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Biomedical subjects

A B Santos

Publications and source records attributed to A B Santos.

At least 19 recordsLinked to original sources
PubMed2005

Study of dental enamel and synthetic hydroxyapatite irradiated by EPR at K-band.

In this preliminary work the EPR spectra of a small dental enamel block and a synthetic B-type hydroxyapatite in powder form, both irradiated with gamma rays, were analyzed in K-band. The spectra of the dental enamel block allow the analysis of independent components with different angular orientations, while the study of the dosimetric properties of the synthetic hydroxyapatites showed good performance of this spectrometer. K-band spectra show better resolution when compared to X-band, while using significantly less sample material.

Body Burden↗
PubMed2001

Report of three cases of circulating heparin-like anticoagulants.

Clinically significant endogenous circulating heparin-like anticoagulant activity has been associated with hematological malignancies, liver damage, and other pathological conditions. The source of high plasma concentrations of endogenous heparin-like anticoagulants is poorly understood. We report three cases of circulating heparin-like anticoagulants in three patients with hematological malignancies: CLL, multiple myeloma, and T-prolymphocytic leukemia. The severity of bleeding in our patients ranged from severe epistaxis and deep-site hematoma to bleeding of biopsy site and occasional ecchymosis.

Aged↗
PubMed2001

Absenteeism and productivity among mental health employees.

We examined archival data to test the hypothesis that absenteeism is inversely related to work productivity among mental health employees at a Veterans Affairs Medical Center outpatient clinic. Results provided partial support for this hypothesis in that there was an inverse correlation between one measure of productivity and the percentage of sick and family care leave taken on Mondays and Fridays (r=.54). No significant relationship between work productivity and total sick and/or family care leave was found, although there was a trend in that direction (r=.34). These data suggest that mental health clinicians who use high levels of sick and/or family care leave are not necessarily unproductive workers. However, high percentages of absenteeism on Mondays and Fridays may represent a red flag for identifying under-performing clinicians. Examination of absenteeism patterns may prove useful for administrators. Management policy strategies to reduce absenteeism are suggested.

Absenteeism↗
PubMed2001

Cockroach allergens and asthma.

Asthma and allergy are the most common diseases associated with cockroach infestation of houses in the United States and other parts of the world. Sensitization and exposure to cockroach allergens is associated with increased asthma morbidity in the United States, especially among lower socioeconomic groups, including African American and Hispanic populations. Exposure to cockroach allergens in the first 3 months of life has been associated with repeated wheezing and asthma. The principal domestic cockroach species are Blattella germanica and Periplaneta americana. Both species produce several potent allergens, including Bla g 2 (inactive aspartic proteinase), Bla g 4 (calycin), Bla g 5 (glutathione-S-transferase), the group 1 cross-reactive allergens Bla g 1 and Per a 1, and tropomyosin. Structural homology between tropomyosins from cockroaches, mites, and shrimp may explain clinical cases of the oral allergy syndrome. The 3-dimensional structures of several cockroach allergens are known, and biologically active recombinant allergens have been produced in high-level expression vectors. The use of recombinant cockroach allergens should allow mechanisms of cockroach-induced asthma to be investigated and may lead to the development of new approaches to asthma treatment. Environmental allergen measurements of Bla g 1 and Bla g 2 have allowed exposure levels that cause allergic sensitization to be established. Abatement studies have shown that a sustained decrease in cockroach allergen levels is difficult but can be accomplished by professional application of insecticides, together with rigorous household cleaning. Cockroach asthma is an important public health problem that affects patients who are the least likely to be compliant with treatment with asthma medications or environmental control. Patient education, improvements in the housing stock, and improvements in environmental and immunologic treatment strategies are likely to be the most successful approaches to reduce the prevalence of cockroach-induced asthma.

Allergens↗
PubMed2000

Probing the specificity of cysteine proteinases at subsites remote from the active site: analysis of P4, P3, P2' and P3' variations in extended substrates.

