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Biomedical subjects

N Martelli

Publications and source records attributed to N Martelli.

At least 19 recordsLinked to original sources

Platelet/polymorphonuclear leukocyte adhesion: a new role for SRC kinases in Mac-1 adhesive function triggered by P-selectin.

Adhesion of polymorphonuclear leukocytes (PMNLs) to activated platelets requires a P-selectin-triggered, tyrosine kinase-dependent adhesiveness of Mac-1 and is accompanied by tyrosine phosphorylation of a 110-kd protein (P-110) in PMNLs. Inhibitors of SRC tyrosine kinases were found to inhibit PMNL adhesion to activated platelets or to P-selectin expressing Chinese hamster ovary (CHO-P) cells and the tyrosine phosphorylation of P-110. Adhesion of PMNLs to activated platelets or to CHO-P cells stimulated activity of LYN and HCK. Monoclonal antibody blockade of P-selectin or beta2-integrins reduced the activation of both kinases. In PMNLs either adherent to platelets or aggregated by P-selectin-IgG chimera, Mac-1 was rapidly redistributed to the Triton X-100-insoluble cytoskeletal fraction, and large clusters of Mac-1 colocalized with patches of F-actin at the sites of cell-cell contact. In PMNLs stimulated by P-selectin-IgG chimera, SRC kinase inhibition impaired Mac-1 clustering, F-actin accumulation, and CD18 redistribution to the cytoskeleton. Disruption of the actin filament network by cytochalasin D prevented PMNL-platelet adhesion and P-selectin-induced PMNL aggregation and impaired the clustering of Mac-1. In agreement with the requirement for the beta2-integrin in the functional up-regulation of LYN and HCK, integrin blockade by monoclonal antibodies resulted in a complete inhibition of P-selectin-induced Mac-1 clustering and F-actin accumulation. Taken together, the results indicate that, after an initial P-selectin-triggered beta2-integrin interaction with the ligand, SRC kinases are activated and allow the remodeling of cytoskeleton-integrin linkages and integrin clustering that finally strengthen cell-cell adhesion. This model highlights a new role for SRC kinases in a regulatory loop by which the Mac-1 promotes its own adhesive function.

Actins↗

Polymorphonuclear leukocyte apoptosis is inhibited by platelet-released mediators, role of TGFbeta-1.

Platelets regulate several polymorphonuclear leukocyte (PMN) functions. We have found that thrombin-stimulated platelets potently inhibited PMN apoptosis. Cell-free supernatant from increasing concentrations of stimulated platelets inhibited PMN apoptosis in a dose-dependent manner, with an effect similar to that of corresponding concentrations of platelets. At the plateau, platelet supernatant inhibited PMN apoptosis by 54.6 +/- 6.8%, the anti-apoptotic activity being higher than that of GM-CSF and comparable to that of LPS. Neither IL-1ra nor a combination of anti-IL1alpha + betamAb affected the activity of platelet supernatant. In contrast a mAb recognizing the active form of TGF-beta1 significantly decreased this activity. Moreover, exogenous TGF-beta1 inhibited PMN apoptosis in a dose-dependent manner. The active form of this cytokine was indeed present in the supernatant of stimulated platelets at a concentration able to elicit an anti-apoptotic effect. The p38 MAPK inhibitor SB203580 prevented the anti-apoptotic effect of TGF-beta1 in a dose-dependent manner. Interestingly, it also prevented the anti-apoptotic effect of IL-1alpha, but not that of GM-CSF, LPS and dexamethasone. In conclusion, we report for the first time that PMN apoptosis is potently inhibited by platelet-released mediators, that TGF-beta1 mediates an important part of this effect, and that p38 MAPK is involved in the TGF-beta1 signaling leading to its anti-apoptotic effect. These results provide novel evidence to support the central role of platelets in inflammation.

Apoptosis↗

Platelet/polymorphonuclear leukocyte interaction: P-selectin triggers protein-tyrosine phosphorylation-dependent CD11b/CD18 adhesion: role of PSGL-1 as a signaling molecule.

