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Biomedical subjects

A R Smith

Publications and source records attributed to A R Smith.

At least 55 records · Page 3Linked to original sources
PubMed1998

Nursing model of hospitalization events.

PURPOSE: To provide a model of hospitalization events from a nursing perspective. Hospitalization has become an event of highly technical care coupled with intense nursing care requirements. This proposed model is needed to support clinical nursing research among hospitalized patients. SCOPE: Hospitalization occupying space and time as a discrete event on the health-illness continuum. First developed to provide a framework for a descriptive study, the model shows the factors involved in hospitalization and provides a framework for understanding the nursing care that occurs. Selected results from descriptive research that used patients hospitalized with AIDS as subjects are reported as an example of use of the model. CONCLUSIONS: Research about hospitalization events continues to be critical for the advancement of clinical nursing. This model is presented to provide a conceptual framework for future research.

Clinical Nursing Research↗
PubMed1997

Treatment planning for adenocarcinoma of the rectum and sigmoid: a patterns of care study. PCS Committee.

PURPOSE: To conduct a study of the process of treatment planning and treatment of adenocarcinoma of the rectum and sigmoid in the United States, and to compare survey results to consensus guidelines. METHODS AND MATERIALS: A consensus committee developed guidelines for the radiotherapeutic management of adenocarcinoma of the rectum and sigmoid, and also developed a survey form that was used to gather data to evaluate the practice patterns for patients treated in 1989 and 1990 against the consensus guidelines. Seventy-three facilities were randomly selected for site visits from the 1321 radiation therapy facilities in the US: 21 academic, 26 hospital based, and 26 free standing. During the site visits, the radiotherapy records were examined by the surveyor physicist and radiation oncologist to extract and record the required data. Data collected included items related to treatment specific parameters, including treatment planning considerations. Analyses included stratification as to the types of institutions, academic, hospital based, or free standing. RESULTS: For many treatment parameters there are discrepancies between the patterns of practice determined by the surveys and the consensus guidelines for radiotherapy treatment of adenocarcinoma of the rectum and sigmoid. Significant differences in practice among the stratified institution types were found in only a few parameters.

Adenocarcinoma↗
PubMed1997

Spatial disorientation blocks reliable goal location on a plus maze but does not prevent goal location in the Morris maze.

Cue control in spatial learning was investigated in a plus maze and a Morris maze. Rats transported in opaque containers with prior rotation to a plus maze, but not a Morris maze, could not find a goal defined by external cues. Rats transported in clear containers without rotation found the goal in both mazes. In the Morris maze, goal location was readily relearned following cue removal by rats in clear containers but not by rats in the opaque/rotation group. B. L. McNaughton et al.'s (1996) theory that during spatial learning sensory information is bound to preconfigured internal maps in the hippocampus, whose metric is self-motion and whose orientation depends on input from an inertial based head direction system, may explain this study's findings.

Animals↗
PubMed1997

Urodynamic services, personnel and training in the United Kingdom.

OBJECTIVE: To audit the provision of urodynamic services in the UK, with particular emphasis on the personnel involved and the training they received. METHODS: A questionnaire was sent to 163 centres carrying out urodynamics in the UK asking for information on the department providing the service, the frequency of use, the number of patients investigated, professional training of the personnel and whether the personnel thought that the training was adequate. RESULTS: Most urodynamic facilities in the UK function on a part-time basis. Urodynamics are carried out by a variety of healthcare professionals but most are performed by doctors and nurses. Half the respondents considered the training to be inadequate. CONCLUSION: Consideration should be given to requiring a minimum standard of training for personnel carrying out urodynamics in the UK to ensure that a quality service is provided.

Delivery of Health Care↗
PubMed1997

Comparison of the cellular fatty acid composition of a bacterium isolated from a human and alleged to be Bacillus sphaericus with that of Bacillus sphaericus isolated from a mosquito larvicide.