We have determined the kinetic parameters for the hydrolysis by papain, cathepsin B and cathepsin L of internally quenched fluorescent peptides derived from the lead peptides Abz-AAFRSAQ-EDDnp [in which Abz and EDDnp stand for o-aminobenzoic acid and N-(2,4-dinitrophenyl)ethylenediamine respectively], to map the specificity of S(4) and S(3) subsites, and Abz-AFRSAAQ-EDDnp, to identify the specificity of S(2)' and S(3)'. Abz and EDDnp were the fluorescent quencher pair. These two series of peptides were cleaved at the Arg-Ser bond and systematic modifications at P(4), P(3), P(2)' and P(3)' were made. The S(4) to S(2)' subsites had a significant influence on the hydrolytic efficiencies of the three enzymes. Only papain activity was observed to be dependent on S(3)', indicating that its binding site is larger than those of cathepsins B and L. Hydrophobic amino acids were accepted at S(4), S(3), S(2)' and S(3)' of the three enzymes. The best substrates for cathepsins L and B had Trp and Asn at P(2)' respectively; variations at this position were less accepted by these enzymes. The best substrates for papain were peptides containing Trp, Tyr or Asn at P(3)'. Basic residues at P(3) and P(4) were well accepted by cathepsin L and papain. We also explored the susceptibility of substrates Abz-AFRSXAQ-EDDnp, modified at P(2)' (X), to human cathepsin B mutants from which one or two occluding loop contacts had been removed. The modifications at His(111) (H111A) and His(110) (H110A) of cathepsin B led to an increase in k(cat) values of one or two orders of magnitude. The hydrolytic efficiencies of these cathepsin B mutants became closer to those of papain or cathepsin L.

Amino Acid Sequence↗
PubMed2000

Using principles of ACT to integrate community care for people with mental retardation and mental illness.

The authors describe the use of an Assertive Community Treatment (ACT) approach in a community living program for persons with both mental retardation and mental illness. The development of the program occurred in the context of a statewide project to serve more than 1,000 dually diagnosed persons who were members of a class action lawsuit against the State of North Carolina. The use of ACT principles marked a substantive departure from the residential supervision and brokered service model employed for the Class throughout the State. The authors describe the public policy context within which the program was developed, discuss the rationale for selecting the ACT model, describe its implementation, and summarize service utilization and outcome information. Changes by the funding agency in its expectations of program staffing and reimbursement methodology that were made after the program was approved led to its early demise. Although the program lasted less than 2 years, during its tenure most participants realized marked improvement in symptoms and community adjustment. Results may cautiously be interpreted as indicating that ACT may reduce the reliance on 24-hour residential and community supervision for many persons with both mental retardation and mental illness.

Journal Article↗
PubMed2000

Procedural and methodological issues in telepsychiatry research and program development.

OBJECTIVE: The authors reviewed the literature related to telepsychiatry-applications of videoconferencing technology for mental health care-which offers hope for an affordable means of solving long-standing workforce problems, particularly in geographical areas where specialist providers are not readily available. METHODS: To conduct a comprehensive review of the telepsychiatry literature, the authors searched the MEDLINE database (1970 to February 2000), using the keywords telepsychiatry, telemedicine, and videoconferencing. Studies were selected that included the use of videoconferencing technology for the provision of any form of mental health care services. RESULTS AND CONCLUSIONS: Psychiatric interviews conducted by telepsychiatry appear to be generally reliable, and patients and clinicians generally report high levels of satisfaction with telepsychiatry. A significant limitation of the literature is the lack of empirical research on telepsychiatry, especially cost analyses and clinical outcome studies. The authors outline a research agenda addressing the procedural and methodological issues that should shape future research: study design, outcome measurement, consideration of patient characteristics, and program design.

Consumer Behavior↗
PubMed2000

Panic disorder in primary care: patients' attributions of illness causes and willingness to accept psychiatric treatment.

