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P-745 The efficacy of Buscopan® in reducing pain during ultrasound-guided manual vacuum aspiration (USG-MVA): A double-blind randomised placebo-controlled trial. Hum Reprod 2021. [DOI: 10.1093/humrep/deab128.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Study question
Does Buscopan® reduce abdominal pain experienced by women undergoing ultrasound-guided manual vacuum aspiration (USG-MVA)?
Summary answer
The addition of 20mg Buscopan® intravenous injection was not associated with a statistical reduction in pain score but leads to a higher patient satisfaction score.
What is known already
Ultrasound-guided Manual Vacuum aspiration is a feasible and effective out-patient treatment option for treating early pregnancy loss. However, it is associated with a moderate amount of pain due to uterine contraction.
Study design, size, duration
This randomised, double-blinded, placebo-controlled trial was conducted in a university-affiliated tertiary hospital. The study assessed whether 1 ml of 20mg Buscopan® intravenous injection 5 minutes before the USG-MVA will reduce the abdominal pain experienced by the women immediately and 2 hours after the procedure. Participants were randomised between June 2018 to January 2020 using a computer-generated number series in a 1:1 ratio.
Participants/materials, setting, methods
Women aged 18 years or older with first-trimester miscarriage undergoing the USG-MVA procedure were eligible. In total, 122 participants out of 128 eligible were included. Of whom, 111 underwent the USG-MVA procedure, 60 randomised to the Buscopan® group, and 62 to the placebo group.
Main results and the role of chance
The median abdominal pain scores in the Buscopan® group were 16.0% and 21.2% lower than the placebo group immediately post-procedure and 2 hours after the procedure in the Buscopan® group. Repeated measures ANOVA indicated that the both vaginal and abdominal pain scores improved significantly with the time (Vaginal F(1,108)= 180.1,p<0.0001;
Abdominal
F(1,108)=83.41,p<0.001) but not with group. No difference was noted in the complications and side effects profile. The physiological stress measured by Log10 sAA levels reduced significantly with time (F(2.8,286.1)= 6.3, p < 0.001) but not with group (F = 0.1, p = 0.96). Women randomised to Buscopan® had a significantly higher (p = 0.032) mean VAS satisfaction scores compared to those receiving placebo (79.0±17.3 vs 73.4±24.1).
Limitations, reasons for caution
This study was a single-centre study, thus one should be cautious in the overall generalisability of the results.
Wider implications of the findings
Few studies have evaluated the use of anti-spasmodic agents to minimise uterine contraction pain in women undergoing outpatient uterine evacuation. We consider Buscopan® a useful adjunct in the pain control of USG-MVA to specifically reduce uterine cramps. Further larger studies are required to evaluate its efficacy
Trial registration number
ChiCTR1800014590
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P–745 The efficacy of Buscopan® in reducing pain during ultrasound-guided manual vacuum aspiration (USG-MVA): A double-blind randomised placebo-controlled trial. Hum Reprod 2021. [DOI: 10.1093/humrep/deab130.744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Study question
Does Buscopan® reduce abdominal pain experienced by women undergoing ultrasound-guided manual vacuum aspiration (USG-MVA)?
Summary answer
The addition of 20mg Buscopan® intravenous injection was not associated with a statistical reduction in pain score but leads to a higher patient satisfaction score.
What is known already
Ultrasound-guided Manual Vacuum aspiration is a feasible and effective out-patient treatment option for treating early pregnancy loss. However, it is associated with a moderate amount of pain due to uterine contraction.
Study design, size, duration
This randomised, double-blinded, placebo-controlled trial was conducted in a university-affiliated tertiary hospital. The study assessed whether 1 ml of 20mg Buscopan® intravenous injection 5 minutes before the USG-MVA will reduce the abdominal pain experienced by the women immediately and 2 hours after the procedure. Participants were randomised between June 2018 to January 2020 using a computer-generated number series in a 1:1 ratio.
Participants/materials, setting, methods
Women aged 18 years or older with first-trimester miscarriage undergoing the USG-MVA procedure were eligible. In total, 122 participants out of 128 eligible were included. Of whom, 111 underwent the USG-MVA procedure, 60 randomised to the Buscopan® group, and 62 to the placebo group.
Main results and the role of chance
The median abdominal pain scores in the Buscopan® group were 16.0% and 21.2% lower than the placebo group immediately post-procedure and 2 hours after the procedure in the Buscopan® group. Repeated measures ANOVA indicated that the both vaginal and abdominal pain scores improved significantly with the time (Vaginal F(1,108)=180.1,p<0.0001; Abdominal: F(1,108)=83.41,p<0.001) but not with group. No difference was noted in the complications and side effects profile. The physiological stress measured by Log10 sAA levels reduced significantly with time (F(2.8,286.1)= 6.3, p < 0.001) but not with group (F = 0.1, p = 0.96). Women randomised to Buscopan® had a significantly higher (p = 0.032) mean VAS satisfaction scores compared to those receiving placebo (79.0±17.3 vs 73.4±24.1).
Limitations, reasons for caution
This study was a single-centre study, thus one should be cautious in the overall generalisability of the results.
Wider implications of the findings: Few studies have evaluated the use of anti-spasmodic agents to minimise uterine contraction pain in women undergoing outpatient uterine evacuation. We consider Buscopan® a useful adjunct in the pain control of USG-MVA to specifically reduce uterine cramps. Further larger studies are required to evaluate its efficacy.
Trial registration number
ChiCTR1800014590
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Long Island enhanced aerosol event during 2018 LISTOS: Association with heatwave and marine influences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 270:116299. [PMID: 33360597 DOI: 10.1016/j.envpol.2020.116299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
The co-occurrence of enhancement in aerosol concentration, temperatures, and ozone mixing ratio was observed between June 29 and July 4, 2018 (enhanced period, EP) on Long Island (LI) and the greater NYC metropolitan area during part of the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS). Two aerosol formation pathways were identified during the EP, the first being the condensation of semi- and intermediate volatility oxidation products of anthropogenic volatile organic compounds (AVOCs) under stagnant synoptic flow conditions, high temperatures and afternoon sea-breeze circulation. While this first pathway was prevalent, the most abundant organic aerosol factor was less oxidized oxygenated organic aerosol or LO-OOA. The second formation pathway occurred during a period of more persistent (synoptic) on-shore flow transporting more aged aerosol which consisted of an internal mixture of more oxidized oxygenated organic aerosol (MO-OOA), methanesulfonic acid (MSA) and sulfate. It was estimated that 35% of the sulfate observed during the mature period (an average of about 1.2 μg m-3) originated from oceanic dimethyl sulfide (DMS) emissions. These two formation pathways helped elucidate the sources of fine particle pollution, highlighted the interaction between human emissions and natural DMS emission, and will help our understanding of pollution affecting other urban areas adjacent to large bodies of water during hot and stagnant periods.
