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Biomedical subjects

T Anderson

Publications and source records attributed to T Anderson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Additional manal and pedal epiphyseal centres.

One hundred and thirty-six well-preserved medieval skeletons were excavated in advance of re-development in Norwich. Examination of sub-adult hand and feet bones indicated a high percentage of accessory epiphyses. The majority could be identified by traces of a fusion line. The distal first metacarpal and first metatarsal being the preferred sites. Such additional epiphyses have rarely been reported in archaeological samples and the findings are in strong contrast to the figures quoted in modern anatomical texts. The possible reasons for this apparent variation are discussed.

Adolescent↗
PubMed2001

An in vitro system for the study of ultrasound contrast agents using a commercial imaging system.

An in vitro system for the investigation of the behaviour of contrast microbubbles in an ultrasound field, that provides a full diagnostic range of settings, is yet to be presented in the literature. The evaluation of a good compromise of such a system is presented in this paper. It is based on (a) an HD13000 ATL scanner (Bothell, WA, USA) externally controlled by a PC and (b) on the use of well-defined reference materials. The suspensions of the reference ultrasonic scattering material are placed in an anechoic tank. The pulse length ranges from 2 to 10 cycles, the acoustic pressure from 0.08 to 1.8 MPa, the transmit frequency from 1 to 4.3 MHz, and the receive frequency from 1 to 8 MHz. The collection of 256 samples of RF data, at an offset distance from the transducer face, was performed at 20 MHz digitization rate, which corresponds to approximately 1 cm depth in water. Two particle suspensions are also presented for use as reference scatterers for contrast studies: (a) a suspension of Orgasol (ELF Atochem, Paris, France) particles (approximately 5 microm mean diameter) and (b) a suspension of Eccosphere (New Metals & Chemicals Ltd, Essex, UK) particles (approximately 50 microm mean diameter). A preliminary experiment with the contrast agent Definity (DuPont Pharmaceutical Co, Waltham, MA) showed that the above two materials are suitable for use as a reference for contrast backscatter.

Contrast Media↗
PubMed2001

Dietary effects of ortho-phenylphenol and sodium ortho-phenylphenate on rat urothelium.

Ortho-phenylphenol (OPP) and sodium ortho-phenylphenate (NaOPP) are pesticides used commercially in the food industry that have been shown to be carcinogenic to rat urothelium. Dietary administration of 1.25% OPP or 2.0% NaOPP caused increased incidences of urothelial hyperplasia and eventually caused tumors in male F344 rats, with NaOPP apparently having a more potent effect. In other studies, various sodium salts such as saccharin and ascorbate enhanced bladder carcinogenesis, although the acid forms of these salts did not. In studies with high dietary doses of these sodium salts, an amorphous precipitate was produced in the urine; precipitate formation was pH dependent. In previous experiments in which high doses of OPP were fed for up to 17 weeks, severe hyperplasia of the urothelium was produced, but without the formation of an urinary amorphous precipitate, calculi, or abnormal microcrystalluria. In addition, we found no evidence of OPP-DNA adduct formation in the urothelium. The present study was conducted to determine if feeding NaOPP * 4 H(2)0 to male F344 rats as 2.0% of the diet resulted in the formation of an amorphous precipitate in the urine, and if NaOPP caused an increased mineral concentration in the urine and/or kidneys. NaOPP administration produced a higher urinary pH than did OPP fed as 1.25% of the diet. Neither amorphous precipitate nor other solids were observed in the urine of the OPP or NaOPP-treated rats, and urinary calcium concentrations in the treated groups were similar to control. OPP and NaOPP had similar proliferative effects on rat urothelium after 10 weeks of treatment by light microscopy, scanning electron microscopy (SEM), and bromodeoxyuridine (BrdU) labeling indices. The results of this study indicate that formation of abnormal urinary solids is not part of the mechanism by which OPP or NaOPP exert their effects on the rat bladder epithelium.

Animals↗
PubMed2001

Bupropion sustained release as a smoking cessation treatment in remitted depressed patients maintained on treatment with selective serotonin reuptake inhibitor antidepressants.

