Search PubMed⌕ Search

Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 91 records · Page 5Linked to original sources
PubMed2002

Multiple milia due to radiotherapy.

We report the appearance of multiple milia in a 61 year old woman appearing 7 years after irradiation for breast cancer. The lesions were confined to the irradiated field.

Breast Neoplasms↗
PubMed2002

Biological response of chondrocytes to hydrogels.

Primary bovine chondrocytes were encapsulated in alginate and alginate combined with cartilage matrix extract, Cartrigel, for the purpose of cartilage tissue engineering. The cell constructs were incubated in vitro and gene expression of cartilage-specific extracellular matrix molecules was quantitated and localized with in situ hybridization with a decrease in expression observed in the alginate-Cartrigel constructs. Further understanding of cell response to scaffolds will allow rational design and development of hydrogels for cartilage tissue engineering.

Alginates↗
PubMed2002

Adenosine provokes diastolic dysfunction in microvascular angina.

Adenosine stress echocardiography was performed in nine patients (58 (+/-3) years, eight women) with documented microvascular angina. Global ventricular function was assessed by Tc(99m) blood pool imaging and Doppler, whereas longitudinal ventricular function was assessed by simultaneous tissue Doppler echocardiography of the lateral mitral annulus. Adenosine was infused incrementally to onset of chest pain in all patients. There was no significant change in global or longitudinal systolic function. Adenosine induced global diastolic dysfunction, demonstrated by blood pool imaging and by Doppler of the transmitral flow. All patients had long axis diastolic dysfunction at peak adenosine, revealed by a ratio of early to late diastolic velocity of lateral mitral annulus <1, which was absent at rest. Adenosine, as a stress agent, provokes regional and global diastolic dysfunction in microvascular angina, which may be a consequence of subendocardial ischaemia. Long axis diastolic dysfunction can be easily revealed by tissue Doppler of the lateral annular motion.

Adenosine↗
PubMed2002

Breast conservation treatment in Hong Kong-early results of 203 patients: retrospective study.

OBJECTIVE: To study the clinical outcomes of patients with invasive or non-invasive breast cancer after breast conservation treatment. DESIGN: Retrospective study. SETTING: Clinical oncology department of a public hospital, Hong Kong. PATIENTS: Two hundred and three patients who received postlumpectomy radiotherapy at the Pamela Youde Nethersole Eastern Hospital between January 1994 and June 1999. INTERVENTIONS: Adjuvant radiotherapy with or without systemic adjuvant treatment. MAIN OUTCOME MEASURES: Actuarial local control rate, progression-free survival rate, disease-specific survival rate, and cosmetic score. RESULTS: The median follow-up was 3.5 years. Two of the 25 patients with carcinoma in situ only developed local recurrence; the 5-year actuarial local control rate was 91.3%. Among the 178 patients with invasive cancer, seven had a local recurrence and 12 developed distant metastases without local failure. The 5-year actuarial local control, progression-free survival, and disease-specific survival rates for patients with invasive cancer were 95.5%, 85.8%, and 95.2%, respectively. The risk of local recurrence was significantly increased for younger patients (age <40 years) and those with positive final margins. Cosmetic scores were rated good to excellent by 95.6% of patients. CONCLUSIONS: The early clinical outcomes of these patients are comparable to those in large overseas trials, which have demonstrated the equivalence of mastectomy and breast conservation treatment in terms of survival. In addition to mastectomy, with or without breast reconstruction, breast conservation treatment should be offered as an alternative to suitable Chinese women. To maximise local control, further excision or mastectomy is recommended for patients with positive final margins.

Adult↗
PubMed2002

Diagnosis disclosure in cancer patients--when the family says "no!".

It is not uncommon for family members to thwart a doctor's attempt at disclosure of cancer diagnosis to the patient. This stems from concern and love as well as fear of the negative psychological impact of such revelation. Indeed, collusion of this nature was the norm in medical practice till the not too distant past. In this era of patient autonomy and the right to information, we must be careful not to allow attitudes of medical staff or patients' families, language difficulties and organisational issues become barriers to patient's access to information and their psychological coping of the illness. At the same time, we also need to be acutely aware of the unique cultural environment we work in and the families' emotional needs even as we aim to match the patient's desire for information.

Family↗
PubMed2001

Comparison of hepatic artery and portal vein reperfusion during orthotopic liver transplantation.