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Virtual reality for acute pain in outpatient hysteroscopy: a randomised controlled trial. BJOG 2020; 128:87-95. [PMID: 32575151 DOI: 10.1111/1471-0528.16377] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the effectiveness of virtual reality as a distraction technique in the management of acute pain and anxiety during outpatient hysteroscopy. DESIGN Parallel group, prospective randomised controlled trial. SETTING UK University Hospital. METHODS Forty consenting, eligible women were randomised to virtual reality intervention (immersive video content as a distraction method) or standard care during outpatient hysteroscopy from August to October 2018. MAIN OUTCOME MEASURES Pain and anxiety outcomes were measured as a numeric rating score (scale 0-10). RESULTS Compared with standard care, women with virtual reality intervention experienced less average pain (score 6.0 versus 3.7, mean difference 2.3, 95% CI 0.61-3.99, P = 0.009) and anxiety (score 5.45 versus 3.3, mean difference 2.15, 95% CI 0.38-3.92, P = 0.02). CONCLUSION Virtual reality was effective in reducing pain and anxiety during outpatient hysteroscopy in a mixed-methods randomised control trial. Its wide potential role in ambulatory gynaecological procedures needs further evaluation. TWEETABLE ABSTRACT Virtual reality can be used as a part of a multimodal strategy to reduce acute pain and anxiety in patients undergoing outpatient hysteroscopy.
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Percutaneous 60-day peripheral nerve stimulation implant provides sustained relief of chronic pain following amputation: 12-month follow-up of a randomized, double-blind, placebo-controlled trial. Reg Anesth Pain Med 2019; 45:rapm-2019-100937. [PMID: 31740443 DOI: 10.1136/rapm-2019-100937] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/03/2019] [Accepted: 10/27/2019] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Peripheral nerve stimulation (PNS) has historically been used to treat chronic pain, but generally requires implantation of a permanent system for sustained relief. A recent study found that a 60-day PNS treatment decreases post-amputation pain, and the current work investigates longer-term outcomes out to 12 months in the same cohort. METHODS As previously reported, 28 traumatic lower extremity amputees with residual and/or phantom limb pain were randomized to receive 8 weeks of PNS (group 1) or 4 weeks of placebo followed by a crossover 4 weeks of PNS (group 2). Percutaneous leads were implanted under ultrasound guidance targeting the femoral and sciatic nerves. During follow-up, changes in average pain and pain interference were assessed using the Brief Pain Inventory-Short Form and comparing with baseline. RESULTS Significantly more participants in group 1 reported ≥50% reductions in average weekly pain at 12 months (67%, 6/9) compared with group 2 at the end of the placebo period (0%, 0/14, p=0.001). Similarly, 56% (5/9) of participants in group 1 reported ≥50% reductions in pain interference at 12 months, compared with 2/13 (15%, p=0.074) in group 2 at crossover. Reductions in depression were also statistically significantly greater at 12 months in group 1 compared with group 2 at crossover. CONCLUSIONS This work suggests that percutaneous PNS delivered over a 60-day period may provide significant carry-over effects including pain relief, potentially avoiding the need for a permanently implanted system while enabling improved function in patients with chronic pain. TRIAL REGISTRATION NUMBER NCT01996254.
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HIV-1 Gag specifically restricts PI(4,5)P2 and cholesterol mobility in living cells creating a nanodomain platform for virus assembly. SCIENCE ADVANCES 2019; 5:eaaw8651. [PMID: 31616784 PMCID: PMC6774721 DOI: 10.1126/sciadv.aaw8651] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
HIV-1 Gag protein assembles at the plasma membrane of infected cells for viral particle formation. Gag targets lipids, mainly PI(4,5)P2, at the inner leaflet of this membrane. Here, we address the question whether Gag is able to trap specifically PI(4,5)P2 or other lipids during HIV-1 assembly in the host CD4+ T lymphocytes. Lipid dynamics within and away from HIV-1 assembly sites were determined using super-resolution microscopy coupled with scanning fluorescence correlation spectroscopy in living cells. Analysis of HIV-1-infected cells revealed that, upon assembly, HIV-1 is able to specifically trap PI(4,5)P2 and cholesterol, but not phosphatidylethanolamine or sphingomyelin. Furthermore, our data showed that Gag is the main driving force to restrict the mobility of PI(4,5)P2 and cholesterol at the cell plasma membrane. This is the first direct evidence highlighting that HIV-1 creates its own specific lipid environment by selectively recruiting PI(4,5)P2 and cholesterol as a membrane nanoplatform for virus assembly.
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One Year Follow-up of a Randomized, Double-Blind, Placebo-Controlled Trial of Percutaneous Peripheral Nerve Stimulation for Chronic Neuropathic Pain Following Amputation. Neurosurgery 2019. [DOI: 10.1093/neuros/nyz310_144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Percutaneous peripheral nerve stimulation for the treatment of chronic neuropathic postamputation pain: a multicenter, randomized, placebo-controlled trial. Reg Anesth Pain Med 2019; 44:637-645. [PMID: 30954936 DOI: 10.1136/rapm-2018-100109] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/30/2019] [Accepted: 02/16/2019] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND OBJECTIVES Chronic neuropathic pain is a common challenging condition following amputation. Recent research demonstrated the feasibility of percutaneously implanting fine-wire coiled peripheral nerve stimulation (PNS) leads in proximity to the sciatic and femoral nerves for postamputation pain. A multicenter, double-blinded, randomized, placebo-controlled study collected data on the safety and effectiveness of percutaneous PNS for chronic neuropathic pain following amputation. METHODS Twenty-eight lower extremity amputees with postamputation pain were enrolled. Subjects underwent ultrasound-guided implantation of percutaneous PNS leads and were randomized to receive PNS or placebo for 4 weeks. The placebo group then crossed over and all subjects received PNS for four additional weeks. The primary efficacy endpoint evaluated the proportion of subjects reporting ≥50% pain reduction during weeks 1-4. RESULTS A significantly greater proportion of subjects receiving PNS (n=7/12, 58%, p=0.037) demonstrated ≥50% reductions in average postamputation pain during weeks 1-4 compared with subjects receiving placebo (n=2/14, 14%). Two subjects were excluded from efficacy analysis due to eligibility changes. Significantly greater proportions of PNS subjects also reported ≥50% reductions in pain (n=8/12, 67%, p=0.014) and pain interference (n=8/10, 80%, p=0.003) after 8 weeks of therapy compared with subjects receiving placebo (pain: n=2/14, 14%; pain interference: n=2/13, 15%). Prospective follow-up is ongoing; four of five PNS subjects who have completed 12-month follow-up to date reported ≥50% pain relief. CONCLUSIONS This work demonstrates that percutaneous PNS therapy may provide enduring clinically significant pain relief and improve disability in patients with chronic neuropathic postamputation pain. TRIAL REGISTRATION NUMBER NCT01996254.
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Communication between the transverse cervical nerve (C2,3) and marginal mandibular branch of the facial nerve: a cadaveric and clinical study. Br J Oral Maxillofac Surg 2019; 57:232-235. [PMID: 30803734 DOI: 10.1016/j.bjoms.2018.10.289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/05/2018] [Indexed: 11/28/2022]
Abstract
Several branches of the facial nerve are known to anastomose with branches of the cervical plexus, other cranial nerves, and the trigeminal nerve. Communication between the sensory transverse cervical nerve (C2, 3) and marginal mandibular nerve is, however, less well known, and in a previous study of 86 neck dissections we reported a 2.3% incidence of anastomoses between them. In this prospective study, we meticulously searched for more examples using both formalin-fixed cadavers and neck dissections. A total of 102 necks were included (both sides of 36 cadavers (n=72 necks), and 30 patients who had neck dissection for the management of squamous cell carcinoma). We found communications between these nerves on one side of a cadaver and in one neck dissection. When combined with the numbers from our previous study, the overall incidence was 2.1% in 188 necks. The marginal mandibular nerve was inseparable from the anastomosis with the transverse cervical nerve, and the variant should not be forgotten if we are to reduce the chance of postoperative weakness of the lower lip, particularly when operative exposure is more limited (such as during removal of the submandibular gland).
