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Devriese LA, Pot B, Vandamme P, Kersters K, Collins MD, Alvarez N, Haesebrouck F, Hommez J. Streptococcus hyovaginalis sp. nov. and Streptococcus thoraltensis sp. nov., from the genital tract of sows. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1997; 47:1073-7. [PMID: 9336908 DOI: 10.1099/00207713-47-4-1073] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two groups of strains isolated from sows were shown to belong to new sublines in the genus Streptococcus. Based on phenotypic and phylogenetic analyses, we propose that these bacteria should be classified as two new species, Streptococcus hyovaginalis sp. nov. and Streptococcus thoraltensis sp. nov. These two species are found in the genital tract, but the capnophilic species S. thoraltensis may also occur in the intestinal tract of pigs. The type strain of S. hyovaginalis is SHV515 (= LMG 14710), and S69 (= LMG 13593) is the type strain of S. thoraltensis.
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Ramos CP, Falsen E, Alvarez N, Akervall E, Sjödén B, Collins MD. Actinomyces graevenitzii sp. nov., isolated from human clinical specimens. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1997; 47:885-8. [PMID: 9226924 DOI: 10.1099/00207713-47-3-885] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Four strains of a previously unknown, catalase-negative, facultatively anaerobic, gram-positive, rod-shaped organism originating from humans were characterized by biochemical, chemical, and molecular taxonomic methods. The four strains phenotypically closely resembled one another, and although they possessed characteristics consistent with membership in the genus Actinomyces, they differed from all previously recognized species of this genus. The results of comparative 16S rRNA gene sequencing studies demonstrated that the unknown human bacterium was phylogenetically a member of the genus Actinomyces. Within the genus Actinomyces, the unidentified bacterium formed a loose, but statistically significant, association with a subgroup which included Actinomyces bovis, the type species of the genus. 16S rRNA sequence divergence values of > 6%, however, unequivocally demonstrated that the unidentified bacterium represents a new subline of the genus Actinomyces. A new species, Actinomyces graevenitzii, is proposed for the four new isolates. The type strain of A. graevenitzii is CCUG 27294.
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Funke G, Alvarez N, Pascual C, Falsen E, Akervall E, Sabbe L, Schouls L, Weiss N, Collins MD. Actinomyces europaeus sp. nov., isolated from human clinical specimens. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1997; 47:687-92. [PMID: 9226901 DOI: 10.1099/00207713-47-3-687] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ten strains of a hitherto undescribed catalase-negative, facultatively anaerobic, coryneform bacterium were isolated or collected by workers at three European clinical bacteriology laboratories or reference centers. These strains were isolated from humans, and most came from abscess material. Biochemical and chemotaxonomic characterization revealed that the strains belonged to the genus Actinomyces. The phenotypic features of the 10 strains were incompatible with the descriptions of the previously established Actinomyces species. A comparative 16S rRNA gene sequence analysis demonstrated that the previously undescribed strains constitute a new line in the genus Actinomyces. The name Actinomyces europaeus sp. nov. is proposed for these clinical isolates. The type strain is CCUG 32789A.
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Rakowski H, Appleton C, Chan KL, Dumesnil JG, Honos G, Jue J, Koilpillai C, Lepage S, Martin RP, Mercier LA, O'Kelly B, Prieur T, Sanfilippo A, Sasson Z, Alvarez N, Pruitt R, Thompson C, Tomlinson C. Canadian consensus recommendations for the measurement and reporting of diastolic dysfunction by echocardiography: from the Investigators of Consensus on Diastolic Dysfunction by Echocardiography. J Am Soc Echocardiogr 1996; 9:736-60. [PMID: 8887883 DOI: 10.1016/s0894-7317(96)90076-0] [Citation(s) in RCA: 433] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Abnormalities of diastolic filling are increasingly recognized as a cause of symptoms and predictors of outcome in patients with most forms of heart disease. Noninvasive assessment of diastolic filling is possible in almost all patients, but accurate evaluation must relate echocardiographic Doppler measurements to the complex physiologic and hemodynamic factors responsible for normal and abnormal filling. This evaluation has been facilitated by recent correlation of Doppler measurement of mitral and pulmonary venous inflow with hemodynamic studies. These studies have confirmed that when a careful, integrated approach is taken, Doppler flow patterns can document a progressive pattern of abnormality in many conditions. Impaired left ventricular (LV) relaxation is seen early and is recognized by a decrease in early transmitral LV filling and an increased proportion of filling during atrial contraction. As abnormalities progress, increasing LV chamber stiffness and elevated left atrial pressure lead to a "pseudonormal" filling pattern that previously has caused considerable confusion. This can be unmasked by careful evaluation of pulmonary venous inflow and the use of the Valsalva maneuver. When marked diastolic abnormalities are present, LV filling has restrictive features characterized by rapid early filling, a very stiff left ventricle with high filling pressures, and a poor prognosis. Routine measurement of indexes of diastolic filling have been hampered by uncertainty as to what should be measured, what techniques should be used, definition of normal values, and a clear method of reporting findings. This report represents the efforts of a Canadian consensus group to define a national standard for the performance and reporting of echocardiographic Doppler studies of diastolic filling.
