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Biomedical subjects

A Smith

Publications and source records attributed to A Smith.

At least 613 records · Page 34Linked to original sources
PubMed1996

Nested PCR-SSCP assay for the detection of p53 mutations in paraffin wax embedded bone tumours: improvement of sensitivity and fidelity.

DNA extraction and PCR amplification from paraffin wax embedded bone tumour specimens present several difficulties, firstly, because of the abundant matrix they contain and, secondly, because decalcification often causes degradation of DNA. In this report, comparative studies were carried out to determine the most efficient method for DNA extraction and PCR amplification from such specimens. The results indicated that nested PCR produced appropriate strong reaction products with minimal background contamination. A method for DNA extraction from paraffin wax embedded bone tissue and a nested PCR-SSCP technique have been developed for use in such diagnostic specimens.

Journal Article↗
PubMed1996

Establishment of sequence-tagged sites on 15q11-q13 by Alu-vector PCR cloning of YAC-generated fragments.

Angelman syndrome (AS) is caused by the loss of function of undefined gene(s) on human chromosome 15. The majority of subjects have deletions involving maternally-derived chromosome 15q11-q13, and the shortest region of deletion overlap (SRO) has been localized to the region between D15S10 and D15S113. In this study, yeast artificial chromosomes (YACs), 6G-D4, 9H-D2 and 37D-F9, mapping within the AS SRO, were isolated from the ICI YAC library. Alu-vector PCR products were amplified from the YACs and from YACs A229A2 and A33F10 which had been obtained from the St. Louis YAC library. The PCR products were cloned and sequenced, and three new sequence-tagged sites were generated within the AS SRO, facilitating the characterization of gene(s) involved in the Angelman syndrome.

Angelman Syndrome↗
PubMed1996

Prader-Willi syndrome--a case report of the multidisciplinary management of the orofacial problems.

A 24-year-old man with Prader-Willi syndrome presented with a class III malocclusion, featuring maxillary hypoplasia and severe enamel deficiency. Treatment involved orthodontic alignment, surgical advancement of the maxilla and restorative treatment to augment vertical facial height, improve the final occlusion and increase short clinical dental crown heights. The principal features of the syndrome and the management of this case are discussed.

Adult↗
PubMed1996

Screening for psychiatric morbidity in subjects presenting with chronic fatigue syndrome.

BACKGROUND: There is a need for a valid self-rating questionnaire to screen for psychiatric morbidity in patients with chronic fatigue syndrome (CFS). This study had the aim of assessing the utility and validity of two commonly used measures. METHOD: Scores obtained on the General Health Questionnaire (GHQ) and the Beck Depression Inventory (BDI) were compared with various diagnostic and severity ratings obtained via a validating clinical interview, the Schedules for the Clinical Assessment of Neuropsychiatry (SCAN) in 95 consecutively referred subjects at a medical out-patient clinic who fulfilled standard criteria for CFS, and 48 healthy controls. Outcome measures were validating coefficients and receiver operating characteristics (ROC) for different thresholds and scoring on GHQ and BDI and index of definition (ID) as measured by SCAN; and Pearson and point by serial correlation coefficients for different diagnostic groups derived via SCAN and defined according to ICD-10 and DSM-III-R. RESULTS: GHQ and BDI perform poorly as screeners of psychiatric morbidity in CFS subjects when compared with various SCAN derived ratings although results for controls are comparable with other studies. CONCLUSIONS: Neither the GHQ nor BDI alone can be recommended as screeners for psychiatric morbidity in CFS subjects.

Fatigue Syndrome, Chronic↗
PubMed1996

Cephalopod sucker design and the physical limits to negative pressure

Two factors determine the strength of pressure-based adhesive mechanisms such as suction: the magnitude of the pressure differential that their musculature and mechanics can produce and the pressure differential that water can sustain. This paper compares the adhesive strength of the primary cephalopod sucker types: the stalked suckers of decapods (cuttlefish and squid) and the unstalked suckers of octopods. These results are compared with the physical limits imposed by cavitation, the failure of water under negative pressure. The maximum pressure differentials that suckers can produce were measured using a wettable pressure transducer or by measuring their force of attachment on a wettable surface and dividing by the area exposed to reduced pressure. The maximum pressure differentials that water can sustain on a typical marine surface were measured in a Z-tube. Fifteen cephalopod species representing three orders were studied. At sea level, cavitation limits all suckers to the same range of pressure differentials (100-200 kPa), regardless of their morphology. As ambient pressure increases with depth, cavitation ceases to be limiting. In this case, stalked decapod suckers produce greater pressure differentials than unstalked octopod suckers. In addition, small suckers produce greater pressure differentials than large suckers. Suckers larger than 7.5 mm2, both decapod and octopod, typically achieve pressure differentials of 100 kPa. As their size decreases below 7.5 mm2, octopod suckers get slightly stronger, sometimes producing pressure differentials of 250-300 kPa, while decapod suckers get exponentially stronger, sometimes producing pressure differentials near 800 kPa. There were no differences in sucker strength among the four octopod species, but seven of the ten decapod species differed from the overall decapod regression curve. The strongest suckers belonged to the fast-swimming, open-water species in the decapod sub-order Oegopsida.

