Biomedical subjects
Publications and source records attributed to F Pinto.
MRI demonstrated symmetric putaminal and cerebellar changes in a patient who survived a cardiorespiratory arrest due to acute idiopathic polyneuritis. Since similar aspects can be observed following cyanide or methanol poisoning differential diagnosis from these conditions has to rely on the combination of clinical and imaging findings.
This study explored the neurophysiological changes in 87 HIV1+ (20 AIDS, 24 ARC, 24 LAS and 19 AC) patients showing no clinical evidence of neurological impairment. Tracing somatosensory responses by recording SEPs from upper and lower limbs, we found a slowing of both peripheral and central nerve conduction. Peripheral alterations occurred in virtually all patients of the AIDS group. Central anomalies, confined largely to the lower spinal cord, manifested themselves only during the later stages of the disease (ARC and AIDS) and then only in about half of our sample. More marked neurotropic varieties of HIV1 may account for these differences. We feel that SEP studies can serve to reveal pre-clinical NS involvement in HIV1+ subjects and should be included among research strategies aimed at tracing the evolution of AIDS.
Twenty-nine small hepatocellular carcinomas (sHCCs) less than 5 cm in diameter were treated with percutaneous ethanol injection (PEI) under US guidance in 24 cirrhotic patients. The nodules were treated on an outpatient basis with 6-18 ethanol injections; the total amount of alcohol delivered to each lesion was 10-103 ml. Twenty-seven of the 29 HCCs (93.1%) showed no evidence viable neoplastic tissue at a dynamic CT scan combined with multiple fine-needle biopsies performed one month after the end of treatment; in 10 cases MR confirmed the presence of necrosis showing marked hypointensity of the lesions in T2-weighted images. None of the 27 necrotized sHCCs recurred locally during a 4-44 months' follow-up period (mean 18 months). Two lesions larger than 4 cm showed incomplete response to treatment. No complications occurred after a total number of 264 alcohol injections. The 1-year survival rate in the 16 patients with a follow-up longer than 12 months was 93.7%. PEI proved to be a safe and effective treatment for sHCCs. In particular, PEI can be viewed as a reliable alternative to surgery in the management of nodules less than 3 cm in diameter, considering the operative hazards and the high risk of new lesions occurring in resected livers.
Autochthonous human samples of the three westernmost islands of the Canarian Archipelago, La Palma, Gomera, and Hierro, have been analyzed for eight red cell polymorphic enzymes. Only a small intra and inter-insular differentiation exists among these three islands. However, a marked heterogeneity is found when all seven islands of the Archipelago are compared by Nei's genetic distances [1972]. Nevertheless, there is no correlation between genetic and geographic distances. Historical factors could explain the frequency similarities of some distant islands. The rare variant GD*A+Negroid allele, and the endemic GD*Gc allele, previously found in other islands, have also been detected in this survey.
The endoscopic palliative treatment of esophageal and esophagocardial neoplastic stenoses is generally performed in the patients in whom surgery is not indicated for oncological and general reasons and endoscopic dilatation is uneffective. Our experience is reported concerning 92 patients submitted to palliative therapy through placement of Atkinson prostheses; the patients underwent radiologic studies--i.e. (a) plain chest radiographs (before and after intubation), (b) esophagogastric studies with iodate cm, and (c) CT (performed in the last 20 cases only). The mortality rate at 30 days was 6.5% (6 cases), in no case due to specific complications related to intubation. The mean survival was 3.6 months (range: 1-12). As to the complications specifically related to intubation, they were basically 3: perforation, dislocation, and obstruction (of the prosthesis). As to the methods allowing best demonstration of the same: a) CT proved to be superior in revealing perforation, which usually occurs early after intubation. However, considering its low incidence (2 cases only, in our series), the routinary use of CT does not seem justified. CT should be reserved to selected patients in whom the shape of the neoplasm or peculiar anatomical conditions make intubation difficult, with high risks of perforation--e.g., kiphoscoliosis, hiatal hernia, previous surgery or radiotherapy, angulation of the prosthesis, neoplasm of scirrhous or necrotic type or causing luminal deviation; b) if dislocation occurs, as it more often happens (9 cases in our series) in the presence of soft neoplastic tissue or in cases of mild or asymmetrical stenosis, CT seems likewise unnecessary. Conventional radiology proved superior thanks to its more comprehensive view, and therefore sufficient to suggest the correct treatment--e.g. repositioning of the prosthesis by means of fiberoscopy, or withdrawal after gastrostomy; c) CT appeared useless in the cases due to alimentary causes (easily detectable from the clinical history), but proved useful in the cases due to neoplastic overgrowth. In the latter, CT can yield information as to the site and size of the neoplasm, as well as to its relationship to surrounding tissues, and thus help suggest proper treatment--e.g. dilatation and repositioning of the prosthesis, gastrostomy, recanalization by means of NdYAG laser, no treatment at all.
