Polyclonal 111In-IgG, 125I-LDL and 125I-endothelin-1 accumulation in experimental arterial wall injury

To test iodine-125 labelled low-density lipoprotein (¹²⁵I-LDL), polyclonal indium-111 labelled immunoglobulin G (¹¹¹In-IgG) and iodine-125 labelled endothelin-1 uptake in metabolically active atheromatous plaques after arterial wall injury, we performed balloon de-endothelialization of carotid arteries or abdominal aortas in 24 New Zealand male rabbits which were fed with a normal diet (n=14) or a hypercholesterolaemic diet (n=10) after surgery. Six weeks later the animals were injected with 200 Ci of (¹²⁵I-LDL), and/or with 100 Ci of ¹¹¹In-IgG or with 9 Ci of ¹²⁵I-endothelin-1. Forty-eight hours later the animals were sacrificed. Carotid arteries and aortas were removed, counted and fixed for autoradiography and light microscopy examination. Contralateral carotid arteries and thoracic aortas served as controls.Significant ¹¹¹In-IgG uptake was observed in the injured arteries at autoradiography, with localization mainly in the healing edges, and at well counting. The percentage of the injected dose per gram (%D.inj/g) was 0.0188±0.06 versus 0.0059±0.003 in controls (P< 0.05). There was no difference in ¹¹¹In-IgG uptake between arteries with injury alone and those with active atheroma formation at the site of the injury. Significant (¹²⁵I-LDL), uptake was observed only when lipid deposition was present at light microscopy (%D.inj/g of 0.0024±0.0005 vs 0.0010±0.0003 in controls, P < 0.05). ¹²⁵I-endothelin-1 accumulation was observed in four of five injured aortas both at autoradiography, with diffuse localization, and at well counting (%D.inj/g of 0.0012±0.0004 in the abdominal aortas vs 0.0008±0.0003 in the thoracic aortas).Polyclonal IgG may accumulate in injured arteries without active atheroma formation. Inflammatory reaction at the site of the injury may cause ¹¹¹In-IgG uptake independently of atheromatous plaque formation. LDL accumulation takes place only with active atheroma formation at the site of the injury. Use of labelled peptides such as endothelin-1 may provide further insight into the mechanisms of atheromatous plaque formation.     

The effect of taurine on motor behaviour,body temperature and monoamine metabolism in rat brain

Summary Taurine, a putative inhibitory neurotransmitter, was injected in various doses intracerebroventricularly to conscious rats via pre-implanted polythene cannulas. The formation of DOPA and 5-hydroxytryptophan (5-HTP) in various brain regions was investigated by measuring the accumulation of these monoamine precursors induced within 30 min by the intraperitoneal injection of 3-hydroxybenzyl hydrazine HCl (NSD 1015, 100 mg/kg), an inhibitor of the aromatic L-amino acid decarboxylase readily penetrating into the brain. DIPA formation, but not 5-HTP formation was significantly enhanced by taurine in dose-related manner in all brain regions studied, indicating an increased synthesis of both dopamine and noradrenaline. Dopamine depletion induced by -methyltyrosine was significantly retarded by taurine, whereas noradrenaline depletion tended to be enhanced. Endogenous levels of dopamine were increased, whereas the following brain constituents were unchanged: tyrosine, tryptophan, noradrenaline, 5-HT and 5-hydroxyindoleacetic acid. In the exoeriments with NSD 1015, a dose-related decrease in rectal temperature and in motility was observed after taurine treatment, as compared to treatment with the decarboxylase inhibotor alone. Systemic parenteral administration of taurine caused no significant changes in brain monoamines, body temperature or behaviour but decreased the heart noradrenaline levels. The data indicate that taurine, which apparently has to be given intracerebroventricularly in order to reach the brain in sufficient amounts, causes inhibition of firing in central dopamine neurons but has the opposite effect on noradrenaline neurons, perhaps also peripherally, whereas 5-HT neurons appear to be unaffected. In addition, taurine appears to interfere with motor behaviour and temperature regulation, possibly via effects on catecholaminergic systems.     

Computed tomography in the diagnosis of Creutzfeldt-Jacob disease.

Creutzfeldt-Jacob disease manifests clinically as a form of presenile dementia. It is now known to be caused by a transmissible agent, probably a "slow virus". Rapidly progressive atrophic changes on serial computed tomograms of the brain are highly suggestive of the disease. Neuroradiographic and pathological findings in two cases of Creutzfeldt-Jacob disease are documented.     

Anodontites trapesialis: A biological monitor of organochlorine pesticides

The mussel Anodontites trapesialis (Lam, 1819) was used as an indicator of organochlorine pollutants in the Pardo River, located in the municipality of Ribeirão Preto (21° 07S and 47° 45W), State of São Paulo, Brazil.Biological monitoring was performed for one year at the site of a sugar cane grove on the left bank of the river. Forty-three animals were placed in two aluminum enclosures on the river bottom at this site and 4 animals of each enclosure were sacrificed for pesticide analysis at 3-month intervals, each collection corresponding to one season of the year.The animals were found to have been exposed to DDT, lindane, heptachlor, aldrin and dieldrin. Endrin was not detected in any of the analyses.Research supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).     

