Biomedical subjects
Publications and source records attributed to A D Proia.
A 48-year-old man had uniocular neovascular glaucoma, with the only apparent predisposing factor being a primary epithelioid melanoma of the iris. The new vessels disappeared following total excision of the tumor. These findings have implications regarding the mechanisms of neovasculogenesis.
Intraocular injection of the corticosteroid triamcinolone acetonide reduces the incidence of retinal detachment in rabbit eyes injected with tissue-cultured fibroblasts. When the steroid was injected simultaneously with the cells, a reduction of retinal detachment from 93% (control) to 75% (treated) was achieved on day 28. When the steroid was injected 24 h preceding cell injection, the reduction of retinal detachment was from 85% (control) to 43% (treated). The development of retinal detachment is caused by proliferation of injected fibroblasts. Reduction of this proliferation is probably achieved partially through direct inhibition of mitosis, but more important may be the reduction of the reactive inflammatory process.
Phosphatidic acid (PA) is an obligate intermediate in the phosphatidylinositol (PI) cycle and may serve as a sensitive marker for this pathway of reactions. Previously, we have shown that acetylcholine (ACh) stimulates formation of labeled PA in whole rat corneas whose phospholipids were prelabeled with [14C]arachidonate. To determine which layer of the cornea exhibits the ACh effect, intact epithelium was isolated from the rest of the corneal tissue (designated "stroma/endothelium") by incubating rat corneas with neutral protease and then stripping off the epithelium using forceps. The epithelium was ultrastructurally normal and avidly incorporated [14C]arachidonate into phospholipids; the stroma/endothelium had only trace incorporation. [14C]Arachidonyl-PA formation by the epithelium was significantly increased after a 37 second (+58%) and was maximal after a 5.0 minute (+188%) incubation in the presence of 1 mM ACh. The stimulation by ACh was blocked by atropine and scopolamine but not by d-tubocurarine. The epithelium also incorporated significant quantities of [3H]inositol into phosphatidylinositol (PI), phosphatidylinositol monophosphate (PIP), and phosphatidyl-inositol bisphosphate (PIP 2). When [3H]inositol-labeled epithelia were incubated for 5 minutes with 1 mM ACh, [3H]inositol monophosphate (IP) was increased 200%, [3H]inositol bisphosphate (IP2) was increased 225%, and [3H]inositol 2 trisphosphate (IP3) was increased 74%. These results suggest that muscarinic cholinergic receptors may be an important regulator of the PI cycle in corneal epithelium and thus may affect intracellular calcium mobilization and epithelial proliferation and regeneration.
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A 52-year-old man died during reoperation for bleeding after the development of acute postoperative acalculous cholecystitis. While the liver was being manipulated during surgery, the pulmonary artery diastolic pressure increased suddenly, cardiac output and blood pressure decreased, and soon afterward the patient had a cardiac arrest from which he could not be resuscitated. During resuscitative efforts, the maximum partial arterial oxygen pressure achieved was only 55 mm Hg despite 100% inspired oxygen. At autopsy, bile aggregates were found within necrotic liver parenchyma, portal and central vein branches, and numerous pulmonary arterioles and capillaries. The pulmonary arterial bile most likely resulted from embolization of inspissated hepatic bile aggregates during surgical manipulation.
The cornea has one of the highest acetylcholine (ACh) concentrations of any tissue but the function of the ACh has remained enigmatic. During studies on corneal arachidonic acid metabolism, we observed that ACh stimulates formation of labeled phosphatidic acid in rat corneas whose phospholipids were prelabeled with [14C]arachidonate. ACh did not affect the metabolism of free [14C]arachidonate. [14C]Arachidonyl-phosphatidic acid formation was doubled after 10 min of incubation in the presence of ACh concentrations of 10(-4) M or greater. The stimulation by ACh could be completely blocked by atropine and scopolamine and partially blocked by d-tubocurarine. These studies suggest that intact rat cornea has muscarinic cholinergic receptors and that the enzymes of the inositol phospholipids pathway are present since phosphatidic acid is an obligatory intermediate in that cycle of reactions.
Deoxycholate promotes phospholipase C degradation of endogenous phosphatidyl[3H]inositol (Pl), phosphatidyl[3H]inositol monophosphate (PIP) and phosphatidyl[3H]inositol bisphosphate (PIP2) in rat cornea and human platelets. Hydrolysis of phosphatidyl[3H]inositol significantly lags polyphospho[3H]inositide degradation. Concomitantly, formation of [3H]inositol monophosphate (IP1) lags behind [3H]inositol bisphosphate (IP2) and [3H]inositol trisphosphate (IP3) production. These results demonstrate that rat cornea and human platelet phospholipase C cause a preferential hydrolysis of the endogenous polyphosphoinositides rather than phosphatidylinositol.
A 62-year-old man was seen with an ulcer of the left upper eyelid of two weeks' duration. Over the previous 40 years, similar ulcers had intermittently developed elsewhere on his skin and spontaneously resolved over several months leaving atrophic scars. A biopsy specimen of the eyelid lesion showed epidermal ulceration with acute inflammation and liquefactive necrosis of the underlying dermis. Microorganisms and vasculitis were not present. On the basis of the clinical history and a compatible biopsy specimen, the diagnosis of pyoderma gangrenosum was made. This is an uncommon, idiopathic, ulcerating skin disease that may also have ocular manifestations. Eyelid ulcers have not previously been reported, to our knowledge. The diagnosis is established by clinical history and exclusion of other causes of ulceration.
