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1.
J Cardiovasc Transl Res ; 14(4): 595-597, 2021 08.
Article in English | MEDLINE | ID: mdl-33409964

ABSTRACT

Provisional stenting is considered the gold standard approach for most bifurcation lesions, but the benefit of routine side branch (SB) strut dilatation has not been fully elucidated. A benchtop model was used to determine the benefits of routine side branch (SB) dilatation techniques on strut apposition, acute thrombogenicity, and flow disruption. Three different provisional bifurcation techniques were compared: no SB dilatation "keep it open" method (KIO), sequential balloon dilatation (SBD), and kissing balloon inflation (KBI). Stents were deployed in a silicon bifurcation model and perfused with blood at a flow rate of 200 ml/min for 60 min. Optical coherence tomography (OCT) pullbacks were obtained before and after flow perfusion to conduct strut analysis and acute thrombus measurement respectively. Computational fluid dynamics (CFD) models were created using OCT pullbacks and simulated based on experimental conditions to analyze flow disruption. The strut analysis showed that KBI had the lowest percentage of floating (10.6 ± 2.3%) (p = 0.0004) and malapposed (41.2 ± 8.5%) struts (p = 0.59), followed by SBD and then KIO. This correlated to KBI having the lowest amount of thrombus formed at the SB, followed by SBD, with KIO being the most thrombogenic (KBI: 0.84 ± 0.22mm2, SBD: 1.17 ± 0.25mm2, KIO: 1.31 ± 0.36mm2, p = 0.18). CFD models also predicted a similar trend, with KBI having the lowest amount of area of high shear rate as well as flow recirculation. Based on this benchtop model, SB intervention strategies demonstrated a reduction in number of struts and resulting thrombogenicity at the bifurcation ostia. Graphical abstract.


Subject(s)
Angioplasty, Balloon, Coronary/instrumentation , Coronary Artery Disease/therapy , Coronary Vessels/physiopathology , Drug-Eluting Stents , Angioplasty, Balloon, Coronary/adverse effects , Computer Simulation , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Coronary Circulation , Coronary Thrombosis/etiology , Coronary Thrombosis/physiopathology , Hemodynamics , Humans , Hydrodynamics , Models, Anatomic , Models, Cardiovascular , Stress, Mechanical , Tomography, Optical Coherence
2.
J Laryngol Otol ; 134(4): 323-327, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32241312

ABSTRACT

OBJECTIVE: The nasal septal swell body is a normal anatomical structure located in the superior nasal septum anterior to the middle turbinate. However, the impact of the septal swell body in nasal breathing during normal function and disease remains unclear. This study aimed to establish that the septal swell body varies in size over time and correlates this with the natural variation of the inferior turbinates. METHOD: Consecutive patients who underwent at least two computed tomography scans were identified. The width and height of the septal swell body and the inferior turbinates was recorded. A correlation between the difference in septal swell body and turbinates between the two scans was performed using a Pearson's coefficient. RESULTS: A total of 34 patients (53 per cent female with a mean age of 58.3 ± 20.2 years) were included. The mean and mean difference in septal swell body width between scans for the same patient was 1.57 ± 1.00 mm. The mean difference in turbinate width between scans was 2.23 ± 2.52 mm. A statistically significant correlation was identified between the difference in septal swell body and total turbinate width (r = 0.35, p = 0.04). CONCLUSION: The septal swell body is a dynamic structure that varies in width over time in close correlation to the inferior turbinates. Further research is required to quantify its relevance as a surgical area of interest.


Subject(s)
Nasal Obstruction/pathology , Nasal Septum/diagnostic imaging , Rhinitis/pathology , Turbinates/diagnostic imaging , Adult , Aged , Australia/epidemiology , Female , Humans , Hypertrophy , Male , Middle Aged , Nasal Obstruction/etiology , Nasal Obstruction/therapy , Nasal Septum/pathology , Paranasal Sinuses/diagnostic imaging , Petrous Bone/diagnostic imaging , Tomography, X-Ray Computed , Turbinates/pathology
3.
J Med Microbiol ; 68(3): 346-354, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30724730