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Chan KL, Alvarez N, Cujec B, Dumesnil J, Koilpillai C, Patton N, Pollick C. [Standards for performing echocardiography in adults. Subcommittee on Echocardiography. Committee on Standards of the Canadian Society of Cardiology]. Can J Cardiol 1996; 12:722-6. [PMID: 8925470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Chan KL, Alvarez N, Cujec B, Dumesnil J, Koilpillai C, Patton N, Pollick C. Standards for adult echocardiography training. Canadian Cardiovascular Society Committee. Can J Cardiol 1996; 12:473-6. [PMID: 8640591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Ruiz L, Alvarez N, Nuñez I, Montes I, Solano R, Fuentes D, Pedroso R, Palma G, Brem G. Effect of body condition on the developmental competence of IVM/IVF bovine oocytes. Theriogenology 1996. [DOI: 10.1016/0093-691x(96)84765-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pisani P, Oliver WE, Parkin DM, Alvarez N, Vivas J. Case-control study of gastric cancer screening in Venezuela. Br J Cancer 1994; 69:1102-5. [PMID: 8198977 PMCID: PMC1969457 DOI: 10.1038/bjc.1994.216] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A screening programme for early gastric cancer was introduced in the state of Tachira, Venezuela, in 1980. Screening was performed by photofluorography, using two mobile units. The efficacy of this programme in reducing mortality from stomach cancer was evaluated by means of a case-control study. Cases were 241 individuals who died from stomach cancer in the period 1985-89. Ten live controls per case were drawn from the electoral rolls, matched by sex, age and residence. Exposure to the screening examination of cases and controls was assessed through individual linkage with the programme's centralised database. After the exclusion of examinations occurring within the 6 months preceding the case's diagnosis, the odds ratio (OR) of dying from stomach cancer for those screened was 1.26 (CI 0.83-1.91) and the OR in females was lower than in males: 0.77 (CI 0.33-1.78) and 1.52 (CI 0.94-2.47) respectively. Odds ratios associated with years since last test and number of tests did not differ significantly from 1. These results show the inefficacy of the programme in reducing mortality from gastric cancer in the area. In an attempt to determine whether this result was due to selection bias, an analysis restricted to subjects who had been screened at least once was performed. When examinations occurring after an index date at various intervals before the case's diagnosis were excluded, the screening test appeared to protect from death, although confidence intervals of the odds ratios are large, for example OR = 0.47 (CI 0.24-0.98) when excluding tests within 1 month.