BACKGROUND: During orthotopic liver transplantation (OLT), it is standard procedure to reperfuse the liver via the portal vein (PV) despite having a lower oxygen content and perfusion pressure than the hepatic artery (HA). There are no published studies that describe graft function and outcome when the HA is used for reperfusion. We report a retrospective comparison of graft outcome after HA or PV reperfusion when the piggyback technique was used. METHODS: We identified 26 patients who had undergone OLT with HA reperfusion and 26 patients reperfused via the PV. Demographics, primary diagnosis, surgeon, warm and cold ischemic times, and blood product use were recorded. In each patient, whole blood lactate concentration, prothrombin time (PT), and alanine aminotransferase (ALT) were measured at defined time points during and after surgery as indices of graft lactate metabolism, synthetic function, and reperfusion injury, respectively. Thirty-day and 1-year outcome data were recorded. Data were compared between the HA and PV groups. RESULTS: Demographics, blood product use, primary diagnosis, cold ischemic time, and surgeon were similar between the groups. Warm ischemic time was longer in the HA group (mean [SD] HA 51.2 [14.7], PV 40 [9.1] min, P=0.002). Blood lactate concentrations were similar at all time points. There was no difference in 24-hr postoperative PT between the groups (median [InterQuartile (IQ) range] HA 17.5 [16-28.3], PV 19 [16-24] sec, P=0.85). Peak postoperative ALT values were comparable (median [IQ range] HA 1031 [668-1701], PV 1107 [754-1824] IU/ml, P=0.78). There were no statistically significant differences in 30-day or 1-year mortality, but more early deaths occurred in the HA group. Using our data, we calculated that a prospective randomized trial would need approximately 300 patients to be sure that mortality was the same with both techniques. CONCLUSION: We have demonstrated no clinically or statistically significant differences in indices of graft function, reperfusion injury, or outcome between primary HA or PV reperfusion.

Adolescent↗
PubMed2001

Parallel solution-phase synthesis of mechanism-based cysteine protease inhibitors.

[reaction--see text] A seven-step parallel solution-phase synthesis has been developed for access to ketone-containing mechanism-based cysteine protease inhibitors. The use of liquid-liquid extractions, volatile or solid-supported reagents, and resin-bound scavengers eliminates the need for intermediate column chromatographic purification during this synthesis sequence.

Amides↗
PubMed2001

Referral patterns and social deprivation in paracetamol-induced liver injury in Scotland.

Paracetamol overdose is the commonest cause of acute liver failure in the UK, which has led to measures to restrict its sale. We aimed to establish whether changes in the referral of patients with paracetamol-induced acute liver failure have occurred since the introduction of legislation. We compared data from patients admitted to the Scottish Liver Transplantation Unit in 1992-98 with those admitted in 1998-2001. The incidence of paracetamol-induced liver failure, severity of patients' illness, and outcome did not differ between the groups. Patients with paracetamol-induced acute liver failure had higher Carstairs scores (1.99 [95% CI 1.33-2.65]; n=190) than patients with non-paracetamol acute liver failure (0.02 [-0.79 to 0.84]; n=68). We have shown an association between paracetamol-induced acute liver failure and social deprivation.

Acetaminophen↗
PubMed2001

Membrane structure.

Explore the source record for details and available documents.

Calcium-Transporting ATPases↗
PubMed2001

On the stability of double stranded nucleic acids.

We present the first pressure-versus-temperature phase diagram for the helix-to-coil transition of double stranded nucleic acids. The thermodynamic stability of a nucleic acid duplex is a complex function of temperature and pressure and strongly depends on the denaturation temperature, T(M), of the duplex at atmospheric pressure. Depending upon T(M), pressure, and temperature, the phase diagram shows that pressure may stabilize, destabilize, or have no effect on the conformational state of DNA. To verify the phase diagram, we have conducted high-pressure UV melting experiments on poly(dIdC)poly(dIdC), a DNA duplex, poly(rA)poly(rU), an RNA duplex, and poly(dA)poly(rU), a DNA/RNA hybrid duplex. The T(M) values of these duplexes have been modulated by altering the solution ionic strength. Significantly, at low salt, these three duplexes have helix-to-coil transition temperatures of 50 degrees C or less. In agreement with the derived phase diagram, we found that the polymeric duplexes were destabilized by pressure if the T(M) is < approximately 50 degrees C. However, these duplexes were stabilized by pressure if the T(M) is > approximately 50 degrees C. The DNA/RNA hybrid duplex, poly(dA)poly(rU), with a T(M) of 31 degrees C in 20 mM NaCl undergoes a pressure-induced helix-to-coil transition at room temperature. This is the first report of pressure-induced denaturation of a nucleic acid duplex and provides new insights into the molecular forces stabilizing these structures.