ABSTRACT

PURPOSE: Non-albicansCandida species have emerged as fungal pathogens that cause invasive infections, with many of these species displaying resistance to commonly used antifungal agents. This study was confined to studying the characteristics of clinical isolates of the C. rugosa complex and C. pararugosa species. METHODOLOGY: Seven isolates of the C. rugosa complex and one isolate of C. pararugosa were obtained from two tertiary referral hospitals in Malaysia. Their antifungal susceptibilities, biofilm, proteinase, phospholipase, esterase and haemolysin activities were characterized. Biofilms were quantified using crystal violet (CV) and tetrazolium (XTT) reduction assays at 1.5, 6, 18, 24, 48 and 72 h.Results/Key findings. The E-test antifungal tests showed that both species have elevated MICs compared to C. albicans and C. tropicalis. The highest biomass was observed in one of the C. rugosa isolates (0.237), followed by C. pararugosa (0.206) at 18 h of incubation. However, the highest bioactivity was observed in the C. rugosa ATCC 10571 strain at 24 h (0.075), followed by C. pararugosa at 48 h (0.048) and the same C. rugosa strain at 24 h (0.046), with P<0.05. All isolates exhibited high proteinase activity (+++) whereas six isolates showed very strong esterase activity (++++). All the isolates were alpha haemolytic producers. None of the isolates exhibited phospholipase activity. CONCLUSION: Elevated MICs were shown for the C. rugosa complex and C. pararugosa for commonly used antifungal drugs. Further studies to identify virulence genes involved in the pathogenesis and genes that confer reduced drug susceptibility in these species are proposed.


Subject(s)
Biofilms , Candida/drug effects , Peptide Hydrolases/metabolism , Phospholipases/metabolism , Antifungal Agents/pharmacology , Candida/enzymology , Candida/isolation & purification , Candidemia , Candidiasis , Hospitals, Teaching , Humans , Malaysia , Microbial Sensitivity Tests , Skin/microbiology , Tertiary Care Centers
4.
Surgeon ; 10(6): 309-13, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22123434

ABSTRACT

AIMS: To analyse the outcome of patients with gastrointestinal stromal tumour (GIST) who receive imatinib therapy and undergo subsequent resection of focally progressive disease. METHODS: We reviewed the records of all cases of GIST discussed at the West of Scotland Sarcoma regional multi-disciplinary team meeting between January 2002 and December 2009 inclusive. We analysed all patients who had undergone surgery for progressive disease on imatinib therapy. Focally progressive disease was diagnosed on computated tomography (CT) and positron-emission tomography-CT and was defined by a GIST lesion initially responsive to imatinib therapy but then underwent growth with evidence of metabolic activity. All procedures were undertaken in a university teaching hospital by a single surgeon. RESULTS: Nine patients were identified who underwent ten resections of focally progressive GIST. Six had previously undergone resection of their primary tumour while three had presented with un-resectable disease. Nine operations were for resection of a solitary progression while one operation was for three foci of progression. Five patients underwent liver resection which was confined to the segments were there was focal progression of GIST; of these one patient had multiple liver metastases and portal hypertension with a mass at the porta hepatis. The absolute survival for patients after resection was 18.4±13.7 months (mean±standard deviation), with progression free survival of 14.1±13.5 months equating to 56% at 1-year. Four patients had been switched from imatinib to sunitinib, for further multi-focal progression. CONCLUSIONS: Surgical resection of focally progressive GIST may prolong survival and a second or third resection is a feasible option in selected patients.


Subject(s)
Benzamides/therapeutic use , Digestive System Surgical Procedures/methods , Drug Resistance, Neoplasm , Gastrointestinal Stromal Tumors/surgery , Piperazines/therapeutic use , Pyrimidines/therapeutic use , Adult , Aged , Antineoplastic Agents/therapeutic use , Disease-Free Survival , Female , Follow-Up Studies , Gastrointestinal Stromal Tumors/drug therapy , Humans , Imatinib Mesylate , Male , Middle Aged , Retrospective Studies , Treatment Outcome
5.
AJNR Am J Neuroradiol ; 32(2): E29-32, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20223883

ABSTRACT

We evaluated the intraobserver and interobserver variability for WA measurement of an atherosclerotic BA by using HRMRI. Ten consecutive patients underwent HRMRI, and the WA of the BA at the level of the trigeminal ganglion was measured by 2 independent readers and repeated by 1 reader 1 month later. There was strong agreement for intraobserver and interobserver measurements in the ICC and by the Bland-Altman method. Measurement of the WA in an atherosclerotic BA by HRMRI was reproducible.


