Laparoscopic Heller's cardiomyotomy achieved lesser recurrent dysphagia with better quality of life when compared with endoscopic balloon dilatation for treatment of achalasia.

Achalasia is a rare primary motility disorder of esophagus; treatments include endoscopic balloon dilatation (EBD) and laparoscopic Heller's cardiomyotomy (LC). This study compared EBD versus LC for treatment of achalasia with focus on quality of life (QoL) and prevalence of post-treatment gastroesophageal reflux disease. This was a retrospective cohort study of all patients diagnosed with achalasia older than 16 treated with either EBD or LC from January 1998 to April 2008. Patients' demographic data, comorbidities, postintervention GERD symptoms, QoL, recurrence of dysphagia, reintervention rate, hospital stay, and time to resumption of diet were collected. Sixty-eight patients were recruited into the study (EBD n= 50; LC n= 18). A significant improvement in QoL was found in patients undergoing LC (0.917 vs. 0.807, P= 0.006). A higher proportion of patients treated with EBD developed post-treatment gastroesophageal reflux symptoms (60.5% vs. 43.8%) when compared with LC, although statistically insignificant (P= 0.34). Patients treated with balloon dilatation had a greater percentage of recurrence of dysphagia (55.1% vs. 26.7%; P= 0.235) and need of reintervention (42.1% vs. 9.1%; P= 0.045). However, these patients had a shorter median hospital stay (1d [range 0-4]) and earlier resumption of diet (0d [range 0-3]). Although EBD is associated with a quicker perioperative recovery, LC accomplished a better QoL, lower incidence of recurrence of dysphagia, and need of reintervention after treatment for achalasia.

Clinical significance of Trichomonas vaginalis detected in Papanicolaou smear: a survey in female Social Hygiene Clinic.

OBJECTIVES: To evaluate the clinical significance of Trichomonas vaginalis detected in Papanicolaou (Pap) smears in our local population. DESIGN: Retrospective study. SETTING: A sexually transmitted disease clinic in Hong Kong. PATIENTS: All patients having Pap smear, wet mount microscopy, and high vaginal swab culture performed in Tuen Mun Social Hygiene Clinic from April 2005 to December 2006 were recruited. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values of the Pap smear for the diagnosis of Trichomonas vaginalis. RESULTS: A total of 209 patients had the diagnosis of Trichomonas vaginalis in the study period. From among these, the results of 149 patients who had Pap smears, wet mount microscopy, and high vaginal swab culture performed were used in the analysis. Sixty cases were excluded because treatments were initiated before the consultation or because the Pap smear had not been done. Among the Trichomonas vaginalis cases with positive Pap smears, 58% (85/146) were symptomatic and 41% (60/146) had concomitant sexually transmitted disease. The respective sensitivity and specificity of the Pap smear in our study were: 98% (128/131; 95% confidence interval, 94-100%) and 96% (440/458; 94-98%). In total, 128 patients were defined as true positives by wet mount microscopy or culture, while 18 were defined as false positives. In our study population, the positive predictive value was 88% (128/146; 95% confidence interval, 82-93%). On comparing the clinical features of patients with true-positive and false-positive Pap smears, the odds ratio for the presence of symptoms and concomitant sexually transmitted disease was 1.9 (95% confidence interval, 0.7-5.1) and 2.0 (0.7-5.8), respectively. There were no statistically significant differences in the univariate analysis by Chi squared testing. CONCLUSION: Treatment for vaginal trichomoniasis is recommended if Trichomonas vaginalis is detected in a Pap smear.

Asymptomatic urethral infection in male sexually transmitted disease clinic attendees.

The purpose of this study is to determine the prevalence of asymptomatic male patients with urethral infections attending a government sexually transmitted infection clinic in Hong Kong and their microbiological profile. A total of 274 consecutive male patients without any symptoms for urethral infections were recruited. A questionnaire was used to record the symptoms, sexual history and demographics. Further assessment, including urethral smear for Gram stain, gonococcal culture and polymerase chain reaction (PCR) for Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Ureaplasma urealyticum (UU) were performed. In 274 asymptomatic patients, 36 patients had non-gonococcal urethritis (NGU) and two patients had positive gonococcal culture. Among the asymptomatic patients with NGU, there were 6 (16.6%), 10 (22.8%) and five (13.9%) patients with positive PCR for CT, UU and MG, respectively. In addition, there were 14 asymptomatic patients with positive PCR for CT but without evidence of NGU. In conclusion, urethral infections were identified in a significant number of asymptomatic male patients and therefore, routine screening for this group is warranted.