Polymorphonuclear leukocyte (PMN) adhesion to activated platelets is important for the recruitment of PMN at sites of vascular damage and thrombus formation. We have recently shown that binding of activated platelets to PMN in mixed cell suspensions under shear involves P-selectin and the activated beta2-integrin CD11b/CD18. Integrin activation required signaling mechanisms that were sensitive to tyrosine kinase inhibitors.1 Here we show that mixing activated, paraformaldehyde (PFA)-fixed platelets with PMNs under shear conditions leads to rapid and fully reversible tyrosine phosphorylation of a prominent protein of 110 kD (P approximately 110). Phosphorylation was both Ca2+ and Mg2+ dependent and was blocked by antibodies against P-selectin or CD11b/CD18, suggesting that both adhesion molecules need to engage with their respective ligands to trigger phosphorylation of P approximately 110. The inhibition of P approximately 110 phosphorylation by tyrosine kinase inhibitors correlates with the inhibition of platelet/PMN aggregation. Similar effects were observed when platelets were substituted by P-selectin-transfected Chinese hamster ovary (CHO-P) cells or when PMN were stimulated with P-selectin-IgG fusion protein. CHO-P/PMN mixed-cell aggregation and P-selectin-IgG-triggered PMN/PMN aggregation as well as P approximately 110 phosphorylation were all blocked by antibodies against P-selectin or CD18. In each case PMN adhesion was sensitive to the tyrosine kinase inhibitor genistein. The antibody PL-1 against P-selectin glycoprotein ligand-1 (PSGL-1) blocked platelet/PMN aggregation, indicating that PSGL-1 was the major tethering ligand for P-selectin in this experimental system. Moreover, engagement of PSGL-1 with a nonadhesion blocking antibody triggered beta2-integrin-dependent genistein-sensitive aggregation as well as tyrosine phosphorylation in PMN. This study shows that binding of P-selectin to PSGL-1 triggers tyrosine kinase-dependent mechanisms that lead to CD11b/CD18 activation in PMN. The availability of the beta2-integrin to engage with its ligands on the neighboring cells is necessary for the tyrosine phosphorylation of P approximately 110.

Adult↗

Platelet/polymorphonuclear leukocyte interaction in dynamic conditions: evidence of adhesion cascade and cross talk between P-selectin and the beta 2 integrin CD11b/CD18.

Adhesion between platelets and polymorphonuclear leukocytes (PMN) is a key event in thrombosis and inflammation. Double color fluorescence-activated cell sorter (FACS) analysis was used to determine the extent and kinetics of adhesion of thrombin-activated platelets to resting or activated PMN when mixed cell populations were incubated in dynamic conditions. Activated platelets bound very rapidly to PMN. Mixed cell conjugates reached a maximum at 1 minute and were reversible within 10 minutes. Platelet/PMN adhesion required both Ca2+ and Mg2+ and was markedly increased by the presence of Mn2+. The latter made mixed cell conjugates stable up to 10 minutes. Adhesion of platelets required metabolic activity of PMN and was abolished by tyrosine kinase inhibitors. Furthermore, adhesion of platelets to PMN resulted in binding of a monoclonal antibody (MoAb 24) known as beta 2 integrins "activation reporter." When PMN were activated by exogenous stimuli, the adhesion of platelets was markedly increased: fMLP induced a rapid and transient effect, while PMA resulted in a slower, but stable, increase in mixed conjugates formation. The hypothesis that activated PMN beta 2 integrins are able to bind a counter-receptor on platelets was directly demonstrated by the increase of mixed cell conjugates following PMN treatment with KIM127 and KIM185, two anti-CD18 antibodies able to induce the active conformation of beta 2 integrins. Consistently, two other anti-CD18, as well as an anti-CD11b inhibitory antibody abolished platelet/PMN adhesion. PMN beta 2 integrin activation was not the only mechanism for activated platelet/PMN adhesion to occur: indeed, this phenomenon could also be inhibited by two anti-P-selectin antibodies. Resting platelets did not adhere to resting PMN, but markedly adhered to fMLP- or PMA-activated PMN. Resting platelet/fMLP-activated PMN adhesion was abolished by anti-CD18 antibodies, but not by anti-P-selectin antibodies. In conclusion, activated platelet/PMN interaction can be modeled as an adhesion cascade involving a P-selectin-dependent recognition step and a functional signal. The latter proceeds through tyrosine kinase activation and enables a beta 2 integrin-dependent adhesion to a not yet identified counter-receptor constitutively expressed on platelet surface.