Subject(s)
Atherosclerosis/pathology , Basilar Artery/pathology , Magnetic Resonance Imaging/statistics & numerical data , Magnetic Resonance Imaging/standards , Trigeminal Ganglion , Aged , Brain Ischemia/pathology , Humans , Ischemic Attack, Transient/pathology , Male , Middle Aged , Observer Variation , Prospective Studies , Reproducibility of Results , Stroke/pathology
6.
Hong Kong Med J ; 16(6): 455-62, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21135422

ABSTRACT

OBJECTIVES: To assess time management of stroke thrombolysis triage and functional outcomes in patients receiving recombinant tissue plasminogen activator for hyperacute stroke, and identify bottlenecks in delivery of the treatment. DESIGN: Prospective study. SETTING: A university teaching hospital in Hong Kong. PATIENTS: Patients with suspected hyperacute stroke referred to the stroke thrombolysis team during October 2008 to September 2009. MAIN OUTCOME MEASURES: Time performance records including door-to-stroke team, door-to-needle, and onset-to-thrombolysis times. Functional outcomes by modified Rankin Scale score at 3 months, and thrombolysis-related complications including haemorrhagic transformations and mortality. RESULTS: During the 12-month period, 95 thrombolysis calls were received; recombinant tissue plasminogen activator was given intravenously to 17 (18%) of the patients and intra-arterially to 11 (12%). The mean (standard deviation) door-to-stroke team and the door-to-needle times for intravenous recombinant tissue plasminogen activator patients were 33 (25) and 80 (25) minutes, respectively; both were about 20 minutes longer than that recommended by the National Institute of Neurological Disorders and Stroke. The mean National Institute of Health Stroke Scale score for patients received intravenous recombinant tissue plasminogen activator was 16 (standard deviation, 7). The mean (standard deviation) onset-to-treatment time was 144 (42) minutes. Nine (53%) patients who received intravenous recombinant tissue plasminogen activator achieved favourable outcomes at 3 months, with a modified Rankin Scale score of 0 to 1. Symptomatic haemorrhage and mortality occurred in one (6%) patient. CONCLUSION: A dedicated stroke triage pathway is essential to ensure efficient and safe delivery of thrombolysis therapy. Improvements in door-to-stroke team time through integration with emergency medicine staff and neuroradiologists may improve thrombolysis eligibility.


Subject(s)
Stroke/drug therapy , Thrombolytic Therapy , Triage , Aged , Female , Humans , Male , Middle Aged , Prospective Studies , Stroke/mortality , Thrombolytic Therapy/adverse effects , Time Management , Tissue Plasminogen Activator/therapeutic use
7.
J Neurointerv Surg ; 2(2): 99-103, 2010 Jun.
Article in English | MEDLINE | ID: mdl-21990587

ABSTRACT

BACKGROUND AND AIM: Intracranial vertebrobasilar artery (VBA) stenosis portends a stroke and death rate of 8.5-22.8% annually despite medical therapy. Stenting has emerged as a treatment option but also carries substantial risk. Awake stenting under local anesthesia to minimize major procedural complication was investigated. METHODS: Between January 2007 and December 2008, 43 of 46 consecutive patients with severe symptomatic intracranial VBA stenosis underwent elective angioplasty assisted with self-expanding Wingspan stent under local anesthesia at our institute. All data were collected prospectively. RESULTS: All 43 patients tolerated the stenting procedure under local anesthesia well. Forty-two patients (97.7%) were stented successfully. Within 30 days, there were three periprocedural strokes, including thromboembolic infarct, pontine perforator infarct and intracranial hemorrhage, without fatality. In addition, five patients had intraoperative brainstem transient ischemic attacks (TIAs) seconds after the deployment of the stent delivery system across the tortuous VBA. The symptoms and signs included impaired consciousness (n=5), dysarthria (n=3), convulsion (n=2), conjugate horizontal gaze palsy (n=2), nystagmus (n=2) and pinpoint pupils (n=1). There was angiographic evidence of VBA straightening without thromboembolism. The TIAs resolved within minutes of prompt removal of the delivery catheter. CONCLUSIONS: VBA stenting under local anesthesia is feasible with a 7% periprocedural stroke risk. Awake stenting allows timely detection of intraoperative TIAs. The mechanism of intraoperative TIA appears to be stent delivery system induced VBA straightening and distortion of its vascular tree. A devastating stroke may ensue if the TIA is not detected and distortion of VBA perforators is not reversed promptly.


