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Biomedical subjects

A Boyle

Publications and source records attributed to A Boyle.

At least 19 recordsLinked to original sources
PubMed2000

Eighteenth and nineteenth century dental restoration, treatment and consequences in a British nobleman.

This paper examines unusual eighteenth and nineteenth century dental treatment and its consequences, in a nobleman excavated from beneath St. Nicholas' Church, Sevenoaks, Kent, UK in the early 1990s. This rare archaeological case exhibits erosion of dental enamel on the labial surface of all the anterior dentition. A programme of historical research suggests that this might be attributed to the application of an acid-based dental tincture or the use of an abrasive substance to whiten the teeth. Palliative treatment for the consequence of this application was prescribed by Dr Robert Blake of Dublin. Further, it bears witness to three dental restorations, two of gold and one tin. The two gold (foil) fillings are an occlusal in the upper-right second molar and a cervical on the labial surface of the upper left canine. The tin filling is an occlusal in the upper left second molar. Excavation of the carious tissue appears to have been undertaken using a spoon shaped implement.

Dental Caries↗
PubMed2000

Alcohol-induced locomotor activation in C57BL/6J, A/J, and AXB/BXA recombinant inbred mice: strain distribution patterns and quantitative trait loci analysis.

RATIONALE: Quantitative trait loci (QTLs) for initial sensitivity to alcohol have been identified in a number of mouse strains (e.g. BXD); however, confirmation is required. OBJECTIVES: The present paper aimed to characterize the C57BL/6J, A/J, and AXB/BXA recombinant inbred (RI) strains of mice for basal and ethanol-induced locomotor activation as measured in an open field and to provide provisional location of QTLs for these phenotypes. METHODS: A/J and C57BL/6J mice were habituated to handling and then randomly assigned to receive one of four alcohol doses (0, 0.5, 1.0, 2.0 g/kg). Subsequently, all available strains of the AXB/BXA RI were tested with the 2 g/kg dose of ethanol or vehicle control. RESULTS: Simple regression and interval mapping were used initially to identify significant gene markers associated with ethanol-induced activation (calculated as total activity on alcohol day-total activity on saline day). Subsequently, composite interval mapping (CIM) was used to increase the accuracy in mapping individual loci. Genetic markers on chromosomes 2, 3, 8, 13, 16, 18 and 19 were associated with ethanol-induced activation. CONCLUSIONS: Three significant markers identified through CIM accounted for 86% of the genetic variance in the ethanol-induced activation. QTLs on chromosome 16 (45.6 cM) and 19 (24 cM) previously associated with alcohol consumption in the AXB/BXA RI mice were found to overlap with QTLs for ethanol-induced activation identified in the present study.

Animals↗
PubMed1999

A descriptive survey of acute bed usage for dementia care in old age psychiatry.

OBJECTIVE: To examine the reasons why patients are admitted to acute dementia care assessment beds in one large district health authority (Leicestershire). DESIGN: A prospective questionnaire was completed by the RMO for every admission to dementia care assessment beds over a 6-month survey period. RESULTS: The most common reasons for admission were behavioural problems (most frequently aggression). Other common reasons included self-neglect, psychotic symptoms and comorbidity with functional psychiatric illness. Classification of patients by their social circumstances before admission indicated different patterns of presenting features, length of stay and place of discharge. CONCLUSIONS: The need for acute beds is demonstrated by the large number of emergencies, with a significant proportion admitted under the Mental Health Act, the type and complexity of reasons for admission and the preceding involvement of community mental health services. Multi-axial classifications including presenting problems and social circumstances, rather than the traditional method of looking purely at diagnosis, may offer some advantage in assessing outcomes.

Acute Disease↗
PubMed1997

Pharmacokinetic profile of ABELCET (amphotericin B lipid complex injection): combined experience from phase I and phase II studies.