Antibodies, Monoclonal↗

Subarachnoid hemorrhage after aneurysm surgery.

The surgical treatment of intracranial aneurysms by clipping is recognized as effective and definitive. However some cases that suffered a new subarachnoid hemorrhage (SAH) some time after they were submitted to aneurysm clipping have raised doubts about the concept of "cure" after this treatment. Eleven patients previously submitted to aneurysm clipping who presented a new SAH were analyzed. The time elapsed from surgery to SAH varied from 3 to 10 years. After SAH four patients had a poor outcome. The new episode of SAH occurred due to intrinsic factors of the cerebral vasculature: 1. a weak point of the vessel wall near the previous aneurysm, 2. a weak point of another vessel far from the previous aneurysm, 3. a previous infundibular dilation of the posterior communicating artery; and due to technical problems: 1. aneurysm not identified during the previous treatment, 2. aneurysm deliberately left untreated, 3. persistence of the aneurysm due to inappropriate surgery, 4. persistency of part of the aneurysm neck after clipping and 5. slipping of the clip from the neck of the aneurysm. The measures to prevent new SAH after surgery start with adequate preoperative angiographic studies, a careful inspection of the position of the clip and emptying of the aneurysm. Early angiography studies may reveal a persistent neck and later ones may reveal newly developed aneurysms. In conclusion, SAH after aneurysm clipping is a late and severe phenomenon and the concept of "cure" after this surgery should be interpreted with caution.

Adult↗

Spontaneous and glucocorticoid-induced apoptosis in human mature T lymphocytes.

Glucocorticoid (GC)-induced apoptosis is a well-recognized physiologic regulator of murine T-cell number and function. We have analyzed its mechanisms in human mature T cells, which have been thought to be insensitive until recently. Peripheral blood T cells showed sensitivity to GC-induced apoptosis soon after the proliferative response to a mitogenic stimulation, and were also sensitive to spontaneous (ie, growth factor deprivation-dependent) apoptosis. CD8+ T cells were more sensitive to both forms than CD4+ T cells. Acquisition of sensitivity to GC-induced apoptosis was not associated with any change in number or affinity of GC receptors. Both spontaneous and GC-induced apoptosis were increased by the macromolecular synthesis inhibitors, cycloheximide (CHX) and puromycin. A positive correlation between the degree of protein synthesis inhibition and the extent of apoptosis was observed. Interleukin-2 (IL-2) IL-4, and IL-10 protected (IL-2 > IL-10 > IL-4) T cells from both forms of apoptosis in a dose-dependent manner. Our data suggest that spontaneous and GC-induced apoptosis regulate the human mature T-cell repertoire by acting early after the immune response and differentially affecting T-cell subsets.

Apoptosis↗

Cysticercosis of the central nervous system. I. Surgical treatment of cerebral cysticercosis: a 23 years experience in the Hospital das Clínicas of Ribeirão Preto Medical School.

Cysticercosis is the most frequent parasitosis of the nervous system and nowadays it is widespread through the world. Despite the development of anticysticercal drugs (praziquantel and albendazole), their efficacy is more marked in cases with parenchymal active cysts and they do not prevent complications such as hydrocephalus. Thus, many patients with neurocysticercosis require surgical intervention, generally of palliative nature, but that may occasionally produce a cure. The clinical outcome of 180 patients with cerebral cysticercosis who underwent surgical treatment form 1970 to 1993 was analyzed. Surgical treatment was performed to control increased ICP in 177 patients and due to local compression of cranial nerves or brainstem in five. Some patients had more than one surgical procedure, totalizing 287 interventions. Increased intracranial pressure (ICP) was caused by hydrocephalus in 91%, by intracranial mass lesion (tumoral form) in 6.2% and by pseudotumor cerebri (pseudotumoral form) in 2.8% of the case. Based on the pathophysiological mechanisms of intracranial hypertension identified through conventional CT-scan, ventriculography, cysternotomography, ventriculotomography and MRI, different surgical approaches were indicated. Patients with tumoral form were submitted to direct approach and cyst removal and generally they had benefits from this procedure. Patients with pseudotumoral form whose clinical treatment failure underwent decompressive craniectomies and had a poor outcome (40% of good results). Direct removal of ventricular/cisternal cysts and/or ventriculoatrial/peritoneal shunting (VA/VPS) was performed in patients with hydrocephalus. Removal of free ventricular cysts in patients who had no ependimitis/arachnoiditis generally allowed a good outcome. Patients with adherent cysts and inflammatory process needed a VA/VPS posteriorly and the outcome was not so good. One hundred thirty-two patients were submitted to VA/VPS (109 as the first procedure and 23 after another surgical treatment). The VA/VPS was effective to control increased ICP, despite many complications observed mainly during the two first postoperative years. After this period the surviving patients generally had a better outcome. The patients submitted to cyst removal due to local compression of cranial nerves/brainstem generally had good results. Based on the experience acquired with the management of these patients we present our recent policy for the treatment of patients with neurocisticercosis.