Subject(s)
Anesthesia, Local , Hospitalization , Intraoperative Complications/diagnostic imaging , Ischemic Attack, Transient/diagnostic imaging , Stents , Vertebrobasilar Insufficiency/surgery , Aged , Anesthesia, Local/adverse effects , China/epidemiology , Female , Follow-Up Studies , Hospitalization/trends , Humans , Intraoperative Complications/epidemiology , Intraoperative Complications/etiology , Ischemic Attack, Transient/epidemiology , Ischemic Attack, Transient/etiology , Male , Middle Aged , Prospective Studies , Radiography , Stents/adverse effects , Treatment Outcome , Vertebrobasilar Insufficiency/epidemiology , Wakefulness
8.
J Psychopharmacol ; 24(3): 341-8, 2010 Mar.
Article in English | MEDLINE | ID: mdl-18719049

ABSTRACT

Asenapine, a novel psychopharmacologic agent being developed for the treatment of schizophrenia and bipolar disorder, has high affinity for a wide range of receptors, including the serotonergic receptors 5-HT(1A), 5-HT(1B), 5-HT(2A), 5-HT( 2B), 5-HT(2C), 5-HT(5A), 5-HT(6) and 5-HT( 7). We examined the long-term effects in rat brain of multiple doses of asenapine on representative serotonin receptor subtypes: 5-HT(1A), 5-HT(2A) and 5-HT(2C). Rats were given asenapine (0.03, 0.1 or 0.3 mg/kg) subcutaneously twice daily or vehicle for 4 weeks. Brain sections were collected from the medial prefrontal cortex (mPFC), dorsolateral frontal cortex (DFC), caudate putamen, nucleus accumbens, hippocampal CA( 1) and CA(3) regions, and entorhinal cortex and processed for in-vitro receptor autoradiography. Asenapine 0.1 and 0.3 mg/kg significantly increased 5-HT(1A) binding in mPFC (by 24% and 33%, respectively), DFC (27%, 31%) and hippocampal CA(1) region (23%, 25%) (all P < 0.05). All three asenapine doses (0.03, 0.1 and 0.3 mg/kg) significantly decreased 5-HT(2A) binding by a similar degree in mPFC (40%, 44%, 47%, respectively) and DFC (45%, 51%, 52%) (all P < 0.05), but did not alter 5-HT(2A) binding in the other brain regions studied. In contrast to the effects on 5-HT(1A) and 5-HT(2A) receptors, asenapine did not alter 5-HT(2C) binding in any brain region examined at the doses tested. Our results indicate that repeated administration of asenapine produces regional-specific effects on 5-HT(1A) and 5-HT(2A) receptors in rat forebrain regions, which may contribute to the distinctive psychopharmacologic profile of asenapine.


Subject(s)
Antipsychotic Agents/pharmacology , Brain/drug effects , Heterocyclic Compounds, 4 or More Rings/pharmacology , Receptors, Serotonin/metabolism , 8-Hydroxy-2-(di-n-propylamino)tetralin/analysis , Animals , Brain/metabolism , Dibenzocycloheptenes , Dose-Response Relationship, Drug , In Vitro Techniques , Male , Radioligand Assay , Rats , Rats, Sprague-Dawley
9.
AJNR Am J Neuroradiol ; 30(9): 1694-9, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19581340

ABSTRACT

BACKGROUND AND PURPOSE: Germinomas originating from the basal ganglia (BG) are rare. Early diagnosis is important for favorable prognosis, but it is difficult due to the slow clinical course and subtle changes on neuroimaging. The purpose of this study was to evaluate the usefulness of susceptibility-weighted imaging (SWI) in the diagnosis of early BG germinoma. MATERIALS AND METHODS: From 2006 to 2008, 6 BG germinomas were diagnosed in children at our institution by pathology. Conventional MR imaging and SWI were available in all cases. Clinical, neuroradiologic, and follow-up features were retrospectively studied. RESULTS: Three cases were classified as early BG germinomas. Conventional MR imaging demonstrated that the tumor size was <10 mm in the largest diameter. The tumors were invisible or showed slight hyperintensity on T1-weighted images (T1WI) and patchy slight hyperintensity on T2-weighted images (T2WI) without mass effect or enhancement. On SWI, the tumors appeared as obvious hypointensity in the globus pallidus and putamen, and the size was larger than that on conventional T1WI and T2WI. The other 3 cases with tumor size >10 mm in largest diameter were classified as late BG germinomas, with tumor necrosis, fluid-fluid levels, and perifocal edema, including 1 case with subependymal spread. On SWI, only the solid portion of the tumors showed hypointensity. No recurrence was noted on follow-up. CONCLUSIONS: SWI appears to be more sensitive in detecting early BG germinomas than conventional MR imaging. This capability may prove to be useful in future attempts to characterize early BG germinomas.


