Magnetic and elemental characterization of the particulate matter deposited on leaves of urban trees in Santiago, Chile.

Airborne particulate matter is a serious threat to human health, especially in fast-growing cities. In this study, we carried out a magnetic and elemental study on tree leaves used as passive captors and urban dust from various sites in the city of Santiago, Chile, to assess the reliability of magnetic and elemental measurements to characterize particulate matter pollution from vehicular origin. We found that the magnetic susceptibility and saturation isothermal remanent magnetization measured on urban tree leaves is a good proxy for tracing anthropogenic metallic particles and allow controlling the exposure time for particulate matter collection, in agreement with other studies carried out in large cities. Similar measurements on urban soil can be influenced by particles of detritic (natural) origin, and therefore, magnetic measurements on tree leaves can help to identify hotspots where fine particles are more abundant. Elemental particle-induced X-ray emission analysis of tree leaves showed the presence of a number of elements associated with vehicular emissions, in particular Cu, Zn, Fe, K and S which are present at every site, and As, Se, V, Ni, Sr, Zr, Mo and Pb identified at some sites. We observed a correlation between magnetic parameters and the concentrations of S and Br as well as Cu to a smaller extent. Moreover, this study shows the importance of selecting carefully the tree species as well as the location of trees in order to optimize phytoremediation.

Proyecto de fabricación de generadores de tecnecio - 99m / A project to manufacture technetium-99m generators

Introducción. El Tecnecio-99m (99mTc) es el radioisótopo más utilizado en medicina nuclear. Su uso en diagnóstico permite visualizar imágenes de estructuras anatómicas y brindar información sobre distintas funciones orgánicas. La gran demanda de este radionucleído se debe a sus favorables propiedades nucleares, a la gran cantidad de compuestos que se pueden marcar con él y al hecho de poder contar con generadores de 99mTc, lo que posibilita su obtención en lugares alejados de los centros de producción. Un generador de radioisótopos es un sistema mediante el cual un radionucleído padre genera por decaimiento radiactivo un radionucleído hijo de vida media más corta que la del padre. En el caso del generador de 99mTc, el radionucleído padre es el Molibdeno-99 (99Mo) cuya vida media es de 66 horas, mientras el radionucleído hijo, el 99mTc, tiene una vida media de 6 horas. Objetivo. La Comisión Chilena de Energía Nuclear (CCHEN) a través del Laboratorio de Producción de Radioisótopos realiza diariamente una producción de 99mTc, la cual entrega a Centros de Medicina Nuclear de la Región Metropolitana. Siin embargo, debido al método por el cual se obtiene, no es posible abastecer a los Centros de Medicina Nuclear de provincias. Conciente de esta necesidad, la CCHEN ha decidido poner en marcha el proyecto de fabricación de generadores de 99Mo - 99mTc, con lo cual nos situaremos en un breve plazo dentro del contexto de países que ya poseen esta tecnología. Materiales y Método. El método de fabricación se basa en la adsorción selectiva del 99Mo en óxido de aluminio (Al2O3 ), mientras el 99mTc que se genera por decaimiento radiactivo del 99Mo y que está débilmente unido a la alúmina, se puede eluir diariamente. Este tipo de generador es simple de operar y está diseñado en un sistema cerrado que permite mantener la esterilidad y proporcionar un producto de alta pureza. Resultados y Conclusión. La preparación de la alúmina, el acondicionamiento del Mo y las característica...

Comparación de los niveles séricos de óxidos nítrico y malondialdehído en pacientes con pie diabético con o sin infección / Comparison of serum nitric oxide and malondialdehyde levels in patients with infected and non infected diabetic foot