Journal Article↗
PubMed1996

Aggressive behavior on an inpatient geriatric unit.

1. Violent or aggressive behavior may be a consequence of poor frustration tolerance, ineffective individual coping, impulsivity, and real or imagined threats to the individuals territory, body space, or life. 2. It is ironic that at the same time that the numbers of elderly are increasing, available services are decreasing and the number of beds in nursing homes and rest homes are lower than in the past. 3. Nurses must look at the environment in which these patients function to develop strategies and techniques to maximize independence while decreasing aggression.

Aged↗
PubMed1996

Neural-network-based classification of Space Acceleration Measurement Systems (SAMS) data via supervised learning.

This paper illustrates the applicability of neural networks in classifying events using Space Acceleration Measurement System (SAMS) data. Computer programs have been written in the MATLAB environment for the following purposes: automatic retrieval of SAMS data from NASA CDROM disks, computation of power spectral densities for SAMS data and construction of input patterns for the training of a multi-layer neural network (MNN). The MNN has been trained using the backpropagation learning algorithm and the SAMS data collected on the STS-50 Space Shuttle mission for three crew exercise events. It is found that the trained MNN is highly successful in classifying events. In addition, the performance of MNN is found to be better than that of the nearest neighbor classifier.

Acceleration↗
PubMed1996

Minimally invasive treatment of renal abscess.

PURPOSE: We critically evaluated the most appropriate management of renal abscesses, and identified the set of patients that most benefits from conservative treatment. MATERIALS AND METHODS: We retrospectively reviewed charts regarding discharge diagnoses, radiological studies, pathological specimens, epidemiology factors and outcomes. Statistical analysis was performed using loglinear and covariant analysis. RESULTS: Nine years of experience (1984 to 1993) at 2 affiliated hospitals (1 public and 1 private) were reviewed. A total of 52 patients with renal abscesses was identified with a followup rate of 98%. In immunocompetent patients 100% of small abscesses (less than 3 cm.) managed by antibiotics and observation alone resolved. Of medium abscesses (3 to 5 cm.) treated with percutaneous abscess drainage alone 92% resolved. Large abscesses (greater than 5 cm.) often required more than 1 percutaneous drainage procedure (33%) or adjunct open surgical intervention (37%). Statistical analysis revealed that no single treatment modality yielded a superior resolution rate or shorter hospitalization for abscesses stratified by size, patient age or treatment instituted early (1984 to 1993) or late (1992 and 1993) in the study period. CONCLUSIONS: Our series suggests that percutaneous drainage is as effective as open surgery for large and medium renal abscesses. Small abscesses may be effectively treated with a course of intravenous antibiotic therapy. A treatment algorithm is reported.

Abscess↗
PubMed1996

Data initiatives: building a managed care network utilizing clinical performance data.

Responding to the rising health care costs of its traditional indemnity health care plan, Hershey Foods Corporation developed its own managed care plan as part of the company strategy to better control its health care costs. In developing a provider network for its managed care plan, Hershey Foods utilized data from the Pennsylvania Health Care Cost Containment Council and the expertise of many different groups, health care data consultants (Healthcare Research Affiliates), the insurance provider (Capital Blue Cross/Pennsylvania Blue Shield), health care providers, as well as the employees and their union representatives. Selection of providers for the network necessitated a data initiative that analyzed indicators of quality and cost efficiency. This article explores the roles of these different groups in building the managed care network for Hershey and examines the organizational changes within these different groups to accommodate the Hershey Foods project.

Blue Cross Blue Shield Insurance Plans↗
PubMed1996

Melatonin receptors are present in non-optic regions of the brain of a deep-sea fish living in the absence of solar light.

Pineal melatonin hormonally transduces photoperiod to influence daily and seasonal cycles in most vertebrates (1, 2). Evidence of melatonin receptors throughout the brain of several fish species (3-5), particularly in retinorecipient structures, also indicates a role in visual processing. Despite the absence of solar light many deepsea organisms show seasonality (6-8). The presence of central melatonin receptors was investigated by quantitative in vitro autoradiography in the deep-sea fish Coryphaenoides (Nematonurus) armatus. Specific, time-dependent, saturable, high affinity and guanine nucleotide sensitive, 2-[125I]iodomelatonin binding was found over the mid-brain tegmentum and hindbrain. Competing ligand potency was iodomelatonin > melatonin >> 5-HT. Although C.(N.) armatus has well developed eyes no 2-[125I]iodomelatonin binding occurred in optic tectum, cerebellum or hypothalamus. Thus melatonin involvement in processing of visual information and control of seasonal physiology via hypothalamic areas appears to be absent in this species. The presence of central G-protein coupled receptors indicates a function for melatonin unrelated to solar light.