Subject(s)
Basal Ganglia Diseases/diagnosis , Basal Ganglia/pathology , Brain Neoplasms/diagnosis , Diffusion Magnetic Resonance Imaging/methods , Adolescent , Child , Humans , Male
10.
AJNR Am J Neuroradiol ; 30(4): 840-4, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19279273

ABSTRACT

BACKGROUND AND PURPOSE: Patients with symptomatic atherosclerotic stenosis of the intracranial vertebrobasilar artery (VBA) have a poor prognosis, and those with coexistent intracranial and extracranial stenoses have worse outcomes despite medical therapy. Our aim was to study the long-term outcome of patients with symptomatic atherosclerotic tandem stenoses at the intracranial VBA and the vertebral artery ostium (VAO) after elective stent placement. MATERIALS AND METHODS: Ten consecutive patients (mean age, 65.3 years) with this condition underwent elective stent placement at our institution between September 2001 and December 2007. Technical success was defined as stent placement of both VAO and intracranial VBA stenoses with complete stent coverage of the lesions, residual stenosis of < or = 30%, and good antegrade blood flow. The study end point was a composite of any stroke or death within 30 days and ischemic stroke in the VBA territory after 30 days. RESULTS: Technical success was obtained in 9 of 10 patients without any stroke or death within 30 days. During a median follow-up duration of 32 months, 1 patient had a fatal ischemic stroke in the VBA territory at 4 months, and the other 9 patients were free from stroke recurrence. Thus, the annual stroke rate in VBA territory (including any stroke or death within 30 days) was 3.8%. CONCLUSIONS: This pilot study shows that elective stent placement for patients with symptomatic atherosclerotic tandem stenoses at the intracranial VBA and VAO has an acceptable long-term outcome and may be considered as an alternative to medical therapy.


Subject(s)
Angioplasty, Balloon/methods , Intracranial Arteriosclerosis/therapy , Stents , Vertebrobasilar Insufficiency/therapy , Aged , Cerebral Angiography , Cerebrovascular Circulation , Female , Follow-Up Studies , Humans , Intracranial Arteriosclerosis/diagnostic imaging , Male , Middle Aged , Pilot Projects , Treatment Outcome , Vertebral Artery/diagnostic imaging , Vertebrobasilar Insufficiency/diagnostic imaging
11.
J Psychopharmacol ; 23(1): 65-73, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18308814

ABSTRACT

Asenapine is a novel psychopharmacologic agent under development for the treatment of schizophrenia and bipolar disorder. We determined and compared the human receptor binding affinities and functional characteristics of asenapine and several antipsychotic drugs. Compounds were tested under comparable assay conditions using cloned human receptors. In comparison with the antipsychotics, asenapine showed high affinity and a different rank order of binding affinities (pKi) for serotonin receptors (5-HT1A [8.6], 5-HT1B [8.4], 5-HT2A [10.2], 5-HT2B [9.8], 5-HT2C [10.5], 5-HT5 [8.8], 5-HT6 [9.6] and 5-HT7 [9.9]), adrenoceptors (alpha1 [8.9], alpha2A [8.9], alpha2B [9.5] and alpha2C [8.9]), dopamine receptors (D1 [8.9], D2 [8.9], D3 [9.4] and D4 [9.0]) and histamine receptors (H1 [9.0] and H2 [8.2]). It had much lower affinity (pKi

Subject(s)
Heterocyclic Compounds, 4 or More Rings/pharmacology , Histamine Release/drug effects , Psychotropic Drugs/pharmacology , Receptors, Adrenergic/drug effects , Receptors, Dopamine D2/drug effects , Receptors, Dopamine/drug effects , Receptors, Muscarinic/drug effects , Receptors, Serotonin/drug effects , Benzodiazepines/pharmacology , Bipolar Disorder/drug therapy , Clinical Trials as Topic , Cloning, Molecular , Clozapine/pharmacology , Dibenzocycloheptenes , Heterocyclic Compounds, 4 or More Rings/chemistry , Heterocyclic Compounds, 4 or More Rings/therapeutic use , Histamine Release/genetics , Humans , Inhibitory Concentration 50 , Molecular Structure , Olanzapine , Psychotropic Drugs/chemistry , Psychotropic Drugs/therapeutic use , Radioligand Assay , Receptors, Adrenergic/genetics , Receptors, Dopamine/genetics , Receptors, Dopamine D2/physiology , Receptors, Muscarinic/genetics , Receptors, Serotonin/genetics , Schizophrenia/drug therapy , Substrate Specificity
12.
Q J Nucl Med Mol Imaging ; 52(2): 185-92, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18043536

