26
|
Ryu S, Ali ST, Cowling BJ, Lau EHY. Effects of School Holidays on Seasonal Influenza in South Korea, 2014-2016. J Infect Dis 2020; 222:832-835. [PMID: 32277239 PMCID: PMC7399705 DOI: 10.1093/infdis/jiaa179] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 04/09/2020] [Indexed: 12/22/2022] Open
Abstract
School closures are considered as a potential nonpharmaceutical intervention to mitigate severe influenza epidemics and pandemics. In this study, we assessed the effects of scheduled school closure on influenza transmission using influenza surveillance data before, during, and after spring breaks in South Korea, 2014-2016. During the spring breaks, influenza transmission was reduced by 27%-39%, while the overall reduction in transmissibility was estimated to be 6%-23%, with greater effects observed among school-aged children.
Collapse
|
27
|
Ali ST, Wang L, Lau EHY, Xu XK, Du Z, Wu Y, Leung GM, Cowling BJ. Serial interval of SARS-CoV-2 was shortened over time by nonpharmaceutical interventions. Science 2020; 369:1106-1109. [PMID: 32694200 PMCID: PMC7402628 DOI: 10.1126/science.abc9004] [Citation(s) in RCA: 210] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
Abstract
In epidemiology, serial intervals are measured from when one infected person starts to show symptoms to when the next person infected becomes symptomatic. For any specific infection, the serial interval is assumed to be a fixed characteristic. Using valuable transmission pair data for coronavirus disease (COVID-19) in mainland China, Ali et al. noticed that the average serial interval changed as nonpharmaceutical interventions were introduced. In mid-January 2020, serial intervals were on average 7.8 days, whereas in early February 2020, they decreased to an average of 2.2 days. The more quickly infected persons were identified and isolated, the shorter the serial interval became and the fewer the opportunities for virus transmission. The change in serial interval may not only measure the effectiveness of infection control interventions but may also indicate rising population immunity. Science, this issue p. 1106 Studies of novel coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have reported varying estimates of epidemiological parameters, including serial interval distributions—i.e., the time between illness onset in successive cases in a transmission chain—and reproduction numbers. By compiling a line-list database of transmission pairs in mainland China, we show that mean serial intervals of COVID-19 shortened substantially from 7.8 to 2.6 days within a month (9 January to 13 February 2020). This change was driven by enhanced nonpharmaceutical interventions, particularly case isolation. We also show that using real-time estimation of serial intervals allowing for variation over time provides more accurate estimates of reproduction numbers than using conventionally fixed serial interval distributions. These findings could improve our ability to assess transmission dynamics, forecast future incidence, and estimate the impact of control measures.
Collapse
|
28
|
Ali ST, Wang L, Lau EHY, Xu XK, Du Z, Wu Y, Leung GM, Cowling BJ. Evolution of effective serial interval of SARS-CoV-2 by non-pharmaceutical interventions. RESEARCH SQUARE 2020. [PMID: 32702717 PMCID: PMC7336698 DOI: 10.21203/rs.3.rs-32486/v1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Studies of novel coronavirus disease (COVID-19) have reported varying estimates of epidemiological parameters such as serial intervals and reproduction numbers. By compiling a unique line-list database of transmission pairs in mainland China, we demonstrated that serial intervals of COVID-19 have shortened substantially from a mean of 7.8 days to 2.6 days within a month. This change is driven by enhanced non-pharmaceutical interventions, in particular case isolation. We also demonstrated that using real-time estimation of serial intervals allowing for variation over time would provide more accurate estimates of reproduction numbers, than by using conventional definition of fixed serial interval distributions. These findings are essential to improve the assessment of transmission dynamics, forecasting future incidence, and estimating the impact of control measures.