BACKGROUND: Patients with depressive disorders smoke tobacco more often than the population at large and find quitting more difficult. Furthermore, when they quit smoking, they are more likely to suffer a relapse of depression. We evaluated the addition of bupropion sustained release (SR) for smoking cessation among patients with a history of depressive disorders being maintained in a euthymic state with selective serotonin reuptake inhibitor (SSRI) antidepressants. METHOD: Twenty-five adults with DSM-IV major depressive disorder or depressive disorder NOS currently receiving SSRI maintenance treatment and smoking > or = 15 cigarettes per day participated in the 9-week study. Bupropion SR, 150 mg/day, was added to SSRI treatment and increased to 300 mg/day. Subjects were counseled on smoking cessation measures and chose a target quit date 2 or 4 weeks after the initiation of bupropion SR. Self-reported smoking status, expired carbon monoxide (CO) measurements, Hamilton Rating Scales for Depression and Anxiety scores, and weight were measured at each visit. Subjects were abstinent if they reported not smoking during the prior 7 days, confirmed with an expired-air CO value of < or = 10 ppm. RESULTS: Eight (32%) of 25 subjects were abstinent after 9 weeks. At 3-month follow-up, 3 subjects remained abstinent, 3 relapsed, and 2 were lost to follow-up. Eleven subjects (44%) were nonresponders, and 6 (24%) dropped out prior to 3 weeks of treatment due to side effects (N = 3) or were lost to follow-up (N = 3). Mean weight gain was approximately 0.5 lb (0.2 kg) for those completing 9 weeks of bupropion SR treatment. During the 9-week study and the 3-month follow-up, there was no evidence of emergent depression in any subject. Four subjects (16%) spontaneously reported an improvement in SSRI-associated sexual dysfunction. CONCLUSION: These open data suggest modest effectiveness for and the safety of bupropion SR as a smoking cessation agent in individuals with depression maintained on treatment with SSRIs. Minimal weight gain, lack of emergent depressive episodes, and improvement of SSRI-associated sexual dysfunction are added advantages.

Adolescent↗
PubMed2000

Infusion of alpha-galactosidase A reduces tissue globotriaosylceramide storage in patients with Fabry disease.

Fabry disease is a lysosomal storage disorder caused by a deficiency of the lysosomal enzyme alpha-galactosidase A (alpha-gal A). This enzymatic defect results in the accumulation of the glycosphingolipid globotriaosylceramide (Gb(3); also referred to as ceramidetrihexoside) throughout the body. To investigate the effects of purified alpha-gal A, 10 patients with Fabry disease received a single i.v. infusion of one of five escalating dose levels of the enzyme. The objectives of this study were: (i) to evaluate the safety of administered alpha-gal A, (ii) to assess the pharmacokinetics of i.v.-administered alpha-gal A in plasma and liver, and (iii) to determine the effect of this replacement enzyme on hepatic, urine sediment and plasma concentrations of Gb(3). alpha-Gal A infusions were well tolerated in all patients. Immunohistochemical staining of liver tissue approximately 2 days after enzyme infusion identified alpha-gal A in several cell types, including sinusoidal endothelial cells, Kupffer cells, and hepatocytes, suggesting diffuse uptake via the mannose 6-phosphate receptor. The tissue half-life in the liver was greater than 24 hr. After the single dose of alpha-gal A, nine of the 10 patients had significantly reduced Gb(3) levels both in the liver and shed renal tubular epithelial cells in the urine sediment. These data demonstrate that single infusions of alpha-gal A prepared from transfected human fibroblasts are both safe and biochemically active in patients with Fabry disease. The degree of substrate reduction seen in the study is potentially clinically significant in view of the fact that Gb(3) burden in Fabry patients increases gradually over decades. Taken together, these results suggest that enzyme replacement is likely to be an effective therapy for patients with this metabolic disorder.

Adult↗
PubMed2000

Resection of invasive pulmonary aspergillosis in immunocompromised patients.

BACKGROUND: Immunocompromised patients are prone to develop invasive pulmonary aspergillosis (IPA). Relapse and high mortality rates are seen in those patients who receive subsequent immunotoxic therapy. Standard antifungal regimens often fail to completely eradicate IPA, which then warrants an aggressive surgical approach. METHODS: We performed a retrospective chart review of 13 immunocompromised patients who were considered to have IPA and who underwent surgery between 1988 and 1998. RESULTS: Twelve patients had a hematological malignancy and one patient had breast cancer. The diagnosis of IPA was based on a chest computed tomographic scan in all patients. A preoperative diagnosis of aspergillosis was made in three patients, and mucormycosis in one patient, by bronchoalveolar lavage. Before surgery, seven patients received chemotherapy, one patient underwent bone marrow transplantation, and five patients received a combination of chemotherapy and bone marrow transplantation. Symptoms included cough (54%), fever (54%), hemoptysis (30%), and shortness of breath (8%). Three patients (23%) were asymptomatic. The mean preoperative absolute neutrophil count was 4881 cells/microl. Seventeen thoracic operations were performed, i.e., 12 wedge resections, 4 lobectomies, and 1 pneumonectomy. One patient also underwent nephrectomy for invasive aspergillosis and one patient underwent craniotomy to resect an aspergillus brain mass. Surgical pathology revealed IPA in 13 (76%), invasive mucormycosis in 2 (15%), aspergilloma in 1, and diffuse alveolar hemorrhage in 1. Postoperative complications included the following: operative bleeding requiring transfusion, three patients; prolonged air leak, two patients; death because of hepatic/renal failure, one patient; and death because of overwhelming multisystem aspergillosis, one patient. Seven (54%) patients underwent further immunotoxic treatment with no aspergillosis recurrence. After a mean follow-up of 12 months, five (38%) patients are alive and seven (54%) have died without evidence of aspergillosis and/or mucormycosis. CONCLUSIONS: Surgical resection, in combination with antifungal agents, is a safe and effective form of therapy for invasive mycoses. It prevents recurrence and allows for subsequent cytotoxic therapies.