ABSTRACT

Copper-64 (t(1/2)=12.7 h; beta+: 17.4%; E(beta+max)=656 keV; beta-: 39%; E(beta-max)=573 keV) has emerged as an important non-standard positron-emitting radionuclide for positron emission tomography imaging of diseased tissues. A significant challenge of working with copper radionuclides is that they must be delivered to the living system as a stable complex that is attached to a biological targeting molecule for effective imaging and therapy. Significant research has been devoted to the development of ligands that can stably chelate (64)Cu, in particular, the cross-bridged (CB) macrocyclic chelators. This review describes the coordination chemistry and biological behavior of (64)Cu-labeled CB complexes.


Subject(s)
Chelating Agents/chemistry , Copper/chemistry , Cross-Linking Reagents/chemistry , Macrocyclic Compounds/chemistry , Radioisotopes/chemistry , Isotope Labeling/methods , Positron-Emission Tomography/methods , Radiopharmaceuticals/chemistry
13.
Indian J Med Microbiol ; 25(4): 391-4, 2007 Oct.
Article in English | MEDLINE | ID: mdl-18087092

ABSTRACT

Fluorescent in situ hybridization (FISH) was carried out using two different oligonucleotide probes specific for Pseudomonas spp. and Acinetobacter spp. These probes were tested against different organisms and were found to be highly specific. Sensitivity testing showed that the probes were able to detect as low as 10 3 CFU/mL. In addition, FISH was carried out directly on positive blood culture samples and the detection of microorganisms took less than 2 h. We believe that FISH is a rapid method that can be used as a routine laboratory diagnostic technique for the detection of Acinetobacter spp. and Pseudomonas spp. in clinical samples.


Subject(s)
Acinetobacter Infections/microbiology , Acinetobacter/isolation & purification , Bacteremia/microbiology , In Situ Hybridization, Fluorescence/methods , Pseudomonas Infections/microbiology , Pseudomonas/isolation & purification , Acinetobacter/genetics , Bacteriological Techniques/methods , Blood/microbiology , Humans , Pseudomonas/genetics , Sensitivity and Specificity
14.
Curr Pharm Des ; 13(1): 3-16, 2007.
Article in English | MEDLINE | ID: mdl-17266585

ABSTRACT

Molecular imaging is an important scientific discipline that plays a major role in clinical medicine and pharmaceutical development. While several imaging modalities including X-ray computed tomography (CT) and magnetic resonance imaging (MRI) generate high-resolution anatomical images, positron emission tomography (PET) and single photon emission computed tomography (SPECT) offer insight into the physiological processes that occur within a living organism. Of these two nuclear medicine imaging techniques, PET has advantages with respect to sensitivity and resolution, and this has led to the production and development of many positron emitting radionuclides that include non-traditional radionuclides of the transition metals. Copper-64 (t(1/2) = 12.7 h, beta(+): 17.4%, E(beta+max) = 656 keV; beta(-): 39%, E(beta-max) = 573 keV) has emerged as an important positron emitting radionuclide that has the potential for use in diagnostic imaging and radiotherapy. However, (64)Cu must be delivered to the living system as a stable complex that is attached to a biological targeting molecule for effective imaging and therapy. Therefore, significant research has been devoted to the development of ligands that can stably chelate (64)Cu. This review discusses the necessary characteristics of an effective (64)Cu chelator, while highlighting the development and evaluation of (64)Cu-complexes attached to biologically-targeted ligands.


Subject(s)
Chelating Agents/chemistry , Copper Radioisotopes/chemistry , Positron-Emission Tomography , Radiopharmaceuticals/chemical synthesis , Animals , Cyclams , Cyclohexylamines/chemistry , Dipeptides/chemical synthesis , Drug Design , Drug Stability , Heterocyclic Compounds/chemistry , Humans , Ligands , Molecular Structure , Radiopharmaceuticals/chemistry
15.
Singapore Med J ; 47(4): 276-80, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16572237