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A ‘Real-World’ Comparison of TEG 5000 and TEG 6s Measurements and Guided Clinical Management. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.02.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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The Obesity Paradox Within Cardiothoracic Surgery. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.02.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Risk Reducing Salpingooophorectomy Versus Ovarian Preservation Among BRCA Mutation Carriers. Gynecol Oncol 2016. [DOI: 10.1016/j.ygyno.2016.08.256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Intra-articular injection of synovial mesenchymal stem cells improves cartilage repair in a mouse injury model. Sci Rep 2016; 6:23076. [PMID: 26983696 PMCID: PMC4794799 DOI: 10.1038/srep23076] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 02/23/2016] [Indexed: 12/20/2022] Open
Abstract
Controversy remains whether articular cartilage has an endogenous stem/progenitor cell population, since its poor healing capacity after injury can lead to diseases such as osteoarthritis. In the joint environment there are mesenchymal stem/progenitor cells (MSCs) in the synovial membrane and synovial fluid that can differentiate into cartilage, but it is still under debate if these cells contribute to cartilage repair in vivo. In this study, we isolated a Sca-1 positive, chondrogenesis capable population of mouse synovial MSCs from C57BL6 and MRL/MpJ “super-healer” strains. Intra-articular injection of Sca-1 + GFP + synovial cells from C57BL6 or MRL/MpJ into C57BL6 mice following cartilage injury led to increased cartilage repair by 4 weeks after injury. GFP expression was detected in the injury site at 2 weeks, but not 4 weeks after injury. These results suggest that synovial stem/progenitor cells, regardless of strain background, have beneficial effects when injected into an injured joint. MSCs derived from MRL/MpJ mice did not promote an increased repair capacity compared to MSCs derived from non-healing C57BL6 controls; however, MRL/MpJ MSCs were observed within the defect area at the time points examined, while C57BL6 MSCs were not.
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Atmospheric benzenoid emissions from plants rival those from fossil fuels. Sci Rep 2015; 5:12064. [PMID: 26165168 PMCID: PMC4499884 DOI: 10.1038/srep12064] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/16/2015] [Indexed: 11/11/2022] Open
Abstract
Despite the known biochemical production of a range of aromatic compounds by plants and the presence of benzenoids in floral scents, the emissions of only a few benzenoid compounds have been reported from the biosphere to the atmosphere. Here, using evidence from measurements at aircraft, ecosystem, tree, branch and leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers, and phytoplankton) emits a wide variety of benzenoid compounds to the atmosphere at substantial rates. Controlled environment experiments show that plants are able to alter their metabolism to produce and release many benzenoids under stress conditions. The functions of these compounds remain unclear but may be related to chemical communication and protection against stress. We estimate the total global secondary organic aerosol potential from biogenic benzenoids to be similar to that from anthropogenic benzenoids (~10 Tg y−1), pointing to the importance of these natural emissions in atmospheric physics and chemistry.
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Evaluating endogenous repair of focal cartilage defects in C57BL/6 and MRL/MpJ mice using 9.4T magnetic resonance imaging: A pilot study. Magn Reson Imaging 2015; 33:690-4. [PMID: 25597446 DOI: 10.1016/j.mri.2015.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 12/12/2014] [Accepted: 01/09/2015] [Indexed: 11/17/2022]
Abstract
The use of magnetic resonance imaging (MRI) for evaluating joint injuries is often considered superior to radiography due to the capacity of MRI for visualizing both soft and hard tissues. While longitudinal studies regarding cartilage repair have been undertaken on patients and in larger animal models, a method has yet to be developed for mouse cartilage to be repeatedly and non-invasively evaluated over time. The aim of this pilot study was to investigate if morphological changes following a focal cartilage injury in mice could be measured by 9.4T magnetic resonance imaging. Focal cartilage defects were induced in the left knee of 4-6weeks old C57BL/6 and MRL/MpJ mice. At endpoints 0, 2, and 4weeks post-injury, legs were dissected out and imaged ex vivo. The defect could be detected by MRI immediately after injury, appearing as a hyperintense focal point and with size similar to that of the surgical tool used. Defects were visible in both strains up to 4weeks post-injury, although signal intensity decreased over time. One C57BL/6 in particular, displayed extensive fibrosis in the patellar tendon at 4weeks as assessed by histology, while the MR images of the same animal displayed a clear, structural distinction between the patella and the new tissue growth. Overall, our results suggest that MRI could be used for longitudinal studies in murine cartilage injury models to evaluate certain characteristics of repair not detectable through histology.
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Peritoneal cytology in risk-reducing salpingo-oophorectomy: Implications for cancer outcomes. Gynecol Oncol 2012. [DOI: 10.1016/j.ygyno.2012.07.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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The role of conformational change in HIV maturation revealed by SAXS. Acta Crystallogr A 2011. [DOI: 10.1107/s010876731109903x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Impact of income and education on drug purchasing decisions in Hong Kong Chinese cancer patients: a pilot study. Asian Pac J Cancer Prev 2011; 12:2093-2096. [PMID: 22292657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND The affordability of diagnostic, preventive and therapeutic interventions is a global concern, particularly in the developing world. To clarify the educational and financial factors that influence purchasing decisions, we conducted a survey of Hong Kong cancer patients across a broad social spectrum. METHODS A questionnaire was designed to assess the effect of costs on purchasing decisions relating to six drug-related variables: efficacy, tolerability, convenience, safety, peer pressure, and uncertainty. Validation of the original 31-part survey resulted in a final set of 22 core questions that was administered to 51 consecutive oncology patients who were characterized in terms of varying household income and educational level. RESULTS Most respondents (87.6%) were Hong Kong-born or mainland Chinese. There was a strong correlation between household income and education. Demand for drug tolerability and safety was high and cost-inelastic across all educational and income groups. An unexpected finding was that patients from low-income/education households were keen to purchase costly medications (whether Western, or Chinese herbs) of reputed high efficacy, whereas patients from middle-income/-education backgrounds were more negatively influenced by considerations of cost. Only the most affluent and well-educated patients valued overall survival above disease-free survival when making drug purchasing decisions; this cohort was also the least influenced by peer pressure, and the most willing to pay extra for drugs offering more convenience alone. CONCLUSION Low-income/education Asian patients had paradoxically high expectations of costly drug interventions. Although larger studies addressing this issue are needed to confirm these conclusions, public education initiatives aimed at protecting low-income/education patients from exploitation or disappointment may be desirable.
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Reducing chimera formation during PCR amplification to ensure accurate genotyping. Gene 2010; 469:45-51. [PMID: 20833233 DOI: 10.1016/j.gene.2010.08.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/27/2010] [Accepted: 08/30/2010] [Indexed: 11/28/2022]
Abstract
Measurements of population diversity are fundamental to the reconstruction of the evolutionary and epidemiological history of organisms. Commonly used protocols to measure population diversity using the polymerase chain reaction (PCR) are prone to the introduction of artificial chimeras. These are often difficult to detect and can confound the correct interpretation of results due to the false generation of recombinants when the underlying DNA sample contains multiple distinct templates. This study presents a standardised procedure to suppress the formation of artificial chimeras during PCR amplification. The solution is based on the accurate determination of the efficiency and end point of the log-linear phase of a PCR. This procedure will facilitate the generation of data sets that more accurately reflect the underlying population diversity rather than artifacts introduced by the process itself.