Primary intracranial arachnoidal cysts

Sixty-seven cases (41 males and 26 females) of arachnoidal cysts in children under 11 years are reported. About 53% of cases were diagnosed before 1 year of life. Thirty-one (42.2%) were supratentorial (interhemispheric 9, temporal fossa 10, convexity 5, sylvian fissure 3, supra- and/or retrosellar 4); 31 (46.2%) infratentorial (supra- and/or retrocerebellar 22, foramen of Magendie 3, quadrigeminal cistern 5, pontocerebellar 1); 5 (7.5%) supra-and infratentorial. Macrocephaly was the presenting symptom in 48 cases (71.5%). Associated features were frequent: cranial asymmetry in 24; aqueductal stenosis in 10; agenesis of corpus callosum in 8; deficient cerebellar lobullation in 4; Chiari I malformation in 2; neurofibromatosis type 1 with dysgenetic zones of the brain in 1; arteriovenous malformation in 1. Diagnosis was made at autopsy in six cases in the days before computed tomography and magnetic resonance: three patients had a cyst in the supra-and retrocerebellar midline; two had a cyst in the quadrigeminal cistern and the sixth was a rare case with the cyst passing from the posterior fossa to the left lateral ventricle through a hole in the basal surface of the brain. Small and some middle-sized cysts were not treated. Big and some middle-sized cysts were usually treated by cysto- and/or ventriculoperitoneal shunts. Arachnoidal cysts of the quadrigeminal cistern usually present with aqueductal stenosis and have to be treated with ventriculoperitoneal shunt. Craniotomy and fenestration of the cysts were performed in some cases with good results. The average mental level of these children is usually moderately low.     

Avoiding hypothermia in trauma: use of the flameless heater pack, meal ready to eat, as a field-expedient means of warming crystalloid fluid

Forward-deployed medical units do not have the capability to warm intravenous (i.v.) fluids before their administration. We intend to demonstrate a field-expedient means of warming i.v. fluids and preventing hypothermia using the flameless heater available in the Meal, Ready to Eat (MRE). Room-temperature and refrigerated lactated Ringer's solution were organized into three data collection groups using either one or two MRE heaters. The temperature change of the fluid was recorded. Average temperature increases ranged from 15.8 to 31.2 degrees C in times ranging from 8 to 20 minutes. Therefore, we conclude that the flameless MRE heater provides a simple, field-expedient means of warming i.v. fluids before their administration.     

Left ventricular hypertrophy in hypertensive patients with autosomal dominant polycystic kidney disease: influence of blood pressure and humoral and neurohormonal factors

Left ventricular hypertrophy (LVH) is a common finding in hypertensive autosomal dominant polycystic kidney disease (ADPKD) patients. There are few studies on the influence of blood pressure (BP) and nonhemodynamic factors on LVH in these patients. The aim of this study was to evaluate the relationship between BP, humoral and neurohormonal factors and left ventricular mass (LVM) in hypertensive ADPKD patients. In 20 hypertensive ADPKD patients, ambulatory BP was monitored for 24 h, left ventricular dimensions were estimated by echocardiography, and plasma renin activity (PRA), plasma noradrenaline (NA), angiotensin II (Ang II), aldosterone, atrial natriuretic peptide (ANP) and insulin-like growth factor I (IGF-I) were also determined. Twenty age- and sex-matched essential hypertensive subjects served as controls. Ambulatory BP and LVM index were similar in the two groups, although male ADPKD patients had higher LVM indices than their matched controls. Eight ADPKD patients (40%) and 6 essential hypertensives (30%) showed LVH. PRA, Ang II, aldosterone, ANP and IGF-I levels were similar in the two groups, but plasma NA levels were higher in ADPKD patients than in controls (281 +/- 158 vs. 160 +/- 62 pg/ml, p = 0.004). ADPKD patients with LVH did not differ from those without LVH with regard to humoral and neurohormonal parameters, but had higher ambulatory BP levels. In ADPKD patients, correlation analysis revealed a significant association between LVM index and 24-hour systolic and diastolic BP, but not with any of the hormonal factors evaluated. On multiple regression analysis, 24-hour diastolic BP was the only independent variable linked to LVM index. In conclusion, ambulatory BP is one of the most important determinants of LVM in hypertensive ADPKD patients. Further studies are warranted to elucidate the role of nonhemodynamic factors in the pathogenesis of LVH in this population.     

Conformal index and radiotherapy]

Goal of radiotherapy is to treat patient with the best therapeutic ratio, i.e. the highest local control and the lowest toxicity rates. The conformal approach, three-dimensional conformal radiotherapy or intensity-modulated radiotherapy, is based on imageries, up-dated 3-D treatment planning systems, immobilization systems, restricted quality assurance and treatment verification. The aim is to ensure a high dose distribution tailored to the limits of the target volume, while reducing exposure of normal tissues. The evaluation tools used for optimizing treatment are the visual inspection of the dose distribution in various planes, and the dose-volume histograms, but they do not fully quantify the conformity of dose distributions. The conformal index is a tool for scoring a given plan or for evaluating different treatment plans for the same patient. This paper describes the onset and evolution of conformal index and his potential application field.