Burnout and well-being in young doctors in Hong Kong: a territory-wide cross-sectional survey.

INTRODUCTION: This territory-wide study evaluated the level of burnout and health status among young doctors in Hong Kong. METHODS: All young doctors in Hong Kong, defined as residents-in-training or doctors within 10 years of their specialist registration, were invited to participate in an online cross-sectional survey. This survey used standardised questionnaires including the Copenhagen Burnout Inventory (CBI) for burnout, Patient Health Questionnaire-9 for depression, and general health questionnaires. RESULTS: In total, 514 doctors completed the survey; 284 were doctors within 10 years of their specialist registration, while 230 were residents-in-training. There were 277 women (54%); among all respondents, the mean age was 33.7 ± 6.1 years. Using a CBI subscale cut-off score of ≥50 (moderate and higher), 72.6% (n=373) of respondents reported personal burnout; 70.6% (n=363) of respondents reported work-related burnout; and 55.4% (n=285) of respondents reported client-related burnout. Furthermore, 24% (n=125) of respondents were "somewhat dissatisfied" with their present job position; 4% (n=19) of respondents were "very dissatisfied" with their present job position. The prevalence of depression among respondents was 21% (n=110). CONCLUSIONS: In this territory-wide cross-sectional survey of young doctors in Hong Kong, a high prevalence of burnout was identified among young doctors; respondents exhibited a considerable level of depression and substantial dissatisfaction with their current positions. Strategies to address these problems must be formulated to ensure the future well-being of the medical and dental workforce in Hong Kong.

Immediate pars plana vitrectomy for dislocated intravitreal lens fragments during cataract surgery.

PURPOSE: To assess the outcome of patients who underwent instantaneous pars plana vitrectomy for dislocated lens fragments during cataract surgery. METHODS: The medical records of 29 patients who underwent immediate pars plana vitrectomy for dislocated lens fragments at the same sitting of phacoemulsification surgery were reviewed. Data including patients' demographics, preoperative and postoperative vision, risk factors for lens fragment dislocation, and intraoperative and postoperative complications were recorded. RESULTS: The mean follow-up period of the patients was 12.3 months (range, 3-47 months). The median preoperative visual acuity was 6/90 (range, LP to 6/15). The median final postoperative visual acuity was 6/18 (range, NLP to 6/9) and the mean improvement in vision after the operation was 4.5 lines. The commonest risk factors for dislocation of lens fragment were late detection of posterior capsule tear, splitting of anterior capsulorrhexis, and hard nucleus. After excluding nine eyes with other pre-existing ocular comorbidities, 10 (50%) eyes had a final visual acuity of 6/12 or better. Complications after surgery included three (10%) cases of retinal detachment and one (3%) patient developed epiretinal membrane. None of the patients in the study developed secondary glaucoma or cystoid macular oedema following surgery. CONCLUSION: Immediate vitrectomy in the same sitting of the cataract surgery is a surgical option in the management of dislocated intravitreal lens fragments when vitreoretinal support is available. Most patients achieve a good visual outcome with reduced risk of secondary glaucoma and cystoid macular oedema after surgery.

Who are the residents of a nursing home in Singapore?