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Peteiro J, Alvarez N, Calviño R, Penas M, Ribera F, Castro Beiras A. Changes in left ventricular mass and filling after renal transplantation are related to changes in blood pressure: an echocardiographic and pulsed Doppler study. Cardiology 1994; 85:273-83. [PMID: 7850816 DOI: 10.1159/000176695] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To examine changes in left ventricular (LV) mass and function (diastolic and systolic) after successful renal allograft transplantation (RT), we prospectively studied 30 patients (19 men, 11 women, aged 37 +/- 13 years) by M-mode, two-dimensional and pulsed Doppler echocardiography at the time of surgery and 10 +/- 1.8 months later. At the time of transplantation all patients had been undergoing dialysis (4 peritoneal dialysis, 26 hemodialysis) for 2.5 +/- 3.2 years. A hematocrit of < or = 30% was present in 26 patients. After RT the mean hematocrit increased from 26 +/- 4 to 40 +/- 7 (p < 0.01), whereas systolic, diastolic and mean blood pressure (BP) remained unchanged. The LV mass index (LVMI) decreased from 201 +/- 56 to 171 +/- 41 g/m2, (p < 0.01); LV diastolic diameter corrected by body surface area (LVDDI) decreased from 298 +/- 38 to 279 +/- 35 (p < 0.01) and the LV end-diastolic volume index (LVEDVI) from 72 +/- 18 to 63 +/- 15 (p < 0.01). There were no changes in LV fractional shortening or LV end systolic wall stress. Peak late transmitral velocity (A wave) decreased from 77 +/- 16 to 68 +/- 12 cm/s (p < 0.01) with no changes in other Doppler-derived indexes of diastolic function. No fistula patency influence on changes in LV mass and function was found. After RT, BP decreased in 21 patients from 150 +/- 20 to 132 +/- 15 (p < 0.001; group I) and increased in 9 patients from 130 +/- 14 to 153 +/- 16 (p < 0.05, group II). Patients in group I suffered a reduction in LVMI (p < 0.001), LV end-diastolic diameter (p < 0.05), LVDDI (p < 0.001); LV end-diastolic volume (p < 0.05); LVEDVI (p < 0.01); cardiac index (p < 0.05), and peak late transmitral velocity (p < 0.01), but no changes in group-II patients were observed. We concluded that BP is a major determining factor with regard to changes in LV hypertrophy and function following RT. LV mass and volumes can be expected to decrease after RT in patients with BP reduction.
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MESH Headings
- Adult
- Blood Flow Velocity
- Blood Glucose/analysis
- Blood Pressure/physiology
- Creatinine/blood
- Echocardiography, Doppler, Pulsed
- Female
- Follow-Up Studies
- Heart Rate
- Hematocrit
- Humans
- Hypertrophy, Left Ventricular/diagnostic imaging
- Hypertrophy, Left Ventricular/etiology
- Hypertrophy, Left Ventricular/physiopathology
- Kidney Failure, Chronic/blood
- Kidney Failure, Chronic/complications
- Kidney Failure, Chronic/surgery
- Kidney Failure, Chronic/therapy
- Kidney Transplantation
- Male
- Middle Aged
- Peritoneal Dialysis
- Postoperative Care
- Potassium/blood
- Prospective Studies
- Renal Dialysis
- Stroke Volume
- Ventricular Function, Left/physiology
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Hagel I, Lynch NR, Di Prisco MC, Rojas E, Pérez M, Alvarez N. Ascaris reinfection of slum children: relation with the IgE response. Clin Exp Immunol 1993; 94:80-3. [PMID: 8403522 PMCID: PMC1534372 DOI: 10.1111/j.1365-2249.1993.tb05981.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Total and Ascaris-specific serum IgE levels were measured in a group of 98 Ascaris-infected children from a slum area of Caracas, Venezuela, in whom the infections were eliminated by regular treatment for 22 months with the anthelmint Oxantel/Pyrantel ('Quantrel'). The children were re-evaluated at the end of the treatment programme, and then 8 months later, at which time reinfection was assessed. Total IgE levels at the beginning of the study were significantly higher in the children who became reinfected after treatment, compared with those who did not. The anthelmint treatment caused a significant decrease in the total IgE levels in most of the children, and after a period of 8 months without treatment these continued to decrease in the non-reinfected group, but increased again in the reinfected children. The reverse pattern was found for Ascaris-specific IgE antibody levels, and in fact an inverse correlation was found between total and anti-Ascaris IgE levels. Striking associations were found between reinfection and high pretreatment values of total IgE, but low levels of specific IgE antibody. These data support the concept that specific IgE antibody may participate in the protection against helminthic infection, and suggest that the polyclonal stimulation of IgE synthesis caused by these parasites may reduce the effectiveness of such responses. The results also indicate that different individuals have varying propensities to respond polyclonally to the helminths, and this influences their resistance to infection.