Collapse
|
29
|
Cowling BJ, Ali ST, Ng TWY, Tsang TK, Li JCM, Fong MW, Liao Q, Kwan MY, Lee SL, Chiu SS, Wu JT, Wu P, Leung GM. Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study. Lancet Public Health 2020; 5:e279-e288. [PMID: 32311320 DOI: 10.1101/2020.03.12.20034660] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/01/2020] [Accepted: 04/07/2020] [Indexed: 05/20/2023]
Abstract
BACKGROUND A range of public health measures have been implemented to suppress local transmission of coronavirus disease 2019 (COVID-19) in Hong Kong. We examined the effect of these interventions and behavioural changes of the public on the incidence of COVID-19, as well as on influenza virus infections, which might share some aspects of transmission dynamics with COVID-19. METHODS We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt) for COVID-19 and influenza A H1N1 to estimate changes in transmissibility over time. Attitudes towards COVID-19 and changes in population behaviours were reviewed through three telephone surveys done on Jan 20-23, Feb 11-14, and March 10-13, 2020. FINDINGS COVID-19 transmissibility measured by Rt has remained at approximately 1 for 8 weeks in Hong Kong. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% CI 34-53%) reduction in transmissibility in the community, from an estimated Rt of 1·28 (95% CI 1·26-1·30) before the start of the school closures to 0·72 (0·70-0·74) during the closure weeks. Similarly, a 33% (24-43%) reduction in transmissibility was seen based on paediatric hospitalisation rates, from an Rt of 1·10 (1·06-1·12) before the start of the school closures to 0·73 (0·68-0·77) after school closures. Among respondents to the surveys, 74·5%, 97·5%, and 98·8% reported wearing masks when going out, and 61·3%, 90·2%, and 85·1% reported avoiding crowded places in surveys 1 (n=1008), 2 (n=1000), and 3 (n=1005), respectively. INTERPRETATION Our study shows that non-pharmaceutical interventions (including border restrictions, quarantine and isolation, distancing, and changes in population behaviour) were associated with reduced transmission of COVID-19 in Hong Kong, and are also likely to have substantially reduced influenza transmission in early February, 2020. FUNDING Health and Medical Research Fund, Hong Kong.
Collapse
|
30
|
Ryu S, Ali ST, Lim JS, Chun BC. Estimation of the Excess COVID-19 Cases in Seoul, South Korea by the Students Arriving from China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E3113. [PMID: 32365703 PMCID: PMC7246702 DOI: 10.3390/ijerph17093113] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/17/2020] [Accepted: 04/25/2020] [Indexed: 01/04/2023]
Abstract
Background: In March 2020, overall, 37,000 international students from China, a country at risk of the 2019-novel coronavirus (COVID-19) infection has arrived in Seoul, South Korea. Individuals from the country at risk of COVID-19 infection have been included in the Korean home-quarantine program, but the efficacy of the program is uncertain. Methods: To estimate the possible number of infected individuals within the large influx of international students from China, we used a deterministic compartmental model for epidemic and performed a simulation-based search of different rates of compliance with home-quarantine. Results: Under the home-quarantine program, the number of the infected individuals would reach 40-72 from 12 March-24 March with the arrival of 0.2% of pre-infectious individuals. Furthermore, the number of isolated individuals would peak at 40-64 from 13 March-27 March in Seoul, South Korea. Our findings indicated when incoming international students showed strict compliance with quarantine, epidemics by the international student from China were less likely to occur in Seoul, South Korea. Conclusions: To mitigate possible epidemics, additional efforts to improve the compliance of home-quarantine of the individuals from countries with the virus risk are warranted along with other containment policies.