The cellular fatty acid (CFA) composition of the cytoplasmic membrane of a bacillus isolated from a human lung and deposited in the National Collection of Type Cultures as Bacillus sphaericus NCTC 11025 was determined by gas-liquid chromatography. The CFA composition of B. sphaericus 2362, isolated from a microbial larvicide, and those of B. sphaericus reference strains obtained from public collections were also determined. Samples were grouped by hierarchical cluster analysis based on the unpaired-group method using arithmetic averages. Samples that linked at a Euclidean distance of < or = 2.0 U were considered to belong to the same strain. NCTC 11025 and the type strain of B. sphaericus, ATCC 14577, were mixed; all other isolates were monotypic. The predominant fatty acid in NCTC 11025 was 12-methyltetradecanoic acid, while the predominant fatty acid in the remaining isolates was 13-methyltetradecanoic acid. NCTC 11025 linked to the other isolates at a Euclidean distance of 83.8 U, and we concluded that it belongs to a different species that we could not identify. We could distinguish among six DNA homology groups of B. sphaericus by using fatty acids. Within DNA homology group IIA, strain 2362 could be distinguished from other strains belonging to serotype H5a, 5b. We concluded that CFA analysis is a useful technique to determine if future human isolates identified as B. sphaericus in fact belong to other species of bacteria or whether the isolates originated from commercial products.

Animals↗
PubMed1997

The potential role of proton beams in radiation oncology.

Historically, major gains in the local control of large, deep-seated tumors treated with radiation have occurred whenever dose distributions have become more localized to the tumor. Better dose localization permits the delivery of higher tumor doses while delivering less dose to dose-limiting normal tissues. High-energy protons, because they stop abruptly in tissue at the end of their range and deposit most of their energy there, provide dose distributions that are superior to x-rays when used in comparable beam configurations. The installation of a hospital-based proton therapy facility at the Massachusetts General Hospital in Boston, MA, and the existing facility at Loma Linda University Medical Center, Loma Linda, CA, provide a potential for achieving higher rates of local control in tumors throughout the body.

Clinical Trials as Topic↗
PubMed1996

Identification and sequencing of a novel insertion sequence, IS1471, in Burkholderia cepacia strain 2a.

A novel insertion sequence (IS), IS1471, has been identified which is inserted into IS element IS1071 possessed by plasmid pIJB1 in Burkholderia cepacia strain 2a. Nucleotide sequencing has revealed that IS1471 is 1112 bp in length and is flanked by 22/21-bp imperfect inverted repeats with a 3-bp duplication of the target sequence IS1471 contains a single open reading frame encoding a putative polypeptide of 345 amino acids with molecular mass of 39406 Da. Searches of DNA and protein sequence databases did not result in the detection of any homologous IS elements, suggesting that IS1471 is novel and may not belong to any known IS groups.

Amino Acid Sequence↗
PubMed1996

Treatment planning for primary breast cancer: a patterns of care study.

PURPOSE: The 1989 Patterns of Care Study included treatment planning for early breast cancer. A Consensus Committee of radiation physicists and oncologists determined current guidelines and developed questionnaires to determine treatment planning and delivery processes used by the participating institutions (e.g., use of portal films). This article presents and analyzes the results of that survey. METHODS AND MATERIALS: The survey included 449 respondents, distributed as follows: 136 (30%) from Strata I (academic facilities); 169 (38%) from Strata II (hospital based facilities); and 144 (32%) from Strata III (freestanding facilities). The treatment planning procedures surveyed included: whether individualized tissue compensators are used, whether inhomogeneity corrections are used in dose calculations, the use of computerized tomography, whether isodose distributions for external beam tangents and interstitial implants are generated, the use of lymphoscintigraphy, immobilization devices, simulations, portal films, etc. RESULTS: The survey results demonstrated that out of 305 patients from Strata I and II institutions, 237 (78%) had simulated tangential fields. Consistent with this finding is that 76% of patients from Strata I and II institutions were immobilized, while only 51% of Strata III patients were. Moreover, only 18 out of the 449 (4%) of cases did not have any type of external beam dose distribution calculated--presumably, in these cases missing tissue compensation would be unlikely. On the other hand, 41% of the Strata II, 27% of Strata III, but only 19% of Strata I (p < 0.0002) cases received CT. Surprisingly, 19% of the Strata I, 35% of the Strata II, and 25% of the Strata III (p = 0.0011) patients received lymphoscintigraphy, perhaps reflecting the use of wide tangents to encompass the internal mammary nodes in these patients. In terms of optimizing treatments, 74% of Strata I, 70% of Strata II, and 78% of Strata III patients had wedges used on both tangential fields, although in 5, 12, and 14%, respectively, no beam modification of any sort was used. Furthermore, it should be noted that in 7% of the Strata I, 23% of Strata II, and 37% of Strata III cases there was no attempt to reduce the divergence of the tangential fields into the lung. On the other hand, if one considers the 135 (of 449) patients where matching of the tangential and supraclavicular fields was applicable, 41% of Strata I, 22% of Strata II and 46% of Strata III patients had those fields matched in a vertical plane, which would involve sophisticated alignment procedures. Quality control of treatment delivery was high: 97% of all surveyed received portal films at least once. The use of thermoluminescent dosimetry (TLD) to measure the dose to the contralateral breast was of little interest: only 4 of the 305 Strata I and II patients received in vivo measurements. CONCLUSIONS: This national survey has established the patterns of treatment planning for early breast cancer. It shows a generally consistent approach-although a number of statistically significant variations have been identified.

