Relationships between γ-aminobutyrate and succinate cycles during and after cerebral ischemia

Some metabolites (glycogen, glucose, glucose-6-phosphate, pyruvate, lactate, citrate, α-ketoglutarate, succinate, fumarate, malate, glutamate, aspartate, γ-aminobutyrate, glutamine, alanine, NH⁺₄) were measured in rat cerebral cortex after 5 minutes of complete compression ischemia, as well as after 5, 15, or 30 minutes of recirculation following 5 minutes of ischemia. Complete ischemia induced a drop of glycolytic substrates and intermediates, consistent with the increase of lactate, succinate, alanine, and γ-aminobutyrate, and with the decrease of malate, fumarate, and α-ketoglutarate. These events may be regarded as an expression of the activation of the γ-aminobutyrate cycle and of the succinate cycle, where succinate itself, in the absence of O₂, acts as a terminal electron acceptor. During post-ischemic recovery, cerebral parameters tended to normalize, except for the further increase of alanine and the still higher than normal content of both succinate and γ-aminobutyrate, as an expression of the possible activation of the γ-glutamyl and γ-aminobutyrate cycles during recovery.     

A rare condition of Hand-Schüller-Christian disease

The authors present the clinical case of a 61-year-old patient with Hand-Schüller-Christian disease associated with multisystemic involvement. The onset of such puzzling symptoms and the extremely rarity of this disease in a patient of such advanced age resulted in a delayed diagnosis and subsequently delayed treatment of the patient.     

Therapeutic vaccination with MVA E2 can eliminate precancerous lesions (CIN 1, CIN 2, and CIN 3) associated with infection by oncogenic human papillomavirus

Human papillomavirus (HPV) infection is associated with cervical cancer. Papillomaviruses can induce diseases ranging from warts and condylomata to lesions that can progress to malignant neoplasias. Cervical cancer is a serious problem in developing countries because it is usually not detected at an early stage. In Mexico, a woman dies every 2 hr from this malignancy. In a phase I/II clinical trial, we evaluated the potential use of the MVA E2 recombinant vaccinia virus to treat cervical intraepithelial neoplasia CIN 1, CIN 2, and CIN 3 lesions associated with human papillomavirus (HPV) infection. Seventy-eight women with CIN 1-, CIN 2-, and CIN 3-grade lesions were treated with either an MVA E2 recombinant virus vaccine or with cryosurgery. Thirty-six women received the recombinant virus vaccine at a total of 10(7) MVA E2 virus particles injected directly into the uterus once every week over a 6-week period. Forty-two patients were treated with cryosurgery. Reduction of lesions was monitored weekly by colposcopy and cytologic analysis. The type of immune response after MVA E2 injection was determined by measuring antibody titers against MVA E2 virus and the E2 protein, and by the presence of cytotoxic activity against cancer cells bearing papillomavirus DNA. The presence of papillomavirus was determined by with the hybrid capture method. Thirty-four of 36 patients showed complete elimination of precancerous lesions after treatment with the MVA E2 vaccine. In two patients, precancerous lesions were reduced from grade CIN 3 to CIN 1. Three other patients presented isolated koilocytes after treatment with MVA E2. Colposcopy revealed no lesions in 85% of patients, and only small aceto-white spots were detected in 15% of patients after treatment with MVA E2. All patients developed antibodies against the MVA E2 vaccine, and vaccination generated a specific cytotoxic response against HPV-transformed cells. Furthermore, 50% of patients showed no evidence of papillomavirus after treatment with MVA E2, while the remaining 50% showed persistence of HPV DNA, but at approximately only 10% of the original viral load. The presence of cells cytotoxic to HPV-transformed cells, and the generation of antibodies against MVA E2, correlated with the elimination of lesions and with a remarkable reduction of HPV viral load in all patients treated with MVA E2. Additionally, the MVA E2 vaccine did not produce any apparent side effects in any of the patients treated. Cryosurgery eliminated the lesions of CIN 1 in all patients, but patients so treated did not develop cytotoxic activity against cancer cells. These results show that therapeutic vaccination with MVA E2 vaccine is an excellent prospective means for stimulating the immune system and causing the regression of precancerous CIN 1, CIN 2, and CIN 3 lesions when the vaccine is given locally.     

