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Biomedical subjects

W Blau

Publications and source records attributed to W Blau.

At least 19 recordsLinked to original sources
PubMed2002

The effect of Nd:YAG radiation at nanosecond pulse duration on dentine crater depth.

The effect of laser parameters on laser-dentine interaction is little known. The aim of this in vitro study was to determine the effect on dentine crater depth of Nd:YAG laser radiation in relation to pulse repetition rate, total delivered energy, dentine site and the presence or absence of a dye. One hundred and forty-four sound third molars were extracted and sectioned transversely to provide 288 upper and lower cut surfaces. The upper surfaces were painted with a layer of dye (IR5) suitable for absorption at 1064 nm. The specimens were divided into 12 sub-groups each containing 12 upper and 12 lower specimens. These were exposed to a Nd:YAG laser with a 30 nanosecond (ns) pulse duration. This laser operated in a non-contact mode (spot diameter 165 microm) with pulse repetition rates of 2.5, 5.4 and 10.5 Hz. Four total energies were delivered at each repetition rate; 2.3, 3.63, 3.96, 4.29 joule (J) at 2.5 Hz repetition rate; 2.3, 2.64, 3.63, 4.29 J at 5.4 and 10.5 Hz repetition rates. Five outer and three inner sites were irradiated on each specimen. Each dentine crater depth was measured five times using a Reflex Microscope and a three-dimensional centre of gravity derived. An upper and lower specimen were taken from each sub-group and viewed under a scanning electron microscope (SEM). ANOVA was applied: total delivered energy and dyed/undyed were found to have a statistically significant effect on crater depth (p<0.0001). In general increasing energy and the presence of dye produced deeper craters. Inner/outer dentine location and repetition rate were not found to be statistically significant. All craters were carbonised.

Dentin↗
PubMed2001

The effect of Nd:YAG pulse duration on dentine crater depth.

OBJECTIVES: The effect of alteration of laser parameters on laser-dentine interaction, in particular the effect of pulse duration, has not been well documented. The aim of this in vitro study was to determine the effect on dentine crater depth of Nd:YAG laser pulse duration, and total delivered energy, dentine site and the presence or absence of dye. METHODS: Ninety-six sound third molars were extracted and sectioned transversely to provide 192 upper and lower cut surfaces. The upper surfaces were painted with a layer of dye (IR5) suitable for absorption at 1064 nm. The specimens were divided into 16 sub-groups and exposed to two Nd:YAG lasers; one of pulse duration 7 ms and the second of pulse duration 35 ps. Both lasers operated in a non-contact mode (spot diameter 165 microm) with repetition rates of 10.5 and 10 Hz, respectively. Four total energies (2.28, 2.64, 3.6, 4.2 J) were delivered to eight dyed and eight undyed sub-groups. Eight outer and five inner sites were irradiated on each specimen. Dentine crater depth was measured five times using a Reflex Microscope and a three-dimensional centre of gravity derived. An upper and lower specimen were taken from each sub-group and viewed under a SEM. RESULTS: ANOVA and multiple regression analysis were applied and the following factors were found to have a statistically significant effect on crater depth (p<0.0001): total delivered energy, pulse duration and inner/outer location. CONCLUSIONS: Increasing energy and pulse duration produced deeper craters. Similarly inner dentine sites produced deeper crater depths. Only craters produced at the ms pulse duration were carbonised. It would appear that laser-dentine interaction has a non-thermal component at picosecond pulse duration.

Analysis of Variance↗
PubMed2001

Documentation of pain assessment and treatment: how are we doing?