Breast Neoplasms↗
PubMed1996

Treatment planning for carcinoma of the cervix: a patterns of care study report.

PURPOSE: The Patterns of Care Study (PCS) of patients treated in 1988-89 included "patterns of treatment planning" for radiotherapy of carcinoma of the uterine cervix. A Consensus Committee of radiation physicists and oncologists established current guidelines and developed questionnaires to assess the treatment planning process (i.e., the general structure, methodology, and tools) of institutions involved in the Patterns of Care Study. This paper reports the findings of the assessment. METHODS AND MATERIALS: The PCS surveyed 73 radiotherapy facilities, of which 21 are academic institutions (AC), 26 hospital-based facilities (HB), and 26 free-standing centers (FS). In total, 242 cases were assessed with 39% from academic centers, 33% from hospital-based centers, and 28% from free-standing centers. The survey collected treatment planning information such as the use of computed tomography (CT), simulation procedure, contouring of patient outline, tumor or target delineation, identification of critical structures, method of dose prescription (point or isodose), etc. Data was also obtained concerning implant boosts, e.g., radioisotope used, use of midline block for external beam treatment, availability of remote afterloader, practice of interstitial implants, combination with hyperthermia, etc. RESULTS: There is a high degree of compliance relative to the basic treatment planning standards. For example, 171 cases (out of 173) from AC and HB institutions included simulation and 169 used port film; for cases from FS centers, 61 out of 69 involved simulation and 66 out of 69 included port film. Most institutions used linacs (231 out of 242); in five cases, Co-60 units and in six cases betatron was used. In terms of treatment planning, 53% used skin contours, but only 14% had target volume delineation, with AC and HB being slightly more conscientious in these efforts. Critical organs did not appear to be explicitly considered in external beam treatment planning, with only 3% outlining the bladder, 5% the rectum, and less than 1% the small bowel. Only 11% of the centers used CT in treatment planning, and none reported the use of magnetic resonance imaging (MRI). For patients receiving implants, about 40% had midline blocking during external beam treatment, of which one out of three were shielded by standard blocks and two out of three with customized ones. About 11% of the patients receiving implants were treated with remote afterloading devices, 5% received interstitial implants, and none were treated in combination with hyperthermia. CONCLUSION: The treatment planning aspects of radiotherapy of carcinoma of the cervix have been established by this Patterns of Care Study Survey. There is a high level of uniformity in the approach. Some variations exist among centers in the different strata.

Brachytherapy↗
PubMed1996

The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction.

This article presents a standard system of terminology recently approved by the International Continence Society, the American Urogynecologic Society, and the Society of Gynecologic Surgeons for the description of female pelvic organ prolapse and pelvic floor dysfunction. An objective site-specific system for describing, quantitating, and staging pelvic support in women is included. It has been developed to enhance both clinical and academic communication regarding individual patients and populations of patients. Clinicians and researchers caring for women with pelvic organ prolapse and pelvic floor dysfunction are encouraged to learn and use the system.

Female↗
PubMed1996

Induced radioactivity of LDEF materials and structural components.

We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

Aluminum↗
PubMed1996

Pelvic floor damage.

