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Biomedical subjects

R Gil

Publications and source records attributed to R Gil.

At least 109 records · Page 6Linked to original sources
PubMed1995

Report of six cases of human infection by Serratia plymuthica.

Serratia plymuthica is an uncommon cause of human infection. Only one case of chronic osteomyelitis and two cases of sepsis secondary to central venous catheter infection have been documented. We report the isolation of S. plymuthica from six patients. The organism was recovered from blood cultures in three cases in which the patients had lymphoblastic leukemia, lymphoma, or stroke. Two isolates were recovered from exudates (following knee and abdominal surgery). In the last case, the organism was isolated from the peritoneal fluid of a patient with cholecystitis. The infection was considered nosocomial in five cases and community acquired in the other.

Adult↗
PubMed1995

New concepts for interpretation of intracoronary velocity and pressure tracings.

The development of quantitative angiography and the introduction of new imaging techniques cannot replace functional methods of assessing the severity of stenosis. Measurement of transstenotic pressure gradient and poststenotic flow velocity using miniaturised sensors with guidewire technology offers an alternative to the conventional non-invasive methods that is immediately applicable in the catheterisation laboratory during interventional procedures. The complexity of the coronary circulation, however, makes it difficult to establish simple cut-off criteria to identify the presence of a flow-limiting stenosis. For intermediate lesions or in the presence of variable haemodynamic conditions, the accuracy of the assessment can be improved by the application of more complex indices proposed and validated in the laboratory animals. Two of these indices are myocardial fractional flow reserve and the slope of the instantaneous relation between pressure or pressure gradient and flow velocity.

Blood Flow Velocity↗
PubMed1995

[Anosognosic graphomimia: an uncommon variety of hypergraphia in right sylvian infarction].

Following a massive infarction in the territory of the right sylvian artery, a right-handed patient with a left hemiplegia and anosognosia, developed a peculiar hypergraphia. It consisted of an inappropriate and permanent writing behaviour, disappearing only during sleep. Space-constructional components of writing were severely disturbed. Graphemes were poorly formed. The graphic disturbances were different from hypergraphia previously described in stroke patients who produced linguistically correct but semantically loose writing. They were also different from graphomania reported in a case of fronto-callosal glioma. Our case of anosognosic hypergraphia suggests a sudden loss of inhibition of writing activity of the left hemisphere. The term graphomimia is proposed to distinguish this writing behaviour from the cases of hypergraphia previously reported and from graphomania.

Aged↗
PubMed1995

[Neurologic complications of infectious endocarditis].

Ten patients with neurological complications (NC) among a retrospective series of 53 consecutive cases of infective endocarditis were studied: 6 males and 4 females, mean age 60 years. NC were present at admission in 6 cases: 2 generalized seizures, 4 strokes, associated with 2 meningeal syndromes. Four cases of NC occurred during hospitalization: 1 stroke with come, 1 transient ischaemic attack, 2 generalized seizures. Blood cultures were positive in 7 cases: 6 group D Streptococci, 1 Gram negative bacillus. Five digestive portal of entry were identified. Cerebrospinal fluid was purulent in 1 patient, aseptic in 1, haemorragic in 2, and normal in 1. Cranial computed tomography revealed: infarct in 4 cases, brain abscess in 1 case, absence of abnormality in 1 case. There was no angiographic documentation. Antimicrobial therapy was maintained 5 to 6 weeks. Two patients underwent cardiac surgery. Two patients died of subarachnoid haemorrage. Comparison of patients with NC, and the 43 without NC, revealed two different point: vegetations were more frequent in the NC (8 cases out of 10) than without NC (19 cases out of 43) (p = 0.04). Streptoccus was often more found in NC (6 cases out of 6) than without NC (6 cases out of 24) (p < 0.01). Compared with the previously reported studies, where Staphylococcus was usually described, our results showed a higher frequency of Streptococcus D bovis, an older age, a higher frequency of stroke and digestive portal of entry. Vegetations were more frequent with NC than without.

Adult↗
PubMed1994

Solution structure of Taxotere-induced microtubules to 3-nm resolution. The change in protofilament number is linked to the binding of the taxol side chain.

