Comparison of two methods skipping cell lysis and protein extraction for identification of bacteria from blood cultures by matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry.

OBJECTIVE: Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) is widely used for fast identification of bacteria from blood cultures (BC). We compared the performance of two procedures, one including a pre-enrichment step in brain heart infusion and the other a direct method using vacutainer separator gel tubes (DI), for identification of bacteria from blood cultures by MALDI-TOF MS. METHODS: We first prepared a training set of 20 simulated bacteremia specimens, including 10 Gram-negative and 10 Gram-positive species. A total of 145 non-consecutive BCs flagged as positive (68 Gram-negative rods, and 77 Gram-positive cocci) were prospectively analyzed (validation set). RESULTS: A total of 82% and 49% of isolates were correctly identified to the species level by the respective methods. CONCLUSIONS: The pre-enrichment method outperformed the DI method for identification of virtually all bacterial species included in the panels.

Predicting length of stay in an acute psychiatric hospital.

OBJECTIVE: Multivariate statistical methods were used to identify patient-related variables that predicted length of stay in a single psychiatric facility. The study investigated whether these variables remained stable over time and could be used to provide individual physicians with data on length of stay adjusted for differences in clinical caseloads and to detect trends in the physicians' practice patterns. METHODS: Data on all patients discharged over two six-month periods were collected at an acute psychiatric inpatient facility. Stepwise multiple regression analyses were conducted on the two datasets. RESULTS: The results from both analyses revealed that five variables significantly predicted length of stay and were stable over time. They were a primary diagnosis of schizophrenia, the number of previous admissions, a primary diagnosis of a mood disorder, age, and a secondary diagnosis of an alcohol- or other drug-related disorder. For some physicians, the mean length of stay of their patients differed significantly from the length predicted by the regression model--generally, it was shorter. CONCLUSIONS: The results demonstrate that patient-related predictors of length of stay in a single psychiatric hospital can be identified using relatively simple statistical procedures and can be consistent across a large dataset and over time.

Bacterial contamination of scrub jackets during dental hygiene procedures.

PURPOSE: The purpose of this study was to assess bacterial contamination of uniforms by aerosols produced during dental hygiene procedures, including examination, hand and ultrasonic scaling, and polishing. METHODS: Sterile milipore filters were taped to long-sleeved scrub jackets of 26 senior dental hygiene students and worn during patient appointments. Filters were removed at the end of the appointment and cultured to determine bacterial contamination on the dominant arm, non-dominant arm, and chest. RESULTS: Analysis of filter position by procedure with SPSS MANOVA showed a statistically significant difference (1.95, df = 9,299, p = .045). Univariate statistics showed that filters on the dominant arm (p = .013) and non-dominant arm (p = .030) had significantly higher colony forming unit/filter for ultrasonic scaling than for examination, while chest did not (p = .154). CONCLUSION: Aerosol contamination is produced during dental hygiene procedures, even examination and hand scaling. The number of micro-organisms is higher on the sleeves than the chest of scrub jackets, and is higher when ultrasonic or sonic scalers or air polishers are used.

Survey of ethnicity and academic preparation of faculty in dental hygiene programs.

PURPOSE: The purpose of this study was to determine numbers of minority faculty in dental hygiene programs and to examine the academic preparation of faculty members who are dental hygienists. METHODS: A survey of ethnicity and academic preparation of full- and part-time faculty was sent to directors of all accredited U.S. dental hygiene programs in November 1991. Equal Employment Opportunities Commission (EEOC) categories and definitions were used for ethnic minorities. Professional minorities were defined as male dental hygienists and female dentists. Survey data were analyzed using chi-square and ANOVA for unequal cell frequencies. RESULTS: One hundred twenty-six (62%) of the 203 surveys were returned. Only 41 (32%) of the programs reported one or more ethnic minorities among the full- or part-time faculty. Of the 1,025 dental hygienists employed full- or part-time as faculty, there were 59 ethnic minorities and 10 males. The majority of the dental hygiene programs that had dentists as full- or part-time faculty employed white male dentists. The most common minority among dentists was white female. Most dental hygiene program director respondents (66%) reported no minority faculty in their programs. Of the dental hygiene programs that did have minority faculty, most had only one member of one minority group. No significant differences in educational preparation were found between ethnic minority and white dental hygiene faculty. Significant differences in academic preparation of dental hygiene faculty were found among programs in different educational settings and, for full-time faculty, by degree awarded program graduates. CONCLUSION: The limited numbers of minority faculty in dental hygiene programs restricts the number of dental hygiene students who have access to minorities as professional role models. To increase cultural diversity in dental hygiene education, efforts are needed to recruit more minority students and to encourage them to pursue advanced degrees for careers as dental hygiene educators.