STUDY OBJECTIVE: To determine the influence of echocardiography in the preoperative diagnosis of heart diseases in children. DESIGN: Retrospective study. SETTING: Hospitalized children admitted in Departments of Pediatric Cardiology and Cardiothoracic Surgery. PATIENTS: Children of both sexes, aged from neonate to 14 years old, with heart disease who underwent cardiac surgery. MATERIAL AND METHODS: From January 1989 to July 1990, 220 consecutive cardiac surgeries were performed in children with heart disease. The initial diagnosis was based on data from clinical examination, electrocardiogram, thorax X-Ray and echocardiogram (M-mode, 2D, conventional and colour Doppler). Patients were separated in three groups according to their ages: newborn infants less than 28 days old; infants less than 12 months old; children more than 1 year old and less than 14 years old. Patients were separated according to the investigations used further for preoperative diagnosis: whether they had or not cardiac catheterization performed prior to surgery. RESULTS: From 220 surgical interventions performed, 124 were "open heart" surgeries (9 neonates, 28 infants and 87 children) and the remaining had "closed heart" operations (14 neonates, 37 infants and 45 children). Preoperative diagnosis was mainly dependent on echocardiography, dispensing catheterization in 90 cardiac interventions. The diagnosis was confirmed at surgery or at autopsy. There were 9 deaths, 3 of which occurred in patients not submitted to cardiac catheterization. CONCLUSIONS: Echocardiography is a reliable method for investigation and establishment of the preoperative diagnosis of heart diseases in children. Its use may further reduce the need for diagnostic catheterization in children, particularly in risk groups.
A group of 13 patients suffering from Hodgkin's disease who had undergone chemotherapy and radiotherapy (above and below the diaphragm) approximately 10 years earlier was studied. The total chemotherapeutic dose was similar for all patients; the radiotherapy dose, however, was standard for 7 patients, while the other 6 received much higher dosages over limited regions of the spinal cord. Although most of these patients appeared normal both clinically and on magnetic resonance imaging, a neurophysiological study was performed to determine whether there was any involvement of the central or peripheral nervous system. Motor conduction velocity and sensory conduction velocity were measured in the lower limbs as well as spinal- and scalp-recorded somatosensory evoked potentials (SEPs) in response to stimulation of the posterior tibial and sural nerves at the ankle. In addition, motor evoked potentials were recorded from the upper and lower limbs during cortical stimulation. All neurophysiological data were normal in patients who had received a standard radiation dose, while most of those who had been exposed to higher doses showed altered cortical SEPs and a slowing of central conduction time (D10-P1). Thus even though they were asymptomatic, these patients appeared to have sustained CNS damage, mainly at the level of the spinal cord.
Gel filtration studies show that the thyroglobulin (Tg) molecule (dimer) binds from 18 to 50 Ca2+ ions. At pH 7.5 Tg binds 18 Ca2+ ions with a Kd of 1.3 x 10(-5) M, and 50 Ca2+ ions with a Kd of 5.5 x 10(-4) M. The binding of calcium to bovine thyroglobulin increases the absorption band of iodoamino acid residues at 315 nm. In the presence of Ca2+, the fluorescence intensity of 1-anilino-8-naphthalene sulfonate (ANS) is increased about 5-fold by Tg, with a shift in the fluorescence emission maximum from 505 to 490 nm. Thus, thyroglobulin possesses two classes of calcium binding sites with different affinities. The data reported indicate, also, that Ca2+ binding to Tg increases the hydrophobicity of the surface of the molecule.