The synchrotron x-ray solution scattering profiles of microtubules assembled from purified GDP- or GTP-tubulin with the antitumor drug docetaxel (Taxotere) are consistent with identical non-globular alpha and beta-tubulin monomers ordered within the known surface lattice of microtubules, with a center to center lateral spacing of 5.7 +/- 0.1 nm. The higher angle part of the scattering profile, and therefore the substructure of the microtubule wall is identical in Taxotere- and Taxol-induced microtubules, to the resolution of the measurements. However, Taxotere-induced microtubules have a mean diameter of 24.2 +/- 0.4 nm, which is 1.12 +/- 0.01 times larger than that of paclitaxel (Taxol) induced microtubules. The population of Taxotere microtubules has on average 13.4 protofilaments, which is similar to control microtubules assembled with glycerol but is in marked contrast with Taxol-induced microtubules, which have on average 12 protofilaments under identical solution conditions. Model populations of Taxotere and Taxol microtubules with the distributions of protofilament numbers determined by electron microscopy reproduce the positions and approximate intensities of the experimental x-ray scattering data. Comparison of the structures and activities of both taxoids strongly suggests that the change of the more frequent lateral bond angle between tubulin molecules from 152.3 degrees (13-protofilament microtubules) to 150 degrees (12-protofilament microtubules) is linked to the binding of the side chain of Taxol. Optimal microtubule formation is obtained with unitary Taxotere to tubulin heterodimer ratio; however, ligand molecules in excess over tubulin dimers cause a loss of cylindrical scattering features, consistent with microtubule opening. The results are compatible with the observed biochemical and thermodynamic properties of this ligand-induced microtubule assembly system and also with the simple working hypothesis that taxoids would bind between adjacent microtubule protofilaments.

Docetaxel↗
PubMed1994

[Vasculitis associated with a myelodysplastic syndrome: a report of 5 cases].

In a study of 94 patients with myelodysplastic syndrome (MDS) associated vasculitis was observed in 5, which preceded hematologic diagnosis in 4. Leukocytoclastic vasculitis was observed in 5 cases being associated to lobular panniculitis in one. Three patients had refractory anemia, one sideroblastic anemia (SA) and another refractory anemia with excess blasts (RAEB). In the latter case lymphomatoid papulosis was also observed which, to date, has not been previously described in association with MDS. Another case presented seronegative polyarthritis and renal disease coinciding with vasculitis. Polyarteritis nodosa was diagnosed in a third patient in agreement with the criteria of the American College of Rheumatology, the association of which with MDS is exceptional. In the same case medullary cytogenetic study showed 46, XY,t (12;20), an abnormally which has not been described to date in cases of MDS. All the cases were treated with glucocorticoids in addition to cyclophosphamide in the patient with polyarteritis nodosa, with an improvement in the vasculitis being observed in all the patients. Two patients died, one (SA) due to pneumonia and the other (RAEB) due to subdural hematoma following transformation to acute myeloblastic leukemia. With 5% of the MDS studied presenting vasculitis, this syndrome should be included in the differential diagnosis of vasculitis observed in patients with cytopenia.

Aged↗
PubMed1994

Response of conductance and resistance coronary vessels to scalar concentrations of acetylcholine: assessment with quantitative angiography and intracoronary Doppler echography in 29 patients with coronary artery disease.

