heparin therapy should be reversed with protamine sulfate and the patient treated with low-molecular-weight dextran and warfarin sodium.
This study was performed to determine whether the lung histological changes which occur in rabbits following intravenous injection of killed Bacilli Calmette-Guérin (BCG) are accompanied by measurable changes in pulmonary function. We measured pulmonary function in New Zealand white rabbits 3 weeks after intravenous injection of BCG and in normal rabbits. After a tracheostomy and carotid artery catheterization was performed, each anesthetized rabbit was placed in a body plethysmograph for pulmonary function testing. Following the measurements, the lungs were removed for weighing and histological evaluation. In the BCG-treated rabbits, the lung weight/body weight ratios were 152% greater, the pulmonary resistance was 104% higher, dynamic compliance was 45% lower, minute ventilation was 28% greater, and the delta AaPO2 gradient was 13 torr higher than in the normal control rabbits. Histological evaluation of the BCG-treated animals revealed diffuse pulmonary involvement with non-caseating granulomas.
The chick renal mitochondrial 25-hydroxyvitamin-D3-1 alpha-hydroxylase is composed of three proteins, namely, cytochrome P-450, iron-sulfur protein (ferredoxin) and flavoprotein. Antibodies were raised in rabbits against homogeneous preparations of the ferredoxin. The antibodies were used in indirect immunofluorescence studies to localize the ferrdoxin along the nephron of renal tissues obtained either from vitamin D3-deficient or vitamin D3-sufficient chicks. The ferredoxin is predominantly localized in the glomerulus and proximal convoluted tubules. These results suggest that, in addition to the mitochondrial localization of the 1-hydroxylase, the enzyme may also be present in renal nuclei. The amount of the ferredoxin in kidney, as evidenced by the intensity of fluorescence, appeared to be independent of the vitamin D status of the chick. This finding indicated that changes in the concentration of the renal ferredoxin is not a major factor in the regulation of the 1-hydroxylase activity.
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Human choriogonadotropin (HCG) and its subunits have been studied immunocytochemically using a recently developed unlabeled antibody method. Factors influencing the antigenicity of HCG and its subunits were explored, and optimum conditions were determined. HCG has been successfully localized at the cellular level using paraffin-embedded tissues. Several antibodies to HCG or its subunits were evaluated for specificity using rigorous immunologic controls. This methodology was applied to placental tissue, in vitro choriocarcinoma, and in vitro breast carcinoma. HCGbeta and HCGalpha were localized in the syncytial trophoblast of first trimester placenta with cytotrophoblast cell islands and Langhans' cells being negative. Conditions of stimulated and unstimulated HCG production have been explored in the BeWo line of malignant trophoblast. Stimulation was accomplished by treatment with dibutyryl cyclic AMP and theophylline for varying periods of time. Only 6 per cent of the cells could be shown to be producing HCGbeta and HCGalpha in the unstimulated condition. Stimulation increased this percentage to 70 and 18 per cent, respectively, after 24 hours of treatment. Ultrastructural localization has shown that the mechanism of synthesis and secretion of HCG follows a pathway that is not as extensively developed as that of the pituitary hormones.
Low-dose irradiation of the neck in childhood is associated with a markedly increased incidence of thyroid cancer. Such carcinomas have almost all been well differentiated, papillary or follicular types. This paper describes the development of metastatic anaplastic thyroid carcinoma in cervical lymph nodes a year after subtotal thyroidectomy for well-differentiated papillary carcinoma in a 32-year-old man who had had low-dose cervical irradiation at the age of 7 years. It appears that irradiation-related thyroid carcinomas, in at least a very small number of people, may be associated with aggressive carcinoma.
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Prostaglandin E1 (PGE1) exerted an immediate inhibitory effect upon the induction of platelet aggregation by adenosinediphosphate, epinephrine, thrombin, bovine fibrinogen, or sodium fluoride, whereas dibutyryl cyclic adenosinemonophosphate (DBcAMP) produced a delayed type of inhibition of aggregation induced by these same agents. In addition, however, both PGE1 and DBcAMP, as well as adenosinetriphosphate (ATP) and Mg++, restored, with incubation, the washed platelets to a more discoid shape. Platelet aggregability also correlated well with platelet shape. All of these findings suggest the possibility of mediation of the delayed type of inhibition through restoration of the platelet membrane by increasing the level of metabolically active ATP or the availability of cations. They tend, however, to exclude the possibility that PGE1 exerts its immediate inhibitory effect through the increase of platelet cAMP.
An abnormal chest x-ray film showing hilar adenopathy, diffuse interstitial pulmonary infiltrations, or both, combined with a tissue biopsy revealing noncaseating granuloma, are suggestive of sarcoidosis; however, non-caseating granuloma may also be found in other forms of pulmonary disease. Immunologic and environmental evaluation of three patients with the diagnosis of sarcoidosis made by the above criteria, revealed hypersensitivity pneumonitis in all. Since therapeutic considerations in these two diseases are different (avoidance being the mainstay in hypersensitivity pneumonitis), all methods to ensure a correct diagnosis should be employed.