Tolerance to calcitriol and tacalcitol in three patients with allergic contact dermatitis to calcipotriol

We describe 3 cases of psoriatic patients who developed a severe eczematous eruption after the use of calcipotriol ointment. For all of them, the dermatitis recovered after the suspension of the calcipotriol ointment and topical application of corticosteroids. We performed patch tests with the standard series of SIDAPA (Italian Society of Environmental, Occupational and Allergological Dermatology), with an integrative series of vehicles and preservatives, with the commercial ointment containing calcipotriol, with its excipients and, finally, with a series of diluted calcipotriol in isopropanol and petrolatum. They all revealed a strong allergic reaction to calcipotriol and also to its dilution in isopropanol (for all patients) and in petrolatum (only one patient). It is interesting to underline that the reactions always occurred on the legs, even if the patients had applied the ointment elsewhere. We can hypothesize that the venom stasis dermatitis of the legs, associated with xerosis, may have favored the penetration of the drug through the skin, increasing the risk of allergic contact sensitization. Finally, cross-reactivity to other vitamin D3 analogue, tacalcitol, and calcitriol was excluded.     

The pathobiology of endothelin-1 in vein graft disease: are ETA receptor antagonists the solution to prevent vein graft failure?

Despite the exploration of a large number of disparate drugs in animal models and clinical trials, no pharmacological intervention, with the exception of aggressive lipid lowering therapy has reduced late vein graft failure in man. The importance of devising more effective strategies is exemplified by the considerable economic consequences of vein graft failure. Worldwide, there are currently more than 1,000,000 coronary artery bypass graft surgery (CABG) operations a year, the same number of patients undergoing infrainguinal bypass (IIBS) for vascular diseases of the lower limb. The pathophysiology of vein graft failure is complex, involving disparate factors that include adhesion of platelets and leukocytes, rheological forces, metalloproteinase expression, proliferation and migration of vascular smooth muscle cells, neointima formation, oxidative stress, hypoxia and neural re-organisation. Although this diverse aetiology may seem to preclude any single drug type as being effective in preventing vein graft failure, one factor that is involved in every facet of vein graft pathobiology is endothelin-1 (ET-1). Thus, in this review, we will consider the diverse aetiology of vein graft disease in relation to ET-1 and will then present an argument (with evidence) that ET-1(A) (ET(A)) receptor antagonists constitute a potentially effective means of preventing vein graft failure.     

Confocal microscope analysis and tridimensional reconstruction of papillary thyroid carcinoma nuclei

Nuclei of papillary thyroid carcinoma (PTC) are characterised by diagnostic morphological features, which include optically clear nuclei, irregular nuclear profile, pseudoinclusions and grooves. In the present study, such nuclear features were analysed by means of confocal microscopy using anti-lamin B antibodies to outline the nuclear membrane. Parallel sections of the nucleus, produced by confocal microscope analysis, showed that the nuclear shape is markedly irregular with profound invaginations, clefts and tunnel-like structures, which correspond to the grooves and holes detectable using light microscopy, respectively. A tridimensional (3-D) model of the nuclei, obtained by a computer-based reconstruction of confocal microscope images, showed, in the vast majority of PTC cells, nuclei with crateriform areas, clefts and even tunnel-like structures piercing the whole nuclear thickness. By rotating these models in space, it became evident that the holes and grooves seen in light microscopy correspond to invaginations and tunnels, depending on the viewpoint. In conclusion, this is the first application of confocal microscopy and tridimensional reconstruction to the study of nuclear morphology of PTC and of tumours in general. The light microscopic appearance of PTC nuclei, so familiar to pathologists, is, therefore, due to profound remodelling of the nuclear shape with invaginations and tunnels, which appear as either grooves or holes, according to the viewpoint.