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Lau EC, Cooper C, Lam D, Chan VN, Tsang KK, Sham A. Factors associated with osteoarthritis of the hip and knee in Hong Kong Chinese: obesity, joint injury, and occupational activities. Am J Epidemiol 2000; 152:855-62. [PMID: 11085397 DOI: 10.1093/aje/152.9.855] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In 1998, a case-control study was conducted in Hong Kong on hospital patients with osteoarthritis of the hip (n = 138) and osteoarthritis of the knee (n = 658). Age- and sex-matched controls were recruited consecutively from general practice clinics in the same region. The following three risk factors were found to be associated with osteoarthritis of both the hip and the knee: first, a history of joint injury: for osteoarthritis of the hip, the odds ratio = 25.1 (95% confidence interval (CI): 3.5, 181) in men and 43.3 (95% CI: 11.7, 161) in women; for osteoarthritis of the knee, the odds ratio = 12.1 (95% CI: 3.4, 42.5) in men and 7.6 (95% CI: 3.8, 15.2) in women; second, climbing stairs frequently: for osteoarthritis of the hip, the odds ratio = 12.5 (95% CI: 1.5, 104.3) in men and 2.3 (95% CI: 0.6, 8.1) in women; for osteoarthritis of the knee, the odds ratio = 2.5 (95% CI: 1.0, 6.4) in men and 5.1 (95% CI: 2.5, 10.2) in women; third, lifting heavy weight frequently: for osteoarthritis of the hip, the odds ratio = 3.1 (95% CI: 0.7, 14.3) in men and 2.4 (95% CI: 1.1, 5.3) in women; for osteoarthritis of the knee, the odds ratio = 5.4 (95% CI: 2.4, 12.4) in men and 2.0 (95% CI: 1.2, 3.1) in women. In addition, subjects whose height and weight were in the highest quartile were at increased risk of osteoarthritis of the hip and knee, respectively (p < 0.05).
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139 |
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Houang E, Lam D, Fan D, Seal D. Microbial keratitis in Hong Kong: relationship to climate, environment and contact-lens disinfection. Trans R Soc Trop Med Hyg 2001; 95:361-7. [PMID: 11579873 DOI: 10.1016/s0035-9203(01)90180-4] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Microbial keratitis has been studied in Hong Kong as a representative sub-tropical climate of south China. An 18-month investigation in 1997/98 of 223 cases of ulcerative keratitis (presumed microbial) was conducted in the 2 million population of Shatin and Kowloon at the Prince of Wales and Hong Kong Eye Hospitals respectively with comprehensive microbiology. A case-control study was pursued at the same time between 45 contact-lens wearers (CLW) developing microbial keratitis and 135 lens-wearing volunteers matched for age, sex, educational status and visual acuity. Home water supplies were sampled for Acanthamoeba. Previous ocular surface disease and trauma (preventable by wearing goggles for grinding) were common predisposing causes while cosmetic wear of contact lenses was responsible for 26% of cases overall. Pseudomonas aeruginosa was the commonest bacterium isolated, from both CLW and non-CLW, with infection being acquired within the community. These 28 pseudomonads remained fully sensitive to the third-generation cephalosporins, aminoglycosides and quinolone antibiotics, which is very encouraging. Fungi were isolated, predominantly Fusarium sp., but less commonly than expected. A fungal/bacterial ratio was obtained of 1/17, while in comparison, the expected ratio for a tropical climate ranges from 1/5 (Singapore) to 1/2 (South India). Acanthamoeba was the second commonest microbe isolated from keratitis of CLW. The domestic water environment of 8% of homes of both patients and controls wearing contact lenses was colonized with Acanthamoeba. Lack of hygiene, use of tap water for storing lenses, failure to air-dry lens-storage cases or use of one-step hydrogen peroxide disinfectant were identified as risk factors for keratitis in CLW. The study results commend use of multipurpose solutions by CLW in Hong Kong to achieve the lowest expected rates of infection.
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Reid G, Denstedt JD, Kang YS, Lam D, Nause C. Microbial adhesion and biofilm formation on ureteral stents in vitro and in vivo. J Urol 1992; 148:1592-4. [PMID: 1433574 DOI: 10.1016/s0022-5347(17)36976-8] [Citation(s) in RCA: 126] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Thirty ureteral stents, inserted for 5 to 128 days following extracorporeal shock wave lithotripsy, were examined for the presence of bacterial biofilms. Of these, 90% had adherent pathogens (44% mixed organisms) on the stents, 45% of which were present in low numbers (10(1)-10(2) per 1 cm3 section) and 55% were in small and large microcolony biofilms (> 2 x 10(2)-10(7)). The organisms were recovered from the stents even though urine culture was only positive in 27% of patients. Of the organisms isolated, 77% were Gram positive cocci, 15% Gram negative rods and 8% Candida. No blockage of the stents occurred. All of the patients had received antimicrobial therapy post-insertion, and in 15 cases biofilms were found while on treatment. None of the patients received therapy for urinary tract infections while the stent remained in place. In vitro experiments demonstrated the ability of Escherichia coli, Proteus mirabilis, Staphylococcus epidermidis and Enterococcus faecalis uropathogens to adhere and form biofilms on ureteral stents within 24 hours. Clearly, bacterial biofilms do occur on ureteral stents and urinary culture may not detect their presence. The high recovery rate of Gram positive organisms may indicate a preferential adhesion to the biomaterial surface. The findings also indicate that unlike biofilm formation on many other prosthetic implants, colonization with Gram positive organisms on ureteral stents does not necessarily coincide with the development symptomatic infection.