Patients with Myotonic Dystrophy (MyD) frequently suffer from a dysfunction of the primary sensory pathways, as documented by abnormalities of short-latency evoked potentials. Impairment of intellectual functions has been less extensively investigated. Short-latency brainstem auditory evoked potentials (BAEPs) as well as long-latency auditory event-related potentials (ERPs) were recorded from 5 female and 6 male patients affected by MyD. A simple discrimination ("oddball") paradigm was used to record ERPs to tones from Fz, Cz, Pz. Both BAEPs and ERPs were significantly altered as compared to normals. BAEP abnormalities were detected in 9 patients and ERP components N2 and P3 were delayed or absent for all patients, who nonetheless correctly discriminated between tones. These data indicate that CNS dysfunction in MyD involves not only primary sensory systems but also neural mechanisms underlying cognitive events and ERP generation.
The effect of adenosine on 45Ca2+ uptake by rat brain synaptosomes stimulated by electrical pulses was investigated. 45Ca2+ uptake was voltage dependent. Adenosine (1 nM-1 microM) decreased the uptake of 45Ca2+ induced by electrical stimulation (amplitude, 20 V; duration, 400 microseconds; frequency, 10 pulses/s) in a concentration-dependent manner. At a concentration of 1 microM, adenosine almost abolished the 45Ca2+ uptake induced by electrical stimulation (92.9 +/- 5.3% inhibition), but when the calcium uptake was induced by high-K+ (60 mM) medium, the effect of adenosine (1 microM) was smaller (43.8 +/- 5.2% inhibition). The inhibitory effect of 1 microM adenosine on calcium uptake induced by electrical stimulation was antagonized by 1,3-dipropyl-8-p-sulfophenylxanthine (5 microM). The possibility that adenosine interacts with the calcium channels opened by electrical stimulation is discussed.
Fifty-two patients, 17 acute and 35 chronic, underwent US of the shoulder. The first class of patients had clinical history of blunt trauma occurred 2 to 30 days before examination. The second class of patients included 15 patients with history of trauma occurred 3 months (or more) before examination and 20 patients affected with impingement syndrome. As to the US signs of rotator cuff tear reported in the literature, the results of the study, supported by arthrographic (21 cases), MR (2 cases) and surgical (24 cases) findings, indicate that their presence and significance differ in the acute and in the chronic patient and that: 1) Focal discontinuity, appearing as a hypoechoic area, is demonstrable only in the acute patient. The sign is due to a tear filled with blood and/or bursal liquid and holds high diagnostic accuracy. It is rare that an acute lesion appears as a hyperechoic linear density--which has doubtful diagnostic accuracy. 2) Non-visualization of the cuff is observable in both the acute and the chronic patient and indicates rupture in both of them. This sign has high diagnostic accuracy. 3) Thinning of the cuff is also observable both in the acute and in the chronic patient. Nevertheless, while in the former the sign can be regarded with confidence as indicating a tear in almost all cases, in the latter it may be due either to a tear or to degeneration. Arthrography or MR Imaging are therefore advisable in this group of patients, especially if surgical treatment is considered.
The authors report their experience on the therapeutic value, in terms of efficacy and tolerance, of percutaneous ethanol injection (PEI) in the treatment of autonomous thyroid nodules (ATN). A group of 15 patients, 13 in clinical pretoxicity and 2 in initial thyrotoxicosis, were submitted to fine-needle ethanol injection (95%) performed under US guidance. The amount of injected alcohol was measured on the basis of the volume and diffusion of alcohol itself within the nodule, in the whole of 79 injections given. Follow-up lasted 3-15 months. Thyroid scanning demonstrated a complete or partial recovery of extranodular parenchymal function in 80% and 20% of cases, respectively. In all cases a volume reduction greater than 50% was obtained, with an initial sharp fall, already after the first month, thanks to early alcohol cytotoxicity. In the 2 patients with toxic ATN serum, normal values of free hormones have been observed ever since the third weekly injection. Good tolerance to treatment was observed, and no permanent complications. In agreement with other authors, we believe our experience to show that PEI represents a new therapeutic approach in patients with ATN. PEI will certainly play a preferential role, relative to other conventional therapies, in the management of clinical pretoxic ATN, regarding which no uniform treatment protocol exists yet.