Collapse
|
31
|
Cowling BJ, Ali ST, Ng TWY, Tsang TK, Li JCM, Fong MW, Liao Q, Kwan MY, Lee SL, Chiu SS, Wu JT, Wu P, Leung GM. Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study. LANCET PUBLIC HEALTH 2020; 5:e279-e288. [PMID: 32311320 PMCID: PMC7164922 DOI: 10.1016/s2468-2667(20)30090-6] [Citation(s) in RCA: 713] [Impact Index Per Article: 178.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/01/2020] [Accepted: 04/07/2020] [Indexed: 02/03/2023]
Abstract
Background A range of public health measures have been implemented to suppress local transmission of coronavirus disease 2019 (COVID-19) in Hong Kong. We examined the effect of these interventions and behavioural changes of the public on the incidence of COVID-19, as well as on influenza virus infections, which might share some aspects of transmission dynamics with COVID-19. Methods We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt) for COVID-19 and influenza A H1N1 to estimate changes in transmissibility over time. Attitudes towards COVID-19 and changes in population behaviours were reviewed through three telephone surveys done on Jan 20–23, Feb 11–14, and March 10–13, 2020. Findings COVID-19 transmissibility measured by Rt has remained at approximately 1 for 8 weeks in Hong Kong. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% CI 34–53%) reduction in transmissibility in the community, from an estimated Rt of 1·28 (95% CI 1·26–1·30) before the start of the school closures to 0·72 (0·70–0·74) during the closure weeks. Similarly, a 33% (24–43%) reduction in transmissibility was seen based on paediatric hospitalisation rates, from an Rt of 1·10 (1·06–1·12) before the start of the school closures to 0·73 (0·68–0·77) after school closures. Among respondents to the surveys, 74·5%, 97·5%, and 98·8% reported wearing masks when going out, and 61·3%, 90·2%, and 85·1% reported avoiding crowded places in surveys 1 (n=1008), 2 (n=1000), and 3 (n=1005), respectively. Interpretation Our study shows that non-pharmaceutical interventions (including border restrictions, quarantine and isolation, distancing, and changes in population behaviour) were associated with reduced transmission of COVID-19 in Hong Kong, and are also likely to have substantially reduced influenza transmission in early February, 2020. Funding Health and Medical Research Fund, Hong Kong.
Collapse
|
32
|
Xu XK, Liu XF, Wang L, Ali ST, Du Z, Bosetti P, Cowling BJ, Wu Y. Household transmissions of SARS-CoV-2 in the time of unprecedented travel lockdown in China. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.03.02.20029868. [PMID: 32511615 PMCID: PMC7276042 DOI: 10.1101/2020.03.02.20029868] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Importance Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in the city of Wuhan, China, in December 2019 and then spread globally. Limited information is available for characterizing epidemiological features and transmission patterns in the regions outside of Hubei Province. Detailed data on transmission at the individual level could be an asset to understand the transmission mechanisms and respective patterns in different settings. Objective To reconstruct infection events and transmission clusters of SARS-CoV-2 for estimating epidemiological characteristics at household and non-household settings, including super-spreading events, serial intervals, age- and gender-stratified risks of infection in China outside of Hubei Province. Design Setting and Participants 9,120 confirmed cases reported online by 264 Chinese urban Health Commissions in 27 provinces from January 20 to February 19, 2020. A line-list database is established with detailed information on demographic, social and epidemiological characteristics. The infection events are categorized into the household and non-household settings. Exposures Confirmed cases of SARS-CoV-2 infections. Main Outcomes and Measures Information about demographic characteristics, social relationships, travel history, timelines of potential exposure, symptom onset, confirmation, and hospitalization were extracted from online public reports. 1,407 infection events formed 643 transmission clusters were reconstructed. Results In total 34 primary cases were identified as super spreaders, and 5 household super-spreading events were observed. The mean serial interval is estimated to be 4.95 days (standard deviation: 5.24 days) and 5.19 days (standard deviation: 5.28 days) for households and non-household transmissions, respectively. The risk of being infected outside of households is higher for age groups between 18 and 64 years, whereas the hazard of being infected within households is higher for age groups of young (<18) and elderly (>65) people. Conclusions and Relevance The identification of super-spreading events, short serial intervals, and a higher risk of being infected outside of households for male people of age between 18 and 64 indicate a significant barrier to the case identification and management, which calls for intensive non-pharmaceutical interventions (e.g. cancellation of public gathering, limited access of public services) as the potential mitigation strategies.
Collapse
|
33
|
Ali ST, Cowling BJ, Lau EHY, Fang VJ, Leung GM. Mitigation of Influenza B Epidemic with School Closures, Hong Kong, 2018. Emerg Infect Dis 2019; 24:2071-2073. [PMID: 30334723 PMCID: PMC6200008 DOI: 10.3201/eid2411.180612] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In winter 2018, schools in Hong Kong were closed 1 week before the scheduled Chinese New Year holiday to mitigate an influenza B virus epidemic. The intervention occurred after the epidemic peak and reduced overall incidence by ≈4.2%. School-based vaccination programs should be implemented to more effectively reduce influenza illnesses.