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Abstract
BACKGROUND Ruminating when depressed is thought to lower mood and impair problem-solving, while distraction is thought to alleviate mood and assist problem-solving. The present study investigates each of these proposals using both naturally occurring and experimentally induced rumination and distraction in a sample of patients with major depression. METHOD Thirty-six patients with major depression and 36 control participants were randomly allocated to either a rumination or distraction induction condition. Levels of trait rumination and distraction were measured at baseline, mood and problem-solving were measured before and after the inductions. RESULTS In terms of trait measures, depressed patients with higher levels of trait rumination reported poorer mood and gave less effective problem solutions than those who were less ruminative. Trait distraction was not associated with mood or problem-solving. In terms of induced responses, depressed patients who were made to ruminate experienced a deterioration in their mood and gave poorer problem solutions. For those receiving the distraction induction, mood improved in all patients and problem-solving improved in patients who were not naturally ruminating at a high level. Neither induction had an impact on mood or problem-solving in control participants. CONCLUSIONS Treatment for depression associated with adverse life events may need to target rumination as well as problem-solving deficits if interventions are to be effective. The differential effects of self-applied versus experimentally induced distraction require further investigation. Future research will need to consider that high levels of trait rumination may interfere with the impact of experimental inductions.
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Abstract
BACKGROUND Patients suffering from bipolar affective disorders are generally reported to be able to detect prodromes. Insight is also said to be desirable for a good outcome. However, very little is known about the effect of insight and patients' spontaneous strategies for coping with prodromes on their social functioning. METHOD In a cross-sectional study 40 bipolar patients, who were not in an acute episode, were interviewed about their prodromes of depression and mania, their coping strategies for these prodromes, their levels of insight and their levels of social functioning. RESULTS A quarter of subjects reported that they could not detect any early warnings of depression compared with only 7.5% of subjects who reported that they could not detect prodromes of mania. Subjects reported both spontaneous cognitive and behavioural strategies for coping with prodromes of depression but only behavioural strategies for prodromes of mania. Subjects' current levels of depression, how they coped with prodromes of mania and their ability to recognize early warnings for depression contributed significantly to their level of social functioning. Insight also had a weaker but significant contribution. CONCLUSION No causal link was made in this study. However, it did show that patients' level of social functioning was related to their level of insight, and to how well they coped with the prodromes of mania and whether they could detect prodromes of depression. The results suggest that it is worth exploring ways of teaching patients to monitor their moods and to promote insight and good strategies for coping with their prodromes.
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Pimenta de Castro I, Costa AC, Lam D, Tufi R, Fedele V, Moisoi N, Dinsdale D, Deas E, Loh SHY, Martins LM. Genetic analysis of mitochondrial protein misfolding in Drosophila melanogaster. Cell Death Differ 2012; 19:1308-16. [PMID: 22301916 PMCID: PMC3392634 DOI: 10.1038/cdd.2012.5] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Protein misfolding has a key role in several neurological disorders including Parkinson's disease. Although a clear mechanism for such proteinopathic diseases is well established when aggregated proteins accumulate in the cytosol, cell nucleus, endoplasmic reticulum and extracellular space, little is known about the role of protein aggregation in the mitochondria. Here we show that mutations in both human and fly PINK1 result in higher levels of misfolded components of respiratory complexes and increase in markers of the mitochondrial unfolded protein response. Through the development of a genetic model of mitochondrial protein misfolding employing Drosophila melanogaster, we show that the in vivo accumulation of an unfolded protein in mitochondria results in the activation of AMP-activated protein kinase-dependent autophagy and phenocopies of pink1 and parkin mutants. Parkin expression acts to clear mitochondria with enhanced levels of misfolded proteins by promoting their autophagic degradation in vivo, and refractory to Sigma P (ref(2)P), the Drosophila orthologue of mammalian p62, is a critical downstream effector of this quality control pathway. We show that in flies, a pathway involving pink1, parkin and ref(2)P has a role in the maintenance of a viable pool of cellular mitochondria by promoting organellar quality control.