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OBJECTIVE: Assessment of the results of percutaneous transluminal balloon pulmonary valvuloplasty (BPV) in children. DESIGN OF THE STUDY: Retrospective analysis of the methodology and results between October 1985 and October 1990. SITE OF THE STUDY: Pediatric Cardiology Service, Santa Marta Hospital, Lisbon. PATIENTS: 43 consecutive children with pulmonary valve stenosis. 4 children with Noonan's Syndrome were excluded from the study and the results of 45 valvuloplasties in 39 patients are analysed. METHODS: Full diagnostic catheterization and right ventricular cineangiography were performed. One or two balloon dilatation catheters were inserted percutaneously in one or both femoral veins and positioned across the pulmonary valve under fluoroscopic control. The balloons were then inflated to their maximum pressure with diluted contrast medium. In 18 children follow up cardiac catheterization was performed 3 to 12 months after valvuloplasty (mean 6.7 /+- 2.7). RESULTS: A satisfactory dilatation was achieved in 35 patients (89%) with a substantial decrease in right ventricular systolic pressure (RVP) and in transvalvar peak systolic gradient (GR) (p less than 0.0001). A further significant spontaneous reduction in RVP and GR was recorded on follow up catheterization (p less than 0.01). A repeat BVP was performed in 6 children and was successful in 5. In cases a satisfactory relief of the stenosis was not achieved and 3 of them were submitted to surgery. There were no deaths. One child had cardiac arrest leading to successful surgical valvotomy and with no sequelae. Another child had cerebral embolism with hemiparesis. Ligation of a femoral vein was required in one case for haemorrhage. Mild pulmonary insufficiency resulted in 15 children. CONCLUSIONS: Our experience confirms that BPV is the method of choice for the treatment of children with pulmonary valve stenosis either isolated or associated to small ventricular septal defect. It proved to be a safe and effective technique for reduction of GR. Mortality, morbidity, costs of the treatment and hospitalisation time are lower for BPV than for surgery with comparable short term results.
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OBJECTIVE: To evaluate age group and i.v. thrombolytic therapy (TT) influences on cardiac rupture complicating acute myocardial infarction (AMI). CONCEPTION: Retrospective analysis of patients (pts) admitted during 1988-89 to an Intensive Care Unit of a Terciary Hospital (UCIM) with AMI. POPULATION: 430 pts were admitted with AMI. During this period 89 pts were submitted to TT (25% age greater than or equal to 65 years). Eighty four pts died during hospital stay and 42 had autopsy study (50%). Only 7 of nonautopsied pts died of undetermined cause. Dead pts had age m +/- SD 72 +/- 11 years old (yo) (37% female, 63% male and 74% age greater than or equal to 65 yo). RESULTS: Nineteen pts died of cardiac rupture (CR) (23%). CR prevalence was 1.4% (3/218) in pts less than 65 yo and 7.5% (16/212) in pts greater than or equal to 65 yo (p less than 0.01). CR prevalence in pts submitted to TT (4.5%) 4/89, was similar to pts not submitted to TT (4.4%) 15/341 (n.s.). Pts less than 65 yo had nonsignificant differences in CR wether submitted or not to TT (0% vs 2%). Elderly pts (greater than or equal to 65 yo) CR prevalence was 18% (4/22) in those submitted to TT vs 6% (12/190) in those not submitted to TT (p less than 0.05). CONCLUSIONS: Thrombolytic therapy may carry an additional risk for cardiac rupture in elderly patients (greater than or equal to 65 yo).