Role of Mycoplasma genitalium and Ureaplasma urealyticum in non-gonococcal urethritis in Hong Kong.

OBJECTIVE: To determine the association of Mycoplasma genitalium and Ureaplasma urealyticum in symptomatic male patients presenting with non-gonococcal urethritis in a sexually transmitted infection clinic in Hong Kong. DESIGN: Cross-sectional study. SETTING: A sexually transmitted infection clinic, Department of Health, Centre for Health Protection, Hong Kong. PATIENTS: A cohort of consecutive new male patients attending the government sexually transmitted infection clinic. MAIN OUTCOME MEASURES: Prevalence of Mycoplasma genitalium and Ureaplasma urealyticum among symptomatic male patients with non-gonococcal urethritis and asymptomatic patients without non-gonococcal urethritis. RESULTS: Specimens of 22 and 10 patients tested positive by polymerase chain reaction for Ureaplasma urealyticum and Mycoplasma genitalium respectively, among the symptomatic non-gonococcal urethritis group (n=98). In the asymptomatic control group (n=236), corresponding patient numbers whose specimens tested positive were 47 and 5. There was no statistically significant difference between the two groups, in terms of the proportion of patients infected with Mycoplasma genitalium (P=0.799) or Ureaplasma urealyticum (P=0.535). CONCLUSIONS: In our study, demonstration of Mycoplasma genitalium and Ureaplasma urealyticum by polymerase chain reaction was not associated with symptomatic non-gonococcal urethritis in male patients attending a Hong Kong government clinic for sexually transmitted infections.

A cluster of chilblains in Hong Kong.

OBJECTIVE: To report a recent clustering of chilblain cases in Hong Kong. DESIGN: Case series. SETTING: A regional hospital and a social hygiene clinic in the New Territories West, Hong Kong. PATIENTS: Patients with a clinical diagnosis of chilblains in February 2008. RESULTS: Eleven patients with chilblains were identified; seven (64%) gave an antecedent history of prolonged exposure to cold. They all presented with erythematous or dusky erythematous skin lesions affecting the distal extremities, especially fingers and toes. Laboratory tests revealed elevated antinuclear antibodies titres in two, positive rheumatoid factor in two, presence of cold agglutinins in one, and a raised anti-DNA titre (>300 IU/mL) in one. Skin biopsies were performed in six patients, four of them showed typical histopathological features of chilblains. In the patient with systemic lupus erythematosus, features of vasculitis were suspected, and in the one with pre-existing juvenile rheumatoid arthritis, there were features of livedo vasculitis. In 10 (91%) of the patients, the skin lesions had resolved when they were last assessed (at the end of March 2008), but had persisted in the patient who had pre-existing systemic lupus erythematosus. CONCLUSION: The recent clustering of chilblains was possibly related temporally to the prolonged cold weather at the end of January to mid-February. In our series, most of the patients developed chilblains as an isolated condition and resolved spontaneously within a few weeks. Laboratory tests and skin biopsies for chilblains are not necessary, unless the condition persists, the diagnosis in doubt or an underlying systemic disease is suspected.

Epidemiology of leprosy and response to treatment in Hong Kong.

OBJECTIVES: To review the reported trend of leprosy in Hong Kong. DESIGN: Retrospective study. SETTING: Three major leprosy clinics in Hong Kong. PATIENTS: Leprosy patients registered between 1970 and 2004. MAIN OUTCOME MEASURES: Incidence, rate of deformities, distribution of leprosy subtypes, age distribution, and relapses after therapy. RESULTS: The incidence of leprosy has decreased from 3.2 per 100,000 population in 1970 to 0.088 per 100,000 population in 2004. The proportion of the three subtypes of leprosy has remained roughly equal. There have been 87 relapses within this period with 54 (62%) cases of lepromatous leprosy, 22 (25%) borderline leprosy, and 11 (13%) tuberculoid leprosy. The overall relapse rate was 6.7% (0.2 per 100 person-years); this can be subdivided as a relapse rate for multidrug therapy of 3.2% (0.33 per 100 person-years) and for dapsone monotherapy of 8.3% (0.2 per 100 person-years). The mean interval to relapse for multidrug therapy and dapsone monotherapy was 1.83 and 5.8 years, respectively. The mean duration till relapse for patients on dapsone monotherapy was 15.6 years. CONCLUSION: Treatment with recommended WHO-multidrug therapy is effective and well tolerated. Dapsone monotherapy is no longer effective. Leprosy is well controlled in Hong Kong but continued surveillance is required to detect relapses and to ensure good patient compliance with treatment.

Human health risk assessment of organochlorines associated with fish consumption in a coastal city in China.