The purpose of this analysis was to evaluate documentation of practice provided by a multidisciplinary team of nurses, physicians, and pharmacists who participated in an educational program on postoperative pain management. Chart audit of 787 patient charts at 6 sites revealed documentation of pain histories in approximately 75% of the charts, most often in the surgeon's history and physical examination. Examination of multiple assessment items indicated that the experimental group, relative to the control group, experienced an increase of more than 10% in the documentation of pain intensity, pain quality, pain duration, numeric rating scale used, pain behavior, factors that increase pain, vital signs, sedation level, cognitive status, social interaction, and mood from before the program to 6 months after the program. Across all sites, documentation of assessment, treatment, and treatment outcome data was infrequent and inconsistent. Calculation of documentation of 4 items that constituted a focused assessment of postoperative pain on the surgical floor revealed a significant program effect for assessment of pain quality and pain intensity. A postprogram survey of participants in the educational program revealed an increase in discussion of postoperative pain management with other practitioners and an increase in use of a 0 to 10 scale to rate pain. More documentation of patient pain history, clinical problems, treatment, and follow-up action is needed to improve practice and research.

Clinical Competence↗
PubMed2000

Effect of Nd:YAG radiation at millisecond pulse duration on dentine crater depth.

BACKGROUND AND OBJECTIVE: The effect of laser parameters on laser-dentine interaction has not been explored fully. This in vitro study investigated the effect on dentine crater depth of Nd:YAG laser radiation with varying repetition rates, total delivered energy, and dentine site either dyed or undyed. STUDY DESIGN/MATERIALS AND METHODS: One hundred forty-four caries-free third molars were sectioned transversely to provide 288 upper and lower cut surfaces. The upper surfaces were dyed (IR5). These upper and lower cut surfaces were exposed to an Nd:YAG laser with a 7 millisecond (msec) pulse duration, pulse repetition rates (RR) of 2. 5, 5.4, and 10.5 Hz, and four total energies (2.28, 2.64, 3.6, 4.2 joules). Dentine crater depth was measured by using a Reflex microscope. Results were statistically analysed with analysis of variance. RESULTS: Crater depth increased with increase in total delivered energy and in dyed and inner dentine sites (P<0.0001) but decreased with increasing repetition rate (P< 0.0001). CONCLUSIONS: Increasing energy, dyed, and inner dentine sites produced deeper craters.

Analysis of Variance↗
PubMed2000

Fatal thrombotic thrombocytopenic purpura as a rare complication following allogeneic stem cell transplantation.

Thrombotic thrombocytopenic purpura (TTP) is a rare disease which, together with hemolytic uremic syndrome, is subsumed under thrombotic microangiopathy. After stem cell transplantation (SCT), this syndrome represents a possibly fatal complication with a higher incidence in allogeneic SCT than in autologous SCT. Although plasmapheresis offers an encouraging treatment modality in classic TTP, this seems less effective in bone marrow transplant-associated microangiopathy. This is probably due to a different etiology. We present a case of transplant-associated TTP with a fatal outcome despite multiple courses of plasmapheresis.

Fatal Outcome↗
PubMed2000

Clinical economics: calculating the cost of acute postoperative pain medication.

Few data are available that address the cost of postoperative pain management, although such knowledge would enhance our understanding of caregiver choices related to direct medical costs, such as type, frequency, and route of medication. This article describes the cost of postoperative pain medications before and after an educational program provided to nurses, pharmacists, and physicians in six community hospitals. Medication costs were calculated by averaging across all brands the average wholesale price of the most common dose administered in the sample for each medication. The median cost of postoperative pain medication across all days, all surgeries, was $9.46. Calculating the cost of acute postoperative pain medication suggested that cost over stay is highly influenced by the use of a few expensive medications. The relationship of medication cost to length of stay (LOS), function, and pain intensity is discussed.

Acute Disease↗
PubMed2000

Allogeneic transplantation of G-CSF mobilized peripheral blood stem cells from unrelated donors: a retrospective analysis.