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RNase H active site inhibitors of human immunodeficiency virus type 1 reverse transcriptase: design, biochemical activity, and structural information. J Med Chem 2009; 52:5781-4. [PMID: 19791799 DOI: 10.1021/jm900597q] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyrimidinol carboxylic acids were designed as inhibitors of HIV-1 RNase H function. These molecules can coordinate to two divalent metal ions in the RNase H active site. Inhibition of enzymatic activity was measured in a biochemical assay, but no antiviral effect was observed. Binding was demonstrated via a solid state structure of the isolated p15-Ec domain of HIV-1 RT showing inhibitor and two Mn(II) ions bound to the RNase H active site.
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How much cost can one patient bear? The influence of income and education on drug purchasing decisions in Hong Kong Chinese cancer patients. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.19584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
19584 Background: Inflation of anticancer drug prices is a growing problem worldwide. This problem is especially challenging in Asia, where rising healthcare expectations clash with low incomes and weak insurance. To clarify the factors influencing drug purchasing decisions in this context, we conducted a survey of Hong Kong oncology patients. Methods: A questionnaire was designed to assess the effect of cost on purchasing decisions relating to drug variables such as (1) efficacy, (2) tolerability, (3) convenience, (4) safety, (5) novelty and (6) reliability. Validation of the original 33-part survey resulted in a final set of 21 questions that was administered to 51 oncology patients. These respondents were characterised in terms of age, household income, insurance, educational level, family circumstances, occupation, ethnicity, religious beliefs, prognosis, and co-morbidity. Results: Most respondents were Hong Kong (68.8%), mainland Chinese (18.8%) or Caucasian (10.4%). There was a strong correlation between household income and education. Patients from middle-income (US$7,000–14,000 per month) households were most influenced in their decisions by costs and insurance rebates, whereas those from low-income households (less than US$3,000 per month) were keenest to purchase expensive medications, whether Western or traditional Chinese remedies. Demand for drug safety was cost-inelastic across all income groups, independent of gains in efficacy. Even when free treatment was offered, therapeutic uncertainties (e.g., early-phase drugs or randomization) proved unpopular with all income groups. Only the most affluent and well-educated patients valued overall survival above disease-free survival in making decisions, suggesting that less educated cohorts did not understand these concepts. Conclusion: These data suggest that low-income cancer patients and their families may have unrealistic expectations of high-priced medications, based either on misunderstanding or cultural pressures. Greater educational efforts targeting this large population sector may be needed to avoid worsening dissatisfaction and social unrest in the future. No significant financial relationships to disclose.
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Skin and soft tissue necrosis from calcium chloride in a deicer. J Emerg Med 2007; 32:41-4. [PMID: 17239731 DOI: 10.1016/j.jemermed.2006.05.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 10/19/2005] [Accepted: 05/09/2006] [Indexed: 11/25/2022]
Abstract
Calcium chloride salt is the principle ingredient of many commercially available deicers. Calcium chloride melts snow and ice by its osmotic action. We present a case of skin and soft tissue necrosis associated with the use of a calcium chloride-containing deicer. Although calcium chloride is known to produce soft tissue necrosis if it extravasates during intravenous administration, necrosis and skin sloughing has rarely been described after topical exposure to this salt. Calcium chloride likely produces tissue injury from the heat liberated by mixing calcium chloride with water (exothermic reaction) and from direct calcium deposits in the skin (calcinosis cutis) and soft tissue.
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Cardiac Myosin Activator CK-1316719 Increases MyoFibril ATPase Activity and Myocyte Contractility in a Rat Model of Heart Failure. J Card Fail 2006. [DOI: 10.1016/j.cardfail.2006.06.298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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WITHDRAWN: Food viscosity as a determinant of caloric compensation and utilization. Appetite 2006. [DOI: 10.1016/j.appet.2006.03.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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WITHDRAWN: Intake suppression following intracerebroventricular and intrahippocampal CCK-8. Appetite 2006. [DOI: 10.1016/j.appet.2006.03.173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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P-290 Manganese superoxide dismutase and catalase geneticpolymorphisms, activity levels and lung cancer risk in Chinese in Hong Kong. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80784-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Genetic counseling and testing for BRCA mutations: A comparison of ethnically diverse families in a public hospital with Caucasian families in a university hospital. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.9667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
BACKGROUND The clinical efficacy of inhaled corticosteroid (ICS) treatment has not been evaluated in bronchiectasis, despite the presence of chronic airway inflammation. METHODS After three consecutive weekly visits, 86 patients were randomised to receive either fluticasone 500 mug twice daily (n = 43, 23F, mean (SD) age 57.7 (14.4) years) or matched placebo (n = 43, 34F, 59.2 (14.2) years) and reviewed regularly for 52 weeks in a double blind fashion. RESULTS 35 and 38 patients in the fluticasone and placebo groups completed the study. Significantly more patients on ICS than on placebo showed improvement in 24 hour sputum volume (OR 2.5, 95% CI 1.1 to 6.0, p = 0.03) but not in exacerbation frequency, forced expiratory volume in 1 second, forced vital capacity, or sputum purulence score. Significantly more patients with Pseudomonas aeruginosa infection receiving fluticasone showed improvement in 24 hour sputum volume (OR 13.5, 95% CI 1.8 to 100.2, p = 0.03) and exacerbation frequency (OR 13.3, 95% CI 1.8 to 100.2, p = 0.01) than those given placebo. Logistic regression models revealed a significantly better response in sputum volume with fluticasone treatment than with placebo among subgroups of patients with 24 hour sputum volume <30 ml (p = 0.04), exacerbation frequency </=2/year (p = 0.04), and sputum purulence score >5 (p = 0.03). CONCLUSIONS ICS treatment is beneficial to patients with bronchiectasis, particularly those with P. aerurginosa infection.
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Relaxin modulates cardiac fibroblast proliferation, differentiation, and collagen production and reverses cardiac fibrosis in vivo. Endocrinology 2004; 145:4125-33. [PMID: 15155573 DOI: 10.1210/en.2004-0209] [Citation(s) in RCA: 212] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cardiac fibrosis is a key component of heart disease and involves the proliferation and differentiation of matrix-producing fibroblasts. The effects of an antifibrotic peptide hormone, relaxin, in inhibiting this process were investigated. We used rat atrial and ventricular fibroblasts, which respond to profibrotic stimuli and express the relaxin receptor (LGR7), in addition to two in vivo models of cardiac fibrosis. Cardiac fibroblasts, when plated at low density or stimulated with TGF-beta or angiotensin II (Ang II), accelerated fibroblast differentiation into myofibroblasts, as demonstrated by significantly increased alpha-smooth muscle actin expression, collagen synthesis, and collagen deposition (by up to 95% with TGF-beta and 40% with Ang II; all P < 0.05). Fibroblast proliferation was significantly increased by 10(-8) m and 10(-7) m Ang II (63-75%; P < 0.01) or 0.1-1 microg/ml IGF-I (27-40%; P < 0.05). Relaxin alone had no marked effect on these parameters, but it significantly inhibited Ang II- and IGF-I-mediated fibroblast proliferation (by 15-50%) and Ang II- and TGF-beta-mediated fibroblast differentiation, as detected by decreased expression of alpha-smooth muscle actin (by 65-88%) and collagen (by 60-80%). Relaxin also increased matrix metalloproteinase-2 expression in the presence of TGF-beta (P < 0.01) and Ang II (P < 0.05). Furthermore, relaxin decreased collagen overexpression when administered to two models of established fibrotic cardiomyopathy, one due to relaxin deficiency (by 40%; P < 0.05) and the other to cardiac-restricted overexpression of beta2-adrenergic receptors (by 58%; P < 0.01). These coherent findings indicate that relaxin regulates fibroblast proliferation, differentiation, and collagen deposition and may have therapeutic potential in diseased states characterized by cardiac fibrosis.