La patogenia de la infecciones del pie diabético involucra la polineuropatía, la enfermedad macro y microvascular y el déficit funcional de los neutrófilos. La vasodilatación dependiente del endotelio, relacionada con el Oxido Nítrico (NO), está comprometida en diabéticos predispuestos a ulceración del pie. El NO, es producido también por neutrófilos y macrófagos estimulados por citoquinas o lipopolisacáridos bacterianos mediante la sintetasa de NO inducible (iNOS), ejerciendo actividad microbicida. La peroxidación lipídica reflejada por la producción de malondialdehido (MDA), está implicada en el desarrollo de microangiopatía diabética. Para comparar los niveles séricos de NO y MDA en pacientes con pie diabético con o sin infección, se estudiaron 27 individuos diabéticos tipo 2 con edades entre 38 y 65 años divididos en 3 grupos: 8 controles sin afección de los pies (A), 10 con pie diabético sin infección (B) y 9 con pie diabético infectado (C). El NO fué determinado mediante ensayo de diazotización y el MDA mediante la relación de Acido Thiobarbitúrico. B y C mostraron niveles de NO menores (p= 7.636 x 10-5 y p= 0,006) que A. El NO fue mayor en el grupo infectado que en el grupo sin infección (p=0,05), sin embargo los valores obtenidos no coinciden con lo esperado teniendo en cuenta las grandes cantidades de NO producido mediante iNOS, sugiriendo un defecto más del leucocito del diabético. No hubo diferencia significativa en el MDA entre los grupos, indicando ausencia de stress oxidativo relevante

The formation and regression of a flow-related cerebral artery aneurysm.

The authors report a patient with an aneurysm of the right cerebral posterior communicating artery (PCoA) developing after thrombotic pseudo-occlusion of the right internal carotid artery (ICA). The aneurysm regressed spontaneously subsequent to ipsilateral ICA endarterectomy and reversal of blood flow in the PCoA. The formation and regression of the aneurysm was well documented by repeat cerebral digital subtraction angiography studies, computed tomography and magnetic resonance imaging. The authors conclude that the formation and regression of this 'flow-related' aneurysm was associated with hemodynamic changes in blood flow of the right PCoA and the right ICA.

Role of prostaglandins in hypertension.

The role of prostaglandins (PGs) in hypertension (HT) is reviewed, emphasising their biochemical characteristics, physiological effects and functions, especially in the cardiovascular area, and the current evidence of their participation in the antihypertensive activity of a balanced mechanism to maintain normal blood pressure. Also, the clinical use of PGs and the future of such autacoids in the treatment of HT and other diseases or conditions is mentioned.

Movement disorders following nonfunctional neurosurgery.

OBJECT: Knowledge is scarce about movement disorders that follow neurosurgical operations other than functional stereotactic surgery. The cases of 14 patients who suffered from movement disorders secondary to craniocerebral or spinal surgery are analyzed. None of these patients was initially treated by any of the authors. METHODS: Twelve patients underwent surgery for cerebral diseases. Nine of these patients harbored tumors and three patients had neurovascular disorders. Two patients underwent spinal surgery for cervicothoracic ependymoma or for multiple cervical disc herniations. Twelve of the 14 patients had immediate postoperative side effects such as hemiparesis, ataxia, and somnolence. In all but two patients, movement disorders became manifest only after a delay. Dystonic movement disorders developed in eight patients, unilateral tremors in three patients, unilateral facial myokymia in one patient, and hemichorea-hemiballism in two patients. The mean delay of onset for tremor was 5 weeks and that for dystonic movement disorders was 5.5 months. Movement disorders were transient in three patients; however, they were persistent in 11 patients at a mean follow-up period of 5 years. These movement disorders caused marked persistent disability in four patients. Lesions of the contralateral striatum were identified in patients with dystonic syndromes and lesions of the dentatothalamic outflow in patients with tremors. In three patients who had postoperative basal ganglia lesions after partial removal of astrocytomas, tumor regrowth was later documented. Medical treatment in patients with persistent movement disorders rendered only limited benefit. Two patients improved with botulin injections. In one patient postoperative hemidystonia was alleviated by contralateral thalamotomy. CONCLUSIONS: Dystonic syndromes and tremors are the most common movement disorders that occur after craniocerebral and spinal surgery. Postoperative movement disorders can lead to various degrees of functional disability. The pathoanatomical correlations are similar to those described in other patients with secondary movement disorders.

MR angiography with ultrashort echo time in cerebral aneurysms treated with Guglielmi detachable coils.

We evaluated a time-of-flight three-dimensional MR angiographic sequence with an ultrashort echo time for its ability to characterize the perfusional state of cerebral aneurysms that had been treated with Guglielmi detachable coils and to depict adjacent cerebral arteries. The results were compared with findings at conventional MR angiography and digital subtraction angiography. Adjacent vessels were seen better in 36% of patients imaged with the new technique. Both MR angiographic methods detected residual cerebral aneurysmal perfusion with a tendency to overestimate the patent portion of the aneurysm.