Abnormal vasoreactivity of the large conductance arteries has been observed in the presence of impaired endothelial function. More recently, experimental and clinical reports have shown that in early coronary atherosclerosis the impairment of the endothelium-mediated vasodilatation also involves the resistance arteries. The aim of this study is the correlation of endothelium-dependent vasodilatation of conductance and resistance vessels in coronary arteries without significant stenoses. In 29 patients (aged 57 +/- 9 years, 24 men and 5 women) undergoing coronary angioplasty, a Doppler guide wire and a perfusion catheter were introduced into the proximal segment of an artery with less than 30% diameter stenosis. Selective infusions of papaverine (bolus of 7 mg), acetylcholine (continuous infusion of 0.036, 0.36, and 3.6 micrograms/ml at a flow rate of 2 ml/min), and isosorbide dinitrate (bolus of 3 mg) were sequentially performed. Heart rate, aortic blood pressure, and blood flow velocity were continuously measured. Mean cross-sectional areas of a proximal and a distal arterial segment were measured in baseline conditions, at the end of each infusion of acetylcholine, and at the peak effect of isosorbide dinitrate with quantitative angiography (CAAS System; Pie Medical Data, Maastricht, The Netherlands). Coronary blood flow was calculated from the time-averaged flow velocity and the cross-sectional area at the site of the Doppler sample volume. Coronary flow resistance was calculated as mean aortic pressure divided by coronary flow. All of the concentrations of acetylcholine induced a significant vasoconstriction of the studied artery. At the maximal concentration of acetylcholine all but three patients (90%) showed a reduction of cross-sectional area (-24% +/- 20% and -22% +/- 20% for the proximal and distal segments, respectively, p < 0.00001). Flow velocity showed a significant increase only with the two highest concentrations of acetylcholine. The maximal concentration induced a 105% +/- 138% increase from the baseline flow velocity (p < 0.001). The coronary flow changes after acetylcholine showed a large interpatient variability, with a mean increase from baseline after the highest dose of +43% +/- 85% (range, -60% +/- 239%), with the presence of a flow reduction in 10 patients (35%). No clinical or angiographic variables showed a significant correlation with the cross-sectional area, flow velocity, and flow changes after infusion of acetylcholine.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗
PubMed1994

X-linked spastic paraplegia and Pelizaeus-Merzbacher disease are allelic disorders at the proteolipid protein locus.

Three forms of X-linked spastic paraplegia (SPG) have been defined. One locus (SPG 1) maps to Xq28 while two clinically distinct forms map to Xq22 (SPG2). A rare X-linked dysmyelinating disorder of the central nervous system, Pelizaeus-Merzbacher disease (PMD), has also been mapped to Xq21-q22, and is caused by mutations in the proteolipid protein gene (PLP) which encodes two myelin proteins, PLP and DM20. While narrowing the genetic interval containing SPG2 in a large pedigree, we found that PLP was the closest marker to the disease locus, implicating PLP as a possible candidate gene. We have found that a point mutation (His139Tyr) in exon 3B of an affected male produces a mutant PLP but a normal DM20, and segregates with the disease (Zmax = 6.63, theta = 0.00). It appears, therefore, that SPG2 and PMD are allelic disorders.

Alleles↗
PubMed1994

Slope of the instantaneous hyperemic diastolic coronary flow velocity-pressure relation. A new index for assessment of the physiological significance of coronary stenosis in humans.

BACKGROUND: Coronary flow reserve (CFR), the functional index of stenosis severity more frequently used in the catheterization laboratory, is greatly affected by the hemodynamic conditions at the time of measurement and cannot be applied in the immediate assessment of the outcome of coronary interventions. The aim of the present study was to establish the feasibility and reproducibility of the assessment of the slope of the instantaneous diastolic relation between coronary flow velocity and aortic pressure during maximal hyperemia (IHDVPS) using a spectral analysis of the intracoronary Doppler signal, to assess the sensitivity and specificity of this index in the detection of flow-limiting coronary stenoses in comparison with CFR, and to study the possibility of determining the zero-flow pressure from the intercept of the velocity-pressure relation on the pressure axis during a controlled cardiac arrest. METHODS AND RESULTS: The instantaneous peak coronary flow velocity measured after intracoronary papaverine with a Doppler guidewire was plotted against the simultaneously measured aortic pressure, and the slope of the velocity-pressure relation in the phase of progressive diastolic velocity decrease was calculated during four consecutive beats. In nine normal arteries, a controlled diastolic cardiac arrest was induced by an intracoronary bolus injection of 3 mg adenosine. The IHDVPS could be assessed in 79 of 95 patients (83%), with a moderate intraobserver variability (0.4 +/- 11% after independent selection of different beats during maximal hyperemia). The IHDVPS showed no significant correlation with heart rate, mean diastolic aortic pressure, type of vessel studied, and cross-sectional area at the site of the velocity recording. The IHDVPS was significantly lower in arteries with > or = 30% diameter stenosis than in normal or near-normal arteries (0.71 +/- 0.48 versus 1.73 +/- 0.80 cm.s-1.mm Hg-1, P < .0000002). In the stenosis group, both IHDVPS and CFR were significantly correlated with the minimal luminal cross-sectional area (r = .46, P < .05 and r = .62, P < .002, respectively). The study of the velocity-pressure relation during long diastolic pauses showed a curvilinear relation between velocity and pressure in the lower pressure range, with an upward concavity to the velocity axis and no intercept with the pressure axis in most cases. CONCLUSIONS: The IHDVPS can distinguish between arteries with and without coronary stenoses and has a significant inverse correlation with the severity of the stenosis. Under the stable hemodynamic conditions of this study, the IHDVPS and CFR had similar sensitivities and specificities in distinguishing normal and stenotic vessels and demonstrated similar correlation with minimal luminal cross-sectional area. The curvilinearity of the velocity-pressure relation during long diastolic pauses, possibly due to a significant reduction of luminal cross-sectional area at low pressures, complicates the use of the flow velocity-pressure relation for the assessment of the zero-flow pressure.