Birth attendants must keep up to date with the recommendations made in good clinical studies, and incorporate these into their practice. There is no justification for routine, liberal use of episiotomy, and when performed it must be a mediolateral incision, not midline. The indications for episiotomy are fetal distress, prolonged active second stage of labour and if severe perineal damage is thought to be imminent. Further study of the effect of overstretching tissues is required, to establish if episiotomy would protect against prolapse. Perineal trauma should be repaired by an experienced member of staff, with a polyglycolic acid suture, preferably using a continuous subcuticular technique. It is possible that women who are particularly at risk of pelvic floor damage, such as those who have already experienced postpartum anorectal incontinence, should be offered an elective caesarean section.

Delivery, Obstetric↗
PubMed1996

Effects of fumonisin-containing culture material on pulmonary clearance in swine.

OBJECTIVE: To determine the potential effects of feeding tumonisin-containing culture material on the pulmonary clearance of blood-borne particulates and bacteria in swine. ANIMALS: 21 healthy male pigs randomly assigned to control and treated groups. PROCEDURE: Control pigs were fed a standard grower ration while culture material containing fumonisins (20 mg of hydrolyzed fumonisin B1/kg of body weight/d) was added to the feed of treated pigs for 7 days. On day 8, pigs were anesthetized with halothane and catheterized, using a sterile cut-down procedure. 18 hours after recovery from anesthesia, Monastral Blue or Pseudomonas aeruginosa was infused into the right atrium of treated and control pigs for 30 minutes and pulmonary clearance was determined. RESULTS: Pigs that were fed fumonisin-containing culture material had a significantly (P < 0.05) decreased ability to clear Monastral Blue and P aeruginosa. Ultrastructural examination of the lung indicated that uptake of copper pigment by pulmonary intravascular macrophages was decreased in treated pigs. CONCLUSIONS AND CLINICAL RELEVANCE: Fumonisins, even when fed to pigs at sub-lethal concentrations, can inhibit pulmonary intravascular macrophages from removing particulate matter and bacteria from the circulation, thus potentially predisposing swine to infectious disease.

Animal Feed↗
PubMed1995

Patterns of care survey results: treatment planning for carcinoma of the prostate.

PURPOSE: Treatment planning has been defined differently at various institutions to encompass tasks ranging from the initial evaluation of the patient to the delivery of the treatment as well as a more narrow view, focused primarily on isodose computation. To evaluate the impact of much of the new treatment-planning technology that has become available, it is necessary to define and develop recommended guidelines for the treatment-planning process. METHODS AND MATERIALS: The 1989 Patterns of Care Study (PCS) included questionnaires to access treatment planning practices currently in use for the entire census of oncology facilities in the United States. These questionnaires were developed by a consensus committee consisting of both physicists and radiation oncologists whose charge was to formulate a description of current treatment-planning practices. The description was based on the committee's experience and knowledge of the treatment-planning process considered to be widely available and in general use, as well as a review of the literature. From the description of the treatment-planning process, a set of guidelines for treatment planning was developed for prostate as well as each of the other disease sites included in the PCS. Data from the study defined the general structure, methodology, process, and tools used by each institution involved in the Patterns of Care Survey Study. National averages for all of the variables were calculated with weighted averages, with the weights reflecting the sample design and number of patients in the different types of facilities. The data were stratified according to academic, hospital, or free-standing facility and were compared with the Consensus Guidelines for Treatment Planning of the Prostate. DISCUSSION: Based on the consensus statement, the treatment-planning process was separated into the following categories: (a) Treatment-Planning Workup, (b) Treatment Plan Implementation, (c) Treatment Delivery, (d) Treatment Verification, and (e) Quality Assurance. The results from the survey were summarized for each category and compared with the consensus statement. CONCLUSIONS: Although there is an increasing trend toward using computed tomography (CT) information to acquire individualized patient data, volume definition and localization are often completed in the simulator without the direct use of CT information (47%). As more sophisticated beam arrangements and blocking are used, one needs to look at the full three-dimensional (3D) volume to ensure that there are no marginal misses due to blocking and beam arrangement. Improved and more widespread use of immobilization devices is also required with conformal treatments and reduced margins. The results of the survey helped to identify and establish the standard of practice for treatment planning of the prostate as well as to provide documentation for better defining a complete description of the treatment planning process. Well-documented guidelines will provide more consistent treatment of patients, which should have an impact on outcome.

Clinical Protocols↗
PubMed1995

Treatment planning for Hodgkin's disease: a patterns of care study.