BACKGROUND AND OBJECTIVES: Allogeneic peripheral blood stem cell transplantation (PBSCT) from matched siblings has lead to clinical results comparable to those of standard bone marrow transplantation (BMT). We report the outcome of 79 patients transplanted with PBSC from unrelated donors. DESIGN AND METHODS: In 61 cases PBSC were used for primary transplantation whereas 18 patients were treated for relapse or graft-failure. In 35 patients receiving primary transplants, T-cell depletion (TCD) using CD34 positive selection of PBSC with or without additional T-cell depletion had been performed to reduce the risk of graft-versus-host-disease (GvHD). RESULTS: The rate of primary graft-failure was higher (20%) in the TCD group than in that receiving unmanipulated grafts (UM) (5%, p=0.007). Patients with standard risk (n=34) receiving first transplants had a significantly better overall (60.4% vs. 24%, p=0.02) and disease-free survival (57.2% vs. 22.3%, p=0.006) compared to a high risk group of patients (n=21). There were no differences in the speed of neutrophil and platelet engraftment between TCD and UM transplants. As expected, the cumulative risk for acute GvHD grade II.-IV was significantly higher in the patients who had received UM grafts (71.8% vs. 38.1%, p=0.005). Although a trend towards a better survival rate was observed after TCD transplantation (52.2%) compared to the UM group (38.1%), this difference was not statistically significant. The probability of relapse was significantly higher in patients after UM transplants (38.8% vs. 8. 4%). This apparent paradox is explained by the higher number of high-risk patients in this group (p=0.03). Multivariable analysis of disease-free survival revealed risk category (p=0.02) and use of ATG (p=0.03) to be of significant impact. All patients (n=6) with non-malignant diseases are alive with full donor chimerism. INTERPRETATION AND CONCLUSIONS: These data show that PBSC from unrelated donors can be transplanted either unmanipulated or CD34 selected. Prospective studies comparing BMT with PBSCT from unrelated donors are needed in defined disease categories.

Adolescent↗
PubMed1999

Changing acute pain management to improve patient outcomes: an educational approach.

The United States Agency for Health Care Policy and Research (AHCPR) Acute Pain Management Guidelines were written to provide a scientific basis for practice. Educational programs designed to promote use of the guidelines may change practice in community hospitals. This article describes the development and implementation of an education program for nurses, physicians, and pharmacists in six community hospitals. Program content addressing the use of continuous quality improvement (CQI) teams, detailed pain histories, application of algorithms and dose calculation is described; direct and indirect outcome measures are reviewed. Six months after the program, all three experimental sites reported use of the AHCPR Guidelines in practice. Nurses reported that assessment and documentation of patients' duration of pain were perceived to be the most important caregiver behaviors providing benefit to patients: Across all respondents' reports of regularly performed activities, the activity performed by the largest proportion was assessing and documenting pain using a 0-10 rating scale.

Acute Disease↗
PubMed1998

Total body irradiation and cyclophosphamide is a conditioning regimen for unrelated bone marrow transplantation in a patient with chronic myelogenous leukemia and renal failure on hemodialysis.

Five years after the diagnosis of Ph chromosome-positive chronic myeloid leukemia (CML) a 31-year-old patient developed malignant nephrosclerosis with renal failure. He then underwent an allogeneic unrelated BMT in first chronic phase CML. The preparative regimen consisted of fractionated total body irradiation (TBI) and cyclophosphamide (CY). We studied the pharmacokinetics of cyclophosphamide on hemodialysis and compared clinical parameters including time to engraftment and toxicity with parameters of a patient with normal renal function who also received an unrelated marrow as treatment for CML in first chronic phase. Our results suggest that TBI/CY is a suitable conditioning regimen for allogeneic transplantation in patients with hematological malignancy and renal failure on hemodialysis.

Adult↗
PubMed1996

Changing the relationship among nurses' knowledge, self-reported behavior, and documented behavior in pain management: does education make a difference?

An educational program designed to change knowledge in order to change pain management practices and patient outcomes was offered to nurses who provide day-to-day care to patients with cancer in communities in a predominantly rural state. A quasi-experimental time-series design was used to measure the effectiveness of the program in changing nurse knowledge, attitude and behavior, and to evaluate the relationships between the outcomes. Data were collected from nurses (N = 29) and patient charts before (N = 209) and after (N = 163) the program. Nurses' knowledge increased, but the change was not statistically significant; the mean percent of correct answers on the three subtests were different and differences persisted throughout the study. Nurses believed that patients should be "pain free." Documentation of behaviors, for example, practice activities, occurred infrequently and showed little change until 6 months after the program. Increase in documentation of pain-intensity ratings, pain location, number of sites of pain, presence of confusion, anxious or depressed mood, sleep, nausea and vomiting, constipation, and general activity were noted. Documentation of the use of a propoxyphene-containing analgesic decreased; increase in the use of hydromorphone methadone and transdermal fentanyl was noted. Analysis of the relationships between correct responses to nurse knowledge questions and documentation of behavior provided interesting, statistically insignificant results that need to be reexamined in future research. Future programs should emphasize analgesic dosing and calculation of equianalgesic doses. Current practices in chart documentation may provide incomplete information regarding change in practice behaviors; more detailed documentation of pain management practices is needed. Nurses who participated in the program anecdotally reported feelings of increased credibility and effectiveness. Although change in behavior is slow to occur, education does make a difference.