Amphotericin B (AmB) has been the most effective systemic antifungal agent, but its use is limited by the dose-limiting toxicity of the conventional micellar dispersion formulation (Fungizone). New formulations with better and improved safety profiles are being developed and include ABELCET (formerly ABLC), but their dispositions have not been well characterized; hence, the reason for their improved profiles remains unclear. This report details the pharmacokinetics of ABELCET examined in various pharmacokinetic and efficacy studies by using whole-blood measurements of AmB concentration performed by high-pressure liquid chromatography. The data indicated that the disposition of AmB after administration of ABELCET is different from that after administration of Fungizone, with a faster clearance and a larger volume of distribution. It exhibits complex and nonlinear pharmacokinetics with wide interindividual variability, extensive distribution, and low clearance. The pharmacokinetics were unusual. Clearance and volume of distribution were increased with dose, peak and trough concentrations after multiple dosings increased less than proportionately with dose, steady state appeared to have been attained in 2 to 3 days, despite an estimated half-life of up to 5 days, and there was no evidence of significant accumulation in the blood. The data are internally consistent, even though they were gathered under different conditions and circumstances. The pharmacokinetics of ABELCET suggest that lower concentrations in blood due to higher clearance and greater distribution may be responsible for its improved toxicity profile compared to those of conventional formulations.

Amphotericin B↗
PubMed1994

Kidney and retinal defects (Krd), a transgene-induced mutation with a deletion of mouse chromosome 19 that includes the Pax2 locus.

The semidominant mutation Krd (kidney and retinal defects) was identified in transgenic line Tg8052. Krd/+ mice have a high incidence of kidney defects including aplastic, hypoplastic, and cystic kidneys. Retinal defects in Krd/+ mice include abnormal electroretinograms and a reduction of cell numbers that is most extreme in the inner cell and ganglion layers. Viability of Krd/+ mice is strongly influenced by genetic background, and growth retardation is observed in young animals. Homozygosity results in early embryonic lethality. Fluorescence in situ hybridization of a transgene-specific probe localized the insertion site to the distal region of mouse Chromosome 19. The sequence of the insertion site revealed transgene insertion into a LINE element with deletion of a single nucleotide from the 3' terminus of the transgene. A polymorphic microsatellite, D19Umi1, was identified in a junction clone and mapped in several large crosses. D19Umi1 is located 1.7 +/- 1.0 cM distal to Pax2, which encodes a paired type transcription factor expressed in embryonic kidney and eye. Deletion of Pax2 from the transgenic chromosome was demonstrated by Southern analysis of genomic DNA from (Krd/+ x SPRET/Ei)F1 mice. Additional genetic and molecular data are consistent with an approximately 7-cM deletion that includes the loci stearoyl CoA desaturase (Scd1), pale ear (ep), D19Mit17, D19Mit24, D19Mit27, D19Mit11, and Pax2. This deletion, Del(19)TgN8052Mm, will be useful for genetic and functional studies of this region of mouse Chromosome 19.

Abnormalities, Multiple↗
PubMed1994

Polymer chain packing analysis using molecular modeling.

This article describes the methodology used in applying molecular modeling to investigate the chain packing of polymers. Models for polyethylene and trans-polyacetylene were developed in order to study the cell packing energy as a function of the chain setting angles. This approach was found to yield chain setting angle values that corresponded to those determined experimentally by other authors. The limitations of the method are also discussed.

Acetylene↗
PubMed1994

Detection of psychiatric disorders in elderly medical inpatients.

In a psychiatric census of a 196-bed acute inpatient Medicine for the Elderly unit, 76.1% of patients resident during 1 week were screened and interviewed in a two-stage diagnostic procedure. Of 153 patients studied, 11.1% were delirious, 26.8% were demented, and 9.2% were depressed. Overall, 56.9% of the cases were identified by ward nurses, and 55.5% by the ward doctors; taken together, ward staff identified 75.0% of the cases (kappa = 0.46), indicating that detection of psychiatric disorder in this population might be improved if doctors and nurses pooled their observations on this aspect of patient assessment.

Aged↗
PubMed1994

Insertional mutation on mouse chromosome 18 with vestibular and craniofacial abnormalities.

A dominant mutation was generated in transgenic mice as a consequence of insertional mutation. Heterozygous mice from transgenic line 9257 (Tg9257) are hyperactive with bidirectional circling behavior and have a distinctive facial appearance due to hypoplasia of the nasal bone. Morphological analysis of the inner ear revealed asymmetric abnormalities of the horizontal canal and flattening or invagination of the crista ampullaris, which can account for the circling behavior. The sensory epithelium appeared to be normal. The transgene insertion site was localized by in situ hybridization to the B1 band of mouse chromosome 18. Genetic mapping in an interspecific backcross demonstrated the gene order centromere--Tg9257--8.8 +/- 3.4--Grl-1, Egr-1, Fgf-1, Apc--14.7 +/- 4.3--Pdgfr. The phenotype and the mapping data suggest that the transgene may be inserted at the Twirler locus. Homozygosity for the transgene results in prenatal lethality, but compound heterozygotes carrying the Tw allele and the transgene are viable. The function of the closely linked ataxia locus is not disrupted by the transgene insertion. This insertional mutant will provide molecular access to genes located in the Twirler region of mouse chromosome 18.