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MESH Headings
- Amino Acid Sequence
- Angiotensin II/pharmacology
- Animals
- Cardiomyopathies/drug therapy
- Cardiomyopathies/pathology
- Cell Differentiation/drug effects
- Cell Division/drug effects
- Cells, Cultured
- Collagen/metabolism
- Cyclic AMP/metabolism
- Disease Models, Animal
- Fibroblasts/cytology
- Fibroblasts/pathology
- Fibrosis
- Matrix Metalloproteinases/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Sequence Data
- Muscle, Smooth, Vascular/cytology
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/pathology
- Nerve Tissue Proteins/genetics
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-2/genetics
- Receptors, G-Protein-Coupled
- Receptors, Peptide/genetics
- Relaxin/genetics
- Relaxin/pharmacology
- Transforming Growth Factor beta/pharmacology
- Vasoconstrictor Agents/pharmacology
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Abstract
Several members of the kinesin family of microtubule motor proteins play essential roles in mitotic spindle function and are potential targets for the discovery of novel antimitotic cancer therapies. KSP, also known as HsEg5, is a kinesin that plays an essential role in formation of a bipolar mitotic spindle and is required for cell cycle progression through mitosis. We identified a potent inhibitor of KSP, CK0106023, which causes mitotic arrest and growth inhibition in several human tumor cell lines. Here we show that CK0106023 is an allosteric inhibitor of KSP motor domain ATPase with a Ki of 12 nM. Among five kinesins tested, CK0106023 was specific for KSP. In tumor-bearing mice, CK0106023 exhibited antitumor activity comparable to or exceeding that of paclitaxel and caused the formation of monopolar mitotic figures identical to those produced in cultured cells. KSP was most abundant in proliferating human tissues and was absent from cultured postmitotic neurons. These findings are the first to demonstrate the feasibility of targeting mitotic kinesins for the treatment of cancer.
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Continuous-flow isotope analysis of the deuterium/hydrogen ratio in atmospheric hydrogen. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2004; 18:299-306. [PMID: 14755615 DOI: 10.1002/rcm.1309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A convenient method is described for analyzing the deuterium/hydrogen (D/H) ratio of atmospheric molecular hydrogen (H(2)) based on mass spectrometric isotope-ratio monitoring. The method requires small amounts of air ( approximately 300 mL STP), is operated on-line, and comprises four steps: (1). the condensation of the air matrix at approximately 40 K; (2). the collection of the non-condensed components of the air sample (H(2), Ne, He, and traces of N(2)) in a 5 A molecular sieves pre-concentration trap at approximately 63 K; (3). gas chromatographic purification of H(2) in a flow of He; and (4) quantification of the D/H ratio in an isotope-ratio mass spectrometer. The precision of the determination of the D/H ratio is better than 2 per thousand, which is comparable to, or better than, that obtained by conventional duel-inlet off-line analysis. There are, however, discrepancies relative to the D/H ratios determined by conventional duel-inlet analysis. This is due to differences in peak shape between reference and sample air, depending on the amount of H(2) injected. Consequently, calibration runs are required. After the calibration of the system, we obtained an accuracy of 1.5 per thousand, so that the accumulated uncertainty is estimated to be less than 4 per thousand. The method also allows determination of the H(2) concentration, with an uncertainty estimated to be 2%.
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The dimer initiation sequence stem-loop of human immunodeficiency virus type 1 is dispensable for viral replication in peripheral blood mononuclear cells. J Virol 2003; 77:8329-35. [PMID: 12857902 PMCID: PMC165254 DOI: 10.1128/jvi.77.15.8329-8335.2003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2002] [Accepted: 05/14/2003] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) contains two copies of genomic RNA that are noncovalently linked via a palindrome sequence within the dimer initiation site (DIS) stem-loop. In contrast to the current paradigm that the DIS stem or stem-loop is critical for HIV-1 infectivity, which arose from studies using T-cell lines, we demonstrate here that HIV-1 mutants with deletions in the DIS stem-loop are replication competent in peripheral blood mononuclear cells (PBMCs). The DIS mutants contained either the wild-type (5'GCGCGC3') or an arbitrary (5'ACGCGT3') palindrome sequence in place of the 39-nucleotide DIS stem-loop (NL(CGCGCG) and NL(ACGCGT)). These DIS mutants were replication defective in SupT1 cells, concurring with the current model in which DIS mutants are replication defective in T-cell lines. All of the HIV-1 DIS mutants were replication competent in PBMCs over a 40-day infection period and had retained their respective DIS mutations at 40 days postinfection. Although the stability of the virion RNA dimer was not affected by our DIS mutations, the RNA dimers exhibited a diffuse migration profile when compared to the wild type. No defect in protein processing of the Gag and GagProPol precursor proteins was found in the DIS mutants. Our data provide direct evidence that the DIS stem-loop is dispensable for viral replication in PBMCs and that the requirement of the DIS stem-loop in HIV-1 replication is cell type dependent.
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Abstract
The mechanisms for Pseudomonas aeruginosa colonisation in the airways of patients with bronchiectasis and cystic fibrosis are poorly understood. P. aeruginosa could evade mucociliary clearance by adhering to the basement membrane at areas denuded of intact respiratory epithelium. The authors have developed an in vitro model to study P. aeruginosa adherence to human basement membrane type-IV collagen by using scanning electron microscopy. P. aeruginosa adherence density was determined as the number of P. aeruginosa per 20 microscope fields (2,000x) to log inocular size after incubation at 37 degrees C for 45 min. The presence of phytohaemagglutinin (PHA)-E, which binds specifically to D-galactose-beta1-4-D-N-acetylglucosamine, significantly reduced P. aeruginosa adherence density compared with control. The presence of heparin and calcium also significantly reduced P. aeruginosa adherence density. P. aeruginosa adherence was not affected by the presence of proline, trans-hydroxyproline, glycine, galactose, N-acetylneuraminic acid, N-acetylglucosamine or Arachis hypogea. Pseudomonas aeruginosa adherence probably acts via recognition of the D-galactose-beta1-4-D-N-acetylglucosamine sequence on type-IV collagen and this process could be inhibited by heparin and calcium. As persistent Pseudomonas aeruginosa colonisation is detrimental to patients with cystic fibrosis and bronchiectasis and there is currently no effective treatment for its eradication, these results could lead to novel therapy for persistent Pseudomonas aeruginosa infection.
