PubMed Health⌕ Search

Biomedical subjects

M L Sanchez

Publications and source records attributed to M L Sanchez.

At least 19 recordsLinked to original sources
PubMed2003

Can the weighted criteria improve our ability to capture a larger number of lupus patients into observational and interventional studies? A comparison with the American College of Rheumatology criteria.

The objective of this study was to determine if the modified weighted criteria have better psychometric properties than the ACR criteria for the classification of patients with systemic lupus erythematosus (SLE). A computerized list of all patients with the diagnosis of SLE (ICD9 code 710.0) attending an outpatient rheumatology clinic was generated and their medical records reviewed. The attending rheumatologists validated the diagnosis of SLE; this assessment was used as the gold standard to compute the sensitivity, specificity and accuracy of both the American College of Rheumatology (ACR) and the modified weighted criteria. A total of 363 patients were identified and included in the study. Ninety percent were women; the mean age was 44.0 (+/- 14.4) years, and 51% were Caucasians. The modified weighted criteria had a sensitivity of 90.3% and specificity of 60.4%. The ACR criteria had a sensitivity of 86.5% and specificity of 71.90%. Both methods had comparable positive and negative predictive values as well as similar overall accuracy. The modified weighted criteria allow the identification of more lupus patients for clinical or interventional studies; some of these patients, however, may not have SLE according to experienced rheumatologists.

Adult↗
PubMed2001

Comparative analysis of the morphological, cytochemical, immunophenotypical, and functional characteristics of normal human peripheral blood lineage(-)/CD16(+)/HLA-DR(+)/CD14(-/lo) cells, CD14(+) monocytes, and CD16(-) dendritic cells.

Human peripheral blood (PB) CD14(lo)/HLA-DR(+) cells were initially described as a subset of mature monocytes. Recently, it has been suggested that these represent a part of a new subset of dendritic cells (DC), characterized by the coexpression of MDC-8/HLA-DR/CD16. The aim of the present paper was to analyze the morphological, cytochemical, phenotypical, and functional characteristics of PB CD16(+)/HLA-DR(+) cells compared to both PB CD14(+) monocytes and CD16(-) DC. In contrast to CD14(+) monocytes, purified CD16(+)/HLA-DR(+) cells displayed cytoplasmic veils and lacked cytoplasmic myeloperoxidase and alpha-naphthyl acetate esterase. Normal human PB CD16(+)/HLA-DR(+) cells also displayed phenotypic characteristics different from those of CD14(+) monocytes: they lacked the CD64 Fcgamma receptor, showed lower levels of CD32, and expressed higher amounts of CD16 compared to CD14(+) monocytes. They also displayed a different pattern of expression of other antigens, including CD14, HLA-DR, CD45RA, CD45RO, complement receptors and complement regulatory surface proteins, adhesion and costimulatory molecules, and cytokine receptors, among others. When compared to CD16(-) DC, CD16(+)/HLA-DR(+) cells showed reactivity for CD16, dim positivity for CD14, higher expression of both Ig- and complement-receptors and lower reactivity for HLA-DR, adhesion, and costimulatory molecules (with the exception of CD86). The CD16(+)/HLA-DR(+) cell subset displayed a higher Ig/complement-mediated phagocytic/oxidative activity than CD16(-) DC, although this activity was significantly lower than that of mature monocytes. Regarding cytokine production at the single cell level, LPS plus IFN-gamma-stimulated PB CD16(+)/HLA-DR(+) cells produced significant amounts of IL1beta, IL6, IL12, TNFalpha, and IL8; however, the percentage of cytokine-producing cells and the amount of cytokine/cell were lower in CD16(+)/HLA-DR(+) cells than in CD14(+) monocytes. In addition, upon comparing CD16(+)/HLA-DR(+) cells with CD33(+++)/CD16(-) DC, we found that the percentage of cytokine-producing cells and the amount of cytokine/cell were significantly different in both cell subsets. In summary, our results show that CD16(+)/HLA-DR(+) cells clearly display different morphologic, cytochemical, immunophenotypical, and functional characteristics compared to both mature monocytes and CD16(-) DC. Interestingly, these cells are more frequent than other DC in normal human adult PB and cord blood samples, while they are less represented in normal bone marrow.

Adult↗
PubMed2001

Two-dimensional echo Doppler findings in juvenile and adult onset ankylosing spondylitis with long-term disease.