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Research Support, Non-U.S. Gov't |
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Smith N, Lam D, Bifulco A, Checkley S. Childhood Experience of Care and Abuse Questionnaire (CECA.Q). Validation of a screening instrument for childhood adversity in clinical populations. Soc Psychiatry Psychiatr Epidemiol 2002; 37:572-9. [PMID: 12545234 DOI: 10.1007/s00127-002-0589-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Interview measures for investigating adverse childhood experiences, such as the Childhood Experience of Care and Abuse (CECA) instrument, are comprehensive and can be lengthy and time-consuming. A questionnaire version of the CECA (CECA.Q) has been developed which could allow for screening of individuals in research settings. This would enable researchers to identify individuals with adverse early experiences who might benefit from an in-depth interview. This paper aims to validate the CECA.Q against the CECA interview in a clinical population. METHODS One hundred and eight patients attending an affective disorders service were assessed using both the CECA interview and questionnaire measures. A follow-up sample was recruited 3 years later and sent the questionnaire. The questionnaire was also compared with the established Parental Bonding Instrument (PBI). RESULTS Agreement between ratings on the interview and questionnaire were high. Scales measuring antipathy and neglect also correlated highly with the PBI. The follow-up sample revealed the questionnaire to have a high degree of reliability over a long period of time. CONCLUSIONS The CECA.Q appears to be a reliable and valid measure which can be used in research on clinical populations to screen for individuals who have experienced severe adversity in childhood.
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Validation Study |
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Lam D, Wong G, Sham P. Prodromes, coping strategies and course of illness in bipolar affective disorder--a naturalistic study. Psychol Med 2001; 31:1397-1402. [PMID: 11722154 DOI: 10.1017/s003329170100472x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Psychosocial interventions for bipolar patients often include teaching patients to recognize prodromal symptoms and tackle them early. This prospective study set out to investigate which bipolar prodromal symptoms were reported frequently and reliably over a period of 18 months. Furthermore, we have also investigated which types of coping strategies were related to good outcome. METHOD Forty bipolar patients were interviewed for their bipolar prodromal symptoms and their coping strategies at recruitment and 18 months later. Patients were also assessed as to whether they had experienced relapses. RESULTS Bipolar patients were able to report bipolar prodromal symptoms reliably. Mania prodromal symptoms tended to be behavioural symptoms. A quarter of patients reported difficulties in detecting depression prodromes, which tended to be more diverse and consisted of a mix of behavioural, cognitive and somatic symptoms. Significantly fewer patients who reported the use of behavioural coping strategies to curb excessive behaviour during the mania prodromal stage experienced a manic episode. Similarly, significantly fewer patients who reported the use of behavioural coping strategies experienced depression relapses. How well patients coped with mania prodromes predicted bipolar episodes significantly when the mood levels at baseline were controlled. Ratings of how well subjects coped with mania prodromal symptoms also predicted manic symptoms significantly at T2 when manic symptom at T1 was controlled. CONCLUSION Our study suggests that bipolar patients are able to report prodromal symptoms reliably. It is advisable to teach patients to monitor their moods systematically and to promote good coping strategies.
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Lam D, Smith N, Checkley S, Rijsdijk F, Sham P. Effect of neuroticism, response style and information processing on depression severity in a clinically depressed sample. Psychol Med 2003; 33:469-479. [PMID: 12701667 DOI: 10.1017/s0033291702007304] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND It is postulated that individuals who score high on neuroticism would ruminate when faced with stress. A ruminative response style to depression is associated with faulty attribution and higher dysfunctional beliefs, which in turn is associated with a higher level of depression and hopelessness. Distraction is associated with less severe depression. Evidence supporting these hypotheses mainly comes from a non-clinical population. Hence it is not clear if these theories apply to clinical depression. METHOD One hundred and nine out-patients suffering from unipolar major depressive disorder were recruited to test these theories, using model-fitting analysis technique. RESULTS Certain rumination responses to depression were associated with higher levels of depression and hopelessness, faulty attribution and dysfunctional attitudes when gender and the level of depression were controlled. Principal component analysis of the Rumination Scale yielded four factors: 'symptom-based rumination', 'isolation/introspection', 'self-blame' and 'analyse to understand'. Unlike the other factors, 'analyse to understand' did not correlate with the level of depression. Model fitting analysis, though not reflecting entirely the true model, captures most of the hypothesized relationships between important variables. Neuroticism was associated with stress. Rumination was associated with an increased level of dysfunctional beliefs and faulty attribution, which in turn was associated with increased severity of depression. Distraction, in contrast, was associated with lower levels of negative mood. CONCLUSION The results of our study support the importance of teaching depressed patients to manage their depressive symptoms by avoiding rumination about their symptoms and engaging in distracting and pleasurable activities.