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Overexpression and incorporation of GagPol precursor does not impede packaging of HIV-1 tRNA(Lys3) but promotes intracellular budding of virus-like particles. J Biomed Sci 2002; 9:697-705. [PMID: 12432236 DOI: 10.1159/000067295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We have recently demonstrated that alteration of the human immunodeficiency virus type 1 (HIV-1) Gag/GagPol ratio in virus-producing cells reduces the infectivity of progeny viruses and hinders the formation of stable virion RNA dimers without impairing virion packaging of the viral genomic RNA. In addition, we have previously shown that the expression of GagPol mediates the selective packaging of tRNA(Lys3). In this study we report that overexpression of uncleaved GagPol in the virus-producing cell did not alter the packaging levels of tRNA(Lys3). Similarly, altering the virion-associated Gag/GagPol ratio did not affect the virion packaging of the HIV-1 envelope protein nor cyclophilin A. Thin section electron microscopy analysis of the cells overexpressing protease-defective [PR(-)] GagPol revealed immature virions but no mature virions. These immature virions were seen both extracellularly and in membrane-bound cytoplasmic vacuoles. Furthermore, an accumulation of electron-dense material was occasionally found at the plasma membrane and associated with intracytoplasmic membranous vacuoles in cells expressing excess PR(-) GagPol. No intracellular HIV was seen in the wild-type control. Density gradient analysis showed that the overall density of these mutant virions with excess PR(-) GagPol was identical to that of the wild-type HIV-1. The findings indicate that overexpression of PR(-) GagPol, in the presence of Gag synthesis, promotes intracellular budding of the mutant virions and inhibits virus maturation.
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Overexpression and incorporation of GagPol precursor does not impede packaging of HIV-1 tRNA Lys3 but promotes intracellular budding of virus-like particles. J Biomed Sci 2002. [DOI: 10.1007/bf02254998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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The conformation of the mature dimeric human immunodeficiency virus type 1 RNA genome requires packaging of pol protein. J Virol 2002; 76:4331-40. [PMID: 11932399 PMCID: PMC155102 DOI: 10.1128/jvi.76.9.4331-4340.2002] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The packaging of a mature dimeric RNA genome is an essential step in human immunodeficiency virus type 1 (HIV-1) replication. We have previously shown that overexpression of a protease (PR)-inactive HIV-1 Gag-Pro-Pol precursor protein generates noninfectious virions that contain mainly monomeric RNA (M. Shehu-Xhilaga, S. M. Crowe, and J. Mak, J. Virol. 75:1834-1841, 2001). To further define the contribution of HIV-1 Gag and Gag-Pro-Pol to RNA maturation, we analyzed virion RNA dimers derived from Gag particles in the absence of Gag-Pro-Pol. Compared to wild-type (WT) dimeric RNAs, these RNA dimers have altered mobility and low stability under electrophoresis conditions, suggesting that the HIV-1 Gag precursor protein alone is not sufficient to stabilize the dimeric virion RNA structure. The inclusion of an active viral PR, without reverse transcriptase (RT) and integrase (IN), rescued the stability of the virion RNA dimers in the Gag particles but did not restore the mobility of the RNAs, suggesting that RT and IN are also required for virion RNA dimer maturation. Thin-section electron microscopy showed that viral particles deficient in RT and IN contain empty cone-shaped cores. The abnormal core structure indicates a requirement for Gag-Pro-Pol packaging during core maturation. Supplementing viral particles with either RT or IN via Vpr-RT or Vpr-IN alone did not correct the conformation of the dimer RNAs, whereas expression of both RT and IN in trans as a Vpr-RT-IN fusion restored RNA dimer conformation to that of the WT virus and also restored the electron-dense, cone-shaped virion core characteristic of WT virus. Our data suggest a role for RT-IN in RNA dimer conformation and the formation of the electron-dense viral core.
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Sudden permanent hearing loss following anterior inferior cerebellar artery infarction. Int J Clin Pract 2002; 56:153-4. [PMID: 11926705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Anterior inferior cerebellar artery infarction with the only sequel being a permanent unilateral hearing loss is described. The damage was confirmed by magnetic resonance imaging. Hearing loss of vascular cause may be more common and permanent than realised, and missed if the other neurological deficits have resolved.
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Proteolytic processing of the p2/nucleocapsid cleavage site is critical for human immunodeficiency virus type 1 RNA dimer maturation. J Virol 2001; 75:9156-64. [PMID: 11533179 PMCID: PMC114484 DOI: 10.1128/jvi.75.19.9156-9164.2001] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Differences in virion RNA dimer stability between mature and protease-defective (immature) forms of human immunodeficiency virus type 1 (HIV-1) suggest that maturation of the viral RNA dimer is regulated by the proteolytic processing of the HIV-1 Gag and Gag-Pol precursor proteins. However, the proteolytic processing of these proteins occurs in several steps denoted primary, secondary, and tertiary cleavage events and, to date, the processing step associated with formation of stable HIV-1 RNA dimers has not been identified. We show here that a mutation in the primary cleavage site (p2/nucleocapsid [NC]) hinders formation of stable virion RNA dimers, while dimer stability is unaffected by mutations in the secondary (matrix/capsid [CA], p1/p6) or a tertiary cleavage site (CA/p2). By introducing mutations in a shared cleavage site of either Gag or Gag-Pol, we also show that the cleavage of the p2/NC site in Gag is more important for dimer formation and stability than p2/NC cleavage in Gag-Pol. Electron microscopy analysis of viral particles shows that mutations in the primary cleavage site in Gag but not in Gag-Pol inhibit viral particle maturation. We conclude that virion RNA dimer maturation is dependent on proteolytic processing of the primary cleavage site and is associated with virion core formation.
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Abstract
BACKGROUND Lipid rafts are currently an intensely investigated topic of cell biology. In addition to a demonstrated role in signal transduction of the host cell, lipid rafts serve as entry and exit sites for microbial pathogens and toxins, such as FimH-expressing enterobacteria, influenza virus, measles virus and cholera toxin. Furthermore, caveolae, a specialised form of lipid raft, are required for the conversion of the non-pathogenic prion protein to the pathogenic scrapie isoform. OBJECTIVES A number of reports have shown, directly or indirectly, that lipid rafts are important at various stages of the human immunodeficiency virus type-1 (HIV-1) replication cycle. The purpose of this paper is to provide a brief overview of the role of membrane-associated lipid rafts in cell biology, and to evaluate how HIV-1 has hijacked this cellular component to support HIV-1 replication. Special sections are devoted to discussing the role of lipid rafts in (1) the entry of HIV-1, (2) signal transduction regulation in HIV-1-infected cells, (3) the trafficking of HIV-1 proteins via lipid rafts during HIV-1 assembly; and a further section discusses the role of cholesterol in mature HIV-1. SUMMARY Like a number of other pathogens, HIV-1 has evolved to rely on the host cell lipid rafts to support its propagation during multiple stages of the HIV-1 replication cycle. This review has highlighted the importance of lipid rafts in HIV-1 replication.
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Gag-Pol supplied in trans is efficiently packaged and supports viral function in human immunodeficiency virus type 1. J Virol 2001; 75:6835-40. [PMID: 11435562 PMCID: PMC114410 DOI: 10.1128/jvi.75.15.6835-6840.2001] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The intracellular trafficking and subsequent incorporation of Gag-Pol into human immunodeficiency virus type 1 (HIV-1) remains poorly defined. Gag-Pol is encoded by the same mRNA as Gag and is generated by ribosomal frameshifting. The multimerization of Gag and Gag-Pol is an essential step in the formation of infectious viral particles. In this study, we examined whether the interaction between Gag and Gag-Pol is initiated during protein translation in order to facilitate the trafficking and subsequent packaging of Gag-Pol into the virion. A conditional cotransfection system was developed in which virion formation required the coexpression of two HIV-1-based plasmids, one that produces both Gag and Gag-Pol and one that only produces Gag-Pol. The Gag-Pol proteins were either immunotagged with a His epitope or functionally tagged with a mutation (K65R) in reverse transcriptase that is associated with drug resistance. Gag-Pol packaging was assessed to determine whether the Gag-Pol incorporated into the virion was preferentially packaged from the plasmid that expressed both Gag and Gag-Pol or whether it could be packaged from either plasmid. Our data show that translation of Gag and Gag-Pol from the same mRNA is not critical for virion packaging of the Gag-Pol polyprotein or for viral function.