The authors' objective was to determine by 2-dimensional echo Doppler (2DECHO) the cardiac abnormalities in juvenile onset ankylosing spondylitis (JOAS) and adult onset ankylosing spondylitis (AOAS) in male patients with long-term disease. Twenty patients with JOAS, 31 with AOAS, and 20 healthy controls of the same age and gender without cardiopulmonary symptoms were studied. Using 2DECHO, the heart dimensions were determined according to American Society of Echocardiography guidelines. The left ventricle ejection fraction (LVEF) was calculated by Teichholz's formula. Cardiomyopathy was established when 2DECHO had diminished LVEF. Statistics used were the Student t and Fisher test, chi2, and ANOVA. Ninety percent of JOAS and 51% of AOAS patients were B27+ (p=0.005). The disease duration was 19.3 +/- 8.8 years in JOAS and 14.8 +/- 12.8 years in AOAS (p=NS). Age at the time of the study was 30.7 +/- 9.9 years in JOAS vs 40.3 +/- 12.7 in AOAS (p=0.003), and vs 40.2 +/- 17 years in controls (p=NS). There was a higher frequency of cardiomyopathy in AOAS (32.2%) than in JOAS (25%) and the controls (0%) (p=0.01). Patients with JOAS had a higher mitral valve gradient (25%) than AOAS patients (19%, p=NS) and controls (0%, p=0.04). Abnormal aortic ring reflectance was shown in 19% of AOAS vs 0% abnormalities in JOAS and controls (p=0.01). The aortic root diameter was increased in 58% of AOAS, 30% of JOAS, and 0% of controls (p=0.001). The frequency of 2DECHO abnormalities was increased in cardiopulmonary asymptomatic spondylitis patients. Despite the high frequency of B27+, JOAS had a lower frequency of aortic abnormalities than AOAS. Mitral valve gradient was found in JOAS and in AOAS that could contribute to a decreased ejection fraction and to left ventricular dysfunction.

Adolescent↗
PubMed1999

Extensive characterization of the immunophenotype and pattern of cytokine production by distinct subpopulations of normal human peripheral blood MHC II+/lineage- cells.

Dendritic cells (DC) represent the most powerful professional antigen-presenting cells (APC) in the immune system. The aim of the present study was to analyse, on a single-cell basis by multiparametric flow cytometry with simultaneous four-colour staining and a two-step acquisition procedure, the immunophenotypic profile and cytokine production of DC from 67 normal whole peripheral blood (PB) samples. Two clearly different subsets of HLA-II+/lineage- were identified on the basis of their distinct phenotypic characteristics: one DC subset was CD33strong+ and CD123dim+ (0.16 +/- 0.06% of the PB nucleated cells and 55.9 +/- 11. 9% of all PB DC) and the other, CD33dim+ and CD123strong+ (0.12 +/- 0.04% of PB nucleated cells and 44.53 +/- 11.5% of all PB DC). Moreover, the former DC subpopulation clearly showed higher expression of the CD13 myeloid-associated antigen, the CD29 and CD58 adhesion molecules, the CD2, CD5 and CD86 costimulatory molecules, the CD32 IgG receptor and the CD11c complement receptor. In addition, these cells showed stronger HLA-DR and HLA-DQ expression and a higher reactivity for the IL-6 receptor alpha-chain (CD126) and for CD38. In contrast, the CD123strong+/CD33dim+ DC showed a stronger reactivity for the CD4 and CD45RA molecules, whereas they did not express the CD58, CD5, CD11c and CD13 antigens. Regarding cytokine production, our results show that while the CD33strong+/CD123dim+ DC are able to produce significant amounts of inflammatory cytokines, such as IL-1beta (97 +/- 5% of positive cells), IL-6 (96 +/- 1.1% of positive cells), IL-12 (81.5 +/- 15.5% of positive cells) and tumour necrosis factor-alpha (TNF-alpha) (84 +/- 22.1% of positive cells) as well as chemokines such as IL-8 (99 +/- 1% of positive cells), the functional ability of the CD123strong+/CD33dim+ DC subset to produce cytokines under the same conditions was almost null. Our results therefore clearly show the presence of two distinct subsets of DC in normal human PB, which differ not only in their immunophenotype but also in their functionality, as regards cytokine production.

AC133 Antigen↗
PubMed1998

Population-based prevalence of symptomatic and asymptomatic astrovirus infection in rural Mayan infants.