Collapse
|
34
|
Ali ST, Wu P, Cauchemez S, He D, Fang VJ, Cowling BJ, Tian L. Ambient ozone and influenza transmissibility in Hong Kong. Eur Respir J 2018; 51:13993003.00369-2018. [PMID: 29563172 DOI: 10.1183/13993003.00369-2018] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/27/2018] [Indexed: 02/02/2023]
|
35
|
Abstract
The treatment of rosacea is challenging because several pathophysiologic processes may be involved, including neurovascular dysregulation and alterations in innate immune status. Demodex mites may play a role in the latter mechanism. Topical ivermectin is a new therapeutic modality which demonstrates antiparasitic and anti-inflammatory properties. This article reviews published evidence related to the efficacy and safety of topical ivermectin. PubMed was utilized to search for key words "topical ivermectin", "ivermectin cream" and "rosacea". Three clinical trials were found that studied topical ivermectin as a treatment option for rosacea. Ivermectin was effective, safe and well tolerated.
Collapse
|
36
|
Beacham TA, Macia VM, Rooks P, White DA, Ali ST. Altered lipid accumulation in Nannochloropsis salina CCAP849/3 following EMS and UV induced mutagenesis. ACTA ACUST UNITED AC 2015; 7:87-94. [PMID: 26753128 PMCID: PMC4691955 DOI: 10.1016/j.btre.2015.05.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 05/15/2015] [Accepted: 05/29/2015] [Indexed: 11/24/2022]
Abstract
EMS and UV mutagenesis of Nannochloropsis salina combined with FACS for mutant enrichment. Productivity of EMS mutants increased by 76% and showed range of FA profile changes. Dual EMS and UV mutants accumulated 3 fold more lipid than the wild type. Elevation in lipid content comes with a cost to growth rate impacting productivity. Mutants suitable for divergent industries generated (biofuel, high value PUFA production).
Microalgae have potential as a chemical feed stock in a range of industrial applications. Nannochloropsis salina was subject to EMS mutagenesis and the highest lipid containing cells selected using fluorescence-activated cell sorting. Assessment of growth, lipid content and fatty acid composition identified mutant strains displaying a range of altered traits including changes in the PUFA content and a total FAME increase of up to 156% that of the wild type strain. Combined with a reduction in growth this demonstrated a productivity increase of up to 76%. Following UV mutagenesis, lipid accumulation of the mutant cultures was elevated to more than 3 fold that of the wild type strain, however reduced growth rates resulted in a reduction in overall productivity. Changes observed are indicative of alterations to the regulation of the omega 6 Kennedy pathway. The importance of these variations in physiology for industrial applications such as biofuel production is discussed.
Collapse
|
37
|
Ali ST, Kadi AS, Ferguson NM. Transmission dynamics of the 2009 influenza A (H1N1) pandemic in India: the impact of holiday-related school closure. Epidemics 2013; 5:157-63. [PMID: 24267871 DOI: 10.1016/j.epidem.2013.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 08/08/2013] [Accepted: 08/15/2013] [Indexed: 11/30/2022] Open
Abstract
The role of social-distancing measures, such as school closures, is a controversial aspect of pandemic mitigation planning. However, the timing of 2009 pandemic provides a natural experiment for evaluating the impact of school closure during holidays on influenza transmission. To quantify the transmission intensity of the influenza A (H1N1) pdm'09 in India, by estimating the time varying reproduction number (Rt) and correlating the temporal changes in the estimates of Rt for different regions of India with the timing of school holidays. We used daily lab-confirmed case reports of influenza A (H1N1) pdm'09 in India (during 17 May'09 to 17 May'10), stratified by regions. We estimated the transmissibility of the pandemic for different regions from these time-series, using Bayesian methods applied to a branching process model of disease spread and correlated the resulting estimates with the timing of school holidays in each region. The North-west region experienced two notable waves, with the peak of the first wave coinciding with the start of a 4 week school holiday (September-October'09). In the southern region the two waves were less clear cut, though again the first peak of the first wave coincided with the start of school holidays--albeit of less than 2 weeks duration (August'09). Our analysis suggests that the school holidays had a significant influence on the epidemiology of the 2009 pandemic in India. We estimate that school holidays reduced the reproduction number by 14-27% in different regions of India, relative to levels seen outside holiday periods. The estimates of the reproduction number obtained (with peak R values below 1.5) are compatible with those reported from other regions of the world. This work reinforces past studies showing the significant impact of school holidays on spread of 2009 pandemic virus, and by inference the role of contact patterns in children on transmission.