Amylases↗
PubMed1994

Polydipsia amongst adults with a learning disability in an institution.

A hospital-based adult learning disabled population (n = 371) was screened for polydipsia with the help of a purpose-designed questionnaire. Polydipsia was defined as excessive drinking of more than 3 l of non-alcoholic fluid over a 24-h period. Altogether, 23 (6.2%) subjects were found to have polydipsia. The polydipsic group was compared with the whole hospital population on variables such as age and IQ distribution. A matched group of 23 individuals without a history of polydipsia was drawn from the same hospital population. The polydipsic and the matched group were compared using various biochemical and psychological measures. Thirty-five per cent of polydipsic patients, compared to 13% of the matched group, showed evidence of compensated hyponatraemia. This difference was not significant. There was no significant difference between the polydipsic and the matched group in the frequency of psychiatric illness, behavioural problems or autism. There also was no significant difference in the IQ levels of the polydipsic patients and the total hospital population. Polydipsia in this population is largely seen as part of an abnormal behavioural repertoire without any evidence of possible organic cause, except unidentified diabetes mellitus. Klein Levin syndrome and pica were represented in the polydipsic group, but not amongst the matched group.

Adult↗
PubMed1994

A convenient method for guarding against localized mucositis during radiation therapy.

Metal restorations, such as full gold crowns and dental implants, can cause forward and back scatter radiation during radiation therapy with a dose enhancement to adjacent tissues. Mucositis, one of the most common complications of the radiation treatment of oral, as well as other head and neck malignancies can result. A method for constructing a buccolingual guard in the clinical setting using hydroplastic material is described. The guard can be easily oriented and adapted to an existing radiation stent, adding positional stability and patient comfort. When adequate thickness of material is used, the guard can attenuate forward and back scatter radiation, separate the adjacent tissues from metal restorations, and protect the oral mucosa from localized incidents of mucositis.

Carcinoma, Squamous Cell↗
PubMed1993

Alterations in glucocorticoid inducible RNAs in the limbic system of learned helpless rats.

Glucocorticoids (GC) have an important effect on mood in humans and influence learned helplessness, an escape avoidance paradigm that is considered one of the best animal models of depression. A strong genetic component underlies the development of learned helplessness as shown by the emergence of a line of highly vulnerable rats (LH strain) through selective inbreeding. In addition, hormonal factors play a role. Adrenalectomy (adx) for example is known to increase the vulnerability to acquire learned helplessness, an effect that is reversed by glucocorticoids (GC). Since GC function primarily by modulating gene expression, hormone mediated alterations in mRNAs expressed in the brain may be important in the development of an adequate escape avoidance response. Conversely, we postulate that the deficit in escape avoidance behavior exhibited by the LH strain may be associated with an alteration in GC-mediated gene expression in the brain. To test this hypothesis, we analyzed GC-responsive mRNAs that are expressed in the hippocampus. Control Sprague-Dawley (SD) rats showed consistent alterations in mRNAs that are modulated by GC, such as type II GC receptor (GR) and metallothionein-1 (MT-1). Under our experimental conditions, both GR and MT-1 mRNA are significantly increased in the hippocampus of hormone-treated SD rats. An increase in hypothalamic GR mRNA was also observed. However, under the same experimental conditions, LH rats showed more selective hormone induced changes since GC had no effect on hypothalamic and hippocampal GR mRNA whereas a significant increase in MT-1 mRNA was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenalectomy↗
PubMed1993

Magnesium enhances function of postischaemic human myocardial tissue.