Symptomatic and asymptomatic astrovirus infection was prospectively determined in a 3-year birth cohort of Mayan infants. Stool samples from 271 infants and 268 older siblings were tested for astrovirus, adenovirus 40/41, rotavirus and Salmonella, Shigella and Campylobacter species. Concurrent diarrhea, vomiting, fever, or anorexia were noted. Astrovirus was detected in 164 infants (61%) and 20 siblings (7%). Rotavirus (4%) and adenovirus 40/41 (13%) were isolated less frequently. Of all diarrheal episodes reported at a visit, 26% (78/305) were associated with astrovirus; 17% (78/452) of astrovirus infections were associated with diarrhea and 9% with other symptoms. Only diarrhea was associated with astrovirus infection (odds ratio, 1.4; 95% confidence interval [CI], 1.07-1.92; P = .01). Of infants with astrovirus, 70% shed at multiple visits over a period of 2-17 weeks (median, 5). The point prevalence of astrovirus infection was significantly higher among infants than siblings (relative risk, 6.18; 95% CI, 3.93-9.72; P < .0001, chi2). Astrovirus was identified throughout the year, peaked in March and May, and decreased in September. In this population, astrovirus was the most common enteric pathogen isolated; symptomatic infection was prevalent among infants.

Adenoviridae Infections↗
PubMed1994

Antimicrobial activity of a new antipseudomonal dual-action drug, Ro 25-0534.

Ro 25-0534, a tertiary amine-linked dual action combination (DAC) of a catechol cephalosporin and ciprofloxacin, was compared with a previously described DAC (Ro 23-9424), ciprofloxacin and cefotaxime. A total of 688 recent clinical isolates were tested and an additional collection of 110 Gram-negative bacilli possessing documented resistance to broad-spectrum antimicrobials were used. Ro 25-0534 was active against all tested species of Enterobacteriaceae (MIC90 range, 0.06-2 micrograms/ml), oxacillin-susceptible staphylococci, beta-hemolytic streptococci, and penicillin-susceptible pneumococci (MIC90 range, 1-2 micrograms/ml). Haemophilus influenzae (MIC90 range, 0.25-0.5 micrograms/ml), Moraxella catarrhalis (MIC90, 0.5 microgram/ml), and most nonenteric Gram-negative bacilli (MIC90 range, 2-4 micrograms/ml) such as Pseudomonas aeruginosa, Acinetobacter spp., and Xanthomonas maltophilia. Enterococci and Bacteroides fragilis isolates were resistant to Ro 25-0534. The Ro 25-0354 potency against most susceptible strains was generally severalfold less than that of Ro 23-9424 (except for Pseudomonas-Xanthomonas) or ciprofloxacin alone.

Anti-Bacterial Agents↗
PubMed1994

Reduced number of Langerhans cells in oral mucosal washings from HIV-1 seropositives.

In order to elucidate mucosal immunity in HIV-1 seropositive individuals, we investigated oral mucosa washings from 20 HIV-1 seropositive patients for the presence of Langerhans cells (LC) and HIV-1 antigen-positive cells, and compared the results with those obtained from 20 HIV-1 seronegative healthy individuals. Monoclonal antibodies directed against CD1a, HLA-DR, CD3, and p24 were used to identify LC, T cells and HIV-1 core-antigens, respectively. In oral mucosa washings from HIV-1 seropositive patients there was a significant reduction in the number of CD1a+ cells as compared with the healthy subjects. HIV-1 antigen-positive cells were not detected. The reduction of LC in oral mucosa washings from HIV-1 seropositive patients is probably associated with HIV-1 infection. The frequent occurrence of oral mucosal disorders in HIV-1 infected patients may in part be caused by a reduced LC-number and/or function.

AIDS-Related Opportunistic Infections↗
PubMed1992

Diagnosis of disseminated candidiasis in hospitalized patients using the Cand-Tec latex agglutination assay.

A total of 1,303 sera from 202 patients at risk for disseminated candidiasis were analyzed for the presence of Candida antigen using a commercially available latex agglutination test (Cand-Tec). Twenty-three patients had disseminated candidiasis documented by positive blood cultures, deep biopsy culture and histopathology or autopsy. Six patients had transient candidemia, 15 patients had candiduria, 62 patients were not colonized yet treated empirically with amphotericin B, and 46 patients were not colonized and not treated with amphotericin B. The sensitivity and specificity of the Candida antigen test for the diagnosis of disseminated candidiasis was 87% and 36% (threshold titer of greater than or equal to 1:2), 70% and 60% (greater than or equal to 1:4), and 30% and 85% (greater than or equal to 1:8), respectively. In contrast to previous studies we were unable to demonstrate a prognostic role for the Candida antigen test in patients with documented disseminated candidiasis. The lack of sensitivity and specificity of the Cand-Tec Candida antigen test precludes its use in the diagnosis of disseminated candidiasis.