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Levine JD, Lam D, Taiwo YO, Donatoni P, Goetzl EJ. Hyperalgesic properties of 15-lipoxygenase products of arachidonic acid. Proc Natl Acad Sci U S A 1986; 83:5331-4. [PMID: 3014543 PMCID: PMC323945 DOI: 10.1073/pnas.83.14.5331] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Induction of hyperalgesia by leukotriene B4 (LTB4), a potent chemotactic factor for polymorphonuclear leukocytes (PMNLs), depends on the generation by cutaneous PMNLs of mediators that are probably derived from the 15-lipoxygenation of arachidonic acid. The capacity of dihydroxyeicosatetraenoic acid (diHETE) products of the 15-lipoxygenation of arachidonic acid in PMNL to elicit hyperalgesia was evaluated by assessing the effects of intradermal injection of synthetic diHETEs on the pressure nociceptive threshold in rats. (8R,15S)-Dihydroxyeicosa-(5E-9,11,13Z)-tetraenoic acid [(8R,15S)-diHETE] produced a dose-dependent hyperalgesia, as measured by decrease in threshold for paw withdrawal. The isomer (8S,15S)-diHETE antagonized in a dose-dependent manner this hyperalgesia due to (8R,15S)-diHETE but did not suppress prostaglandin E2-induced hyperalgesia. (8S,15S)-DiHETE produced a dose-dependent hypoalgesia, as reflected by an increase in nociceptive threshold, suggesting a contribution of endogenous (8R,15S)-diHETE to normal nociceptive threshold. The hypoalgesic effect of (8S,15S)-diHETE was blocked by corticosteroids but not by the cyclooxygenase inhibitor indomethacin. Neither (8R,15S)-dihydroxyeicosa-(5,15E-9,11Z)-tetraenoic acid nor (8R,15S)-dihydroxyeicosa-(5,11E-9,13Z)-tetraenoic acid exhibited any hyperalgesic or hypoalgesic activity. The stereospecificity of the effect of (8R,15S)-diHETE suggests that the induction of hyperalgesia is a receptor-dependent phenomenon and that (8S,15S)-diHETE may be an effective receptor-directed antagonist. The (8R,15S)-diHETE and (8S,15S)-diHETE from PMNL, keratinocytes, and other epithelial cells may modulate normal primary afferent function and contribute to inflammatory hyperalgesia.
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research-article |
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Abstract
OBJECTIVE To estimate the prevalence of hip osteoarthritis (OA hip) and hip dysplasia in a sample of Hong Kong men who were unselected with respect to hip symptoms. METHODS The postmicturition films of 999 men aged 60-75 years, consecutive attenders for intravenous urography between 1987 and 1990 at a regional hospital, were reviewed. OA hip was diagnosed as the occurrence of two or more features of OA using a modified version of the Kellgren and Lawrence scale, or a minimal joint space of 1.5 mm or less. Hip dysplasia was defined as a centre-edge angle of less than 25 degrees, or an acetabular depth of less than 9 mm. The results were compared with British data obtained by similar methods. RESULTS In the Hong Kong sample, the proportion of men with two or more features of osteoarthritis in at least one hip was about 50% that of the men in the British study (5.4% and 11.0%, respectively). Severe joint space narrowing (of 1.5 mm or less) occurred in 0.7% of the hips in Hong Kong men, compared with 2% in the British men. The proportion of hips with centre-edge angles less than 25 degrees was 4.5% in Hong Kong, compared with 3.6% in Britain, and the prevalence of shallow acetabular depth was greater in Chinese (14.5%) than in the British (2.1%). Radiographic measures of hip dysplasia were not associated with minimal joint space. CONCLUSIONS Our results have confirmed the lower prevalence of radiographic hip osteoarthritis in Hong Kong men compared with British men. However, acetabular dysplasia was as prevalent among Chinese men as in the British sample. This is evidence against the hypothesis that variations in the frequency of hip osteoarthritis are caused by differences in the occurrence of hip dysplasia.
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Comparative Study |
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74 |
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Lau EM, Cooper C, Fung H, Lam D, Tsang KK. Hip fracture in Hong Kong over the last decade--a comparison with the UK. JOURNAL OF PUBLIC HEALTH MEDICINE 1999; 21:249-50. [PMID: 10528950 DOI: 10.1093/pubmed/21.3.249] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Hip fracture is a major public health problem in Asia and the UK. The objectives of this study were to describe the trends of hip fracture in Hong Kong over the last decade, and to compare the incidence in Hong Kong with that from the Wessex Health Region of the UK in 1995. METHODS The number of hip fractures was calculated using hospital discharge records for all public hospitals in Hong Kong in 1991 and 1995. Age-specific incidence rates were then calculated using the mid-year census population for the two years. These rates were presented with previously reported age-specific rates for Hong Kong in 1966 and 1985. These age-specific rates for Hong Kong in 1995 were compared with rates for the Wessex Health Region of the UK. The total number of hip fracture expected in 2010 was calculated by applying the age-specific rates of 1995 to the projected population for 2010. RESULTS In 1995, a total of 1138 men and 2782 women in Hong Kong fractured their hip. The age-specific rates had remained static from 1985 to 1995, after substantial rise from 1966 to 1985. In 1995, the rates of hip fracture rates were 11/1000 in women and 5/1000 in men who were 70 years and older. These rates were almost identical to those observed in the Wessex Health Region of the UK. CONCLUSION The age-specific incidence rates of hip fracture had not risen in Hong Kong in the last decade. The incidence of hip fracture in Hong Kong was similar to that in the UK in 1995. The total number of patients with hip fracture in Hong Kong will increase substantially in the future, as a result of the ageing of the population.