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Lynch NR, Hagel I, Perez M, Di Prisco MC, Lopez R, Alvarez N. Effect of anthelmintic treatment on the allergic reactivity of children in a tropical slum. J Allergy Clin Immunol 1993; 92:404-11. [PMID: 8360391 DOI: 10.1016/0091-6749(93)90119-z] [Citation(s) in RCA: 228] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It is well known that helminthic infection can cause a polyclonal stimulation of the synthesis of IgE, which is dependent on interleukin-4 (IL-4) production, and it has been suggested that this can modulate the expression of allergic reactivity in tropical populations. We evaluated the effect of regular anthelmintic treatment, for a period of 22 months, on certain aspects of the allergic reactivity of children in a slum area of Caracas, Venezuela, where helminths are endemic. The treatment (Oxantel-Pyrantel; Quantrel) effectively eliminated intestinal helminthic infection and resulted in a significant decrease in the initially elevated total serum IgE levels. IL-4 was detectable in the serum, and a significant reduction in IL-4 was also observed after treatment. In contrast, both the immediate-hypersensitivity skin-test reactivity and serum levels of specific IgE antibody against environmental allergens were markedly increased in the treated children. In a group of children who were also evaluated in the same slum, but who declined treatment, a substantial increase in helminthic infection occurred, which was related to an acute deterioration of the socioeconomic conditions of Venezuela over the course of our study period. This was paralleled by a considerable increase in total IgE levels in these children and a decrease in the skin-test reactivities and specific IgE levels. The application of Prausnitz-Küstner passive transfer tests and analysis of specific IgE antibody levels indicated that the polyclonal stimulation of IgE synthesis by helminthic parasites results in mast cell Fc epsilon receptor saturation and suppression of specific IgE antibody synthesis. This inhibition of allergic reactivity is reversible by anthelmintic treatment.
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Llinares P, Miguez E, Echaniz A, Juffé A, Prado G, Alvarez N. [Infected atrial myxoma simulating infective endocarditis]. Enferm Infecc Microbiol Clin 1993; 11:378-81. [PMID: 8399475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND We present a case of infected atrial myxoma simulating bacterial endocarditis. MATERIAL AND METHODS A 75 year old male, without any antecedents of interest, with fever an evolution a month, and a cardiac murmur. Blood cultures were practiced by BACTEC N.R. 730 system. The diagnosis was performed by the bidimensional and transesophageal echo, and confirmed with the resection from surgery. The method of bibliographical review used, has been the data base of comprehensive Medline, cvc since 1987 up June 1992 and the Oncodise's Concerlit archive from the year 1985 up to june 1992 the date base of the IME (Indice Médico Español) was also review up to April 1992. RESULTS The blood cultures were positive, 7/7 Streptococcus viridans and 3/7 a Staphylococcus epidermidis resistant to meticiline, we them with the same antibiogram. Echocardiography and angiography show a lef atrial mass, surgical resection of the mass, confirmed the hystological diagnostic of the myxoma and signs of infection. CONCLUSIONS This is the first case in our country, with shows the rarity of it. We analyze the differential diagnosis with the non infected myxoma and the bacterial endocarditis. We think that there should be an early surgical treatment, together with antibiotic therapy, due to the high incidence of embolism in theses patients.
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Di Prisco MC, Hagel I, Lynch NR, Barrios RM, Alvarez N, López R. Possible relationship between allergic disease and infection by Giardia lamblia. ANNALS OF ALLERGY 1993; 70:210-3. [PMID: 8452315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In order to better understand the possible relationship between allergic reactivity and infection with G. lamblia, specific IgE responses and skin test reactivity were evaluated in allergic or nonallergic Venezuelan children, with or without G. lamblia infection. Two groups of children were studied: one from our Allergy Clinic and the other from a slum area of Caracas. The total serum IgE levels in children from the slum area were significantly higher in those with intestinal helminthic parasites and giardiasis, compared with those with helminthiasis only (P < .001). In atopic children with giardiasis we also found an enhanced IgE antibody response to common environmental allergens (P < .05). As G. lamblia produces intestinal mucosal damage, we also studied the reactivity to cow milk and found that 22% of the children belonging to the low socioeconomic level demonstrated the presence of significant levels of specific IgE against this antigen. Of these milk-positive subjects, 40% were infected by G. lamblia in contrast to only 21% of the milk-negative children (P < .05). These results suggest that children with giardiasis may be exposed to greater amounts of intestinally absorbed antigens. We also studied the specific allergic response to G. lamblia, and found that in an unselected group of children of low socioeconomic level, 25% had positive skin tests, as did 50% of persons with symptomatic giardiasis. The presence of serum anti-Giardia IgE was also demonstrated in 22% of patients with giardiasis.