Collapse
|
38
|
White DA, Hird LC, Ali ST. Production and characterization of a trehalolipid biosurfactant produced by the novel marine bacterium Rhodococcus sp., strain PML026. J Appl Microbiol 2013; 115:744-55. [PMID: 23789786 DOI: 10.1111/jam.12287] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/13/2013] [Accepted: 06/16/2013] [Indexed: 11/30/2022]
Abstract
AIMS The aim of this study was to evaluate biosurfactant production by a novel marine Rhodococcus sp., strain PML026 and characterize the chemical nature and properties of the biosurfactant. METHODS AND RESULTS A novel marine bacterium (Rhodococcus species; strain PML026) was shown to produce biosurfactant in the presence of hydrophobic substrate (sunflower oil). Biosurfactant production (identified as a trehalolipid) was monitored in whole-batch cultures (oil layer and aqueous phase), aqueous phase (no oil layer) and filtered (0·2 μm) aqueous phase (no oil or cells; extracellular) and was shown to be closely associated with growth/biomass production. Extracellular trehalolipid levels increased postonset of stationary growth phase. Purified trehalolipid was able to reduce the surface tension of water to 29 mN m(-1) at Critical Micellar Concentration (CMC) of c. 250 mg l(-1) and produced emulsions that were stable to a wide range of conditions (pH 2-10, temperatures of 20-100°C and NaCl concentrations of 5-25% w/v). Separate chemical analyses of the intact trehalolipid and its constituents demonstrated the compound was in fact a mixture of homologues (>1180 MW) consisting of a trehalose moiety esterified to a series of straight chain and hydroxylated fatty acids. CONCLUSIONS The trehalolipid biosurfactant produced by the novel marine strain Rhodococcus sp. PML026 was characterized and exhibited high surfactant activity under a wide range of conditions. SIGNIFICANCE AND IMPACT OF STUDY Strain PML026 of Rhodococcus sp. is a potential candidate for bioremediation or biosurfactant production for various applications.
Collapse
|
39
|
Ali ST. Post Ejaculatory Effects of Sildenafil Citrate (Viagra) On Sexual Responses In Diabetic Neuropathic Men. SUDAN JOURNAL OF MEDICAL SCIENCES 2008. [DOI: 10.4314/sjms.v2i4.38499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
40
|
Siddiqui BS, Aslam H, Ali ST, Khan S, Begum S. Chemical constituents of Centella asiatica. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2007; 9:407-14. [PMID: 17613628 DOI: 10.1080/10286020600782454] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Studies on the chemical constituents of the aerial part of Centella asiatica have led to the isolation of three new compounds, named centellin (1), asiaticin (2), and centellicin (3). Their structures have been elucidated through spectral studies including 2D NMR experiments (HMQC, HMBC, (1)H-(1)H COSY, NOESY and J resolved).
Collapse
|
41
|
Siddiqui BS, Usmani SB, Ali ST, Begum S, Rizwani GH. Further constituents from the bark of Holarrhena pubescens. PHYTOCHEMISTRY 2001; 58:1199-1204. [PMID: 11738407 DOI: 10.1016/s0031-9422(01)00330-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three compounds, pubadysone [11 alpha-hydroxy-18,20-oxido-3-oxo-pregna-1,4,17(20)-triene] (1), puboestrene [3-acetoxy-17-oxo-1,3,5(10)-estratriene] (2) and pubamide [3,18-dioxo-11 alpha-hydroxycona-1,4-diene] (3), have been isolated from the bark of Holarrhena pubescens. Their structures have been established through spectroscopic studies.