AIM OF STUDY: To describe the residents of a nursing home for the elderly in terms of their socio-demographic profile, mental and physical attributes, functional abilities and existing medical problems. METHOD: A random sample of 120 subjects was obtained from a total of 350 residents in a voluntary welfare nursing home. Two subjects were excluded as they did not satisfy inclusion criteria (age > or = 60 years). The subjects' biodata, social background, medical problems and functional status at the time of admission were obtained by a review of the case records. Each of the subjects was examined with attention to their general condition, hearing and vision, presence of postural hypotension, cognition and ability to perform basic activities of daily living (ADL). RESULTS: Results were available for 106 out of the 118 subjects as the rest were either discharged in the course of the study or had died. Single (36%), widowed (41%), female (71%) and age > or = 75 years (73%) consisted the majority. Most subjects (43%) were admitted because of both medical and social factors. Twenty-two percent appeared undernourished and of those who could be assessed, 14% had postural hypotension, 18% were hearing impaired and 53% had visual impairment. Fifty-two per cent suffered from mental problems while 46% and 40% had been diagnosed with hypertension and stroke respectively. Forty-eight percent had probable cognitive impairment (according to ECAQ scores) and 41% were very severely disabled (according to Barthel Index). Fifty-five percent were dependent in bathing, 50% dependent in dressing, 50% incontinent of urine (and requiring diapers), 48% were non-ambulant and 21% dependent in feeding. CONCLUSION: With a significant proportion of the population requiring nursing home care in the future, a closer review of the situation is needed. This study has identified malnutrition, urinary incontinence, falls, functional decline and impaired vision/hearing as issues that deserve greater attention and, where necessary, intervention. Whether implementing recognised effective interventions will truly benefit our nursing home residents would warrant more local studies.

Endoscopic transnasal orbital decompression for thyrotoxic orbitopathy.

OBJECTIVE: To evaluate the efficacy of endoscopic transnasal orbital decompression alone for thyrotoxic orbitopathy. DESIGN: Retrospective review of consecutive procedures. SETTING: Tertiary referral otorhinolaryngology centre. PATIENTS: Twenty-three eyes of 14 patients. INTERVENTION: Endoscopic transnasal orbital decompression. MAIN OUTCOME MEASURES: Proptosis reduction, intra-ocular pressure reduction, exposure keratitis reduction, visual acuity improvement, and complication rate. RESULTS: There were no surgical complications for the 23 orbital decompressions. Proptosis reduction was achieved in 22 (96%) eyes. The mean proptosis reduction was 4.6 mm (median, 5.0 mm; range, 1.0-8.0 mm). The postoperative intra-ocular pressure decreased after surgical decompression in 20 (87%) eyes with a mean reduction of 11 mm Hg (median, 6 mm Hg; range, 1-35 mm Hg). Of the 15 eyes with incomplete closure of the eyelid before the operation, 11 (73%) had complete eyelid closure after surgical decompression. Of the other four eyes that had incomplete closure, the gaps were reduced. The visual acuity was improved for 16 (70%) eyes with a median improvement of 3 Snellen lines (range, 1-8 lines). CONCLUSION: Endoscopic transnasal medio-inferior orbital wall decompression is a safe and adequate treatment for thyrotoxic orbitopathy with proptosis, exposure keratitis, and visual loss.

Clinical features of 46 eyes with calcified hydrogel intraocular lenses.

PURPOSE: To clarify the clinical features of delayed calcification of hydrogel intraocular lenses (IOLs) based on observation of a large case series. SETTING: Ophthalmology department of 2 university teaching hospitals, Hong Kong, China. METHODS: The first 44 patients with a known diagnosis of calcified IOL were recruited. Medical and ophthalmic histories were obtained. Surgical details, surgical complications, and visual acuity before and after IOL implantation were also retrieved. Patients then had a visual acuity test, a slitlamp examination of the features of the IOL calcification, and a fundus examination for clarity of view. RESULTS: Forty-six eyes of 44 patients had IOL calcification. All had a Hydroview IOL. The onset was from 4 to 26 months after surgery. Ninety-three percent of eyes had generalized IOL calcification, and 96% had forceps marks on the IOL. Mean visual acuity deteriorated from 0.4 at 3 months to 0.13 at 19 months. Visual loss was more severe in patients with diabetes mellitus or ischemic heart disease and in those in which the IOL calcified earlier after implantation. CONCLUSION: All cases of IOL calcification were delayed in onset. The presence of forceps marks may provide a clue to the pathogenesis. Bilateral but asymmetric involvement in 2 patients suggests that the IOL was involved in the pathogenesis. Affected patients lost an average of 2.8 Snellen lines of visual acuity. Some eyes progressed more rapidly; however, the modulating factors remain unknown.