Adult↗
PubMed1994

Some factors influencing delay in leprosy diagnosis.

To study delay in leprosy diagnosis in Cuba, home interviews were conducted with all patients whose cases were diagnosed during 1989-1990 in Guantánamo and Havana, where leprosy prevalences are respectively high and moderate. Data from the two cities showed a significant difference in the average time passing between the first appearance of symptoms and definitive diagnosis, this time being 16.6 months in Havana and 10.7 months in Guantánamo (p < 0.01). Moreover, the patterns of delay were different. In Havana, the average patient sought medical advice relatively soon (a month after the first symptoms appeared), but the one or more physicians consulted took an average of 15.6 months to arrive at the diagnosis. In contrast, the average Guantánamo physician reached a definitive diagnosis in 5 months, but the average Guantánamo patient waited 5.7 months before visiting the doctor. These observations demonstrate that delayed diagnosis can have quite different causes in different places, and that interventions seeking to reduce such delay need to consider the contributing causes in the particular locale involved. In the case of leprosy diagnosis in Havana and Guantánamo, future interventions in Havana should aim at increasing the physician's level of clinical suspicion, while in Guantánamo they should encourage patients to seek medical care as soon as they begin to notice symptoms.

Adolescent↗
PubMed1993

Maximal blood flow velocity in severe coronary stenoses measured with a Doppler guidewire. Limitations for the application of the continuity equation in the assessment of stenosis severity.

In vitro and animal experiments have shown that the severity of coronary stenoses can be assessed using the continuity equation if the maximal blood flow velocity of the stenotic jet is measured. The large diameter and the low range of velocities measurable without frequency aliasing with the conventional intracoronary Doppler catheters precluded the clinical application of this method for hemodynamically significant coronary stenoses in humans. This article reports the results obtained using a 12 MHz steerable angioplasty guidewire in a consecutive series of 52 patients undergoing percutaneous coronary angioplasty (61 coronary stenoses). The ratio between coronary flow velocity in a reference segment and in the stenosis was used to estimate the percent cross-sectional area stenosis. A Doppler recording suitable for quantitation was obtained in the stenotic segment in only 10 of 61 arteries (16%). The time-averaged peak velocity increased from 15 +/- 5 to 115 +/- 26 cm/sec from the reference normal segment to the stenosis. Volumetric coronary flow calculated from the product of mean flow velocity and cross-sectional area was similar in the stenosis and in the reference segment (33.2 +/- 14.9 vs 33.5 +/- 17.0 mL/min, respectively, difference not significant). The percent cross-sectional area stenosis and minimal luminal cross-sectional area derived from the Doppler velocity measurements using the continuity equation and calculated with quantitative angiography were also similar (Doppler, 86.7 +/- 5.1% and 1.00 +/- 0.48 mm2; quantitative angiography, 85.9 +/- 7.9% and 1.02 +/- 0.50 mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Granular cell basal cell carcinoma. Light microscopy, immunohistochemical and ultrastructural study.