Antigens, Fungal↗
PubMed1992

Ofloxacin, a new broad-spectrum fluoroquinolone. Results from a Multicenter, National Comparative Activity Surveillance Study. The Ofloxacin Surveillance Group.

Ofloxacin, a newer broad-spectrum fluoroquinolone, was evaluated against 6967 clinical isolates in a multicenter surveillance trial using a standardized disk diffusion method. Thirty-five geographically diverse laboratories contributed zone diameter results for two (ofloxacin and ciprofloxacin) to five (ofloxacin, ciprofloxacin, ampicillin, cefaclor, and cefixime) antimicrobial agents, depending on the site of infection. Ofloxacin was determined to have the widest spectrum of activity and potential empiric use (90.6%, range 87.1%-92.2%) for respiratory tract, urinary tract, and cutaneous infections. The spectrum was superior to ciprofloxacin (average 85.3% versus three sites), ampicillin (35.5%, respiratory tract), cefaclor (60.5%, respiratory tract), cefixime (60.9%, respiratory tract), and norfloxacin (87.3%, urinary tract). Strains resistant to ofloxacin (35 isolates, 0.5%) were confirmed by reference laboratory tests and cross resistance was observed among several current and investigational fluoroquinolone agents. The species most often found to be fluoroquinolone resistant among the Enterobacteriaceae were Klebsiella pneumoniae, Serratia marcescens, and Providencia spp. Monitoring for increasing fluoroquinolone resistance should be considered as greater use of drugs in this class develops. By these cited statistics, ofloxacin appears to have a broad and balanced spectrum of potential use, particularly against Gram-positive pathogens.

Anti-Infective Agents↗
PubMed1992

The E-Test applied to susceptibility tests of gonococci, multiply-resistant enterococci, and Enterobacteriaceae producing potent beta-lactamases.

The E-Test (AB Biodisk, Solna, Sweden), a new and novel approach developed to test antimicrobial susceptibility, was compared with the agar dilution method. A collection of 57 organisms, including those with known resistances to various antimicrobial agents was tested against 15 drugs using the National Committee for Clinical Laboratory Standard (NCCLS) methods. The E-Test quantitative accuracy (+/- 2 log2 dilutions) compared with agar dilution results was 99% for Neisseria gonorrhoeae, 95% for Escherichia coli strains with extended-spectrum beta-lactamases, 100% for Enterobacter-Citrobacter spp. with type-1 stably derepressed enzymes, and 95% for Enterococcus spp. with various drug resistances (penicillins, ciprofloxacin, gentamicin, and vancomycin). The E-Test procedures with these species were easy to perform, reproducible, and quantitatively and qualitatively accurate (89%-100%). The E-Test appears to be an acceptable option for susceptibility testing of these difficult-to-treat, drug-resistant bacterial strains.

Anti-Bacterial Agents↗
PubMed1992

In vitro activity of decaplanin (M86-1410), a new glycopeptide antibiotic.

The in vitro activity of decaplanin (formerly M86-1410), a novel glycopeptide antimicrobial agent, was tested against 169 gram-positive bloodstream isolates from patients at the University of Iowa Hospitals and Clinics and 12 selected vancomycin-resistant strains. Enterococcus faecalis, E. faecium, Staphylococcus aureus, streptococci, bacilli, corynebacteria, and listeria were inhibited by decaplanin (MICs for 90% of the strains tested [MIC90s], 0.12 to 4 micrograms/ml). However, some rarely isolated and selected Enterococcus sp. populations had a MIC90 of 16 micrograms/ml, and S. haemolyticus strains had a MIC90 of 8 micrograms/ml. These in vitro results suggest that decaplanin may be useful against most gram-positive strains, even though some Enterococcus species and coagulase-negative staphylococci were potentially resistant (MICs, greater than or equal to 8 micrograms/ml).

Ampicillin↗
PubMed1992

Use of the E test to predict high-level resistance to aminoglycosides among enterococci.