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Alton KB, Hernandez A, Alvarez N, Patrick JE. High-performance liquid chromatographic determination of N-[2(S)-(mercaptomethyl)-3-(2-methylphenyl)-1-oxopropyl]-L-methionine, the active plasma metabolite of a prodrug atriopeptidase inhibitor (SCH 42495), using a thiol selective (Au/Hg) amperometric detector. JOURNAL OF CHROMATOGRAPHY 1992; 579:307-17. [PMID: 1429978 DOI: 10.1016/0378-4347(92)80396-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A high-performance liquid chromatographic assay for the determination of N-[2(S)-(mercaptomethyl)-3-(2-methylphenyl)-1-oxopropyl]-L-methionine (SCH 42354; II), the active metabolite of the atriopeptidase inhibitor prodrug, N-[2(S)-(acetylthiomethyl)-3-(2-methylphenyl)-1-oxopropyl]-L-methi onine ethyl ester (SCH 42495; I), in human plasma was validated for use in clinical pharmacokinetic studies. Plasma (200 microliters) was processed by protein precipitation with acetone containing the internal standard, N-[2(S)-(mercaptomethyl)-3-(2-methylphenyl)-1-oxopropyl]-L- ethionine (III). Compound II was recovered (ca. 90%) in the supernatant after centrifugation and prepared for injection by the addition of 0.15 M monochloroacetic acid containing 0.2 mM EDTA. Separation of II and III was accomplished on commercially available reversed-phase C8 columns designed for the separation of basic compounds. Both compounds were detected using amperometric detection (+0.125 V versus Ag/AgCl) on a thin-layer Au/Hg amalgam electrode. The lower limit of quantitation was 10 ng/ml, where the inter-assay precision (coefficient of variation) was +/- 11.4% and the inter-assay accuracy (bias) was +1.0%. No endogenous interferences were observed in the extracts obtained from drug-free plasma. The detector response (using either peak area or height ratios of II to III) was linear from 0.01 to 1.0 micrograms/ml. Compound II was stable in plasma supplemented with EDTA and sodium hydrogensulfite for at least 3 months when stored frozen at -78 degrees C; no significant decomposition of II was observed following three freeze-thaw cycles. The feasibility of this liquid chromatographic assay with electrochemical detection was demonstrated with plasma samples from hypertensive subjects administered 100 mg of compound I.
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Lynch NR, Hagel I, Perez M, Di Prisco M, Alvarez N, Rojas E. Bronchoconstriction in helminthic infection. Int Arch Allergy Immunol 1992; 98:77-9. [PMID: 1624209 DOI: 10.1159/000236167] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In order to determine whether infection by helminthic parasites can be associated with a state of bronchoconstriction, we evaluated the response to the inhalation of a bronchodilator before and after long-term anthelmintic treatment of children in a urban slum of Caracas, Venezuela. In untreated children, a direct association was found between the degree of helminthic infection and the increase in peak expiratory flow rates caused by the bronchodilator. The elimination of the infections was accompanied by a significant decrease in response to the bronchodilator. These results indicate that helminthic infection could contribute to the development of asthmatic conditions in areas where these parasites are endemic.
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LeMay M, Alvarez N. The relationship between enlargement of the temporal horns of the lateral ventricles and dementia in aging patients with Down syndrome. Neuroradiology 1990; 32:104-7. [PMID: 2144615 DOI: 10.1007/bf00588558] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Head CT studies of patients with Alzheimer's disease (AD) show global atrophic changes. Tissue loss is especially prominent in the temporal lobes, with widening of the temporal horns of the lateral ventricles and, usually, widening of the temporal sulci. Some recent studies have found a familial form of AD to be mapped to chromosome 21. Down syndrome (DS) results from the inheritance of three chromosomes 21, and it has been shown that after the age of 35 the brains of patients with DS commonly show neuropathological changes similar to those in patients with AD. CT studies of 25 patients with DS (ages 29-64 years) were examined for tissue loss in the temporal regions, and this was compared to the findings commonly seen in patients with AD. The widths of CSF spaces varied considerably in patients with DS, but after the age of 50 most of them showed significant widening of the temporal horns. In some patients the horns were large enough to suggest obstructive hydrocephalus. Because of a new trend toward deinstitutionalization of patients with DS, radiologists will be seeing more studies on these patients and should familiarize themselves with the unique ways in which they manifest the aging process.