Accumulation and apparent oxidation of cis,trans-18 : 2 isomers relative to linoleic acid in rats.

Dietary cis,trans-18 : 2 isomers impair desaturation and elongation of linoleic acid (Delta9cis,12cis-18 : 2), but little is known of their proportional partitioning between accumulation and oxidation. The present study was therefore designed to assess the accumulation and apparent oxidation of cis,trans-18 : 2 isomers compared with that of trans-18 : 1 isomers and Delta9cis,12cis-18 : 2 in rats. Accumulation is defined as whole-body increase in a fatty acid during a given period (i.e. final body content-initial body content). The apparent oxidation (disappearance) is defined as whole-body utilization of a fatty acid relative to its intake for a given period (intake-excretion-accumulation-longer-chain products)/intakex100). The animals were fed on a diet containing 15 % (w/w) partially hydrogenated rapeseed oil with 1.72 % energy as cis,trans-18 : 2 isomers and varying amounts of Delta9cis,12cis-18 : 2. The apparent oxidation of total cis,trans-18 : 2 isomers (72-76 % dietary intake) was greater than that of Delta9cis,12cis-18 : 2 (38-51 % dietary intake) but it was similar to that of total trans-18 : 1 isomers (78-82 % dietary intake). Among the four isomers, the apparent oxidation of Delta9trans,12trans-18 : 2 was greater than that of the other isomers including Delta9trans,12cis-18 : 2, Delta9cis,12trans-18 : 2 and Delta9cis,13trans-18 : 2. Accumulation of Delta5cis,8cis,11cis,15trans-20 : 4 and Delta5cis,8cis,11cis,14trans-20 : 4 derived from chain-elongation and desaturation of Delta9cis,13trans-18 : 2 and Delta9cis,12trans-18 : 2 was decreased when the dietary Delta9cis,12cis-18 : 2 supply was increased.

Mice lacking DNA topoisomerase IIIbeta develop to maturity but show a reduced mean lifespan.

Targeted gene disruption in the murine TOP3beta gene-encoding DNA topoisomerase IIIbeta was carried out. In contrast to the embryonic lethality of mutant mice lacking DNA topoisomerase IIIalpha, top3beta(-/-) nulls are viable and grow to maturity with no apparent defects. Mice lacking DNA topoisomerase IIIbeta have a shorter life expectancy than their wild-type littermates, however. The mean lifespan of the top3beta(-/-) mice is about 15 months, whereas that of their wild-type littermates is longer than 2 years. Mortality of the top3beta(-/-) nulls appears to correlate with lesions in multiple organs, including hypertrophy of the spleen and submandibular lymph nodes, glomerulonephritis, and perivascular infiltrates in various organs. Because the DNA topoisomerase III isozymes are likely to interact with helicases of the RecQ family, enzymes that include the determinants of human Bloom, Werner, and Rothmund-Thomson syndromes, the shortened lifespan of top3beta(-/-) mice points to the possibility that the DNA topoisomerase III isozymes might be involved in the pathogenesis of progeroid syndromes caused by defective RecQ helicases.

Distinct clinical features associated with microsatellite instability in colorectal cancers of young patients.

The Hong Kong Chinese population has an unusually high incidence of colorectal cancer in the young, suggestive of hereditary susceptibility. To search for a genetic basis for this predisposition, we studied the incidence of microsatellite instability (MSI) in paraffin-embedded colectomy specimens of 124 young (<50 years old) Chinese colorectal cancer patients referred to the Hong Kong Hereditary Gastrointestinal Cancer Registry from 1995 to 1998. By medical record review and personal interview, we searched for distinct clinical features associated with the manifestation of MSI in this group of patients. For patients with MSI tumours, blood was taken for detection of germline mutation in 2 mismatch repair (MMR) genes. MSI was present in 33 tumours from 23 males and 10 females (26.6%). Ongoing mutation analysis has so far identified MMR gene mutations in 8 patients with MSI tumours. The incidence of MSI increased significantly with decreasing age at cancer diagnosis. For patients aged 30 to 49, MSI tumours were located mainly at the proximal colon. However, for exceptionally young patients (<30 years), MSI tumours tended to be at the distal large bowel. This observation suggested a differential activity of the MMR pathway in colorectal carcinogenesis in different age groups. On multivariate analysis, young age at cancer diagnosis, proximal tumour location, a strong family history of colorectal cancer, and a personal history of metachronous cancer were independent predictors for MSI status. This knowledge may have an impact on the management of young colorectal cancer patients and their families.