Collapse
|
42
|
Ali ST, Krasowska AE, Murenzi R. Wigner functions from the two-dimensional wavelet group. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2000; 17:2277-2287. [PMID: 11140488 DOI: 10.1364/josaa.17.002277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Following a general procedure developed previously [Ann. Henri Poincaré 1, 685 (2000)], here we construct Wigner functions on a phase space related to the similitude group in two dimensions. Since the group space in this case is topologically homeomorphic to the phase space in question, the Wigner functions so constructed may also be considered as being functions on the group space itself. Previously the similitude group was used to construct wavelets for two-dimensional image analysis; we discuss here the connection between the wavelet transform and the Wigner function.
Collapse
|
43
|
Ali ST. Measurement of the residual urine index in insulin-dependent and non-insulin dependent diabetic men with and without neuropathy. ACTA PHYSIOLOGICA HUNGARICA 1999; 85:243-50. [PMID: 10101538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Value of the residual urine index was evaluated in 40 individuals both insulin-dependent (IDDM) and non-insulin dependent (NIDDM) diabetic male patients with and without an objective evidence of neuropathy and in 20 age matched non-diabetic men serving as controls using post void bladder ultrasonographic technique. These studies revealed striking results in the neuropathic group. Both IDDM and NIDDM diabetic patients with neuropathy exhibited a significant (P < 0.005) increase in residual-volume in comparison with the controls of the same age group and a direct correlation between residual urine retention and neurogenic bladder was found to be established thus suggesting a generalized massive hypotonia of the bladder in these patients. However, non of the two types of non-neuropathic diabetic patients showed significant difference in the above-mentioned parameters compared to that their respective controls. A non-significant association in the values of the study parameters between insulin dependent and non-insulin dependent diabetic men (with and without neuropathy) was also observed. These findings thus suggest a probable neuropathic involvement in the pathway of urinary tract in both IDDM and NIDDM diabetic men with neuropathy. The greater impairment of the values of residual urine index in these patients may be due to overall greater severity of neuropathy with sympathetic as well as parasympathetic damage irrespective of their type of diabetes.
Collapse
|
44
|
Abstract
An in vitro normal human epidermal keratinocytes (NHEK) model was used to study and to characterize the protease stimulated by the mustards 2-chloroethyl ethyl sulphide (CEES), 2-chloro-N-(2-chloroethyl)-N-methylethanamine hydrochloride (nitrogen mustard, HN2), and Bis-2-chloroethyl sulfide (sulfur mustard, HD). The results obtained by using a chromozym (TRY) peptide substrate protease assay showed the optimum mustard concentration and time for protease stimulation to be about 200 microM CEES, 100 microM HN2 or HD, and 16 hours. The mustard-stimulated protease was membrane-bound, and was inhibited by adding a Ca2+ chelator EGTA (2 mM), BAPTA AM (50 microM) or a serine protease inhibitor diisopropyl fluoro-phosphate DFP (1 mM), or a protein synthesis inhibitor cycloheximide (10 microM) in the extracellular medium. These results suggest that one of the mechanisms of mustard toxicity is via the stimulation of a trypsin/chymotrypsin like serine protease, which is dependent on Ca2+ and new protein synthesis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a mustard-stimulated approximately equal to 70-80 KDa protein band that was associated with protease activity which was inhibitable by EGTA, BAPTA, DFP or cycloheximide. This mustard-stimulated protein (protease) may serve as a diagnostic tool for mustard exposure as well as an assay for screening prospective antivesicant protease inhibitor drugs.
Collapse
|
45
|
Ali ST, Coggins JR, Jacobs HT. The study of cell-death proteins in the outer mitochondrial membrane by chemical cross-linking. Biochem J 1997; 325 ( Pt 2):321-4. [PMID: 9230109 PMCID: PMC1218563 DOI: 10.1042/bj3250321] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chemical cross-linking was used to study the interactions of the anti-cell-death protein Bcl2 with other proteins in the outer mitochondrial membrane. Cross-linking of mitochondrial surface proteins produced a large Bcl2-containing complex (>200 kDa), and a Bcl2-derived peptide was shown to cross-link specifically with a mitochondrial protein identified by immunoblotting as Raf-1 kinase.
