Perilesional Tissue Research Articles

???Ex vivo??? release of eicosanoid from human brain tissue

The specific mechanism underlying the genesis of vasogenic brain edema is still debated: the role of arachidonic acid is considered extremely important, as it is a possible activator of self-maintaining reactions enhancing the release of vasoactive and cytotoxic compounds. The relationship between arachidonic acid metabolism and brain edema has been studied primarily in brain tissue samples or in the extracellular fluid, whereas the residual capacity of perilesional tissue to synthesize and release eicosanoids has not been investigated. In the present study, perilesional samples of brain tissue were available from 4 patients operated on for brain metastasis, from 8 patients who had malignant neuroepithelial tumors, from 4 with meningiomas, and from 5 with subarachnoid hemorrhage. A brain edema index was calculated from the preoperative computed tomographic scan. The "ex vivo" method allowed determination of the residual capacity of endogenous arachidonic acid metabolism. The edema index is significantly higher in patients with brain metastasis (6.5 +/- 0.8) and neuroepithelial tumors (3.6 +/- 0.2) than in those with meningiomas (1.5 +/- 0.06), subarachnoid hemorrhage (1.7 +/- 0.18), and in controls. In patients with metastatic and neuroepithelial tumors there is a significant correlation between peritumoral brain edema and the capacity to synthesize leukotriene C4 (P less than 0.05); the capacity to synthesize leukotriene C4 is also significantly elevated after subarachnoid hemorrhage (13.91 +/- 2.6 ng/ml of incubation medium) when compared with control cases (5.56 +/- 0.91). The capacity to synthesize prostacyclin is significantly higher in patients with brain metastasis than in those with neuroepithelial tumors and meningiomas (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Immunodermatology Update: The Immunologically Mediated Vesiculobullous Diseases

Before a specific diagnosis of an immunologically mediated blistering disease can be made, the clinical and histologic features and the results of direct and indirect immunofluorescence studies (with use of multiple substrates in some cases) must be assessed. For both subepidermal and intraepidermal groups of blistering diseases, direct immunofluorescence testing of perilesional tissue is critical for diagnosis. For these conditions, indirect immunofluorescence testing of serum is important for diagnosis and has a role in management of selected diseases. In dermatitis herpetiformis, indirect testing of serum for IgA antiendomysial antibodies is useful for both diagnosis and management. Indirect testing of serum for IgG antibodies to intercellular substance is important for diagnosis and, in conjunction with the clinical findings, can be used as a guide for monitoring disease activity in patients with pemphigus. Immunoelectron microscopy, immunoprecipitation, and immunoblotting studies have identified the sites of immune deposits and the specific antigens in most of the immunologically mediated bullous diseases. From a practical standpoint, however, direct and indirect immunofluorescence testing, in conjunction with clinical and histologic evaluations, is a simple, rapid, and relatively inexpensive tool for diagnosis and management.

Blood–Brain Barrier Breakdown in Cold‐Injured Brain Is Linked to a Biphasic Stimulation of Ornithine Decarboxylase Activity and Polyamine Synthesis: Both Are Coordinately Inhibited by Verapamil, Dexamethasone, and Aspirin

An early increase in ornithine decarboxylase (ODC) activity and polyamine levels in rat cerebral capillaries was previously implicated in the mediation of blood-brain barrier (BBB) breakdown in cold-injured brain. A time course study in rat cerebrum indicated that cold injury evokes a biphasic increase in ODC activity and polyamine levels in perilesional cortex. ODC activity rose sharply (fourfold) within 1 min, remained elevated for 5 min, and then returned to the basal level by 10 min. A transient rise in polyamine concentration followed in the rank order of putrescine greater than spermidine greater than spermine. A secondary rise in ODC activity commenced in perilesional tissue at 2-6 h and peaked (8.8-fold) at 48 h. Major increases in the content of putrescine (330%), spermidine (103%), and spermine (50%) developed at 48-72 h. alpha-Difluoromethylornithine (DFMO), a specific irreversible inhibitor of ODC, suppressed the evoked increase in ODC activity and abolished the associated increase in content of polyamines, findings indicating that the accumulation of polyamines in cryoinjured brain reflects enhanced synthesis resulting from an ODC-mediated increase in putrescine content. Cycloheximide and actinomycin D were without effect on the early increase in ODC activity but inhibited the delayed increase in ODC activity, an observation suggesting that the initial increase in activity reflects an activation of a cryptic ODC via a posttranslational process, whereas the delayed increase in activity results from ODC synthesis mainly under transcriptional control.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial aneurysms: MR imaging.

MR studies of 17 patients with 19 intracranial aneurysms are reviewed. All patients also underwent CT and angiography. MR has been able to visualize the aneurysms in all cases. Aneurysms present various MR appearances because of flow characteristics, thrombosis in different stages of organization, calcific and ferric deposits. Based on MR signal changes it is possible to distinguish between flow effects and histopathological components such as thrombosis. Flow patterns are complex and sometimes it is difficult to define the cause responsible for intraluminal signal. MR allows a precise definition of perilesional brain tissue and demonstrates associated lesions. Angiography remains the definitive procedure in the diagnosis of small aneurysms, but shows only that part of the lesion in continuity with the circulation. MR clearly delineates the size, the residual lumen and the extra-axial location of giant aneurysms. In completely thrombosed aneurysms, when CT suggest a tumor, MR is able to demonstrate the vascular nature of the lesion.