Animals↗
PubMed1996

Serum type III procollagen aminopeptide for assessing liver damage in methotrexate-treated psoriatic patients.

This study was designed to establish whether measurement of a serological marker of fibrosis might reduce the need for liver biopsy in psoriatic patients receiving methotrexate (MTX). Levels of type III procollagen aminopeptide (PIIINP-O and PIIINP-B) and laminin P1 (LamP1-B) were measured in 147 serum samples taken at the time of liver biopsy in 87 patients receiving long-term MTX treatment for severe psoriasis. Biopsies were classified as: (1) normal, (2) steatosis, (3) inflammation, (4) fibrosis, or (5) cirrhosis. Groups 3-5 were considered to show clinically relevant abnormality. Compared with controls, PIIINP-O was significantly raised in the group of MTX-treated psoriatics (P < 0.001). Within this group, levels were significantly higher in patients with inflammation, fibrosis or cirrhosis compared with those with normal histology or steatosis alone (P < 0.0001). In contrast, PIIINP-B and LamP1-B did not distinguish between controls and MTX-treated patients or between histological groups. Forty-two patients had two or more biopsies with simultaneous PIIINP-O measurement. PIIINP-O levels at the time of the first biopsy were normal in six of the seven patients whose histology was initially normal and subsequently became abnormal. A single measurement of PIIINP-O thus did not predict which patients might develop abnormal histology following further MTX. In a group of 17 patients, PIIINP-O was measured 3-monthly for up to 6 years during MTX treatment. PIIINP-O was elevated at some time during follow-up in all three patients who developed abnormal histology but was consistently normal in eight of the 11 patients whose histology remained or became normal. Our findings indicate that PIIINP-O is of value in detecting liver damage and, particularly if measured serially, may reduce the need for liver biopsy in MTX-treated patients. Although the test does not detect all patients with fibrosis, it would appear that the risk of missing significant liver damage in patients with persistently normal PIIINP-O is low.

Adult↗
PubMed1996

New mattresses: how fast do they become a significant source of exposure to house dust mite allergens?

BACKGROUND: Sensitization and exposure to mite allergens is a major risk factor for asthma. Little is known about the rate of build-up of allergens in the mite micro-habitats. OBJECTIVES: To investigate the rate of increase in mite allergen levels in new mattresses. METHODS: Der p 1 was measured in the dust samples collected from six identical new single mattresses over a period of 2 years. RESULTS: Der p 1 increased significantly at 4 months as compared with baseline level (P < 0.01), but no difference was found between the concentrations at 4, 8, 12 and 24 months. There was a significant correlation between Der p 1 concentration in mattresses at 4, 8, 12 and 24 months and Der p 1 levels in the bedroom carpet at the beginning of the study. CONCLUSIONS: New mattresses can become a significant source of exposure to mite allergens after a short period of time (< 4 months). There is little justification for advising mite sensitive patients to replace their mattresses as a part of avoidance regime.

Allergens↗
PubMed1996

Domestic allergens in public places. II: Dog (Can f1) and cockroach (Bla g 2) allergens in dust and mite, cat, dog and cockroach allergens in the air in public buildings.

BACKGROUND: Sensitization and exposure to indoor allergens are the major risk factors for asthma. It is possible that significant exposure to domestic allergens occurs outside the home. OBJECTIVES: To investigate the levels of Can f 1 and Bla g 2 in the dust from carpeted floors and upholstered seats in public buildings and public transport and the airborne concentrations of Der p 1, Fel d 1, Can f 1 and Bla g 2 in schools and offices. METHODS: Can f 1 and Bla g 2 were measured in the dust collected by vacuuming a 1 m2 area of carpet, as well as upholstered seats in five schools, six hotels, four cinemas, six pubs, three buses and two trains. Dust was also collected from the bedroom carpet, living room carpet, mattress and sofa in 20 homes with and 20 homes without a dog in the same area. Personal airborne sampling (2 L/min) was conducted for 8 h in offices (n = 16) and classrooms (n = 9). In addition, airborne samples in schools were collected using a high volume pump (60 L/min) for 1 h in three classrooms immediately after the children vacated the school. Can f 1, Bla g 2, Der p 1 and Fel d 1 were assayed using a two-site monoclonal antibody-based ELISA. RESULTS: Can f 1 was detected in all dust samples from public places, ranging from 0.2 to 52.5 micrograms/g. Significantly higher levels were found in upholstered seats (geometric mean--GM 9.4 micrograms/g) than in carpets (GM 1.5 micrograms/g; P < 0.001), and levels of Can f 1 > 10 micrograms/g were found in 40% of upholstered seats in public places. Can f 1 was significantly higher in upholstered seats in public places than in sofas in homes without a dog (GM 1.8 micrograms/g; P < 0.001). Detectable levels of Bla g 2 were found in all of the schools (GM 2.4 U/g, range 0.8-4.4 U/g). Bla g 2 concentration greater than 2U/g (provisional threshold level representing risk of sensitization) was measured in 65% of the classrooms sampled. Der p 1 and Bla g 2 were below the detection limit in all airborne samples. However, airborne Fel d 1 and Can f 1 were detected in schools and offices, albeit in low concentrations. CONCLUSIONS: Upholstered seats from public places constitute a reservoir for the accumulation of dog allergen, and a source of exposure to Can f 1 inside public buildings or on public transport. Exposure to cockroach allergens in schools may be important for cockroach sensitized asthmatic children.

