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Biomedical subjects

M Aponte

Publications and source records attributed to M Aponte.

7 recordsLinked to original sources
PubMed2001

Patients' perceptions of their bipolar illness in a public hospital setting.

This preliminary study explored the perceptions of illness of people in a public hospital setting for treatment of bipolar disorder. Fifteen inpatients (5 African Americans, 5 Hispanics, and 5 European Americans) participated in audio-recorded, structured interviews. The interviews were designed to identify recurring themes and patterns in their perceptions of bipolar disorder and to assess their cognitive representations of the illness. The interviews were transcribed verbatim, and content analysis procedures were used to identify the illness perceptions and to compare them based upon ethnic orientation. Results indicated that most of the participants' group responses were more alike than they were different. However, discrete themes emerged among the individuals as their stories unfolded. These themes, and the perceived benefit of the interview itself, provide a beginning foundation for further research in the area, and have clinical relevance for health care providers working with this population.

Adult↗
PubMed2001

New subscales for an anchored version of the Brief Psychiatric Rating Scale: construction, reliability, and validity in acute psychiatric admissions.

Attending psychiatrists completed an anchored version of the 18-item Brief Psychiatric Rating Scale (BPRS-A) based on admission and evaluation information on a total of 2,921 adult patients treated at 1 public sector acute psychiatric teaching hospital. Exploratory factor analysis was applied to a 6-month sample to construct 4 nonoverlapping subscales: Resistance, Positive Symptoms, Negative Symptoms, and Psychological Discomfort. Confirmatory factor analysis compared these new subscales to 3 other published subscale models using a second 6-month sample. Internal consistency, rater influence, and interrater agreement were estimated in separate studies. Discriminant validity was explored by comparison of diagnosis-based samples. Application of the BPRS-A as a debriefing instrument in the study of symptomatic change and the multiple challenges inherent in psychometric study of such a rating scale in realistic hospital practice are discussed.

Adult↗
PubMed2001

Detection and characterization of a bacteriocin, garviecin L1-5, produced by Lactococcus garvieae isolated from raw cow's milk.

AIMS: The identification of a bacteriocin-producing lactococcal strain isolated from raw cow's milk is reported, along with production conditions, physical and chemical properties, and mode of action of the bacteriocin. METHODS AND RESULTS: On the basis of resistance to clindamycin, species-specific PCR and amplification of the 16S-23S rDNA spacer region, the strain was identified as Lactococcus garvieae. Its bacteriocin, designated garviecin L1-5, was bactericidal against closely related species and strains of species from different genera, including Listeria monocytogenes and Clostridium spp. Garviecin L1-5 was shown to be proteinaceous by protease inactivation and was unaffected by heat treatments, also at low pH values. When amplifying known lactococcal bacteriocin genes using DNA from strain L1-5 as template, no amplification products were observed on the agarose gel. The molecular weight of garviecin L1-5 was about 2.5 kDa. As far as is known, no bacteriocins have been detected from Lactococcus garvieae. CONCLUSION: The general properties of garviecin L1-5 are characteristic of the low-molecular-weight bactericidal peptide group. SIGNIFICANCE AND IMPACT OF THE STUDY: The survey of micro-organisms for novel antimicrobial substances provided valuable information on their physiology, ecology and practical application.

Animals↗
PubMed1999

Spray-drying of bacteriocin-producing lactic acid bacteria.

Cell survival, cellular damage, and antagonistic activity were investigated after spray-drying of four bacteriocin-producing strains of lactic acid bacteria: Lactococcus lactis subsp. lactis 140, isolated from natural whey culture and producing a narrow-inhibitory spectrum bacteriocin); L. lactis subsp. lactis G35, isolated from pizza dough and producing nisin; Lactobacillus curvatus 32Y and Lactobacillus sp. 8Z, isolated from dry sausages. Trials were performed with bacteria suspended in skimmed milk or directly grown in whey. Three air temperatures at the inlet of the drier (160, 180, and 200 degrees C) and three flow rates (10, 13, and 17 ml/min) were assayed. Cell viability and bacteriocin activity of the dried materials were determined immediately after the process and after 5, 15, 30, and 60 days of storage at 4 degrees C. There was no significant difference between the two feeding suspensions in cell survival, always decreasing with the increase of inlet-air temperature. No loss of bacteriocin activity was detected in reconstituted powders, nor was any loss of ability to produce bacteriocin found after drying. Investigations of sensitivity to NaCl revealed only temporary damage to dried bacteria. During storage for 2 months at 4 degrees C, all samples, but mainly the lactococcal strains, displayed a gradual decrease in cell survival. Bacteriocin activity remained at the same level, allowing powders to be considered as effective biopreservatives.

Aerosols↗
PubMed1998

Random amplified polymorphic DNA and amplified ribosomal DNA spacer polymorphism: powerful methods to differentiate Streptococcus thermophilus strains.

Streptococci from different collections and dairy materials were characterized by conventional and molecular methods. After amplification of the 16S-23S rDNA spacer region, all the strains referable to the genus Streptococcus exhibited a single polymerase chain reaction (PCR) product, allowing their differentiation from enterococci. Cleaving this PCR product with Hae III, two different restriction patterns could be observed, allowing Streptococcus salivarius DSM 20560T, Strep. thermophilus NCDO 822 and two strains of Streptococcus spp. to be gathered in one group and all the other strains in another. In order to achieve strain typing, all the cultures were investigated by random amplified polymorphic DNA (RAPD)-PCR analysis employing two selected primers. The results were treated by cluster analysis, appearing significantly consistent with both the taxonomic position and the origin of the strains. Pulsed-field gel electrophoresis (PFGE) of Sma I digests of the genomic DNA from 11 representative strains with decreasing levels of RAPD similarity allowed their diversity to be confirmed, even though RAPD-PCR proved to be less discriminating than PFGE analysis. The results are discussed with reference to the capability of the analytical procedures used to aid both identification and strain typing of streptococci, as well as the taxonomic structure of the species Strep. thermophilus.

Bacterial Typing Techniques↗
PubMedDate not supplied

Genotyping of Lactobacillus delbrueckii subsp. bulgaricus and determination of the number and forms of rrn operons in L. delbrueckii and its subspecies.

Three different approaches (whole-cell protein profiles, DNA fingerprinting combined with pulsed-field gel electrophoresis and analysis of rDNA genes) were used to characterize thirty-one strains of Lactobacillus delbrueckii subsp. bulgaricus from different dairy products, and three type strains belonging to L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. lactis and L. delbrueckii subsp. bulgaricus. Moreover, the number and different forms of rrn operons in L. delbrueckii and its subspecies were defined. At the strain typing level, Notl macrorestriction analysis permitted grouping of the 32 strains of L. delbrueckii subsp. bulgaricus into 23 restriction patterns, providing a high degree of discriminatory power. Among whole-cell protein profiles, PCR analysis of rDNA genes and ribotyping, the latter method seemed to be the most reliable approach to characterizing the subspecies belonging to L. delbrueckii. Ribotyping combined with enzymes such as HindIII and EcoRI showed that at least six rrn operons were present in L. delbrueckii and its subspecies; two forms of rrn operons were present in the subspecies lactis and bulgaricus and four forms were present in the subspecies delbrueckii.

Blotting, Southern↗