Adult↗
PubMed2000

Quantification of microbubble destruction of three fluorocarbon-filled ultrasonic contrast agents.

The assessment of myocardial blood velocity using ultrasonic contrast agents is based on the premise that the vast majority of contrast microbubbles within a myocardial region can be destroyed by an acoustic pulse of sufficient magnitude. Determination of the period of time after destruction that a region of myocardium needs to reperfuse may be used to assess myocardial blood velocity. In this study, we investigated the acoustic pressure sensitivity of three solutions of intravenous fluorocarbon-filled contrast agents and the magnitude of acoustic pulse required to destroy the contrast agent microbubbles. A novel tissue-mimicking phantom was designed and manufactured to investigate the relationships between mean integrated backscatter, incident acoustic pressure and number of frames of insonation for three fluorocarbon-filled contrast agents (Definity(R), Optison(R), and Sonazoid(R), formerly NC100100). Using a routine clinical ultrasound (US) scanner (Acuson XP-10), modified to allow access to the unprocessed US data, the contrast agents were scanned at the four acoustic output powers. All three agents initially demonstrated a linear relationship between mean integrated backscatter and number of frames of insonation. For all three agents, mean integrated backscatter decreased more rapidly at higher acoustic pressures, suggesting a more rapid destruction of the microbubbles. In spite of the fact that there was no movement of microbubbles into or out of the beam, only the results from Definity(R) suggested that a complete destruction of the contrast agent microbubbles had occurred within the total duration of insonation in this study.

Albumins↗
PubMed2000

An in vitro comparison of ultrasonic contrast agents in solutions with varying air levels.

The performance, in particular, the stability of ultrasound (US) contrast agents has yet to be assessed. An in vitro system has been set up to investigate the properties of ultrasonic contrast agents under different suspension conditions. This is designed to contribute to the optimal use of agents in clinical practice. In this study, the contrast agents were introduced into solutions of different oxygen concentration levels, as might be encountered in blood, and their relative performance was assessed in terms of decay in the solution environment. The partial pressures of oxygen in those solutions ranged between 1.5 and 26 kPa. Three IV and one arterial contrast agents were used: Levovist, DMP115, Quantison and Myomap. Levovist showed the highest sensitivity to oxygen concentration in the solution, and the other three proved tolerant for the above values of oxygen concentrations.

Capsules↗
PubMed2000

Scanning techniques for three-dimensional forward-viewing intravascular ultrasound imaging.

Intravascular ultrasound (US) imaging is a useful tool for assessing arterial disease and aiding treatment procedures. Forward-viewing intravascular US imaging could be of particular use in severely stenosed or totally occluded arteries, where the current side-viewing intravascular US systems are limited by their inability to access the site of interest. In this study, five 3-D forward-viewing intravascular scanning patterns were investigated. The work was carried out using scaled-up vessel phantoms constructed from tissue-mimicking material and a PC-controlled scanning and acquisition system. The scanning patterns were examined and evaluated with regard to the image quality of dense and sparse data sets, the accuracy of quantitative measurements of lumen dimensions and the potential for clinical use. The relative merits and drawbacks of the different patterns are discussed and a preferred scanning pattern is recommended.

Arterial Occlusive Diseases↗
PubMed2000

Evaluation of an experimental system for the in vitro assessment of ultrasonic contrast agents.

The ultrasonic properties of microbubble contrast agents need to be fully understood if reproducible images and quantitative results are to be produced. Additional aspects of the physical and chemical environment into which the contrast agents are introduced also need to be taken into account, and their effect on contrast agent performance evaluated. A setup that provides an accurate and reproducible data-acquisition system is presented and evaluated in this paper. The linear range of this system is assessed, as well as its accuracy and precision. A new approach to the investigation of contrast agents, based on normalised backscatter, is discussed. Also, a common technique of degassing, widely used in other areas, is described and evaluated to determine its appropriateness to contrast agent studies.

Contrast Media↗
PubMed2000

Classification of arterial plaque by spectral analysis of in vitro radio frequency intravascular ultrasound data.