Air Pollution, Indoor↗
PubMed1996

GM-CSF accelerates neutrophil recovery after autologous hematopoietic stem cell transplantation.

Patients with non-myeloid hematologic malignancies (including Hodgkin's and non-Hodgkin's lymphomas, myeloma and acute lymphoid leukemia) or solid tumors underwent cytoreductive conditioning regimens followed by either autologous bone marrow transplantation (ABMT) (n = 343) or transplantation of peripheral blood stem cells (PBSC) with (n = 44) or without bone marrow (BM) (n = 16). In a randomized double-blind phase III multi-center trial, patients received either granulocyte-macrophage colony-stimulating factor (GM-CSF, 10 micrograms/kg/day) or placebo by daily i.v. infusion beginning 24 h after bone marrow infusion and continuing until the absolute neutrophil count (ANC) had recovered to > or = 1000/mm3, or for a maximum of 30 days. Median time to neutrophil recovery was significantly shorter in the GM-CSF group (18 vs 27 days, P < 0.001), and more GM-CSF patients had neutrophil recovery by day 30 (70 vs 48%). Median duration of hospitalization was significantly shorter in the GM-CSF group (29 vs 32 days, P = 0.02). GM-CSF significantly reduced the median time to neutrophil recovery in patients receiving bone marrow only (19 vs 27 days, P < 0.001) or PBSC with or without bone marrow (14 vs 21 days, P < 0.001). The overall incidence of adverse events was comparable in the two groups, although more patients in the GM-CSF group discontinued treatment due to adverse events (17 vs 9%, P < 0.001). No difference was noted in infection incidence or time to platelet independence. GM-CSF had no negative impact on time to relapse or long-term survival. These data indicate the positive influence of GM-CSF on neutrophil recovery and hospital stay in patients receiving ABMT for a variety of clinical indications.

Adolescent↗
PubMed1996

Synchrotron radiation in the study of the variation of dose response in thermoluminescence dosimeters with radiation energy.

Thermoluminescence dosimetry (TLD) is a versatile technique with many applications for dosimetry of ionising radiation. However, in the range of kilovoltage x-rays which is widely used for diagnostic and therapeutic medical applications, problems arise from the differing dose response of most TL dosimeters with the radiation energy. The dose response of various TL detector types was investigated in mono-energetic x-ray beams of 26.8, 33.2, 40, 80.4 and 99.6keV from a synchrotron radiation source at the National Laboratory for High Energy Physics in Japan. This response was studied as a function of TL material (LiF:Mg,Ti, LiF:Mg,Cu,P and Al2O3), the detector geometry and size, and their thermal history. Due to the asymmetric diffraction from a Si crystal employed to produce monoenergetic photons there was more than 50% dose inhomogeneity in some of radiation fields used. Therefore, the different TL dosimeter types were rotated around and the results related to the reading of a set of "standard" LiF:Mg,Ti ribbons which were included in all experiments as reference detectors. No significant influence of the detector shape (physical size, thickness) on the dose response with energy could be found. However, the pre-irradiation thermal history influences the dose response with radiation energy: a fast cool down of LiF:Mg,Ti after a high temperature anneal will increase the sensitivity by more than a factor of two. The relatively new TLD material LiF:Mg,Cu,P (GR-200, obtained from Solid Dosimeter & Detector Laboratories, Beijing) was found to be approximately 100 times more sensitive than the standard LiF:Mg,Ti. In addition it proved to be more tissue equivalent for photon radiation between 27keV and 40keV. The performance of LiF:Mg,Cu,P makes it a very interesting TL material deserving further evaluation for applications in diagnostic and therapeutic x-rays.

Aluminum Oxide↗