Characterization of angiotensin binding in the African Green monkey

The observation that there are differences in the characteristics and distribution of angiotensin receptors in the central nervous system of mammalian species led to the analysis of angiotensin binding in a primate model, the African Green monkey. Initial studies using [¹²⁵I]angiotensin II ([¹²⁵I]AII) as the radioligand showed binding in peripheral tissues but little binding in the central nervous system. Conversely, binding studies using [¹²⁵I]AIII as the radioligand indicated more central nervous binding with diminished peripheral binding. Specific binding of [¹²⁵I]AIII is evident throughout the brain with high binding in the circumventricular organs, striatum, caudate nucleus, olfactory bulb and localized areas of the thalamus and cerebral cortex. This binding was found to posses many of the properties commonly associated with binding to membrane-bound receptors. The specifically bound radioligand extracted from incubations of [¹²⁵I]AIII and central nervous tissue appears to be a product of the metabolism of [¹²⁵I]AIII rather that the peptide itself. Binding of [¹²⁵I]AII does occur in peripheral tissues and to a limited extent in the cerebellum, but to a different receptor from that characterized using [¹²⁵I]AIII. These results are similar to those seen in the gerbil and raise questions concerning the utilization of the rat as the primary model for studying the biochemistry of the brain-angiotensin system in humans.     

The anticardiolipin syndrome

Anticardiolipin antibodies delineate a recently defined syndrome characterized by venous and arterial thrombosis, thrombocytopenia and recurrent fetal loss, usually in the setting of autoimmune disease. A recently standardized enzyme immunoassay for this antibody is becoming widely available. Treatment is controversial and includes prednisone and aspirin in pregnant patients. Anticoagulation therapy has been recommended for thrombosis. The roles of plasmapheresis and cytotoxic agents have not yet been defined.     

An ultrastructural analysis of vascular leiomyoma of the bladder

We report a case of vascular leiomyoma of the bladder in a 62-year-old man. To our knowledge, this is the first ultrastructural study published on vascular leiomyoma of the bladder. The tumoral cells reproduced the smooth muscle cells. The vascular structures corresponded to capillaries and arterioles. We consider that the vascular component is not tumoral and its origin is related to mast cells.     

Amputation neuroma of the orbit. Report of two cases and review of the literature

Two patients developed proptosis and a slowly enlarging mass with increasing discomfort in the orbital socket 17 and 25 years following enucleation. Preoperative CT scans revealed a single cystic structure within the orbits of each case with distinct soft tissue tumors adjacent to the cysts. The cystic structures and the adjacent solid masses were removed en bloc necessitating reconstruction of the orbits with a dermal fat pad (case 1) and a mucous membrane graft (case 2). Postoperatively the patients were free of complaints. Microscopically, the cystic structures were identified as conjunctival inclusion cysts while the soft tissue masses were traumatic neuromas with irregular tangles and whorls composed of proliferated axons, Schwann cells and connective tissue. Only seven amputation neuromas of the orbit have been reported. Pain related to the neuroma is rarely encountered and is probably caused by mechanical irritation of the amputation neuroma, by retracting scar tissue, or compression from an adjacent cystic mass as in one of our cases.     

Beneficial effect of N-acetyl-cysteine on renal injury triggered by ischemia and reperfusion

Reactive oxygen species are critical mediators of the early phase of ischemic (IR) injury. The contribution of antioxidants, such as N-acetyl-cysteine (NAC), in ameliorating the parenchymal lesions, inflammatory parameters, and functional variables in renal IR is still controversial. We studied the effect of NAC administration on renal injury induced by IR. Mice were subjected to renal pedicle occlusion and subsequent reperfusion for 24 or 120 hours. NAC was administered prior to surgery at two concentrations (40 or 300 mg/kg, i.p.). Renal function and acute tubular necrosis were assessed, as well as immune phenotyping of infiltrating cells, by flow cytometry. At 40 mg/dL of NAC, we did not observe any significant improvement in renal function (1.85 +/- 0.43 md/dL, P = .367) or tissue architecture (% of ATN: 2.51 +/- 0.27 mm, P = .852) compared to the controls (1.87 +/- 0.43 mg/dL and 3.12 +/- 0.34 mm, respectively). However, animals that received 300 mg/dL of NAC showed lower serum creatinine values (24 hours: 1.25 +/- 0.54 mg/dL) compared to controls (P = .009) and less extensive acute tubular necrosis (1.54 +/- 0.12 vs, P < .05). Treatment with 300 mg/dL of NAC decreased renal dendritic cell infiltration. The protective effect of NAC was better observed at high concentrations and early times.     

Bis-(2-ethylhexyl) phthalate, an ubiquitous environmental contaminant

Bis-(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizing agent for the widely used plastic polyvinylchloride (PVC). Consequently, this compound is found everywhere in the environment of civilization, where it is in frequent contact with every person. Blood storage bags and tubing, food wrappers, and many children's toys contain appreciable amounts of DEHP. Given this frequency of exposure, the toxic potential of the compound has become a major concern. Many workers have demonstrated its exceedingly low acute toxicity, while results from chronic exposure studies have been mixed. However, in 1982 the National Toxicology Program reported a significantly increased incidence of hepatocellular carcinoma in rats and mice exposed to high doses of DEHP over a period of two years. The significance of these studies remains in question. Bis-(2-ethylhexyl) phthalate is metabolized extensively by mammals, but reports of the direct study of the toxic effects of its metabolites are few. Efficient methods for analysis of biological samples for DEHP are available, but they are complicated by the constant presence of this compound as a contaminant.     

Investigation of epidemiology of neurotrauma in the Republic of Guinea

The paper focuses on analysis of incidence of neurotrauma in economically underdeveloped country such as Republic of Guinea. It is found that leading etiology of central nervous system injuries are road accidents and indoor traumatism. Investigation of system of medical care revealed its poor condition and severe defects which prevent practical application of evidence-based recommendations for management of traumatic brain injury in underdeveloped countries including Republic of Guinea. Development of multiplanar strategy of control of neurotrauma is required which can be achieved only in case of massive governmental and international aid.