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nef-deleted HIV-1 inhibits phagocytosis by monocyte-derived macrophages in vitro but not by peripheral blood monocytes in vivo. AIDS 2001; 15:945-55. [PMID: 11399976 DOI: 10.1097/00002030-200105250-00002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE HIV-1 infection impairs a number of macrophage effector functions, but the mechanism is unknown. We studied the role of HIV-1 Nef in modulating phagocytosis by human monocytes and monocyte-derived macrophages (MDM). DESIGN AND METHODS Using a flow cytometric assay, phagocytosis of Mycobacterium avium complex (MAC) by monocytes in whole blood of Sydney Blood Bank Cohort (SBBC) members infected with a nef-deleted (Delta nef) strain of HIV-1 was compared with that of monocytes from uninfected or wild-type (WT) HIV-infected subjects. The specific impact of Nef on phagocytosis by MDM was determined by either infecting cells in vitro with Delta nef strains of HIV-1 or electroporating Nef into uninfected MDM. RESULTS MAC phagocytic capacity of monocytes from SBBC members was equivalent to that of cells from uninfected individuals (P = 0.81); it was greater than that of cells from individuals infected with WT HIV-1 (P < 0.0001), irrespective of CD4 counts and HIV viral load. In contrast, in vitro infection of MDM with either Delta nef or WT strains of HIV-1 resulted in similar levels of HIV replication and equivalent impairment of phagocytosis via Fc gamma and complement receptors. Electroporation of Nef into MDM did not alter phagocytic capacity. CONCLUSIONS This study provides evidence demonstrating the complex indirect effect of Nef on phagocytosis by peripheral blood monocytes (infrequently infected with HIV-1) in vivo. Conversely, the fact that MDM infected with either Delta nef or WT HIV-1 in vitro (high multiplicity of infection) show comparably impaired phagocytosis, indicates that HIV-1 infection of macrophages can directly impair function, independent of Nef.
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Abstract
In most human cells, the average length of telomere repeats at the ends of chromosomes provides indirect information about their mitotic history. To study the turnover of stem cells in patients with bone marrow failure syndromes, the telomere length in peripheral blood granulocytes and lymphocytes from patients with aplastic anemia (AA, n = 56) and hemolytic paroxysmal nocturnal hemoglobinuria (n = 6) was analyzed relative to age-matched controls by means of fluorescence in situ hybridization and flow cytometry. The telomere lengths in granulocytes from patients with AA were found to be significantly shorter than those in age-adjusted controls (P =.001). However, surprisingly, telomere length in granulocytes from AA patients who had recovered after immunosuppressive therapy did not differ significantly from controls, whereas untreated patients and nonresponders with persistent severe pancytopenia showed marked and significant telomere shortening. These results support extensive proliferation of hematopoietic stem cells in subgroups of AA patients. Because normal individuals show significant variation in telomere length, individual measurements in blood cells from AA patients may be of limited value. Whether sequential telomere length measurements can be used as a prognostic tool in this group of disorders remains to be clarified. (Blood. 2001;97:895-900)
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Maintenance of the Gag/Gag-Pol ratio is important for human immunodeficiency virus type 1 RNA dimerization and viral infectivity. J Virol 2001; 75:1834-41. [PMID: 11160682 PMCID: PMC114093 DOI: 10.1128/jvi.75.4.1834-1841.2001] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2000] [Accepted: 11/21/2000] [Indexed: 11/20/2022] Open
Abstract
Production of the human immunodeficiency virus type 1 (HIV-1) Gag-Pol precursor protein results from a -1 ribosomal frameshifting event. In infected cells, this generates Gag and Gag-Pol in a ratio that is estimated to be 20:1, a ratio that is conserved among retroviruses. To examine the impact of this ratio on HIV-1 replication and viral assembly, we altered the Gag/Gag-Pol ratio in virus-producing cells by cotransfecting HIV-1 proviral DNA with an HIV-1 Gag-Pol expression vector. Two versions of the Gag-Pol expression vector were used; one contains an active protease [PR(+)], and the other contains an inactive protease [PR(-)]. In an attempt to produce viral particles with Gag/Gag-Pol ratios ranging from 20:21 to 20:1 (wild type), 293T cells were cotransfected with various ratios of wild-type proviral DNA and proviral DNA from either Gag-Pol expression vector. Viral particles derived from cells with altered Gag/Gag-Pol ratios via overexpression of PR(-) Gag-Pol showed a ratio-dependent defect in their virion protein profiles. However, the defects in virion infectivity were independent of the nature of the Gag-Pol expression vector, i.e., PR(+) or PR(-). Based on equivalent input of reverse transcriptase activity, we estimated that HIV-1 infectivity was reduced 250- to 1,000-fold when the Gag/Gag-Pol ratio in the virion-producing cells was altered from 20:1 to 20:21. Although virion RNA packaging was not affected by altering Gag/Gag-Pol ratios, changing the ratio from 20:1 to 20:21 progressively reduced virion RNA dimer stability. The impact of the Gag/Gag-Pol ratio on virion RNA dimerization was amplified when the Gag-Pol PR(-) expression vector was expressed in virion-producing cells. Virions produced from cells expressing Gag and Gag-Pol PR(-) in a 20:21 ratio contained mainly monomeric RNA. Our observations provide the first direct evidence that, in addition to proteolytic processing, the ratio of Gag/Gag-Pol proteins is also important for RNA dimerization and that stable RNA dimers are not required for encapsidation of genomic RNA in HIV-1.
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Na(+)-K(+)-ATPase-mediated basolateral rubidium uptake in the maturing rabbit cortical collecting duct. Am J Physiol Renal Physiol 2000; 279:F1161-8. [PMID: 11097635 DOI: 10.1152/ajprenal.2000.279.6.f1161] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Within the renal cortical collecting duct (CCD), transepithelial Na(+) absorption and K(+) secretion are linked to basolateral Na(+)-K(+)-ATPase activity. Our purpose was to examine the developmental changes in basolateral Na(+)-K(+)-ATPase-mediated (86)rubidium (Rb) uptake, its inhibitor sensitivity and relationship to pump hydrolytic activity and Na(+) transport. Multiple CCDs ( approximately 6 mm) from maturing rabbits were affixed to coverslips, preincubated at 37 degrees C for 10 min (+/-1-2.5 mM ouabain or 10 or 100 micro M Schering-28080, an inhibitor of H(+)-K(+)-ATPase), and then transferred to prewarmed incubation solution containing tracer amounts of (86)Rb (+/-inhibitors). After 1 min at 37 degrees C, tubular samples were rinsed and permeabilized and isotope counts were measured to calculate basolateral Rb uptake. Ouabain-inhibitable Rb uptake, an index of basolateral Na(+)-K(+) pump activity, increased approximately 3-fold during the 1st 8 wk of postnatal life (P < 0.03). The approximately 2-fold increase in absolute rate of Rb uptake between 1 and 6 wk (2.64 +/- 0.45 to 5.02 +/- 0.32 pmol. min(-1). mm(-1)) did not reach statistical significance. The rate of basolateral Rb uptake increased further after the 6th wk of life to 7.29 +/- 0.53 pmol. min(-1). mm(-1) in adult animals (P < 0.03 vs. 6 wk). Schering-28080 failed to inhibit Rb uptake, implying that functional H(+)-K(+)-ATPase is absent at the basolateral membrane. Na(+)-K(+)-ATPase hydrolytic activity, determined by using a microassay that measured inorganic phosphate release from [gamma-(32)P]ATP under maximum velocity (V(max)) conditions, also increased in the differentiating CCD (from 316.2 +/- 44.4 pmol. h(-1). mm(-1) at 2 wk to 555.9 +/- 105.1 at 4 wk to 789.7 +/- 145.0 at 6 wk; r = 1.0 by linear regression analysis; P < 0.005). The parallel approximately 2.5-fold increases in Na(+)-K(+)-ATPase activity and ouabain-sensitive Rb uptake between 2- and 6-wk postnatal age suggest that the developmental increase in basolateral transport capacity is due predominantly to an increase in enzyme abundance. The signals mediating the developmental increase in Na(+)-K(+)-ATPase activity in the CCD remain to be defined.