Granular cell basal cell carcinoma (BCC) is a rare histological variant of BCC. In this, the fifth reported case, a 67-year-old male with BCC located on the nose, light microscopy examination showed a tumour with the classical configuration of nodular BCC, in which most cells had finely granular eosinophilic cytoplasm. Ultrastructural observation showed numerous lysosome-like granules filling the cytoplasm of tumour cells, along with numerous well-formed pentalaminate desmosomes. Immunohistochemical profile (including positivity for keratins C 5.2 and AE 1 and for Leu-M1), together with the presence of cytoplasmic tonofilament bundles and desmosomes, are consistent with the proposed epithelial origin of granular cells in this tumour.

Aged↗
PubMed1993

Febrile ulceronecrotic Mucha-Habermann disease.

Febrile ulceronecrotic Mucha-Habermann disease in an 18-year-old man is reported. This disease is a severe form of pityriasis lichenoides et varioliformis acuta (PLEVA) and is characterized by the sudden onset of diffuse coalescent ulcerations associated with high fever and systemic symptoms. In the present case the disease was preceded by typical PLEVA. Histologically, a leukocytoclastic vasculitis was seen in addition to the usual features of PLEVA. Findings of laboratory studies revealed an elevated erythrocyte sedimentation rate, a high white blood cell count, and a mild increase in liver enzymes. No systemic involvement was detected. Findings of T cell receptor gene analysis in skin and peripheral blood showed no abnormality. The patient was treated with PUVA and methotrexate with a good response. We review the eight previously reported cases of febrile ulceronecrotic Mucha-Habermann disease.

Adolescent↗
PubMed1993

Lymphoepithelioma-like carcinoma of the skin.

A 70-year-old patient who presented with a mass on the dorsum of his nose of 2 years evolution is reported. Histologically it was formed by dermal nests and cords of atypical epithelial cells surrounded by an intense inflammatory infiltrate composed of lymphocytes and histiocytes of an usual aspect. The lesion was removed, relapsing 2 years later. The ultrastructural and immunohistochemical results are discussed. We compare another six cases of lymphoepithelioma-like carcinoma, reported in the literature. The differential diagnosis with other related conditions is discussed together with its possible adnexal origin.

Aged↗
PubMed1993

Centroblastic transformation of chronic lymphocytic leukaemia with primary skin involvement--cutaneous presentation of Richter's syndrome.

The development of a large-cell non-Hodgkin's lymphoma in a patient suffering from chronic lymphocytic leukaemia is known as Richter's syndrome, representing one of the possible anaplastic transformations of the leukaemia. Cutaneous involvement is an extremely rare event. The case of a 45-year-old man with B-cell chronic lymphocytic leukaemia is reported. Five years later multiple cutaneous nodules developed on his extremities. Biopsies of the skin showed a diffuse large-cell lymphoma, bearing the same cell surface immunoglobulin light chain isotype as the leukaemia, suggesting the original relationship between both neoplasms.

Adult↗
PubMed1993

X linked spastic paraplegia (SPG2): clinical heterogeneity at a single gene locus.

X linked hereditary spastic paraplegia is a rare condition that has been divided into two forms (the pure spastic form and the complicated form) as a function of clinical course and severity. A gene for pure hereditary spastic paraplegia (SPG2) has been mapped to the proximal long arm of the X chromosome (Xq21) by linkage to the DXS17 locus, while a gene for a complicated form of the disease has been mapped to the distal long arm by linkage to the DXS52 locus (Xq28). Here we report on the mapping of a gene for complicated hereditary spastic paraplegia to the Xq21 region by linkage to the probe S9 at the DXS17 locus (Z = 5 at theta = 0.04) in a three generation pedigree. Multipoint linkage analysis supports the distal location of the disease gene with respect to the DXYS1-DXS17 block (cen-DXYS1-DXS3-DXS17-SPG2-tel). The observation of a complicated form of spastic paraplegia mapping to Xq21 raises the difficult issue of variable phenotypic expression, allelic heterogeneity, or even close proximity of two genes for hereditary spastic paraplegia in this region. However, since our study provides clinical evidence for intrafamilial heterogeneity in complicated X linked spastic paraplegia, the present data support the hypothesis of variable clinical expression of a single gene at the SPG2 locus, as previously suggested for SPG1. Finally, we report here what we believe to be the first evidence of clinical expression in heterozygous carriers, a feature that is relevant to genetic counselling in at risk females.

Adolescent↗