Unusual dyskinesia complicating cardiopulmonary bypass surgery.

Four infants developed dyskinesia after cardiopulmonary bypass surgery three to four days postoperatively. The dyskinesia was choreoathetotic, and involved mainly the mouth, tongue and face. It was absent during sleep. Three of these infants improved over periods of several weeks, but one infant remained dyskinetic one year postoperatively. Neuro-imaging studies and EEGs were of little value in determining the cause of the dyskinesia. The factors responsible for the involuntary movements and for their severity remain unexplained.

Synthesis of ferritin by neuroblastoma.

Ferritin is an iron-containing protein which is a normal component of serum. The levels of ferritin are increased in the sera of some children with neuroblastoma, and this increase appears to be a potent indicator of prognosis. To determine whether synthesis of ferritin by the tumor cells contributes to these increased serum levels, we examined incorporation of radiolabeled leucine by CHP 126, a neuroblastoma derived cell line, into ferritin. Using sequential immunoprecipitation and gel electrophoresis of sonicates from cells maintained in medium containing iron in amounts standard for tissue culture, incorporation of label into ferritin was 0.04% of that into total protein synthesized over the same time period. Addition of up to 40 micrograms of iron as ferric ammonium citrate increased ferritin synthesis to a maximum of 0.16% without altering synthesis of total protein. The pattern of iron-induced enhancement in the neuroblastoma cells was similar to that which was seen using Chang liver cells, a cell line well known to be capable of ferritin synthesis. These results confirm that neuroblastoma cells can synthesize ferritin and that synthesis is regulated by exogenous iron.

Enhancement of in vitro activity against neuroblastoma by doxorubicin and deferoxamine.

A colorimetric assay was used to compare the in vitro effects on neuroblastoma cell viability of 3.75-60 microM deferoxamine or 0.125-2 microM doxorubicin alone with those of the two drugs in combination. For each of two human neuroblastoma cell lines (CHP 100 and CHP 126), exposure to each drug individually produced dose-related cytotoxic effects within 3 days. When these cells were simultaneously exposed to both drugs, even at concentrations achievable in vivo, cell death was greater than what could be accounted for by either drug alone. Cytotoxicity was further potentiated to a variable extent when the cells were sequentially exposed to deferoxamine and doxorubicin at 24-hour intervals. Thus, this combination of drugs warrants further study.

Need for dental hygiene and dental care in Veterans Administration patients.

The Periodontal Treatment Needs System (PTNS) was used to classify needs of 102 patients, 97 males and five females, at the VAMC Dental Service. The PTNS is based on the presence or absence of plaque, calculus or overhangs, inflammation and pocket depth. In addition, need for restorative and prosthetic care was added to the PTNS based on dentists' diagnosis. All classification was done by quadrant. All subjects required dental hygiene or periodontal care; 45% of the subjects need restorative treatment, prosthetic treatment, or both. Differences in numbers of patients requiring each type of treatment were highly significant. Multiple regression showed that age was positively related to type of treatment needed, with a significant difference in dental hygiene or periodontal needs by quadrant. The results of this study show greater need for dental hygiene and periodontal treatment than for dental treatment in these patients.

An analysis of response changes on objective test questions.

Response changes of two classes of 30 dental hygiene students each were tabulated on multiple-choice questions on quizzes, midterms, and final examinations. Response changes were classified as wrong to right, right to wrong, or wrong to wrong. Despite educational myths that changing answers is harmful, significantly more responses were changed from wrong to right than from right to wrong. There were more answers changed for test items of low and moderate difficulty than high difficulty. Students ranked in the top third of the class made the fewest number of response changes. A comparison of actual and revised grades showed that the response changes significantly improved grades. Faculty should encourage students to examine their own pattern of response changes and use this information to their advantage when taking objective tests.