Frequent microsatellite instability and mismatch repair gene mutations in young Chinese patients with colorectal cancer.

BACKGROUND: The incidence of colorectal cancer in persons under 46 years of age is substantially higher in Hong Kong than in Scotland and many other countries. Consequently, we examined whether there is a hereditary predisposition for colorectal cancer in this Southern Chinese population. METHODS: We investigated the incidence of microsatellite instability (MSI) at 10 DNA sites in 117 colorectal cancer specimens from Chinese patients of various ages. Those tumors with new alleles at 40% or more of the sites investigated were identified as highly unstable MSI (MSI-H). In young patients, we also searched for germline mutations in three mismatch repair genes (hMSH2, hMLH1, and hMSH6). RESULTS: The incidence of MSI-H varied statistically significantly with age, being observed in more than 60% of those younger than age 31 years at diagnosis and in fewer than 15% of those age 46 years or older. In 15 patients (<46 years old) whose colorectal cancers showed MSI-H, eight possessed germline mutations in either hMSH2 or hMLH1. When mutations in hMSH6 were included, more than 80% of Chinese colorectal cancer patients younger than 31 years had germline mutations in mismatch repair genes. We found a novel germline missense mutation in hMSH6 in a 29-year-old man whose tumor showed no MSI. Two patients had a 4-base-pair insertion in exon 10 causing a truncated protein; this insertion is a common polymorphism with a population allele frequency in Chinese of 5.6%. CONCLUSIONS: Our results indicate that germline mutations in mismatch repair genes contribute substantially to the pathogenesis and high incidence of colorectal cancer in young Hong Kong Chinese. However, because young Chinese and Caucasians show similar proportions of colorectal cancers with MSI-H, despite the higher incidence in the former, additional factors may underlie the high susceptibility of young Chinese to colorectal cancer.

Interleukin-10 inhibits inducible nitric oxide synthase in an animal model of necrotizing enterocolitis.

BACKGROUND: Nitric oxide (NO) and its role in surgical inflammation are well documented; demonstrating the role of NO in necrotizing enterocolitis (NEC) and ways in which it may be suppressed may provide avenues for immune modulation in the treatment of NEC. AIMS: We sought to demonstrate an increase in inducible nitric oxide synthase (iNOS) mRNA and nitric oxide in an experimental model of necrotizing enterocolitis. In addition, we hypothesized that interleukin-10 (IL-10) would attenuate this response. METHODS: Newborn rats were treated with 25 microliters intraperitoneal IL-10 or vehicle prior to laparotomy, 1 h superior mesenteric artery (SMA) occlusion, 50 micrograms/kg intraluminal platelet activating factor administration, and SMA reperfusion. iNOS mRNA and nitric oxide levels were measured in the liver, small bowel, and serum and compared using Student's t-test. RESULTS: Small bowel iNOS mRNA increased after NEC induction from 0.058 +/- 0.02 to 0.144 +/- 0.05 relative intensity units (RIU) at 2 h (p < 0.01) and from 0 to 0.09 +/- 0.02 RIU at 6 h (p < 0.03). Liver mRNA increased from 0.026 +/- 0.002 to 0.485 +/- 0.09 RIU (p < 0.002) and from 0 to 0.069 +/- 0.02 RIU (p < 0.0001) at 2 and 6 h, respectively. Serum nitric oxide increased in NEC induced animals at 2 h from 28.04 +/- 10.5 to 45.18 +/- 6.8 microM (p < 0.001). IL-10 suppressed iNOS mRNA and nitric oxide expression at 2 h in small bowel, liver, and serum by 60%, 89%, and 11%, respectively. CONCLUSIONS: IL-10 decreases iNOS mRNA response in experimental NEC. This down-regulation may be an avenue for anti-inflammatory intervention in NEC.