Adult↗
PubMed1995

Successful repair of combined septal and biventricular free wall rupture after acute myocardial infarction.

The following case is the first report of successful repair of combined left and right ventricular free wall and ventricular septal rupture. Reports of left ventricular free wall and septal rupture and reports of right ventricular free wall and septal rupture have been published both with and without successful surgical repair. This case demonstrates the presence of left and right ventricular free wall rupture along with septal rupture based upon cardiac catheterization and operative findings. In spite of her severe mechanical complications and prolonged hospital course, the patient is completely functional 1 year after surgical repair.

Aged↗
PubMed1995

Managing cancer pain: content and scope of an educational program for nurses who work in predominantly rural areas.

A great deal of effort is being expended at national, state and local levels to improve cancer pain management in the United States. The fact that cancer patients continue to experience "unrelieved pain" is of concern to professional caregivers and families, as well as to the patients themselves. This article describes the content and scope of an educational program for nurses who work in predominantly rural areas. Content of the program and the evaluation process are described in detail in order to provide other caregivers with a model that could be implemented in similar settings.

Chronic Disease↗
PubMed1994

Radiofrequency catheter ablation as a primary therapy for treatment of ventricular tachycardia in a patient after repair of tetralogy of Fallot.

A 20-year-old man with previous surgical repair of tetralogy of Fallot was admitted with hemodynamically significant ventricular tachycardia that was terminated with cardioversion. He was found at electrophysiological study to have easily inducible ventricular tachycardia that was mapped to the right ventricular outflow tract. Radiofrequency catheter ablation of the ventricular tachycardia focus rendered the patient's arrhythmia noninducible. This case represents a successful radiofrequency catheter ablation of a ventricular tachycardia focus associated with tetralogy of Fallot repair.

Adult↗
PubMed1988

[Effect of cytosine arabinoside on the differentiation of granulocyte-monocyte progenitors (CFU-GM) and myeloid leukemia blasts (CFU-L) in vitro].

The serum concentrations of Ara-C are in the range from 10(-6) to 10(-8) M in LD-Ara-C treated patients. The growth of CFU-GM from bone marrow of healthy volunteers was depressed depending on Ara-C-concentration applied in vitro. The growth of CFU-L from peripheral blood of two patients with AML (M 2) and one patient with CML in blast crisis was differently influenced by Ara-C-application in vitro. An elevated proportion of mature cells was observed in smears of cultured cells with Ara-C from two patients. The usefulness of Ara-C for a differentiation inducing therapy is discussed.

Cell Differentiation↗
PubMed1988

The effect of hematoporphyrin derivative and human erythrocyte ghost encapsulated hematoporphyrin derivative on a mouse myeloma cell line.

The effect of hematoporphyrin derivative (HPD) in combination with HeNe laser radiation on a mouse myeloma cell line, P3X63Ag8U1, has been examined. The effects of varying doses of radiation and photosensitizer were assessed using both dye exclusion and clonogenic assay systems. Development of photosensitivity by those cells in the presence of hematoporphyrin (HP) and HPD has been examined. In addition, with a view towards assessing erythrocyte encapsulation as a vehicle for an immunotargeting system for HPD, the effect of HPD encapsulated in such a manner, on the mouse myeloma cell line has been examined. From the results obtained from these in vitro experiments the authors believe that this may be a convenient means of packaging HPD for antibody-mediated delivery to tumour cells.

Cell Fusion↗