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Alvarez N. Comments on discontinuance of antiepileptic medications. AMERICAN JOURNAL OF MENTAL RETARDATION : AJMR 1989; 93:605-6. [PMID: 2719843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Alvarez N. Discontinuance of antiepileptic medications in patients with developmental disability and diagnosis of epilepsy. AMERICAN JOURNAL OF MENTAL RETARDATION : AJMR 1989; 93:593-9. [PMID: 2783218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fifty patients with developmental disabilities and past history of epilepsy but without reported seizures fo several years underwent trial reductions of an antiepileptic drug. After an 8-year follow-up there was recurrence of seizures in 26 patients. Predictors for a seizure free state off medication were: few documented seizures in lifetime, no gross neurological abnormalities, medication below therapeutic levels at time of discontinuance, and persistently normal EEGs before and after discontinuance. Successful withdrawal of medication may have resulted from early control of seizures or early treatment; lack of actual epileptic seizures but presence of "pseudoseizures"; isolated event seizures; or seizures that could have resulted from nonepileptic, self-limiting factors.
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Ogle JW, Toltzis P, Parker WD, Alvarez N, McIntosh K, Levin MJ, Lauer BA. Oral ribavirin therapy for subacute sclerosing panencephalitis. J Infect Dis 1989; 159:748-50. [PMID: 2926165 DOI: 10.1093/infdis/159.4.748] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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70
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Neill JC, Alvarez N. The effects of the everyday environment on epileptic activity in three mentally retarded individuals. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1989; 72:198-206. [PMID: 2465122 DOI: 10.1016/0013-4694(89)90244-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Three mentally retarded epileptic subjects with frequent epileptiform EEG paroxysms were monitored with simultaneous radio-telemetered EEG and video recording while they were exposed to their everyday environmental conditions. These conditions included prompts and reinforcement for performing vocational training tasks, speech therapy, eating and drinking, and cues for resting, waiting, playing, exercising, and relaxing. Epileptiform EEG activity and the occurrence of clinical seizures varied as a function of the particular environmental conditions. Epileptiform EEG discharges were longer in duration, and clinical seizures were more frequent in all 3 subjects during conditions which produced inactive behavior than during conditions which produced active behavior. The modulation of epileptiform activity by everyday environmental conditions carries implications for (1) the optimum structuring of the environment for mentally retarded patients with frequent, subtle seizures, and (2) the analysis of the effects of epileptiform discharges on behavior.
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Alvarez N, Rubin L. Atlantoaxial instability in adults with Down syndrome: a clinical and radiological survey. APPLIED RESEARCH IN MENTAL RETARDATION 1986; 7:67-78. [PMID: 2938541 DOI: 10.1016/0270-3092(86)90019-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A survey of 129 adults with Down syndrome was undertaken to determine the prevalence of atlantoaxial instability (AAI) and to establish a base line for long term prospective study. Clinical and radiological evaluations were performed to determine optimal screening methods for this condition. The findings indicate that radiological evidence of AAI was found in 40% with anterior atlanto-odontoid distance (AAOD) of 3 mm or more and in 10% with 5 mm or more. These findings are similar to those reported in the pediatric age group. A preponderance of females with symptomatic AAI is noted. Clinical evaluation suggested the presence of spinal cord compression, which was confirmed by CT scan of the atlantoaxial region. There were no false negative clinical results. Among the false positive clinical findings other explanations were present in some cases. A comparison with the literature is offered along with guidelines on screening and management.