ABSTRACT

INTRODUCTION: Children commonly present with fever without source yet there is no reliable and consistent method of identifying those at risk of serious bacterial infection. In this study, we sought to identify predictors of serious bacterial infection in children aged between three to 36 months with fever without source. METHODS: Inpatient records of all children aged three to 36 months admitted from the Emergency Department of Singapore's main paediatric hospital between October 2001 to February 2002 with International Classification of Diseases (ninth revision) diagnosis codes 038 (septicaemia), 079 (viral fever), or 780 (pyrexia of unknown origin), were retrieved and reviewed. Patients identified as having fever without source were enrolled. RESULTS: Of 86 enrolled children, 17 (19.8 percent) had serious bacterial infection. Duration of fever and white blood cell count were found to be significant predictors. Children with white blood cell count equal to or greater than 16,000/cubic mm had 6.9 times (95 percent confidence interval [CI] is 1.7 to 28.4) increased risk of serious bacterial infection, while children with fever of duration exceeding three days before presentation had 3.8 times (95 percent CI is 1.1 to 13.1) increased risk of serious bacterial infection. A combination of white blood cell count less than 16,000/cubic mm and duration of fever three days or less had a negative predictive value of 1.0 (95 percent CI is 0.88 to 1.0) and a sensitivity of 1.0 (95 percent CI is 0.82 to 1.0). CONCLUSION: The two identified predictors offer an estimate of the risk of serious bacterial infection in children aged three to 36 months with fever without source.


Subject(s)
Bacterial Infections/diagnosis , Fever of Unknown Origin/diagnosis , Child, Preschool , Fever of Unknown Origin/microbiology , Humans , Infant , Prognosis , Risk Assessment , Risk Factors
16.
Br J Cancer ; 93(1): 23-8, 2005 Jul 11.
Article in English | MEDLINE | ID: mdl-15942627

ABSTRACT

We retrospectively analysed the results of patients with advanced non-small-cell lung cancer treated with gefitinib to derive clinical factors predictive of response and a favourable survival outcome. Patients were treated with gefitinib 250 mg per day and re-evaluated 4-8 weeks later with repeat CT scan and every 8 weeks thereafter to assess response and the duration of response. Pathology review by a histopathologist was conducted, in particular to confirm a recently published result of bronchioloalveolar carcinoma histology or its components as predictive of response to gefitinib. Logistic regression and Cox regression analytical methods were applied to determine factors that could predict for response and improved overall survival. A total of 110 patients were treated. The overall response rate was 32% partial responses (PRs). Only never-smoking status was predictive of response in the logistic regression analysis, adjusted OR=6.1, 95% CI=1.7, 21.5. The presence of a PR and good performance status were predictive of a favourable survival outcome from the Cox regression modelling. Responders had an adjusted HR of 3.0, 95% CI=1.5-5.8 compared to nonresponders, while patients with ECOG status 0-1 had an adjusted HR of 0.42, 95% CI=0.25-0.72, compared with patients with ECOG status 2-4. Bronchioloalveolar carcinoma or its components were distinctly absent on pathology review. In conclusions, Never-smoking status is an important clinical predictor of a favourable response to gefitinib.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Quinazolines/therapeutic use , Smoking , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Gefitinib , Humans , Logistic Models , Male , Middle Aged , Proportional Hazards Models , Retrospective Studies , Survival Analysis
17.
Gynecol Oncol ; 97(1): 171-7, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15790454

ABSTRACT

PURPOSE: To evaluate the efficacy and toxicity of adjuvant combination of sequential chemotherapy followed by radiotherapy in uterine papillary serous carcinoma (UPSC). METHODS AND MATERIALS: From April 1994 to June 2003, 26 patients (median age 61.7 years, range 46.9-78.4) with UPSC were treated with a platinum-based chemoradiation protocol after definitive surgery. 9 patients were assigned as stage I (35%), 4 were stage II (15%), 11 were stage III (42%), and 2 were stage IV (8%) according to the FIGO staging for gynecological cancers. All patients underwent total hysterectomy, salpingo-oophorectomy, pelvic +/- perioartic lymph nodes dissection/sampling, omentectomy, and peritoneal washing. The adjuvant chemoradiation protocol consists of 4 cycles of platinum-based chemotherapy followed by pelvic irradiation and vaginal vault brachytherapy. In selected stage I patients with no or minimal myometrial invasion, only vault brachytherapy was given after adjuvant chemotherapy. RESULTS: After a median follow-up of 28 months (range 9-113 months), 14 (54%) patients were alive and free of disease. 12 out of these 14 patients were FIGO stage I/II. 9 patients (35%) had died (8 from distant metastases). The Kaplan-Meier 2-year and 5-year survival estimates were 69.5% and 57%, respectively. Only 4 (15%) patients had pelvic recurrence. None of the patients developed local vault recurrence. The treatment was well tolerated, only 1 patient developed congestive cardiac failure from the chemotherapy and 6 patients had grade 2 peripheral neuropathy on follow-up. CONCLUSION: In our series of UPSC patients treated with adjuvant chemotherapy followed by radiotherapy, local control can be achieved in a majority of patients. Distant failure remains the major cause of mortality. Further investigations into finding a more effective systemic therapy are required if improvement in outcome for this form of uterine cancer is to be achieved.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Papillary/drug therapy , Carcinoma, Papillary/radiotherapy , Cystadenocarcinoma, Serous/drug therapy , Cystadenocarcinoma, Serous/radiotherapy , Uterine Neoplasms/drug therapy , Uterine Neoplasms/radiotherapy , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carboplatin/administration & dosage , Carboplatin/adverse effects , Carcinoma, Papillary/surgery , Chemotherapy, Adjuvant , Cystadenocarcinoma, Serous/surgery , Female , Humans , Middle Aged , Paclitaxel/administration & dosage , Paclitaxel/adverse effects , Radiotherapy, Adjuvant , Treatment Outcome , Uterine Neoplasms/surgery
19.
Malays J Pathol ; 27(2): 75-81, 2005 Dec.
Article in English | MEDLINE | ID: mdl-17191389