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Comparative Study |
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Reid G, Hsiehl J, Potter P, Mighton J, Lam D, Warren D, Stephenson J. Cranberry juice consumption may reduce biofilms on uroepithelial cells: pilot study in spinal cord injured patients. Spinal Cord 2001; 39:26-30. [PMID: 11224011 DOI: 10.1038/sj.sc.3101099] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
STUDY DESIGN A pilot study of 15 spinal cord injured patients. OBJECTIVE To determine whether alteration of fluid intake and use of cranberry juice altered the bacterial biofilm load in the bladder. SETTING London, Ontario, Canada. METHODS Urine samples were collected on day 0 (start of study), on day 7 following each patient taking one glass of water three times daily in addition to normal diet, and on day 15 following each patient taking one glass of cranberry juice thrice daily. One urine sample was sent for culture and a second processed to harvest, examine by light microscopy and Gram stain non-squamous uroepithelial cells to generate bacterial adhesion per 50 cells data. RESULTS The results showed that cranberry juice intake significantly reduced the biofilm load compared to baseline (P=0.013). This was due to a reduction in adhesion of Gram negative (P=0.054) and Gram positive (P=0.022) bacteria to cells. Water intake did not significantly reduce the bacterial adhesion or biofilm presence. CONCLUSION The findings provide evidence in support of further, larger clinical trials into the use of functional foods, particularly cranberry juice, to reduce the risk of UTI in a patient population highly susceptible to morbidity and mortality associated with drug resistant uropathogens. SPONSORSHIP This study was funded by Ocean Spray Cranberries, Lakeville, MA, USA.
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Clinical Trial |
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59 |
14
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Parker KN, Chhabra SR, Lam D, Callen W, Duffaud GD, Snead MA, Short JM, Mathur EJ, Kelly RM. Galactomannanases Man2 and Man5 from Thermotoga species: growth physiology on galactomannans, gene sequence analysis, and biochemical properties of recombinant enzymes. Biotechnol Bioeng 2001; 75:322-33. [PMID: 11590605 DOI: 10.1002/bit.10020] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The enzymatic hydrolysis of mannan-based hemicelluloses is technologically important for applications ranging from pulp and paper processing to food processing to gas and oil well stimulation. In many cases, thermostability and activity at elevated temperatures can be advantageous. To this end, the genes encoding beta-mannosidase (man2) and beta-mannanase (man5) from the hyperthermophilic bacteria Thermotoga neapolitana 5068 and Thermotoga maritima were isolated, cloned, and expressed in Escherichia coli. The amino acid sequences for the mannosidases from these organisms were 77% identical and corresponded to proteins with an M(r) of approximately 92 kDa. The translated nucleotide sequences for the beta-mannanase genes (man5) encoded polypeptides with an M(r) of 76 kDa that exhibited 84% amino acid sequence identity. The recombinant versions of Man2 and Man5 had similar respective biochemical and biophysical properties, which were also comparable to those determined for the native versions of these enzymes in T. neapolitana. The optimal temperature and pH for the recombinant Man2 and Man5 from both organisms were approximately 90 degrees C and 7.0, respectively. The presence of Man2 and Man5 in these two Thermotoga species indicates that galactomannan is a potential growth substrate. This was supported by the fact that beta-mannanase and beta-mannosidase activities were significantly stimulated when T. neapolitana was grown on guar or carob galactomannan. Maximum cell densities increased by at least tenfold when either guar or carob galactomannan was added to the growth medium. For T. neapolitana grown on guar at 83 degrees C, Man5 was secreted into the culture media, whereas Man2 was intracellular. These localizations were consistent with the presence and lack of signal peptides for Man5 and Man2, respectively. The identification of the galactomannan-degrading enzymes in these Thermotoga species adds to the list of biotechnologically important hemicellulases produced by members of this hyperthermophilic genera.