OBJECTIVE: This study assessed the causes that primary care patients with panic disorder (PD) attribute to their panic symptoms, and their acceptance of various psychiatric treatment options. METHODS: In a cross-sectional assessment of 306 patients treated at two primary care clinics, 42 met criteria for DSM-IV PD in the past year. The authors classified these 42 PD-positive patients to one of two groups: those receiving both primary and specialty mental health care (PC+MH; n = 19) and those receiving only primary care (PC-only; n = 23). Patients rated the probability of four possible causes of their panic symptoms, and level of acceptability of three psychiatric and two medical treatments for PD. To place primary care patients' ratings into a broader context, a third contrast group of PD-positive patients, recruited from clinical trials of investigational PD pharmacotherapies (n = 31), also rated causes and treatment acceptability. RESULTS: Participants of the three treatment groups attributed psychiatric causes for their panic symptoms in approximately the same proportion (78 percent to 90 percent; p = ns). PC-only participants attributed medical causes for panic symptoms more frequently than PC+MH and PD Clinical Trials participants (48 percent vs. 5 percent and 32 percent; p = .01). Remarkably, the great majority of patients across all groups expressed willingness to see psychiatrists (84 percent to 94 percent) and psychotherapists (95 percent to 100 percent), and to take psychotropic medications (87 percent to 100 percent). CONCLUSIONS: In this study most patients attributed a psychiatric cause for panic symptoms and communicated strong acceptance of psychiatric treatment. Thus, we recommend that primary care clinicians more assertively inform their patients of PD diagnoses and recommend psychiatric treatments with less fear about stigmatizing and alienating them.

Adult↗
PubMed1999

Alcohol dependence and hospitalization in schizophrenia.

Treatment of schizophrenia is often complicated by substance abuse. We report here findings of a retrospective study evaluating readmission rates of patients meeting DSM IV criteria comorbid for schizophrenia and alcohol or drug dependence treated with depot haloperidol or fluphenazine over a 2-year period. During the study period, 14 of the 26 (54%) male veteran patients were admitted to the VAMC, Charleston; 46% of patients met criteria for alcohol, marijuana or cocaine dependence. Patients with alcohol dependence appeared to be at highest risk for hospital admission (p < 0.05). Moreover, patients with alcohol dependence had longer hospital stays (p < 0.05) than patients without alcohol dependence. Marijuana or cocaine dependence was slightly, but not statistically more common among admitted patients. Marijuana or cocaine dependence did not predict length of stay or number of admissions. Alcohol dependence may be an important factor in schizophrenic exacerbation, and may be an important target for treatment.

Adult↗
PubMed1999

Cockroach allergens and asthma in Brazil: identification of tropomyosin as a major allergen with potential cross-reactivity with mite and shrimp allergens.

BACKGROUND: Cockroaches produce several proteins that induce IgE antibody responses. Although cockroaches are abundant in warm and humid areas, sensitization to cockroach allergens has not been investigated in Brazil. OBJECTIVE: The aims of this study were to investigate the frequency of cockroach allergy among patients with asthma, rhinitis, or both in Brazil and to identify American cockroach allergens. METHODS: Skin tests using cockroach extracts were performed on children and young adults with asthma, rhinitis, or both. A Periplaneta americana complementary (c)DNA library was screened by using IgE antibodies from Brazilian patients allergic to cockroaches. Reactivity of an mAb directed to Dermatophagoides pteronyssinus tropomyosin against cockroach tissue was examined by immunofluorescence. RESULTS: Cockroach allergy was present in 55% and 79% of the patients, as determined by using skin prick tests alone or combined prick and intradermal tests, respectively. Five cDNA clones reacted with IgE antibody and contained the same sequence. A representative clone (1300 bp), pa 12, coded for a protein that reacted with 50% of the sera from patients allergic to cockroaches on plaque immunoassay and showed a high degree of homology to tropomyosins, particularly those from invertebrates. P americana tropomyosin showed 80%, 81%, and 82% sequence identity to tropomyosins from D pteronyssinus, D farinae, and shrimp, respectively, which have been previously defined as important allergens. An mAb directed against D pteronyssinus tropomyosin, which also recognizes shrimp tropomyosin, showed binding to cockroach striated muscle. CONCLUSION: Our results support the recommendation that cockroach extracts should be routinely used for the evaluation of patients with asthma, rhinitis, or both in Brazil. The identification of P americana tropomyosin as an important allergen will make it possible to investigate cross-reactivity among cockroaches, mites, and food derived from invertebrates.