PURPOSE: To conduct a survey of the process of treatment planning for the radiation treatment of Hodgkin's Disease in the United States, and to compare survey results with consensus guidelines as determined by recognized experts. METHODS AND MATERIALS: A consensus committee developed guidelines for the radiotherapeutic management of Hodgkin's Disease. A series of survey forms were designed to evaluate the standards of practice and compare these with the consensus guidelines. A total of 61 facilities divided evenly into the strata of academic, hospital based, and free standing had eligible Hodgkin's Disease cases. There were 275 eligible cases of Hodgkin's Disease evaluated. Data collected from the radiation oncology records included treatment-specific parameters such as energy, dose, blocking, and calculations, as well as treatment planning practices. Statistical analysis was performed on each data element and for all institution strata. RESULTS: For a number of treatment parameters, there were some discrepancies note between the current United States practice and the consensus guidelines. Some significant differences were found in practice between the stratified institution types. A representative sample of results are: the majority of Hodgkin's Disease patients are treated with x-ray energies in the recommended range, between 4 and 10 MV. Standard mantle (for upper extended field treatment) and modified spade (for lower extended field treatments) are the fields of choice for all types of facilities. The consensus guidelines recommended that dose calculations at multiple points be obtained; however, 15% of patients in the survey received only a single point calculation. Current irregular field dosimetry calculation software does not take account of inhomogeneities. Thirty percent of Hodgkin's Disease patients do not receive a gap calculation for the abutment of upper and lower extended fields. In 70% of treatment fields, no compensation is used. Very few patients receive any kind of in vivo dosimetry check. CONCLUSION: The survey served to verify that, in general, Hodgkin's Disease treatment planning at all strata of institution has kept pace with recommended practice as delineated in current literature and texts. Small pockets of practice still need improvement in technique and equipment. Changes in practice were identified that can contribute to improved dose uniformity and accuracy.

Consensus Statements as Topic↗
PubMed1995

Treatment planning structure and process in the United States: a "Patterns of Care" study.

PURPOSE: To conduct a study of the structure and process of treatment planning in the United States. METHODS AND MATERIALS: A Patterns of Care treatment planning consensus committee developed a survey form that was used to gather data for 106 items relating to the structure and process of treatment planning. These questions were general in nature and not specific to any particular disease site. Seventy-three facilities were randomly selected for site visits from the 1321 radiation therapy facilities in the United States: 21 academic, 26 hospital, and 26 free-standing. During the site visit the facility physicist, assisted by the site-visit physicist, completed the form. RESULTS: Twenty-nine percent of facilities have cobalt-60 machines; 25% have 4 MV linacs; 75% have photon energies in the range of 5-8 MV; and less than 10% have energies greater than 20 MV. Academic facilities led hospital and free-standing facilities by about 30 percentage points in the availability of all electron energies (88 vs. 58%, approximately, in the range 4-13 MeV and scaling downward to about 60 vs. 30% at the highest energies). The national averages for the availability of Cs-137, Ir-192, and I-125 were 87, 73, and 44%, respectively. Computerized tomography (CT) scanning is not available or not used in 15% of hospital and free-standing facilities. Ninety-six percent of facilities have treatment planning computers; at 10% of facilities physicians do not participate in treatment planning. The estimated national averages of facilities having formal quality assurance (QA) programs for treatment planning systems, simulators, film processors, and blocking systems are 44, 79, 62, and 55%, respectively. Sixty-three percent of facilities obtain independent machine calibrations. CONCLUSION: This is the first patterns of treatment planning study carried out in the United States and the results reported here will establish a baseline for future studies. The present study has identified some elements that were unexpected, such as the percentage of facilities lacking formal QA programs for treatment planning systems; however, it has not established any impact of such findings. It is recommended that future studies include the availability of new technologies such as multileaf collimation, dynamic wedges, digital portal imaging, and CT simulation. With the increasing nationwide concern with the cost of health care, we must continue to monitor the implementation, use, and impact on treatment outcome of new and expensive technologies.

Brachytherapy↗
PubMed1995

Laparoscopic and needle colposuspension.

Laparoscopic colposuspension can produce a similar anatomical result to open colposuspension. The procedure does, however, require additional laparoscopic surgical skills which take time to learn. Whether it is worth investing this time will only be known when a longer-term follow-up is reported by surgeons who have considerable experience with the technique.

Female↗