Glycosaminoglycans in human breast cancer.

Abnormal concentrations of glycosaminoglycans (GAG) have been reported for various types of tumors, suggesting that they may play a role in neoplasia. The correlation between the content of individual GAGs was studied in breast tumor tissues. The total content of GAG was estimated by uronic acid analysis. The relative distributions of dermatan sulphate, heparan sulphate, hyaluronic acid and chondroitin sulphate were measured after cellulose acetate electrophoresis. Mammary tissue samples were obtained at the time of surgery from 11 women, 6 with fibroadenomata and 5 with carcinoma. From each patient, biopsies were obtained centrally in the tumor and perilesional areas adjacent to the tumor, and also from clinically uninvolved tissue in the same region. In the central areas, it was found that carcinoma had a significant increase in chondroitin sulphate and uronic acid content, and a significant decrease in dermatan sulphate content, as compared with fibroadenoma. The chondroitin sulphate content in perilesional carcinomatous tissue was significantly greater than in clinically uninvolved tissue.

(11) Oesophageal strictures in cicatricial pemphigoid

Cicatricial pemphigoid is a rare disease affecting the skin and mucous membranes. It is a disorder characterized by sub-epidermal blisters which heal with fibrosis and scarring. The diagnosis is confirmed by demonstration of immunoglobulins along the basement membrane of perilesional tissue using immunofluorescence. Ten patients with cicatricial pemphigoid who complained of dysphagia were investigated by barium swallow. An upper oesophageal stricture was demonstrated in eight of these. In the remaining two patients indirect laryngoscopy showed hypopharyngeal ulcers which could account for the dysphagia. A benign stricture of the upper third of the oesophagus is a rare finding and cicatricial pemphigoid should be recognized as a possible cause. The other clinical manifestations of cicatricial pemphigoid may be subtle. However, they can be seen on careful examination of the skin and mucous membranes which will enable the diagnosis to be made.

Lichen planus pemphigoides: Report of a case with oral lesions

Lichen planus pemphigoides is a rare condition characterized by the coexistence of lichen planus and bullous pemphigoid. Oral lesions have been reported but have not been studied immunopathologically. We describe a 59-year-old white man with cutaneous and oral lesions of lichen planus pemphigoides. Biopsies were done on these lesions, and the specimens were examined by routine light microscopy and immunofluorescent techniques. Fine keratotic striae on the anterior buccal mucosa were clinically consistent with oral lichen planus. Perilesional tissue associated with ulceration of the posterior buccal mucosa showed histologic and immunopathologic changes consistent with bullous pemphigoid.

On the pathology of meningiomas. A study of 412 cases.

Some pathological features of tumors arising primarily in the meninges are discussed on the basis of 412 surgically treated meningiomas during the period running from 1964 to 1978. Cases of meningeal sarcomas were not considered. Except for a few cases, pathology and clinical course have been generally in agreement. The incidence of histological types like meningotheliomatous, fibroblastic, angioblastic or atypical meningiomas has been verified in relation to sex, age and intracranial or spinal conventional locations. The problem of recurrencies has been studied either comparing the histological features with the first observation or comparing histopathological types with location and details of surgical procedure. Additional criteria like uni or multifocal origin of the tumors and histological features of the peri-lesional tissues, often harbouring small meningiomatous nests, have been taken into account.

Pemphigus: Current Concepts

Pemphigus is an autoimmune intraepidermal bullous disease involving the skin and mucous membranes. There are four clinically recognized variants of this disease. The histopathologic hallmark is acantholysis, which is disruption of normal cell-to-cell adhesion. Patients produce an IgG antibody directed against an antigen present in the intercellular substance of the epidermis. The antibody binds to the intercellular spaces in vivo and can be frequently detected in patients' sera. Immunofluorescent examination of perilesional tissue and serum is an extremely valuable diagnostic technique. Recently, pemphigus-like lesions have been produced in skin explants grown in tissue culture media enriched with pemphigus serum. Before corticosteroid therapy was available, pemphigus was a fatal disease. Steroids, and more recently immunosuppressive agents, have drastically improved the prognosis.

Epileptic activity and anatomical characteristics of different lesions in cat cortex. Ultrastructural study.

Three different types of lesions have been studied in the cortex of the cat, by means of electroencephalography and electron microscopy. These three types of lesions can be listed in order of increasing magnitude according to their capacity to induce abnormal electrical activity: 1. incision of the cortex gives paroxymal activity, 2. intracortical insertion of a resin pellet generates weak epileptic activity, 3. intracortical insertion of a colbalt resin pellet produces epileptic activity. A parallel can be drawn between electrophysiological and anatomical data: there seems to be a quantitative relationship between the degree of epileptic activity and the extent of perilesional tissue. Furthermore, in this perilesional tissue, oedema is observed, the intensity of which varies according to the type of lesion. Thus, the epileptic activity of a lesion seems to be proportional not only to the volume of the perilesional tissue but also to the development of the oedema.