Adolescent↗

Polymorphonuclear leukocyte-platelet interaction: role of P-selectin in thromboxane B2 and leukotriene C4 cooperative synthesis.

In PMN/platelet suspensions stimulated by fMLP giant mixed aggregates are formed and TxB2 and LTC4 are synthesized as the result of the cooperation in the arachidonic acid (AA) metabolism during cell/cell contact. PMN-derived cathepsin G induced the expression of P-selectin on platelet surface. GE12, an antibody against P-selectin, significantly reduced mixed cell aggregates. GE12 did not affect platelet aggregation induced by PMN-derived supernatants, indicating that the inhibitory effect of GE12 on mixed cell aggregation depends on inhibition of PMN/platelet adhesion. GE12 significantly reduced TxB2 and LTC4 production in PMN/platelet mixed cell suspensions stimulated by fMLP. As previously reported, synthesis of 3H-TxB2 in 3H-AA-labeled PMN/unlabeled platelets indicates that platelets utilize 3H-AA from PMN. 3H-LTC4 production in unlabeled PMN/3H-AA-labeled platelets indicates that bidirectional routes are utilized in this system for LTC4 synthesis. GE12 significantly reduced 3H-TxB2 and 3H-LTC4 synthesis. These results show that cathepsin G released by activated PMN induces the expression of P-selectin on platelet membrane: this adhesive glycoprotein modulates cell-cell contact and transcellular metabolism of AA.

Amino Acid Sequence↗

Effects of leukocyte-derived cathepsin G on platelet membrane glycoprotein Ib-IX and IIb-IIIa complexes: a comparison with thrombin.

Cathepsin G is a serine, chymotrypsin-like protease released by activated polymorphonuclear leukocytes (PMN) that may act as a platelet agonist. The effect of this enzyme on platelet surface glycoproteins (Gp) Ib and IIb-IIIa was evaluated by means of a cytofluorimetric assay, using fluorescein isothiocyanate-labeled monoclonal antibodies (MoAbs) directed at the alpha chain of Gp Ib (SZ2), at Gp IX or at the complex Gp IIb-IIIa (P2), and the fibrinogen-receptor-specific MoAb PAC-1. In human washed platelets, cathepsin G increased the binding of P2 and PAC-1, decreased the binding of SZ2, but only slightly affected the binding of anti-Gp IX. SZ2 binding decrease was more rapid in cathepsin G- than in thrombin-stimulated platelets, whereas the increase of P2 and PAC-1 binding occurred to a comparable extent with either agonist. In paraformaldehyde (PFA)-fixed and energy-depleted platelets, no effect on either Gp Ib or Gp IIb-IIIa complex was observed with thrombin. At variance, cathepsin G was still able to reduce binding of SZ2, whereas increased binding of P2 or PAC-1 antibodies was not observed. Triton X-100 permeabilization of cathepsin G-treated, PFA-fixed platelets did not restore SZ2 binding at variance with thrombin. Moreover, platelet incubation with cathepsin G resulted in the loss of ristocetin-induced agglutination in the presence of the von Willebrand factor and in the appearance of Gp Ib-derived proteolytic products in supernatants. After dissociation by EDTA pretreatment of surface Gp IIb-IIIa complexes, cathepsin G still induced increased binding of P2. Aspirin and an adenosine diphosphate scavenger system had only a slight but not significant effect on changes in antibody binding induced by cathepsin G. All these data would indicate that cathepsin G, like thrombin, interacts with platelet-surface Gp, inducing the exposure of the intracellular pool of the Gp IIb-IIIa complex with concomitant expression of a functional fibrinogen receptor. Moreover, it induces a loss of antigenic sites on Gp Ib, but the mechanism involved, a proteolytic cleavage of Gp Ib, is substantially different from that of thrombin. These changes, induced by a product of activated PMN, might reduce the reactivity of platelets to the subendothelium, while increasing their ability to undergo aggregation and release reaction.