ABSTRACT

Antimicrobial resistance to the extended-spectrum cephalosporins is increasingly reported worldwide. In the local setting, nosocomial infections with multi-resistant Gram-negative bacilli are not uncommon and are a growing concern. However, there is limited data on the carriage rates of such organisms in the local setting. In May 2001, a prospective study was carried out to determine the enteric carriage rates of ceftazidime-resistant Gram negative bacilli (CAZ-R GNB) among residents of nursing homes and from in-patients of the geriatric and adult haematology wards of University Malaya Medical Centre. Ceftazidime-resistant Gram-negative bacilli (CAZ-R GNB) were detected in 25 samples (30%), out of which 6 were from nursing home residents, 5 from geriatric in-patients and 14 from the haematology unit. A total of 28 CAZ-R GNB were isolated and Escherichia coli (10) and Klebsiella pneumoniae (7) were the predominant organisms. Resistance to ceftazidime in E. coli and Klebsiella was mediated by extended-spectrum beta-lactamases (ESBLs). Although the majority of the CAZ-R GNB were from patients in the haematology ward, the six nursing home residents with CAZ-R GNB were enteric carriers of ESBL-producing coliforms. Prior exposure to antibiotics was associated with carriage of ESBL organisms and to a lesser extent, the presence of urinary catheters.


Subject(s)
Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/isolation & purification , Feces/microbiology , beta-Lactamases/metabolism , Aged , Anti-Bacterial Agents/therapeutic use , Ceftazidime/therapeutic use , Drug Resistance , Enterobacteriaceae/enzymology , Enterobacteriaceae Infections/complications , Hematologic Diseases/complications , Hematologic Diseases/microbiology , Humans , Inpatients/statistics & numerical data , Nursing Homes/statistics & numerical data , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational , Prevalence , beta-Lactam Resistance
20.
Ann Acad Med Singap ; 32(4): 450-4, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12968548

ABSTRACT

INTRODUCTION: We compare the breath-hold fast recovery fast spin echo (BHFRFSE) T2-weighted and non-breath-hold fast spin echo (NBHFSE) T2-weighted sequences in image quality and lesion characterisation of focal liver lesions. MATERIALS AND METHODS: Fat-suppressed T2-weighted magnetic resonance (MR) images obtained with the 2 sequences (BHFRFSE and NBHFSE) in 79 patients with 113 liver lesions were analysed retrospectively. The image quality and nature of the lesions were evaluated by 2 experienced radiologists. RESULTS: Based on receiver operating characteristic curve analysis, lesion characterisation was comparable for both sequences. The image quality of BHFRFSE was significantly better than that of NBHFSE. The NBHFSE missed 4 malignant lesions while BHFRFSE missed 2 malignant lesions. CONCLUSION: BHFRFSE performs similarly to NBHFSE in image quality and liver lesion characterisation.


Subject(s)
Echo-Planar Imaging/methods , Image Processing, Computer-Assisted/methods , Liver Neoplasms/diagnosis , Liver/pathology , Adult , Aged , Aged, 80 and over , Artifacts , Female , Humans , Liver Diseases/diagnosis , Male , Middle Aged , ROC Curve , Respiration , Risk Assessment , Sensitivity and Specificity , Statistics, Nonparametric
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