Reduced endothelial nitric oxide synthase expression and production in human atherosclerosis.

BACKGROUND: NO regulates vascular tone and structure, platelets, and monocytes. NO is synthesized by endothelial NO synthase (eNOS). Endothelial dysfunction occurs in atherosclerosis. METHODS AND RESULTS: With a porphyrinic microsensor, NO release was measured in atherosclerotic human carotid arteries and normal mammary arteries obtained during surgery. eNOS protein expression was analyzed by immunohistochemistry. In normal arteries, the initial rate of NO release after stimulation with calcium ionophore A23187 (10 micromol/L) was 0.42+/-0.05 (micromol/L)/s (n=10). In contrast, the initial rate of NO release was markedly reduced in atherosclerotic segments, to 0.08+/-0.04 (micromol/L)/s (n=10, P<0.0001). NO peak concentration in normal arteries was 0.9+/-0.09 micromol/L (n=10) and in atherosclerotic segments, 0.1+/-0.03 micromol/L (n=10, P<0.0001). Reduced NO release in atherosclerotic segments was accompanied by marked reduction of immunoreactive eNOS in luminal endothelial cells, although specific endothelial cell markers (CD31) were present (n=13). Endothelial cells of vasa vasorum of atherosclerotic segments, however, remained positive for eNOS, as was the endothelium of normal arteries. CONCLUSIONS: In clinically relevant human atherosclerosis, eNOS protein expression and NO release are markedly reduced. This may be involved in the progression of atherosclerosis.

[Surgical versus medical treatment of idiopathic trigeminal neuralgia]. / Chirurgische versus medikamentöse Behandlung der idiopathischen Trigeminusneuralgie ("tic douloureux").

The primary treatment of idiopathic trigeminal neuralgia is medical. Surgery is reserved for unresponsive patients or in case of long lasting, tedious or dangerous side effects of the medication. The surgeon has to inform the patient about risks and benefits of the different surgical methods and consider the patient's expectations and fears in order to choose the best surgical alternative. We describe the clinical picture of trigeminal neuralgia, the steps leading to the diagnosis. We also discuss the pathogenesis and the different treatment modalities with emphasis on surgical methods.

[Special technics for angioplasty of the brachiocephalic vessels]. / Spezielle Techniken der Angioplastie brachiozephaler Gefässe.

PURPOSE: Description of special techniques for retrograde angioplasty of cerebral arteries with protection of the brain. MATERIAL AND METHOD: During the last 3 years, 51 dilatations of cerebral vessels were carried out in 45 patients; in 8, special techniques were required. In cases with particular operative risks, angioplasty of cerebral vessels can be performed using various techniques (double catheter [8 cases], retrograde PTA [8 cases], kissing balloon technique [3 cases]). RESULTS: All stenoses were successfully dilated, using a local anaesthetic. One patient with a double stenosis of the common carotid artery developed severe headache and visual disturbances in the ipsilateral eye following dilatation of a tight stenosis with total remission of all symptoms within 24 hours. CONCLUSION: Stenoses of cerebral arteries where surgery would be difficult and associated with a high risk can be dilated by retrograde PTA using a double catheter technique with a low complication rate.

Human connective tissue growth factor is expressed in advanced atherosclerotic lesions.

BACKGROUND: Atherosclerosis affects certain but not all vascular beds of the human circulation. Its molecular mechanisms are only partially understood. Human connective tissue growth factor (hCTGF) is a novel cysteine-rich, secreted polypeptide. hCTGF is implicated in connective tissue formation, which may play an important role in atherosclerosis. METHODS AND RESULTS: By using a differential cloning technique, we isolated a cDNA clone from a human aorta cDNA library, which is identical to hCTGF. Northern analysis shows that hCTGF mRNA was expressed at 50- to 100-fold higher levels in atherosclerotic blood vessels compared with normal arteries. In vascular smooth muscle cells, high-level expression of hCTGF mRNA was induced by transforming growth factor-beta 1. Using in situ hybridization and immunohistochemistry, we found that all advanced atherosclerotic lesions of human carotid arteries (eight patients; mean age, 69; age range, 57 to 85 years) and femoral arteries (two patients; mean age, 71.5 years) that we tested expressed high levels of both hCTGF mRNA and protein. hCTGF expression was localized mainly to smooth muscle cells in the plaque lesions that are negative for proliferating cell nuclear antigen staining. In addition, some CD-31-positive endothelial cells of plaque vessels expressed high levels of hCTGF mRNA and protein. hCTGF-positive cells were found predominantly in areas with extracellular matrix accumulation and fibrosis. In contrast, in normal arteries, we were unable to detect either hCTGF mRNA or immunoreactive hCTGF protein. CONCLUSIONS: In the present study, we have shown for the first time that both hCTGF mRNA and protein are expressed in human arteries in vivo and that hCTGF may represent a novel factor expressed at high levels specifically in advanced lesions and may play a role in the development and progression of atherosclerosis.