Adenosine Diphosphate↗

Differences in the glutathione system of cultured aortic smooth muscle cells from young and aged rats.

We studied the relation between the glutathione (GSH) system and cell proliferation in a model of smooth muscle cells (SMC) derived from the thoracic aorta of 4-6-week-old (young) and 15-month-old (aged) rats. SMC from aged rats showed greater levels of total non-protein thiol compounds (T-SH), increased glutathione transferase (GST) and increased glutathione reductase (GSSG-Red) activities compared with cells from young rats. These changes were associated with an increased proliferation rate of SMC from aged rats. To evaluate the role of GSH on cell proliferation better, a specific inhibitor of gamma-glutamyl-cystein synthetase, DL-buthionine-SR-sulphoximine (BSO) was used. BSO showed a dose-dependent inhibition of cell growth, with an IC50 of 10(-4) M, after 48-72 h of incubation. Removal of BSO restored cell growth, further suggesting a link between GSH levels and vascular cell proliferation. The inhibitory effect of BSO was about two times greater on SMC from young than on SMC from aged rats. BSO showed 56% inhibition on the proliferation of SMC from young rats and 32% inhibition on SMC from aged rats (10(-4) M, 72 h of incubation). A parallel reduction of GSH levels of 38% and 19% for SMC from young and aged rats, respectively, was observed, suggesting that age-related factors may influence the involvement of GSH system in cell proliferation.

Aging↗

[Surgical treatment of intracranial aneurysms: comparison between early and late surgery].

The clinical course of patients with subarachnoid hemorrhage (SAH) due to rupture of cerebral aneurysm admitted during the last five years is analysed: 157 patients were treated by direct surgical approach of the aneurysm, 58 localized in the anterior communicating artery (ACoA), 48 in the internal carotid artery (ICA), 43 in the middle cerebral artery (MCA), and 8 in the posterior circulation. Fourty-four patients were operated on during the first 72 hours (early surgery), 40 during the 4th and 7th days, 16 during the 8th and the 10th, and 57 after the 10th (late surgery). According to main localizations, the outcome of patients with aneurysms in the ACoA was good in 79.1%, in the ICA in 69.7%, and in the MCA in 69.7%. Patients treated in Hunt & Hess grade I and II had both good results in 77.5%, grade III patients had good results in 71.3%, and grade IV in 56.2%. According to timing of surgery good results were observed in 61.4% for patients submitted to early surgery, in 80% for patients treated during the 4th and 7th days, in 81.2% for patients treated during the 8th and the 10th days, and in 70.2% for that submitted to late surgery. The overall mortality was 14.6%. For grade I patients mortality was 6.4%, for grade II was 12.2%, for grade III was 15.2%, for grade IV was 25%, and all patients operated on in grade V died.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Standards established by consensus for the treatment of bronchial asthma and its exacerbations].