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Lam DT, Ngan Kee WD, Khaw KS. Extension of epidural blockade in labour for emergency Caesarean section using 2% lidocaine with epinephrine and fentanyl, with or without alkalinisation. Anaesthesia 2001; 56:790-4. [PMID: 11493247 DOI: 10.1046/j.1365-2044.2001.02058-4.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In a randomised, double-blind study, we investigated rapid extension of epidural analgesia to surgical anaesthesia for emergency Caesarean section. Parturients receiving epidural analgesia in labour who subsequently required Caesarean section were given a test dose of 3 ml lidocaine 2% with epinephrine 1 : 200 000, followed 3 min later by 12 ml lidocaine 2% with epinephrine 1 : 200 000 and fentanyl 75 microg, to which was added 1.2 ml sodium bicarbonate 8.4% (bicarbonate group; n = 20) or saline (saline group; n = 20). Mean (SD [range]) time to surgical anaesthesia was less in the bicarbonate group (5.2 (1.5) [2-8] min) than the saline group (9.7 (1.6) [6-12] min; mean difference 4.5 min (95% CI 3.5-5.5) min; p < 0.001). Maternal side-effects and neonatal outcome were similar between groups. We conclude that pH-adjusted lidocaine 2% with epinephrine and fentanyl is effective for rapidly establishing surgical anaesthesia in patients with a functioning epidural catheter for labour who require emergency Caesarean section.
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Clinical Trial |
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Woo J, Lau E, Lau CS, Lee P, Zhang J, Kwok T, Chan C, Chiu P, Chan KM, Chan A, Lam D. Socioeconomic impact of osteoarthritis in Hong Kong: utilization of health and social services, and direct and indirect costs. ARTHRITIS AND RHEUMATISM 2003; 49:526-34. [PMID: 12910559 DOI: 10.1002/art.11198] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE To determine the direct and indirect cost of osteoarthritis (OA) according to disease severity, and to estimate the total cost of the disease in Hong Kong. METHODS This study is a retrospective, cross-sectional, nonrandom, cohort design, with subjects stratified according to disease severity based on functional limitation and the presence or absence of joint prosthesis. Subjects were recruited from primary care, geriatric medicine, rheumatology, and orthopedic clinics. There were 219 patients in the mild disease category, 290 patients in the severe category, and 65 patients with joint replacement. A questionnaire gathered information on demographic and socioeconomic characteristics, function limitation, use of health and social services, and effect on occupation and living arrangements over the previous 12 months. Costs were calculated as direct and indirect. RESULTS Low education and socioeconomic class were associated with more severe disease. OA affected family or close relationships in 44%. The average cost incurred as a result of side effects of medication is similar to the average cost of medication itself. Excluding joint replacement, the direct costs ranged from Hong Kong (HK) dollar $11,690 to $40,180 per person per year and indirect costs, HK $3,300-$6,640. The direct costs are comparable to those reported in Western countries; however, the ratio of direct to indirect costs is much higher than 1, in contrast to the greater indirect versus direct costs reported in whites. The total cost expressed as a percentage of gross national product is also much lower in Hong Kong. CONCLUSIONS The socioeconomic impact of OA in the Hong Kong population is comparable to Western countries, but the economic burden is largely placed on the government, with patients having relatively low out-of-pocket expenditures.
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Abstract
BACKGROUND Laparoscopic cholecystectomy is still done mainly on an inpatient basis at hospitals or on an outpatient basis at ambulatory care departments inside hospitals. STUDY DESIGN We reviewed 213 cases in which outpatient laparoscopic cholecystectomy was done at an ambulatory surgical center not associated with a hospital physically or administratively. Patients were selected solely on the basis of medical history and physical examination results. Patients received general anesthesia as is typical for outpatient procedures. Narcotic use was minimized to prevent postoperative nausea. The procedure did not include intraoperative cholangiography. RESULTS Laparoscopic cholecystectomy took 1 to 2 hours in three quarters of patients. Rate of conversion to open cholecystectomy was 2.8% (6 of 213 patients). The mean recovery period was 6.6 hours, and 97% of patients were discharged on the same day (ie, were treated as outpatients). We identified no cases of retained common duct stone. Wound complications included mainly seroma, wound seepage, and wound infection; 18% of these complications were seen at trocar sites. No major complications were seen. CONCLUSIONS Elective outpatient laparoscopic cholecystectomy can be done safely with low morbidity, high patient acceptance, and same-day discharge in > 95% of cases.