Endothelium-dependent relaxation induced by hawthorn extract in rat mesenteric artery.

The extract prepared from hawthorn (Crataegus fruit) was examined for its relaxant effect in rat isolated mesenteric arteries. Hawthorn extract induced concentration-dependent relaxation of the U46619-precontracted artery with an IC50 of 0.22 +/- 0.02 mg/ml. Removal of the functional endothelium reduced by approximately 85% the maximum relaxant response to hawthorn extract. Pretreatment of the arterial tissues with N(G)-nitro-L-arginine methyl ester (3-10 microM) or methylene blue (3-10 microM) inhibited the relaxation induced by hawthorn extract, while indomethacin (10 microM) had no effect. L-arginine (3 mM) did not affect the relaxation induced by hawthorn extract but partially reversed the effect of 10 microM N(G)-nitro-L-arginine methyl ester. Iberiotoxin (100 nM) slightly but significantly inhibited the relaxant effect of hawthorn extract whilst glibenclamide (3 microM) was ineffective. Glibenclamide at 3 microM reversed the relaxation induced by pinacidil. N(G)-nitro-L-arginine methyl ester and methylene blue markedly inhibited acetylcholine-induced relaxation in endothelium-intact arteries. Hawthorn extract also reduced the contraction induced by phenylephrine (1 microM) or high Ki (60 mM) with respective IC50 values of 0.13 +/- 0.01 mg/ml and 0.11 +/- 0.01 mg/ml. In high K+-contracted arteries, hawthorn extract induced only 55% of relaxation while it caused a complete inhibition of the U46619- or phenylephrine-induced contraction. These results suggest that hawthorn contains active components which cause vasorelaxation in rat isolated mesenteric arteries. Nitric oxide but not other endothelium-derived vasoactive factors was probably involved in the relaxation induced by hawthorn extract.

Inhibitory effect of linoleic acid on chain elongation and desaturation of 18:2 c,t isomers in lactating and neonatal rats.

The previous studies showed that dietary 18:2 c,t isomers could be chain-elongated and desaturated to produce unusual 20:4 isomers. The present study was undertaken to determine the minimal amount of 18:2n-6 required to suppress the chain elongation and desaturation of 18:2 c,t isomers in the lactating and neonatal rats when animals were fed 15% partially hydrogenated canola oil diet containing 1.72% energy as 18:2 c,t isomers and varying amounts of free 18:2n-6. These diets induced marginal essential fatty acid (EFA) deficiency states (0.56% energy 18:2n-6) to EFA adequacy (2.56% energy 18:2n-6). After feeding for 50 d, the female animals were mated with males by overnight pairing. After conception, the lactating rats were killed, together with one pup from each dam, at term and day 26 of lactation. Two unusual 20:4 isomers in both maternal and neonatal liver phospholipids were identified as 20:4delta5c,8c,11c,14t and 20:4delta5c,8c,11c,15t, which were derived from 18:2delta9c,12t and 18:2delta9c,13t, respectively. The results showed that 18:2n-6 at about 2.0% of total energy in maternal diet was required to block the production of 20:4delta5c,8c,11c,14t and 20:4delta5c,8c,11c,15t in the maternal liver, whereas 18:2n-6 at about 2.5% of total energy in maternal diet was required to suppress production of these unusual 20:4 isomers in the neonatal liver.

Breast milk fatty acid composition: a comparative study between Hong Kong and Chongqing Chinese.