A group of pulmonologists from different sites of Argentina convened to establish consensus guidelines for treatment of acute and chronic bronchial asthma. General acceptance that in fatal asthma diagnosis and hospital admission are usually too late and treatment insufficient prompted the need for this meeting. The purpose of treatment was devised to keep the patient symptomless, decrease frequency of exacerbations and the risk of severe attacks. Peak expiratory flow rate (PEFR) measurement in all patients was decided. inhalation of anti-inflammatory drugs (corticosteroids, CE, and/or disodium cromoglycate, DSG, in those younger than 20 years) was established as first line of treatment. Inhaled CE (even in high doses such as 2 mg/day) do not provoke significant adverse systemic effects (immune depression, Cushing syndrome, hyperglycemia in diabetics or osteopenia). Secondary local adverse effects are however frequent: oral and pharyngeal candidiasis and dysphonia. It is advisable considering present evidence, that bronchodilators (Bd) be used preferentially on demand. On account of small bronchodilator effect and frequent secondary adverse effects, use of theophylline should be limited to patients not adequately responsive to anti-inflammatory drugs in high dosage. Immunotherapy is not useful in asthma. Four clinical levels were defined in chronic asthma considering severity of dyspnea, frequency of nocturnal bronchial obstruction, levels of PEFR and amount of required Bd. Guidelines of treatment were established for each clinical level considering increasing dosage of CGS, inhaled CE (up to 2 mg/day) and regular administration of Bd. Indications for systemic CE administration were also established. Three levels of acute asthma (sudden worsening of symptoms) were accepted based on clinical evidence and PEFR values. Treatment was quantitatively adjusted to severity. Criteria for hospital admission either in emergency or intensive care areas and treatment procedures were established.

Administration, Inhalation↗

Infantile hydrocephalus: brain sonography as an effective tool for diagnosis and follow-up.

Infantile hydrocephalus is a common disease. In most affected children the process starts before the age of 2 when the bregmatic fontanel is still open. Brain sonography has emerged as an effective tool in diagnosing progressive ventricle dilation and may be used for continuous follow-up. It gives such important information as: (a) cortical thickness, an expression of proper shunt function and of prognostic value concerning neuropsychological development; (b) position of the tip of the catheter, which is considered by some to be a predictive factor of shunt failure; (c) other complications such as subdural collections, isolated IV ventricle, and slit ventricles. This methodology permits frequent examinations and allows better comprehension of the pathological process by the parents and medical staff.

Cerebral Ventricles↗

[Infantile hydrocephalus: long-term results in 102 patients and the importance of neurosonography].

A personal series (in 94% of the cases) of 102 children who underwent 170 procedures (1.66 procedures/patient) for hydrocephalus has been followed for 5 1/2 years (Jan-83 to June-88). Most of the children were under two years of age (80%) and in these cases brain sonography was the examination of choice for both diagnosis and follow-up (307 examinations, 4.4 per patient). Only occasionally was computed tomography necessary for better study in these cases. Our results suggest that there was no significant difference between our cases and those published in the literature concerning the number or procedures/patient (1.66)., infection rate (5.2%), mortality rate (6.8%) and intellectual performance. We recommend the use of brain sonography both in diagnosis and follow-up studies for hydrocephalic children since this examination is innocuous, inexpensive and easy to perform by neurosurgeons. Also it provides a good interaction between the examiner, the child and the parents, which is of utmost importance for the comprehension of the disease by the parents and early diagnosis of complications by the neurosurgeon.

Cerebrospinal Fluid Shunts↗

Surgical treatment of multiple intracranial aneurysms.

A retrospective study was conducted on 42 patients with multiple aneurysms surgically treated from 1975 to 1986. Thirty one of them had 2 aneurysms 6 had 3, 3 had 4 and 2 had 5 (62 in the internal carotid, 27 in the middle cerebral artery, 11 in the anterior cerebral and 3 in the basilar artery). All patients had subarachnoid hemorrhage and were classified as follows upon admission: 11, grade I; 12, grade II; 15, grade III, and 4, grade IV, and most of them improved before surgery (29, grade I, 7, grade II, and 6, grade III). In most cases, surgery was delayed and the 42 patients needed 57 craniotomies for clipping the aneurysms. Of the 24 patients with bilateral aneurysms, 15 were operated on both sides (11 are asymptomatic, 1 has hemiparesis, and 3 died later). Of the 9 patients submitted to unilateral craniotomy, 4 died and 5 are alive and well. Of the 18 patients with unilateral aneurysms, 11 are asymptomatic, 2 have hemiparesis, 1 has diplegia and behavioral disorders, and 4 died. Overall mortality was 26.1%, intraoperative mortality was 11.9%, and no mortality occurred among the patients operated over the last 5 years. The management of these patients is discussed.