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Neill JC, Alvarez N. Differential diagnosis of epileptic versus pseudoepileptic seizures in developmentally disabled persons. APPLIED RESEARCH IN MENTAL RETARDATION 1986; 7:285-98. [PMID: 3752987 DOI: 10.1016/s0270-3092(86)80002-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
One-hundred and twenty-four mentally retarded persons with behaviors suggestive of epilepsy were monitored with an 8-channel radiotelemetered electroencephalograph-video recording system (TEEG-VR). Target behaviors were identified by the clinical description of the primary care providers before the TEEG-VR sessions. Whenever possible, the known antecedents of those behaviors were replicated. The target behaviors were considered epileptic when they were observed simultaneously with epileptiform EEG patterns, and pseudoepileptic when nonepileptiform patterns were observed. Twenty persons were classified as epileptic, 50 as pseudoepileptic, 11 as both epileptic and pseudoepileptic, and 43 as inconclusive. Among the pseudoepileptics there were 15 with abnormal EEGs and 4 with epileptiform EEGs. The most frequent topographies of behavior were not significantly related to diagnosis. These included myoclonus, eye blink, head drop, cessation of ongoing activity, and hand and arm automatisms. The diagnosis of epilepsy in mentally retarded persons, on the basis of clinical description, interictal EEG, and medical history, may be inaccurate. TEEG-VR is extremely useful for obtaining a definitive diagnosis of each target behavior.
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Alvarez N. Effect of different doses of valproic acid on the serum levels of total and free diphenylhydantoin. CLINICAL EEG (ELECTROENCEPHALOGRAPHY) 1985; 16:104-10. [PMID: 3924446 DOI: 10.1177/155005948501600210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the course of a large prospective study aimed at evaluating the efficacy of Valproic Acid (VPA) in persons with intractable seizures, six patients that were on a steady dose of diphenylhydantoin (DPH) were exposed to different steady doses of VPA. The changes observed in the serum levels of total, free, and percentage of free DPH are reported here. There were no consistent changes in the serum levels of total DPH, but when serum levels of DPH, obtained before VPA was added to the therapeutic plan, were considered, it was found that the total DPH decreased in those patients with the higher baseline levels while it increased in those with the lower baseline levels. There also was an increase in the absolute total and the percentage of free DPH in most instances. The data suggested that the changes occurred soon after VPA was added and remained constant in the same patient as long as the total dose of VPA did not change. The data also suggested that VPA most probably interfered through a dual mechanism, displacement of albumin-fixed DPH, and decreased liver clearance of DPH. The interpersonal variability was such that only broad generalizations are possible. There is a need to measure free DPH in patients on VPA.
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Wilkins DE, Hallett M, Berardelli A, Walshe T, Alvarez N. Physiologic analysis of the myoclonus of Alzheimer's disease. Neurology 1984; 34:898-903. [PMID: 6234478 DOI: 10.1212/wnl.34.7.898] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Ten patients with clinically diagnosed Alzheimer's disease, including three cases of trisomy 21 (Down's syndrome), developed a chronic myoclonic disorder. The technique of jerk-locked averaging of EEG activity was used to analyze the myoclonus. Seven subjects demonstrated a focal, contralateral central, negative cerebral potential antecedent to the myoclonic jerks. This EEG event differs from that previously reported to be associated with the myoclonus of subacute spongiform encephalopathy (Creutzfeldt-Jakob disease).
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Alvarez N, Lombroso CT, Medina C, Cantlon B. Paroxysmal spike and wave activity in drowsiness in young children: its relationship to febrile convulsions. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1983; 56:406-13. [PMID: 6194956 DOI: 10.1016/0013-4694(83)90222-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Paroxysmal rhythmic theta waves appearing during early stages of sleep have long been recognized in the EEGs of normal children. A similar pattern with intermixed spikes appears to have a different correlation. We called this pattern 'hypnagogic paroxysmal spike wave activity' or 'hypnagogic PSW.' This investigation was designed to test whether there exists a relationship between hypnagogic PSW, febrile convulsions (FC) and age. We selected 3 cohorts of children: G-1 or normal control consisted of 94 children selected with the following criteria: complete normal neurodevelopmental examination and no personal or family history of FC, epilepsy, or other neurological disorder. They all had one EEG obtained without drug induction showing a clear sequence of awake-drowsy-sleep-arousal-awake states. G-2 or pathological control group consisted of 126 children selected at random, referred to the Division of Neurophysiology at the Children's Hospital Medical Center for any problem excluding FC. At least one EEG met the criteria mentioned above. G-3 or FC group consisted of 375 children in whom the very first seizure was associated with fever without evidence of other causes for the convulsion. All met the same EEG criteria of G-1 and G-2. The medical record of 169 children of this group (40 with hypnagogic PSW and 129 without hypnagogic PSW) were reviewed.(ABSTRACT TRUNCATED AT 250 WORDS)
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