DNA↗
PubMed2001

Volumetric characterization of the hydration properties of heterocyclic bases and nucleosides.

We have determined the partial molar volumes, expansibilities, and adiabatic compressibilities of six heterocyclic nucleic acid bases, five ribonucleosides, and six 2'-deoxyribonucleosides within the temperature range 18-55 degrees C. We interpret the resulting data in terms of the hydration of the component hydrophobic and polar atomic groups. From our temperature-dependent volumetric studies, we found that the total contraction of water caused by polar groups of each individual heterocyclic base and nucleoside depends on the proximity and chemical nature of other functional groups of the solute. In addition, the compressibility contributions of polar groups vary greatly in sign and magnitude depending on the surrounding functional groups. In agreement with previous studies, our results are suggestive of little or no interaction between the sugar and base moieties of a nucleoside. In general, our data shed light into the hydration properties of individual heterocyclic bases and nucleosides, which may have significant implications for the sequence-dependent hydration of nucleic acids. We discuss the potential importance of our results for developing an understanding of the role that solvent plays in the stabilization/destabilization of nucleic acid structures.

Algorithms↗
PubMed2001

Associations of P50 suppression and desensitization with perceptual and cognitive features of "unreality" in schizotypy.

BACKGROUND: P50 suppression is an electrophysiologic index of early sensory gating and has consistently been found deficient in schizophrenic patients. This gating deficit is thought to lead to sensory overload and cognitive fragmentation, and correspondingly many symptoms of the disorder. However, the link between P50 suppression deficits and symptomatology is yet to be established, and so this study was designed to determine whether such a relation is present within a nonclinical population. METHODS: P50 suppression and schizotypy measures were obtained from 36 healthy volunteers, and correlation analyses determined whether measures of schizotypy were related to P50 suppression. RESULTS: Consistent with the view that P50 gating deficits are related to schizophrenic symptoms, subjects with poorer P50 suppression reported more perceptual anomalies and magical ideation--an unreality syndrome--in contrast to other positive symptoms and to withdrawal. This study also found a trend to P50 suppression desensitization, and that whereas subjects low on "unreality" demonstrated desensitization to the second of the paired clicks, subjects high on "unreality" demonstrated sensitization. CONCLUSIONS: It is concluded that early sensory gating deficits, in the form of poor P50 suppression, are related to unreality aspects of schizotypy. This supports the view that poor P50 suppression in schizophrenia is related to symptomatology.

Cognition Disorders↗
PubMed2001

Conditional tissue-specific expression of the acid alpha-glucosidase (GAA) gene in the GAA knockout mice: implications for therapy.

Both enzyme replacement and gene therapy of lysosomal storage disorders rely on the receptor-mediated uptake of lysosomal enzymes secreted by cells, and for each lysosomal disorder it is necessary to select the correct cell type for recombinant enzyme production or for targeting gene therapy. For example, for the therapy of Pompe disease, a severe metabolic myopathy and cardiomyopathy caused by deficiency of acid alpha-glucosidase (GAA), skeletal muscle seems an obvious choice as a depot organ for local therapy and for the delivery of the recombinant enzyme into the systemic circulation. Using knockout mice with this disease and transgenes containing cDNA for the human enzyme under muscle or liver specific promoters controlled by tetracycline, we have demonstrated that the liver provided enzyme far more efficiently. The achievement of therapeutic levels with skeletal muscle transduction required the entire muscle mass to produce high levels of enzyme of which little found its way to the plasma, whereas liver, comprising <5% of body weight, secreted 100-fold more enzyme, all of which was in the active 110 kDa precursor form. Furthermore, using tetracycline regulation, we somatically induced human GAA in the knockout mice, and demonstrated that the skeletal and cardiac muscle pathology was completely reversible if the treatment was begun early.

Animals↗