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Özdemir-van Brunschot DMD, Braat AE, van der Jagt MFP, Scheffer GJ, Martini CH, Langenhuijsen JF, Dam RE, Huurman VA, Lam D, d'Ancona FC, Dahan A, Warlé MC. Deep neuromuscular blockade improves surgical conditions during low-pressure pneumoperitoneum laparoscopic donor nephrectomy. Surg Endosc 2017. [PMID: 28643056 PMCID: PMC5770501 DOI: 10.1007/s00464-017-5670-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background Evidence indicates that low-pressure pneumoperitoneum (PNP) reduces postoperative pain and analgesic consumption. A lower insufflation pressure may hamper visibility and working space. The aim of the study is to investigate whether deep neuromuscular blockade (NMB) improves surgical conditions during low-pressure PNP. Methods This study was a blinded randomized controlled multicenter trial. 34 kidney donors scheduled for laparoscopic donor nephrectomy randomly received low-pressure PNP (6 mmHg) with either deep (PTC 1–5) or moderate NMB (TOF 0–1). In case of insufficient surgical conditions, the insufflation pressure was increased stepwise. Surgical conditions were rated by the Leiden-Surgical Rating Scale (L-SRS) ranging from 1 (extremely poor) to 5 (optimal). Results Mean surgical conditions were significantly better for patients allocated to a deep NMB (SRS 4.5 versus 4.0; p < 0.01). The final insufflation pressure was 7.7 mmHg in patients with deep NMB as compared to 9.1 mmHg with moderate NMB (p = 0.19). The cumulative opiate consumption during the first 48 h was significantly lower in patients receiving deep NMB, while postoperative pain scores were similar. In four patients allocated to a moderate NMB, a significant intraoperative complication occurred, and in two of these patients a conversion to an open procedure was required. Conclusions Our data show that deep NMB facilitates the use of low-pressure PNP during laparoscopic donor nephrectomy by improving the quality of the surgical field. The relatively high incidence of intraoperative complications indicates that the use of low pressure with moderate NMB may compromise safety during LDN. Clinicaltrials.gov identifier: NCT 02602964.
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Randomized Controlled Trial |
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Salum MR, Lam DT, Wexner SD, Pikarsky A, Baig MK, Weiss EG, Nogueras JJ, Singh JJ. Does limited placement of bioresorbable membrane of modified sodium hyaluronate and carboxymethylcellulose (Seprafilm) have possible short-term beneficial impact? Dis Colon Rectum 2001; 44:706-12. [PMID: 11357033 DOI: 10.1007/bf02234571] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The aim of the study was to assess the impact of sodium hyaluronate and carboxymethylcellulose membrane (Seprafilm) on postoperative intestinal obstruction as judged by the rates of bowel obstruction and laparotomy for bowel obstruction. A secondary aim was to assess early postoperative morbidity. METHODS All patients who had Seprafilm placed during colorectal surgery between June 1993 and October 1998 were included in the study group and compared with a matched group of patients without Seprafilm. All patients were assessed for intestinal obstruction and complications by telephone interview and chart review. Statistical tests for independence were used where appropriate; alpha was 0.05 for all tests, and the two groups were tested for case matching. Fisher's exact test was used to compare gender distribution, nature of diagnosis (inflammatory vs. noninflammatory), and urgency of surgery (elective vs. emergency). The age distribution, number of prior abdominal surgeries, and operative time were compared by Student's t-test. Approximation of Katz test was used for independent proportions to compare the two groups for early postoperative morbidity and overall incidence of intestinal obstruction and surgical enterolysis. The incidence of intestinal obstruction between the two groups was also compared with Kaplan-Meier product limit method and log-rank test. RESULTS Two hundred fifty-nine patients in whom Seprafilm was placed were compared with a well-matched control cohort of 179 patients. The two groups did not differ in gender or age. One-half of each group had inflammatory conditions, and approximately 90 percent of each group underwent elective operations. The operative times were similar. Both groups had a similar number of abdominal operations before inclusion (mean = 1.2, both groups). Early morbidity rates were 17.8 percent for the Seprafilm group and 15.6 percent for the controls, with mortality rates of 0.8 percent and 0.0 percent, respectively. There were 12 intestinal obstructions in 12 patients in the Seprafilm group and 12 intestinal obstructions in 11 patients in the control group at a follow-up period of 65 months in the Seprafilm group and 81 months in the control group. Eight of the 12 intestinal obstructions in the Seprafilm group resolved with conservative management while only 5 of 12 in the control group responded without surgery. Thus the enterolysis rate was 1.5 percent in the Seprafilm group and 3.9 percent in the control group, demonstrating a trend in favor of Seprafilm. There were no statistically significant differences in the incidence of either overall or abdominopelvic septic complications between the Seprafilm (3.4 percent) and control (1.1 percent) groups. CONCLUSION During short-term follow-up in this nonprospective, nonrandomized study, limited placement of Seprafilm did not significantly reduce the need for surgical enterolysis for intestinal obstruction or significantly adversely affect the morbidity rate. However, a long-term, prospective, randomized trial is underway to elucidate these issues.