[Brain tumors of the posterior fossa in childhood. An overview of the patients of the medical university hospital's pediatric department Berne in the years 1990-1994]. / Hirntumoren der Fossa posterior im Kindesalter. Eine Uebersicht der Patienten der Medizinischen Universitäts-Kinderklinik Bern in den Jahren 1990 bis 1994.

During the time period 1990 to 1994 the mean incidence of pediatric brain tumors in Switzerland reached 2.78 new cases per 100,000 children under 16 years of age per year. In the same time period 33 children (18 male, 15 female) were newly diagnosed at the University Hospital of Berne with a tumor located in the posterior fossa. Ten (31%) had a medulloblastoma, nine (27%) an astrocytoma, six (18%) a brain-stem glioma, four (12%) an ependymoma, and four (12%) had other tumor types. Besides typical signs and symptoms of increased intracranial pressure, cranial nerve palsies or visual problems were frequently found (in 70% and 30% of the patients, resp.). The median time interval between the first symptoms and the definite diagnosis was four months. Central in the therapeutic approach remained the neurosurgical removal of the tumor, which was realized in 85% of the cases. As adjuvant weapons, radiotherapy and/or chemotherapy (in 45% and 48.5%, resp.) were used with curative aims. Globally 16 of the 31 evaluable children 51%) survived disease-free at the time of evaluation with a median survival of 42 months. The two-year survival rates were 83% for astrocytoma, 50% for ependymoma, 46.5% for medulloblastoma and 40% for brain-stem glioma. These observations emphasize the prognostic significance of histology in pediatric brain tumors.

Noninvasive differentiation of meningiomas from other brain tumours using combined 111Indium-octreotide/99mtechnetium-DTPA brain scintigraphy.

We have studied prospectively 47 patients with CNS tumours including 16 meningiomas and 33 other tumours using combined 111In-octreotide and 99mTc-DTPA brain scintigraphy. 111In-octreotide scintigraphy was used to image somatostatin receptors (SSR) and 99mTc-DTPA scintigraphy was used to assess the integrity of the blood-brain barrier (BBB). A total of 32 tumours (65%) were detected. All SSR positive tumours also had positive 99mTc-DTPA scans and all SSR negative tumours were negative on 99mTc-DTPA scans. Among the tumours located outside the BBB, all meningiomas and two out of six schwannomas were positive on combined SSR/99mTc-DTPA scintigraphy. Among the tumours located inside the BBB, seven out of nine gliomas grade I-III were negative, whereas all glioblastomas were positive. Other positive tumours included one malignant non-Hodgkin lymphoma and two cerebral metastases. SSR scintigraphy alone was non-specific in the diagnosis of meningiomas, as 16 non-meningiomatous tumours also had positive SSR scans probably due to a breakdown of the BBB (excluding the malignant lymphoma). Measuring the tumour-to-background ratio on SSR scans improved specificity, but sensitivity was decreased below 70% because some meningiomas were only slightly positive. Only the ratio of SSR scintigraphy to conventional 99mTc-DTPA brain scintigraphy (SSR-to-BS index) allowed a reliable differentiation of meningiomas from other CNS tumours, most notable from schwannomas (sensitivity: 94%; specificity: 100%). Our results support the usefulness of combined SSR and conventional brain scintigraphy in the noninvasive pre-operative diagnosis of meningiomas.

Extended anterior subcranial approach for skull base tumors: long-term results.