The E test and the reference agar dilution methods were compared for detecting high-level aminoglycoside resistance (HLAR) among 71 selected clinical isolates, including 62 Enterococcus faecalis and 9 Enterococcus faecium isolates. High-level gentamicin resistance alone was found in 11% (5 E. faecalis and 3 E. faecium strains) and high-level streptomycin resistance was found in 42% (28 E. faecalis, 2 E. faecium strains) of the strains tested, and 31% of the strains demonstrated high-level resistance to both antimicrobial agents (21 E. faecalis and 1 E. faecium strains). The E test detected all HLAR populations, but the streptomycin strip may require recalibration to achieve absolute MIC comparisons with the reference value (twofold less) or the use of an alternative interpretive resistance breakpoint, e.g., > 1,000 micrograms/ml. By the E test, MIC results indicate that ampicillin, imipenem, penicillin, piperacillin, and vancomycin remain active against the HLAR E. faecalis isolates; however, these tested drugs were less effective on the HLAR E. faecium isolates (< 50%).

Agar↗
PubMed1992

A multidisciplinary process to determine, communicate, and manage an antibiotic formulary.

This article describes a collaborate process developed by the Pharmacy & Therapeutics Committee to define, determine, communicate, and manage an effective antibiotic formulary. Multiple professional disciplines represented by the antibiotic subcommittee evaluated each classification of antibiotics and recommended a preferred drug(s) for each classification. Decisions were based on relative safety, efficacy, and cost with minimal duplication of therapeutic equivalent antibiotics. A therapeutic interchange policy was unnecessary because extensive communication measures developed by the committee proved effective. The strategy used strengthened pharmacist/physician working relationships. This process permitted rationality and understanding by the medical staff, which resulted in unanimous formulary acceptance.

Anti-Bacterial Agents↗
PubMed1991

Cardiopulmonary bypass, profound hypothermia, and circulatory arrest for neurosurgery.

Six female and 4 male patients (age, 23 to 75 years) underwent operation for difficult intracranial lesions. Preoperative diagnoses included four giant intracranial aneurysms, three base of skull glomus jugulare tumors, two arteriovenous malformations, and one cerebellar hemangioblastoma. All lesions were inoperable or nearly so by standard neurosurgical techniques. All patients were placed on total bypass via groin cannulations. Bypass times ranged from 111 to 269 minutes (mean, 174 minutes) with cooling times of 26 to 83 minutes (mean, 48 minutes) and warming times of 68 to 110 minutes (mean, 83 minutes). Circulatory arrest times ranged from 1.25 to 60 minutes with 1 patient not requiring arrest. The lowest core temperatures recorded varied from 8.4 degrees to 13.7 degrees C. There was one postoperative death and one major complication, both in patients with arteriovenous malformations. Eight patients (80%) have achieved an excellent result. Profound hypothermia with the option of circulatory arrest and exsanguination has been an indispensable adjunct to the safe management of intracranial aneurysm, glomus jugulare tumor, and hemangioblastoma.

Adult↗
PubMed1990

Effect of tenoxicam on inflammation and immune cellular function.

1. We have shown that nonsteroidal anti-inflammatory drugs are potent inhibitors of neutrophil activation. Tenoxicam is a new compound of the oxicam family which has been shown to be effective for routine clinical use. 2. In the present study we examined the immune pharmacological effects of this compound on lymphocyte function by determining its effect on the expression of IL-2 receptors, on monocyte function by looking at chemotaxis and IL-1 release and on neutrophil function by evaluating the chemotactic response to a standard stimulus. 3. The data show that Tenoxicam inhibits the neutrophil and monocyte functional chemotactic response in vitro, and to some extent in vivo for monocytes, but has no effect on the expression of IL-2 receptors or IL-1 release. Tenoxicam inhibits the mobilization of neutrophils and monocytes to inflammatory sites, even though this effect was not clearly demonstrable when cells were tested after oral use.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1988

Luteinizing hormone triggers a molecular association between its receptor and the major histocompatibility complex class I antigen to produce cell activation.

We studied the involvement of major histocompatibility (MHC) class I antigens on the mechanism of LH/hCG receptor activation. For this purpose we investigated the effects of anti-MHC class I antibodies on hormone-receptor interaction, signal transduction, and MHC class I antigen-receptor interaction. Monoclonal antibodies against MHC class I antigen were able to stimulate testosterone production in mouse Leydig cells with the same potency as LH. This biological effect depends on the concentration of antibody used and could be abolished by a LH antagonist. There is a perfect parallelism, for each monoclonal antibody, between the specificity for a particular haplotype and the response of the target cells from the strains carrying such a haplotype. The same antibodies were able to precipitate the soluble LH/hCG receptors, as both a hormone-receptor complex and a free receptor. The results suggest that bound hormone triggers an association of the MHC class I antigen with the LH/hCG receptor, resulting in activation of the target cell.

Animals↗