Collapse
|
46
|
Green JD, Laue ED, Perham RN, Ali ST, Guest JR. Three-dimensional structure of a lipoyl domain from the dihydrolipoyl acetyltransferase component of the pyruvate dehydrogenase multienzyme complex of Escherichia coli. J Mol Biol 1995; 248:328-43. [PMID: 7739044 DOI: 10.1016/s0022-2836(95)80054-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The structure of a lipoyl domain from the pyruvate dehydrogenase multienzyme complex of Escherichia coli has been determined by means of nuclear magnetic resonance spectroscopy. A total of 549 nuclear Overhauser effect distance restraints, 52 phi torsion angle restraints and 16 slowly exchanging amide protons were employed as input for the structure calculations. These were performed using a combined distance geometry-simulated annealing strategy. The domain is a hybrid between the N and C-terminal halves of the first and third lipoyl domains, respectively, of the dihydrolipoyl acetyltransferase component of the E. coli multienzyme complex, representing residues 1 to 33 and 238 to 289 (wild-type numbering). The lipoyl-lysine residue was also replaced by glutamine. Nonetheless, its structure, two four-stranded beta-sheets forming a flattened beta-barrel, closely resembles that of the lipoyl domain from the pyruvate dehydrogenase multienzyme complex from Bacillus stearothermophilus determined previously. As before, the lipoylation site is physically exposed in a tight turn in one of the beta-sheets, and the N and C-terminal residues are close together at the other end of the molecule in adjacent strands of the other beta-sheet. Another prominently conserved feature of the structure is the 2-fold axis of quasi-symmetry relating the N and C-terminal halves of the domain. Consistent with the high level of sequence similarity between lipoyl domains of 2-oxo acid dehydrogenase multienzyme complexes from many different sources, these results confirm that all lipoyl domains are likely to have closely related structures.
Collapse
|
47
|
Ali ST, Shaikh RN, Siddiqui NA, Raza PQ. Estimation of nor-adrenaline content of human penile tissue in diabeticmen with/without neuropathy. PAKISTAN JOURNAL OF PHARMACEUTICAL SCIENCES 1994; 7:35-44. [PMID: 16414754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Penile tissue consisting of corps cavernosum (cc) and tunica albuginea (TA) was obtained from 35 impotent patients undergoing surgery for implantation of penile prostheses and was examined for nor adrenaline content. 10 patients were classified as a non diabetic non neuropathic group, on the basis of their clinical history and differential diagnostic symptoms which included Peyronie's disease, vascular disease, hypertension and psychogenic impotence. The nor adrenaline content was found to be significantly lower in tunica albuginea than the corpus cavernosum (P<0.02) in this group. The nor adrenaline content of corpus cavernosum from insulin dependent (IDDM) and non insulin dependent (NIDDM) diabetic neuropathic patients was also found to be significantly lower (P <0.02) than that of non diabetic non neuropathic patients. The nor adrenaline content of tunica albuginea however, was similar in both groups. A non significant association in the content of nor adrenaline in corpus cavernosum and tunica albuginea among IDDM and NIDDM diabetic neuropathics was also observed. These results provide evidence that an underlying neuropathic factor itself causes vascular as well as metabolic changes in the adrenergic nerves of the penis in diabetics due to neuropathy in addition to the effect of the disease and thus may contribute to the development of impotence in these patients irrespective of their type of diabetes.
Collapse
|
48
|
Ali ST, Duncan AM, Schappert K, Heng HH, Tsui LC, Chow W, Robinson BH. Chromosomal localization of the human gene encoding the 51-kDa subunit of mitochondrial complex I (NDUFV1) to 11q13. Genomics 1993; 18:435-9. [PMID: 8288251 DOI: 10.1006/geno.1993.1493] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The 51-kDa flavoprotein subunit of mitochondrial NADH:ubiquinone oxidoreductase (Complex I) [NADH dehydrogenase (ubiquinone), flavoprotein 1 (51 kDa); EC 1.6.5.3] plays an important role in the formation of the NADH-binding site and is believed to be the principal site of entry for electrons donated by NADH into the respiratory chain. Human cDNA fragments of the 51-kDa protein were generated by polymerase chain reaction and used to localize the gene (NDUFV1) for this subunit to 11q13 by two separate techniques. This region of the human genome is strongly implicated in a number of different forms of cancer.