The fatty acids of milk samples obtained from 51 Hong Kong Chinese and 33 Chongqing Chinese (Si Chuan Province, China) were analyzed by gas-liquid chromatography. Compared with those of published data for Canadian and other Western countries, the Chinese milk from both Hong Kong and Chongqing contained higher levels of longer-chain polyunsaturated fatty acids, particularly docosahexaenoic acid (22:6n-3) and arachidonic acid (20:4n-6). In contrast, the content of trans fatty acids in the Chinese milk was lower compared with those for Canadian and other Western countries. Longitudinally, the concentrations of 22:6n-3 and 20:4n-6 gradually decreased when lactation progressed from colostrum (week 1) to mature (week 6). Over the same interval, linoleic acid (18:2n-6) remained unchanged in Chongqing Chinese but significantly increased in Hong Kong Chinese. Unlike 18:2n-6, linolenic acid (18:3n-3) increased in Chongqing Chinese but remained unchanged in Hong Kong Chinese throughout the study. The total milk fat also increased with the duration of lactation. In addition, the milk of Chongqing Chinese had higher total milk fat than that of Hong Kong Chinese and Canadians. The content of erucic acid (22:1n-9) increased with the progression of lactation in Chongqing Chinese, indicating that there was a switch in dietary consumption from fats of animal origin to rapeseed oil when lactation reached week 6. The present study showed that Hong Kong and Chongqing Chinese had a different fatty acid profile in many ways, which largely reflected a different dietary habit and life-style in these two places.

Depletion of linoleate induced by weight cycling is independent of extent of calorie restriction.

Recent epidemiological studies have suggested that weight cycling induced by repeated dieting over time may increase the risk of cardiovascular disease. It is speculated that the increased mortality from coronary heart disease for people with a history of excessive weight cycling could be attributed to change in lipid metabolism. Previous studies have demonstrated that repeated cycling of 100% food restriction followed by ad libitum refeeding caused a depletion of linoleate and alpha-linolenate in rats. The objective of the present study was to test the hypothesis that the weight cycling-induced reduction in linoleate and alpha-linolenate is independent of extent of calorie restriction. Two consecutive weight cycles in three experiments were induced by 100% calorie restriction, 60% calorie restriction, and 36% calorie restriction, respectively, followed by ad libitum refeeding. As the consequence of the two weight cycles, linoleate and linolenate were decreased, whereas myristate, palmitate, and palmitoleate were proportionally increased in carcass and adipose tissue lipids. The results of all three experiments showed a preferential depletion of linoleate and alpha-linolenate without changes in final body weight, total body fat, and adipose tissue pads in the weight-cycled rats. In addition, the triacylglycerol species profile in the adipose tissue of weight-cycled rats was significantly remodeled, with a proportional depletion of linoleate-enriched triacylglycerol species (LLL, LLO, and LLP, where L, O, and P are linoleic, oleic, and palmitic acid, respectively) and a proportional accumulation of palmitate-enriched triacylglycerol species (OPPo, PPPo, and PPP, where Po is palmitoleic acid). We conclude that weight cycling changes the ratio of polyunsaturated fatty acids to saturated fatty acids and remodels the adipose tissue triacylglycerol species profile in rats.

Color duplex sonographically guided obliteration of pseudoaneurysm.

Over a 21 month period, 112 patients were seen in the vascular laboratory for evaluation and therapy of possible pseudoaneurysm. Pseudoaneurysm was confirmed by color flow sonographic imaging in 31 patients. Twenty-eight of these patients underwent sonographically monitored extrinsic manual compression to induce thrombosis and subsequent obliteration. Complete manual thrombosis was achieved in 17 patients while partial thrombosis with subsequent spontaneous closure developed in three patients, for a total success rate of 71% (20/28). In eight patients attempts to thrombose the pseudoaneurysm failed (29%). Induction of thrombosis by manual compression was successful in the presence of oral and intravenous anticoagulants. No therapeutic complications were encountered. Under proper sonographic guidance, the technique of manual obliteration of pseudoaneurysms provides a safe and effective alternative to surgical intervention.