Adult↗

Cerebromeningeal hemorrhage. Analysis of autopsies performed over a 10-year period.

A study was conducted on the medical records of 353 patients who died of a subarachnoid hemorrhage (SAH) and who were submitted to autopsy over the last 10 years. SAH was associated with arterial hypertension in 180 (51%) cases, with ruptured aneurysms in 102 (28.9%), and with other pathologies in 71 (20.1%). The patients with hemorrhage associated with arterial hypertension were mostly males, and those with hemorrhage due to aneurysms were mostly females. Of the patients with aneurysms, 36 (35.3%) had aneurysms in the anterior communicating artery, 30 (29.4%) in the internal carotid artery, and 23 (22.6%) in the middle cerebral artery. Among the patients with aneurysms who suffered rebleeding and vasospasm, 59.1% and 61.5%, respectively, were classified as grade I and II upon admission, and all evolved toward grade IV after these complications. Vasospasm predominated from the 3rd to the 10th day after hemorrhage, and rebleeding from the 9 to 16th day and both were most frequent among patients with aneurysms of the anterior communicant artery. Sixty eight percent of the patients with aneurysms died during the first 9 days after hemorrhage. Because of our conduct was to operate systematically late, a considerable number of patients lost the opportunity to be treated surgically with possible favorable evolution due to vasospasm or rebleeding.

Adolescent↗

[Multiple non-neoplastic lesions in computerized cranial tomography].

Multiple intracranial lesions observed in the computerized tomography ever cause worry due to the possibility of neoplastic etiology, although granulomatous diseases (parasitic or not) and vascular diseases can produce this type of lesions. Five patients with clinical picture that suggested expansive intracranial masses and that had multiple lesions in the computerized tomography that suggested neoplastic diseases are presented. In all patients the clinical evolution and/or other complementary diagnostic tests showed the non neoplastic etiology of the lesions. In three patients the lesions were due to parasitic diseases (intracranial tuberculomas in one case and neurocysticercosis in two cases) and in the other two cases the lesions were due to vascular disturbs (cerebral infarcts). The knowledge of the several diseases that can cause multiple intracranial lesions as seen in the computerized tomography allows to direct the etiologic diagnostic that is essential to introduce the correct treatment avoiding irradiation of non neoplastic lesions and unnecessary surgical procedures. In our country, granulomatous parasitic diseases, mainly neurocysticercosis, tuberculosis and fungal diseases must be considered in the differential diagnosis of multiple intracranial lesions observed in the computerized tomography, together with cerebral infarcts and neoplasms.

Adolescent↗

Results of surgical treatment of neurocysticercosis in 69 cases.

The clinical course of 69 patients with neurocysticercosis who underwent surgery to control increased intracranial pressure (ICP) or cyst removal is analyzed. Increased ICP was caused by hydrocephalus in 63 patients, by cerebral edema in four, and by giant cysts in two. Skull x-ray films showed calcifications in 14% and signs of elevated ICP in 46%. Examination of cerebrospinal fluid (CSF) revealed pleocytosis with eosinophils in 52% of cases and a positive complement fixation test for cysticercosis in 66%. Ventriculography allowed localization of the CSF obstruction and ventricular cysts, and generally differentiated between an obstruction due to cysts and an inflammatory process. Computerized tomography showed cysts in the cerebral parenchyma and ventricular dilatation. Ventricular cysts were best seen when intraventricular metrizamide was used. Intracranial shunting and posterior fossa exploration were less effective in the treatment of hydrocephalus than was ventriculoatrial (VA) or ventriculoperitoneal (VP) shunting, although VA or VP shunting was associated with a high percentage of complications. Quality of survival was good in 87% of the cases in the first 3 postoperative months and in 93% of patients who survived 2 years after surgery. Forty-seven patients (68%) were readmitted one or more times for CSF shunt revision; 14 of them for shunt infection (meningitis). The early operative mortality rate was 1.8% for patients with VA or VP shunt placement and 5.3% for those with posterior fossa exploration. The authors conclude that placement of CSF shunts is indicated in the treatment of hydrocephalus, and cyst removal is indicated only when the cyst exhibits tumor-like behavior. Surgical exploration is also indicated when the diagnosis is uncertain.

Adolescent↗