A 65-year-old woman developed chronic redness of both eyes, and, over the ensuing 2 1/2 years, she had progressive conjunctival scarring with symblepharon formation. Other mucosal surfaces were not involved. A conjunctival biopsy specimen 12 months following onset of her disease showed areas of epithelial separation from the basement membrane zone as well as subepithelial chronic inflammation and scarring. Two years later, another conjunctival biopsy specimen showed granular deposition of IgA and C3 along the epithelial basement membrane zone using direct immunofluorescent staining. Electron microscopy confirmed the presence of deposits that were morphologically consistent with antigen-antibody complexes. These findings suggest that antigen-antibody (IgA) immune-complex deposition may provide an alternative pathogenetic mechanism to basement membrane zone autoantibody formation for development of progressive conjunctival scarring.
A 63-year-old man, in good health previously, developed swelling and erythema of the right upper eyelid which progressed to involve both eyelids and surrounding tissues. After one month, he had a 9.0 x 9.0 x 3.5 cm mass despite two attempts at incisional drainage and treatment with antibiotics. Multiple asymptomatic erythematosus nodules (2-3 cm in diameter) developed on his back, trunk, and arms four weeks after onset of the eyelid erythema and swelling. Biopsies of two upper back papules and the eyelid disclosed cutaneous T-cell lymphoma, a lymphoproliferative malignancy of thymus derived lymphocytes originating in the skin. Systemic chemotherapy resulted in a marked decrease in the ocular adnexal mass but lymphomatous meningitis and quadriplegia developed. The patient died four months later; an autopsy was not performed. This case demonstrates that cutaneous T-cell lymphoma may rarely have its initial manifestation as a rapidly enlarging eyelid tumor.
Calcium oxalate crystals stain with alizarin red S at a pH of 7.0 but not at a pH of 4.2. In contrast, calcium phosphate and calcium carbonate stain at a pH of both 7.0 and 4.2. This difference allows presumptive identification of calcium oxalate deposits. The identity of calcium oxalate can then be confirmed by its insolubility in 2M acetic acid, since both calcium carbonate and calcium phosphate are soluble. We have applied this procedure for several years and have found it to be a rapid, reliable, and technically simple procedure for distinguishing calcium oxalate from other calcium deposits.
Carcinoma metastatic to the choroid was diagnosed in three patients by cytopathologic examination of subretinal fluid. The specimen was obtained using a scleral depressor modified to allow controlled aspiration of subretinal fluid through a sharp, angled, 30-gauge needle. This new method provides a useful tool for accurate diagnosis of carcinoma metastatic to the choroid in cases where the diagnosis is in question.
Two cases of malignant syringoma of the eyelid are reported. The first patient, a 20-year-old woman, presented with a one year history of a slowly growing nodule in the left lower eyelid. The lesion recurred five months after excision, slowly grew over the ensuing two and one-half years, and was reexcised. The second case was an 18-year-old man who was first examined by an ophthalmologist because of a slowly enlarging, painless induration of his right lower eyelid for two years. Histologic examination of the excised lesions from both patients disclosed proliferated ducts lined by two layers of epithelium infiltrating the dermis and subcutaneous tissue; there was skeletal muscle and perineural invasion, but only minimal cellular atypia. Malignant syringomas are rare forms of sweat gland carcinoma, which most often occur on the upper lip and to our knowledge have not been reported on the eyelid. These tumors probably arise from eccrine ducts, are more common in women, and have a peak incidence in the fifth decade. The histologic feature that best indicates prognosis is the degree of cellular atypia. Patients with cytologically well-differentiated tumors do well following complete local excision. Features that help to distinguish malignant syringoma from its benign counterpart are the larger size, solitary nature, and subcutaneous, muscular, and perineural invasion.
Four patients who took the antitumor agent mitomycin manifested microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. At autopsy, kidneys from all four patients had a microangiopathy typical of the hemolytic-uremic syndrome (HUS), with thromboses in glomerular capillaries and arterioles, fibrin deposition in mesangium, and prominent cellular intimal proliferation of the interlobular arteries. Development of the HUS was an important factor contributing to death in all four patients. From a review of the literature and our initial results of a randomized chemotherapy protocol for metastatic adenocarcinoma of the colorectum, it appears that mitomycin was the most likely cause for the development of the HUS in these patients. As more patients are being treated with mitomycin, particular care must be taken to monitor them for development of a drug-induced HUS.
Studies were undertaken to determine the influence of diet on the hepatic mixed-function oxidase system in rats after portacaval anastomosis. Male rats fed either a cereal-based or purified diet underwent portacaval anastomosis. Weight gain after surgery was highly dependent on the diet. Because rats fed the cereal-based diet weighed 50% less at 4-5 wk after portacaval shunt surgery than unoperated controls fed the same diet, pair-fed unoperated controls were also studied. Rats fed the purified diet grew normally after shunting and therefore studies with this diet did not require pair-fed controls. Shunted rats fed the cereal-based diet had lower liver weights, hepatic microsomal protein concentrations, ethylmorphine N-demethylase, aniline hydroxylase, and cytochromes P450 and b5 when compared with corresponding values in unoperated controls fed the same diet ad libitum; comparisons with pair-fed controls indicated that decreased intake of the cereal-based diet could account for part but not all of the changes seen after portacaval anastomosis. It was shown in rats fed the purified diet that sham operation had no effect on the mixed-function oxidase system, whereas portacaval anastomosis resulted in reduced liver weight, microsomal protein, ethylmorphine N-demethylase, aniline hydroxylase, and cytochrome P450. In comparing shunted rats fed the two types of diet, in contrast with the effects of these diets in normal rats, these hepatic microsomal mixed-function oxidase system components were generally lower in the shunted rats fed the cereal diet. It is concluded that although decreased mixed-function oxidase activity occurs after portacaval anastomosis in the rat, the diet can have an additional substantial influence. Dietary influences on drug oxidations may be an important consideration in drug therapy after portacaval anastomosis.
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Explore the source record for details and available documents.