OBJECTIVES: The effect of Mg2+ on the developed force and concentrations of high energy phosphate metabolites in isolated human atrial trabeculae has been investigated. METHODS: Human atrial trabeculae, obtained from right atrial appendages of patients undergoing cardiac surgery requiring cardiopulmonary bypass, were dissected at room temperature in modified Krebs-Henseleit buffer containing 1.2 or 16 mM Mg2+, mounted on muscle stands, and rewarmed to 34 degrees C in the same buffer. After 30 minutes, their mechanical function was assessed. At the end of the protocol, trabeculae were fast frozen for measurement of concentrations of metabolites of high energy phosphates. RESULTS: Trabeculae collected and rewarmed in 16 mM Mg2+ Krebs-Henseleit buffer showed significantly higher mean developed force (0.59(SEM 0.10) g, p < 0.01) than those rewarmed in 1.2 mM Mg2+ Krebs-Henseleit buffer (0.32(0.03) g). Trabeculae that had a developed force > or = 0.8 g, a resting force < or = 0.7 g, and a cross sectional area < or = 1 mm2 ("functional" trabeculae) were selected for further comparison. New reverse phase high performance liquid chromatography techniques developed for the analysis of small samples (0.5-5 mg dry weight) were used to measure nucleotide, nucleoside, and creatine compounds. Total adenylate (ATP+ADP+AMP) concentrations in trabeculae revived in the presence of 16 mM Mg2+ (15.4(1.1) mumol.g-1 dry weight) were significantly higher (p < 0.01) than in those revived with 1.2 mM Mg2+ (11.8(1.0) mumol.g-1), but lower (p < 0.01) than in trabeculae fast frozen immediately after removal from the patient (22.6(1.0) mumol.g-1). There were no significant differences in NAD and total creatine (phosphocreatine+creatine) concentrations between the three groups. CONCLUSIONS: The presence of high Mg2+ during the rewarming of human atrial trabecular preparations maintains a significantly higher developed force and a significantly higher total adenylate pool than does collection and rewarming with normal concentrations of Mg2+.

Aged↗
PubMed1992

Mineral metabolism in infants with malignant osteopetrosis: heterogeneity in plasma 1,25-dihydroxyvitamin D levels and bone histology.

A group of 16 infants, 2 weeks to 11 months old, with malignant osteopetrosis were investigated to examine their vitamin D metabolism and parathyroid function. Bone biopsies from 6 children were studied by light microscopic histomorphometry and by electron microscopy. Considerable heterogeneity existed among the patients with respect to the parameters reflecting mineral metabolism and with respect to the histological manifestations of the disease. The most constant findings were as follows. Immunoreactive parathyroid hormone (iPTH) was elevated in all children, except in 1 patient who had tubular acidosis, and plasma calcium was low or normal, suggesting skeletal resistance to PTH. Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] was not constantly elevated and appeared to depend on plasma phosphorus, as both parameters were negatively correlated (r = 0.704, p less than 0.01). Osteoblast activity, as evaluated by circulating alkaline phosphatase and osteocalcin and osteoblast number, measured for 6 children by bone histology, were not increased, despite hyperparathyroidism, suggesting PTH resistance or defective osteoblasts. Osteoclasts could be detected in 5 of the 6 children who had a biopsy. Osteoclast number (5.7-13.3% of bone surface) was normal or mildly increased, and marrow spaces were relatively well developed in 4 patients, whereas 1 child had markedly increased osteoclast number (28.3% of bone surface) and reduced marrow cavities. These 5 children received transplants, and engraftment occurred in all, except in the "hyperosteoclastic" patient. Further studies are necessary to establish the prognostic significance of this histologic feature.

Alkaline Phosphatase↗
PubMed1992

Preimplantation genetic diagnosis. In situ hybridization as a tool for analysis.

In situ hybridization allows one to directly visualize DNA sequences of interest for which probes are available. Fluorescent signals can be detected in single cells in either metaphase or interphase nuclei, thus obviating the need for cell synchronization. The potential to use this technology in conjunction with in vitro fertilization techniques to genetically analyze an embryo before transfer could offer patients at genetic risk an alternative. Currently, these patients wait until 9 to 16 weeks' gestation to find out about the genetic makeup of their pregnancy. As such, sexing the embryos of patients at risk for transmitting sex-linked disorders or for performing numerical chromosome analysis could be performed before embryo transfer. Techniques for applying in situ hybridization to single cells obtained from embryos are presented. Hybridization of specific probes to blastomeres of mouse and human embryos as well as sperm is demonstrated.

Cell Nucleus↗