Adolescent↗
PubMed1999

Home-based multisystemic therapy as an alternative to the hospitalization of youths in psychiatric crisis: clinical outcomes.

OBJECTIVE: The primary purpose of this study was to determine whether multisystemic therapy (MST), modified for use with youths presenting psychiatric emergencies, can serve as a clinically viable alternative to inpatient psychiatric hospitalization. METHOD: One hundred sixteen children and adolescents approved for emergency psychiatric hospitalization were randomly assigned to home-based MST or inpatient hospitalization. Assessments examining symptomatology, antisocial behavior, self-esteem, family relations, peer relations, school attendance, and consumer satisfaction were conducted at 3 times: within 24 hours of recruitment into the project, shortly after the hospitalized youth was released from the hospital (1-2 weeks after recruitment), and at the completion of MST home-based services (average of 4 months postrecruitment). RESULTS: MST was more effective than emergency hospitalization at decreasing youths' externalizing symptoms and improving their family functioning and school attendance. Hospitalization was more effective than MST at improving youths' self-esteem. Consumer satisfaction scores were higher in the MST condition. CONCLUSIONS: The findings support the view that an intensive, well-specified, and empirically supported treatment model, with judicious access to placement, can effectively serve as a family- and community-based alternative to the emergency psychiatric hospitalization of children and adolescents.

Activities of Daily Living↗
PubMed1999

Assertive community treatment for people with severe mental illness: the effect on hospital use and costs.

OBJECTIVE: To determine the effect of the Program for Assertive Community Treatment (PACT) model on psychiatric inpatient service use in a population of non-emergency psychiatric patients with severe chronic mental illness, and to test for variations in this effect with program staffing levels and patient characteristics such as race and age. DATA SOURCES/STUDY SETTING: Data are taken from a randomized trial of PACT in Charleston, South Carolina for 144 patients recruited from August 1989 through July 1991. STUDY DESIGN: Subjects were randomly assigned either to one of two PACT programs or to usual care at a local mental health center. Effects on hospital use were measured over an 18-month follow-up period via multiple regression analysis. DATA COLLECTION METHODS: Data were obtained from Medicaid claims, chart reviews, subject, case manager, and family interviews; searches of the computerized patient and financial databases of the South Carolina Department of Mental Health and relevant hospitals; and searches of the hard copy and computerized financial databases of the two major local hospitals providing inpatient psychiatric care. PRINCIPAL FINDINGS: PACT participants were about 40 percent less likely to be hospitalized during the follow-up period. The effect was stronger for older patients. Lower PACT client/staff ratios also reduced the risk of hospitalization. No evidence of differential race effects was found. Given some hospital use, PACT did not influence the number of days of use. CONCLUSIONS: Controlling for other covariates, PACT significantly reduces hospitalizations but the size of this effect varies with patient and program characteristics. This study shows that previous results on PACT can be applied to non-emergency patients even when the control condition is an up-to-date CMHC office-based case management program.

Adult↗
PubMed1997

Bridging the gap between inpatient and outpatient providers using organizational elements of assertive community treatment.

Even among comprehensive local public mental health systems, there remain large gaps in continuity of care following discharge from inpatient settings. The authors describe a modification of the assertive community treatment (ACT) program model that links inpatients to ongoing community-based care, and provide preliminary evidence of its effectiveness as a component in a rationally organized comprehensive system of care. Given the recent trend toward managed Medicaid arrangements, there will be increased pressure to reduce clients' length of stay in ACT programs. State mental health authorities are cautioned to resist allowing managed care contractors to radically change the conditions under which ACT programs operate until there is greater evidence of the effectiveness of alternative approaches.

Academic Medical Centers↗
PubMed1997

Impact of assertive community treatment on homeless persons with co-occurring severe psychiatric and substance use disorders.

This study evaluated the impact of an integrated (mental health/substance abuse) assertive community treatment program on homeless persons with serious mental and substance use disorders. High rates of retention in treatment, housing stability, and community tenure were attained, and all but the most severe substance users appeared to gain these benefits. While the intervention appears to be an effective means of retaining in services and monitoring such difficult-to-treat and costly populations, it did not yield high rates of abstinence and social benefits in severe users.

Adult↗