The extended anterior subcranial approach differs significantly from more traditional surgical approaches to the skull base in that it allows a broad inferior access to the anterior skull base planes with tumor exposure from below rather than via the transfrontal route. The authors initially used the subcranial approach in 1978 for the treatment of high-velocity skull base trauma and certain craniofacial anomalies. In 1980 they expanded the indications to include the combined neurosurgical-otolaryngological resection of various skull base tumors. Osteotomy of the frontonasoorbital external skeletal frame provides optimum anterior access to the orbital and sphenoethmoidal planes as well as to the nasal and paranasal cavities while avoiding frontal lobe retraction and the external facial incisions characteristic of transcranial and transfacial approaches. The improved visualization of the anterior skull base and clival-sphenoidal region facilitates en bloc tumor removal, optic nerve decompression, exposure of the medial aspect of the cavernous sinus, and watertight realignment of the anterior cranial base dura. In this report the authors present their experience over the past 13 years with 104 patients who underwent operation via the extended subcranial approach. Because extensive frontal lobe manipulation and external facial incisions are avoided with this approach, intensive care unit and overall hospital stay are reduced, related complications are minimized, and postoperative cosmetic appearance is enhanced. The extended anterior subcranial method is therefore an excellent alternative to traditional transfacial-transcranial skull base approaches for the removal of selected skull base tumors.

Somatostatin receptor scintigraphy in central nervous system tumors: role of blood-brain barrier permeability.

UNLABELLED: Somatostatin receptors are expressed in meningiomas and low-grade gliomas, raising the hope that scintigraphy with 111In-DTPA-D-Phe1-octreotide might be helpful in the in vivo localization, differential diagnosis and postoperative/postradiotherapy brain tumor follow-up. METHODS: Indium-111-DTPA-D-Phe1-octreotide scintigraphy and brain scintigraphy using 99mTc-DTPA as a nonspecific tracer for blood-brain barrier integrity were simultaneously performed in 60 patients with CNS tumors using dual-isotope acquisition mode SPECT. For 23 patients, the scintigraphic findings were also compared with in vitro somatostatin receptor autoradiography of surgical biopsy specimens. RESULTS: In meningiomas (located outside the blood-brain barrier), the somatostatin receptor scan showed all tumors and scintigraphic signal intensity correlating with in vitro SSR density positive in all meningiomas. Less contrast was seen on 99mTc-DTPA scans. In all tumors inside the blood-brain barrier, the 111In-DTPA-D-Phe1-octreotide scan visualized the tumors with a disrupted blood-brain barrier, as seen by 99mTc-DTPA scintigraphy. Discrepancies, however, were observed between somatostatin receptor scintigraphy and in vitro receptor autoradiography. CONCLUSION: Combined somatostatin receptor and 99mTc-DTPA scintigraphy may be helpful for noninvasive differentiation between meningiomas and other CNS tumors. False-negative scans were observed as a result of shielding by the intact blood-brain barrier. Interpretation of negative and positive somatostatin receptor scans in CNS tumors must therefore be done with caution.

Successful pregnancy in a severe hypertensive patient treated with nitrendipine. Case report.

Nitrendipine (NIT), a new potent calcium channel blocking agent, was administered to a patient with essential severe (191/119 mm Hg), refractory, and resistant hypertension (HT) to conventional triple drug regime. Three previous pregnancies had been unsuccessful in the past 4 years because of uncontrollable HT and repeated hypertensive crises. NIT (20 mg tablets) was given PO as a single morning dose and 15 months after BP control, she became pregnant again. With a 20 mg/day dose of NIT throughout pregnancy, a healthy 2400 g, 47 cm male boy was delivered by a non-emergency cesarean section at 37 weeks' pregnancy. Both mother and son remain normal months after birth. The results suggest NIT may be considered as an alternative for this type of patients and should be studied in clinical trials.

Long-term (3 years) sustained antihypertensive and metabolic actions of nitrendipine in severe, complicated, and resistant hypertension.

The antihypertensive efficacy of once-daily nitrendipine was studied in 18 patients with severe, resistant, refractory, and complicated hypertension. The dose range was 20-120 mg/day adjusted weekly for a total treatment period of 3 years. Nitrendipine produced a significant reduction in blood pressure compared to pretreatment baseline values with no significant effects on heart rate. Renal function was preserved and there was an increase in urine flow, urinary excretions of Na+, kallikrein, and prostaglandin E2, and plasma renin. Some patients experienced known calcium antagonist side effects but the drug was otherwise well tolerated.