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Laporte C, Kosta A, Klein G, Aubry L, Lam D, Tresse E, Luciani MF, Golstein P. A necrotic cell death model in a protist. Cell Death Differ 2006; 14:266-74. [PMID: 16810325 DOI: 10.1038/sj.cdd.4401994] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
While necrotic cell death is attracting considerable interest, its molecular bases are still poorly understood. Investigations in simple biological models, taken for instance outside the animal kingdom, may benefit from less interference from other cell death mechanisms and from better experimental accessibility, while providing phylogenetic information. Can necrotic cell death occur outside the animal kingdom? In the protist Dictyostelium, developmental stimuli induced in an autophagy mutant a stereotyped sequence of events characteristic of necrotic cell death. This sequence included swift mitochondrial uncoupling with mitochondrial 2',7'-dichlorofluorescein diacetate fluorescence, ATP depletion and increased oxygen consumption. This was followed by perinuclear clustering of dilated mitochondria. Rapid plasma membrane rupture then occurred, which was evidenced by time-lapse videos and quantified by FACS. Of additional interest, developmental stimuli and classical mitochondrial uncouplers triggered a similar sequence of events, and exogenous glucose delayed plasma membrane rupture in a nonglycolytic manner. The occurrence of necrotic cell death in the protist Dictyostelium (1) provides a very favorable model for further study of this type of cell death, and (2) strongly suggests that the mechanism underlying necrotic cell death was present in an ancestor common to the Amoebozoa protists and to animals and has been conserved in evolution.
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Research Support, Non-U.S. Gov't |
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Abstract
This study described the construction and validation of the Coping Inventory for Prodromes of Mania (CIPM)-a newly developed instrument aimed at assessing how manic depressive sufferers dealt with their prodromes of mania. Two hundred and six subjects completed a 40-item measure of coping responses to prodromes of mania, a measure of social functioning and a mood measure. The CIPM yielded four empirically derived subscales: stimulation reduction, problem-directed coping, seeking professional help, denial or blame. All of these subscales provided good reliability and acceptably high internal consistency data. There was also some evidence of good validity of the CIPM.
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Denyer GS, Lam D, Cooney GJ, Caterson ID. Effect of starvation and insulin in vivo on the activity of the pyruvate dehydrogenase complex in rat skeletal muscles. FEBS Lett 1989; 250:464-8. [PMID: 2666160 DOI: 10.1016/0014-5793(89)80777-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The in vivo responses of pyruvate dehydrogenase (PDH) complex to starvation and insulin was assessed in heart, diaphragm and red quadriceps muscle. PDH complex activity was decreased by starvation (3.4-10.2-fold), the magnitude of change depending on muscle type. Insulin increased PDH activity in all muscle types. In fed rats, this effect was relatively small (1.25-1.29-fold). In starved rats there were effects in heart (4.3-fold) and red quadriceps (1.7-fold) but no effect in diaphragm. These results demonstrate that PDH complex in different groups of muscle has different insulin sensitivity (particularly in tissues from starved animals).
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Chan KM, Lam DT, Pong K, Widmer HR, Hefti F. Neurotrophin-4/5 treatment reduces infarct size in rats with middle cerebral artery occlusion. Neurochem Res 1996; 21:763-7. [PMID: 8873080 DOI: 10.1007/bf02532298] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The aim of this study was to determine whether neurotrophin-4/5 (NT-4/5) treatment alters infarction volume following permanent focal cerebral ischemia in the rat. Permanent focal cerebral ischemia was produced in adult male rats by intraluminal occlusion of the right middle cerebral artery. NT-4/5 was administered intraventricularly one day before and immediately following occlusion. Rats were sacrificed at 1, 4 and 7 days after occlusion. NT-4/5 treatment reduced infarction volume by 34% when compared to control rats 1 day after occlusion. Infarction volume was unaltered by treatment 4 to 7 days after occlusion. Middle cerebral artery occlusion led to a significant reduction in levels of mRNAs coding for catalytic and truncated TrkB receptors. This expression was unaffected by NT-4/5 treatment.
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Blazyk JF, Lam D. Effects of substrate and inhibitor binding on thermal and proteolytic inactivation of rat liver transhydrogenase. Biochemistry 1976; 15:2843-8. [PMID: 7289 DOI: 10.1021/bi00658a022] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The thermostability and proteolytic inactivation of rat liver submitochondrial particle transhydrogenase was studied in the presence of pyridine dinucleotide substrates and a variety of divalent metal and nucleotide inhibitors. Relative to the unliganded enzyme, the NADPH-enzyme complex was more thermostable and showed a twofold greater rate of tryptic inactivation, while the NADP+-enzyme complex was more thermolabile and only slightly more susceptible to tryptic inactivation. Neither NAD+ nor NADH significantly affected thermostability or proteolysis. Similar effects of these ligands were observed for the non-energy-linked and energy-linked transhydrogenase reactions, indicating that both activities are catalyzed by the same enzyme. In thermal experiments, acetyl-CoA, 2'-AMP, and NMNH stabilized, palmitoyl-CoAlabilized, and dephospho-CoA, CoA, NMN+, and 5'-AMP had little effect on enzyme stability. Tryptic inactivation was inhibited by 2'-AMP and NMN+ but was not influenced by the other nucleotide inhibitors. Divalent metal ion inhibitors (Mg2+, Ca2+, Mn2+, Ba2+, and Sr2+) stabilized transhydrogenase against thermal inactivation and promoted tryptic inactivation.
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Review |
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