To test whether radio-frequency analysis of coronary plaques predicts the histological classification, r.f. data were collected using a 30 MHz intravascular ultrasound scanner. Two hundred ninety-nine regions-of-interest from eight postmortem coronary arteries were selected and identified by histology as falling into one of seven different tissue types. These are loose fibrous tissue (n = 78), moderate fibrous tissue (n = 27), dense fibrous tissue (n = 33), microcalcification (n = 14), calcified plaque (n = 55), lipid/fibrous mixture (n = 51) and homogeneous areas of lipid pool (n = 29). On the basis of a previous study, four spectral parameters were calculated for each of the regions-of-interest: maximum power (dB), mean power (dB), spectral slope (dB/MHz) over the bandwidth 18-35 MHz and the intercept of the spectral slope with the 0 Hz axis (dB). A minimum-distance classifier using the Mahalanobis (1948) distance was applied to the data. Following resubstitution of the training data into the classifier, the total correctly classified was 54%. The data were reclassified using three broader tissue groups: (1) calcified plaque, (2) lipid pool and (3) a mixed fibrous category, incorporating loose fibrous tissue, moderate fibrous tissue, dense fibrous tissue, lipid/fibrous mixture and microcalcification. The total correctly classified was 86%. Using "leave-one-out" cross-validation, the classification rates were 48% for seven tissue subgroups and 83% for three broader categories of tissue type.

Cadaver↗
PubMed2000

Basilar clefting: a familial condition?

Excavation at the deserted medieval village of Quattro Macine, Apulia revealed two ruined churches and associated cemeteries of stone-lined tombs. Typically, a tomb contained an articulated burial and bundles of disarticulated bone, no doubt, representing family tombs that were re-opened several times during the medieval period. In one tomb, two examples of basilar clefting, a manifestation of occipital vertebra, were recorded. Apparently, this rare condition has not been recorded in archaeological material. Its presence in two individuals from the same grave is the first evidence that there is a genetic component in this rare anatomical variant.

Archaeology↗
PubMed2000

Apoptosis and phagocytosis of tissue-dwelling eosinophils in sinonasal polyps.

OBJECTIVE: Sinonasal polyps contain numerous tissue-dwelling eosinophils, but the mechanisms causing their accumulation, functional activities, and resolution are largely unknown. STUDY DESIGN: Nasal polyp tissue from 14 patients was evaluated for cellular expression of CD95, CD68, and annexin-V, for the degree of apoptosis, and for phagocytosis of eosinophils. MATERIAL AND METHODS: Histological sections were immunostained as single stains for CD95, CD68, and annexin-V, and as an immunostaining for CD68 combined with a modified Vital New Red staining. The latter staining is specific for eosinophils. Other sections were stained by terminal d-UTP nick end labeling (TUNEL) assay and routinely stained for H&E. Evaluation of the amount of stained cells was performed by counting the average number in 10 randomly chosen high-power fields. The TUNEL positivity was in all cases confirmed with apoptotic morphology. RESULTS: The inflammatory infiltrate consisted of numerous eosinophils but also a considerable amount of lymphocytes, mast cells, and macrophage-like CD68+ cells. CD95 was frequently expressed on eosinophils, on numerous other inflammatory cells, and also on morphologically apoptotic cells. annexin-V-positive eosinophils were not as frequent as CD95+ cells, but numerous annexin-V-positive eosinophils were found. CD68+ cells approximately equalled the number of eosinophils. The number of cells phagocytosing eosinophils varied between polyps. Apoptosis of eosinophils (as evaluated by TUNEL combined with apoptotic morphology) was a common finding in six of the polyps. CONCLUSIONS: Previous in vitro and ex vivo findings of CD95 on eosinophils are now supported by demonstration of CD95 on eosinophils in this in vivo study. This investigation revealed a switch of the membrane-bound phosphatidylserine of apoptotic cells, which is a novel observation. The study has demonstrated apoptosis of tissue-dwelling eosinophils, and that CD68+ macrophage-like cells phagocytose eosinophils within the sinonasal polyps.

Annexin A5↗
PubMed2000

Immunohistochemical detection of steroid receptors in breast cancer: a working protocol. UK Receptor Group, UK NEQAS, The Scottish Breast Cancer Pathology Group, and The Receptor and Biomarker Study Group of the EORTC.

The biochemical assay for the oestrogen receptor has shown the clinical value of knowing the concentration of the receptor within tissue. The immunohistochemical assay is rapidly taking over from the biochemical assay. Therefore, it is vital to have an equivalent scoring system that will have the same predictive value. This paper reports both a practical protocol and a scoring system that should achieve this aim. This approach should be applicable to many more biomarkers detected by immunohistochemistry.

Biomarkers, Tumor↗