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The practice of evidence-based medicine in an acute medical ward: retrospective study. Hong Kong Med J 2000; 6:343-8. [PMID: 11177154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
OBJECTIVE To review the practice of evidence-based medicine with respect to drug treatment given to medical in-patients. DESIGN Retrospective study. SETTING Teaching hospital, Hong Kong. PATIENTS Medical records of 129 consecutive patients who were admitted to the acute adult general medical ward from 1 September 1998 to 30 September 1998 were reviewed. MAIN OUTCOME MEASURES Primary diagnoses, drug treatments prescribed, and the level of evidence (based on a literature search of randomised controlled trials and relevant studies) that supported the treatment given. RESULTS For the 129 patients studied, 91 drug interventions had been prescribed on 312 occasions. Treatment that was supported by randomised controlled trials was prescribed in 162 (52.9%) cases. In 121 (38.8%) cases, patients were given standard and commonly used drugs that were not supported by evidence from clinical trials, and in 29 (9.3%) cases, the treatments given had no substantial supporting evidence. The management of some frequently encountered medical conditions was not based on trial data, because the relevant studies had not been conducted. CONCLUSION Basing treatment on comparative efficacy results is a worthwhile goal, but there are limitations in conducting literature searches to identify relevant trials and studies. Evidence-based medical practice is not applicable in a large number of commonly encountered conditions.
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Abstract
BACKGROUND Previous studies of the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on HIV-1 replication in macrophages have had inconsistent results, variously reporting no effect, augmentation or inhibition of viral replication. OBJECTIVE To investigate the regulation of HIV-1 in monocyte-derived macrophages (MDM) by GM-CSF in vitro. METHODS The role of GM-CSF on HIV-1 replication was assessed as supernatant and intracellular p24 antigen concentrations and by HIV-1 DNA and mRNA production under different culture conditions. Expression of CD4 and CCR5 receptors was examined. The effect of GM-CSF with an E21R mutation, which binds only to the alpha-chain of GM-CSF receptor, was used as an additional control. RESULTS GM-CSF consistently suppressed HIV-1 replication in human MDM in vitro, as assessed by supernatant and intracellular p24 antigen concentrations and HIV-1 gag mRNA expression. The inhibitory effect of GM-CSF on HIV-1 replication was observed regardless of HIV-1 strain, source of GM-CSF, stage of MDM maturation or timing of GM-CSF exposure in relation to HIV-1 infection. The effect was dose dependent and reversed by addition of a neutralizing monoclonal antibody (4D4). Flow cytometric analysis of surface expression of CD4 and CCR5 indicates that GM-CSF does not affect HIV-1 entry into MDM. Analysis of intracellular HIV-1 DNA and mRNA suggests that HIV-1 replication is inhibited at or before transcription. E21R GM-CSF had no effect on HIV-1 replication in MDM. CONCLUSIONS GM-CSF regulates HIV-1 replication in MDM, inhibiting HIV-1 replication through binding to the beta-chain of the GM-CSF receptor.
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Abstract
The potential of cloning depends in part on whether the procedure can reverse cellular aging and restore somatic cells to a phenotypically youthful state. Here, we report the birth of six healthy cloned calves derived from populations of senescent donor somatic cells. Nuclear transfer extended the replicative life-span of senescent cells (zero to four population doublings remaining) to greater than 90 population doublings. Early population doubling level complementary DNA-1 (EPC-1, an age-dependent gene) expression in cells from the cloned animals was 3.5- to 5-fold higher than that in cells from age-matched (5 to 10 months old) controls. Southern blot and flow cytometric analyses indicated that the telomeres were also extended beyond those of newborn (<2 weeks old) and age-matched control animals. The ability to regenerate animals and cells may have important implications for medicine and the study of mammalian aging.
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Granulocyte-macrophage colony-stimulating factor augments phagocytosis of Mycobacterium avium complex by human immunodeficiency virus type 1-infected monocytes/macrophages in vitro and in vivo. J Infect Dis 2000; 181:390-4. [PMID: 10608795 DOI: 10.1086/315191] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The role of human immunodeficiency virus type 1 (HIV-1) infection on the ability of human monocytes/macrophages to phagocytose Mycobacterium avium complex (MAC) in vivo and in vitro and the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on this function were investigated. By use of a flow cytometric assay to quantify phagocytosis, HIV-1 infection was found to impair the ability of monocyte-derived macrophages to phagocytose MAC in vitro, whereas GM-CSF significantly improved this defect. Phagocytosis was not altered by exposure to a mutant form of GM-CSF (E21R) binding only to the alpha chain of the GM-CSF receptor, suggesting that signaling by GM-CSF that leads to augmentation of phagocytosis is via the beta chain of the receptor. In a patient with AIDS and disseminated multidrug-resistant MAC infection, GM-CSF treatment improved phagocytosis of MAC by peripheral blood monocytes and reduced bacteremia. These results imply that GM-CSF therapy may be useful in restoring antimycobacterial function by human monocytes/macrophages.
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Abstract
The anti-colon cancer effect of dietary fibre results in part from its fermentation into the short-chain fatty acid butyric acid (BA) by intestinal microflora. BA has potent anti-colon cancer properties owing to its ability to induce apoptosis in colon cancer cells. The colon is not the only location where BA may reach high concentrations, because dietary BA is rapidly absorbed and transported to the liver. We have investigated whether BA could induce apoptosis in transformed human liver (Hep G2) cells. Hep G2 cells treated with BA displayed acetylated histones, increased DNA fragmentation and morphological features consistent with apoptosis. These biochemical features of BA-treated liver cells are identical to those of BA-treated colon cells. In addition, we investigated whether BA present in tributyrin, a triacylglycerol more compatible for inclusion into colloidal lipid structures than BA, could also induce apoptosis in Hep G2 cells. Tributyrin induced DNA fragmentation and morphological features characteristic of apoptotic cells in Hep G2 cells. These results are a significant advance towards delivering BA via colloidal lipid particles to cancerous sites in vivo. This study showed that BA and tributyrin are potent apoptotic agents, and we suggest that sources of dietary BA, such as milk fat, may provide anti-liver cancer properties.
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