Collapse
|
49
|
Ali ST, Shaikh RN, Siddiqi NA, Siddiqi PQ. Comparative studies of the induction of erectile response to film and fantasy in diabetic men with and without neuropathy. ARCHIVES OF ANDROLOGY 1993; 30:137-45. [PMID: 8498864 DOI: 10.3109/01485019308987747] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The present study deals with the diabetic neuropathies prevailing in men. In this investigation 100 insulin-dependent diabetes mellitus (IDDM) and 314 non-insulin-dependent diabetes mellitus (NIDDM) patients with and without an objective evidence of neuropathy, having an age span in between 15 and 60 years and a duration of diabetes distributed over 1-33 years, were included along with their age-matched nondiabetic controls. The diabetic subjects were evaluated for the induction of erectile responses. Investigation of induction of erectile responses to erotic stimulation by film and fantasy revealed striking results in diabetic patients with established neuropathy. Both IDDM and NIDDM patients with neuropathy exhibited a highly significant decrease (P < .0005) in penile diameter and length, penile arterial pulse amplitude, both systolic and diastolic blood pressures, and heart rate compared to controls of the same age group. However, both IDDM and NIDDM patients without neuropathy showed a nonsignificant difference in the above-mentioned parameters compared to control subjects. A nonsignificant association of induction of erectile responses to erotic stimulations among IDDM and NIDDM patients with and without neuropathy was also observed, suggesting that impotence and altered erectile responses are likely to be associated with an increased frequency to autonomic neuropathy in these patients irrespective of their type of diabetes.
Collapse
|
50
|
Ali ST, Shaikh RN, Ashfaqsiddiqi N, Siddiqi PQ. Serum and urinary levels of pituitary--gonadal hormones in insulin-dependent and non-insulin-dependent diabetic males with and without neuropathy. ARCHIVES OF ANDROLOGY 1993; 30:117-23. [PMID: 8470941 DOI: 10.3109/01485019308987744] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Diabetic neuropathies were studied in 100 insulin-dependent diabetes mellitus patients, 314 non-insulin-dependent diabetes mellitus patients with and without an objective evidence of neuropathy (age span, 15-80 years; duration of diabetes distributed over 1-33 years), and their age-matched nondiabetic controls. Serum and urinary levels of pituitary-gonadal hormones were evaluated in the diabetic subjects. There were striking results, i.e., a significantly low serum total and serum free (urinary) testosterone level (p < .0005) and a significantly high serum and urinary FSH and LH and serum prolactin level (p < .0005), specifically in the neuropathic diabetic patients, suggesting a series of pathological reactions in the smooth musculature of genital organs characterized by an increase in the interstitial thickness of seminiferous tubules, peritubular and intertubular fibrosis, and tubular sclerosis. Testicular necrosis, probably due to neuropathy, provided an additional aid to confirm these findings. A decrease in semen volume and sperm motility in the diabetic neuropathic patients further suggested the involvement of the entire smooth musculature of the reproductive tract, leading to atonia of the bladder and urethra. Such complications are purely neurogenic. The low serum and urinary testosterone levels and increased serum and urinary FSH and LH and serum prolactin levels in the diabetic men with neuropathy suggest gonadal disorder (hypogonadotropic hypogonadism), which may be due to testicular necrosis and thickening of seminiferous tubules, causing autonomic lesion.
Collapse
MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/urine
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/urine
- Diabetic Neuropathies/blood
- Diabetic Neuropathies/metabolism
- Diabetic Neuropathies/urine
- Follicle Stimulating Hormone/metabolism
- Gonadotropins, Pituitary/blood
- Gonadotropins, Pituitary/metabolism
- Gonadotropins, Pituitary/urine
- Humans
- Luteinizing Hormone/metabolism
- Male
- Middle Aged
- Prolactin/metabolism
- Testosterone/metabolism
Collapse
|