Food consumption is an important route of human exposure to organochlorines (OCs). In order to assess the potential health risks associated with these contaminants due to fish consumption, five species of fish were collected from a local market in Zhoushan City, an island in the East China Sea. Dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins/ dibenzofurans, in the fish samples were screened by H4IIE-luc cell bioassay, and the concentrations of specific organochlorines were measured by gas chromatograph-electron capture detector (GC-ECD). The bioassay results indicated that concentrations of dioxin-like compounds in the fish samples were below detection limit (0.64 pg/mL). The concentrations of OC pesticides and PCBs ranged from 0.67 to 13 and 0.24 to 1.4 ng/g wet wt., respectively. Significantly, concentrations of p,p'-DDE in fish meat were comparatively high (average 3.9 ng/g wet wt.) compared with the other OC pesticides. The daily fish consumption, based on a dietary survey conducted among 160 local healthy residents, was determined to be 105 g/person. The relevant cancer benchmark concentrations of HCB, dieldrin, chlordane, DDTs and PCBs were 0.36, 0.04, 1.6, 1.7, and 0.29 ng/kg per day, respectively, based on the local diet. The hazard ratios (HRs), based on non-cancer endpoints were all less than 1.0, while the HRs based on cancer were greater than 1.0 for certain contaminants based on the 95th centile concentration in fish tissue.

Surface-modified mutants of cytochrome P450cam: enzymatic properties and electrochemistry.

We report the electrochemistry of genetic variants of the haem monooxygenase cytochrome P450cam. A surface cysteine-free mutant (abbreviated as SCF) was prepared in which the five surface cysteine residues Cys-58, Cys-85, Cys-136, Cys-148 and Cys-334 were changed to alanines. Four single surface cysteine mutants with an additional mutation, R72C, R112C, K344C or R364C, were also prepared. The haem spin-state equilibria, NADH turnover rates and camphor-hydroxylation properties, as well as the electrochemistry of these mutants are reported. The coupling of a redox-active label, N-ferrocenylmaleimide, to the single surface cysteine mutant SCF-K344C, and the electrochemistry of this modified mutant are also described.

Measurements of backscattered radiation from Therac-20 collimator and trimmer jaws into beam monitor chamber.

The field size dependent photon output is known to be influenced by the existence of backscattered radiation (BSR) generated in the collimator or trimmer jaws of a linear accelerator. This paper describes the results of measurements made to study the existence of such backscatter by simulating the geometry of the treatment head of a Therac-20 linear accelerator. The machine's monitor chamber, flattening filter, and collimator jaws were simulated by another real monitor chamber, a 1-cm thick lead sheet and 2.5-cm thick low-melting-point alloy divergent blocks, respectively. BSR from the simulated collimator jaws (SCJ) was measured with the simulated monitor chamber (SMC) as a function of the openings of the SCJ and as a function of distance between SMC and SCJ. The present results demonstrate the presence of BSR in an 18-MV photon beam from a Therac-20 linear accelerator.

Construction of a calorimeter prototype with a high sensitivity pulsed signal detection circuit.

A calorimeter based on a Wheatstone bridge detector is considered to be an ideal absolute absorbed dose measuring device. One drawback of the calorimeter is that its output signals are extremely small. The signal size can be increased by increasing the bridge excitation voltage, which, however, may lead to excess self-heating of a temperature-sensing thermistor in the calorimeter detector and may require corrections. The use of pulsed excitation was investigated in this study in place of a conventional DC excitation to induce higher bridge output voltage while keeping the average self-heating of a thermistor to a reasonably low value. Performance evaluations of our prototype pulsed calorimeter are presented.

Condom use among female commercial sex workers and male clients in Hong Kong.

The use of condoms is an aid to protection against human immunodeficiency virus (HIV) infection and other sexually transmitted diseases (STDs). In a one-and-a-half month period in mid-1993, 190 commercial female sex workers and 633 male clients of 8 Social Hygiene Clinics in Hong Kong were interviewed on their practice in condom usage. For both sex workers and clients, 18.5% and 22.8% never and 55.3% and 50.3% seldom used condoms during sexual contacts with paying partners and non-paying partners respectively. The majority (86%) of male clients claimed that they would use a condom if they knew it could reduce risk of contracting HIV and other STD. Condom promotion activities are necessary, particularly for those at higher risk of infection because of their sexual behaviour.

PIP: To obtain baseline data and reference material for the design of human immunodeficiency virus (HIV) prevention programs, condom use among Hong Kong's commercial sex workers was investigated for the first time. Interviews were conducted with 190 female sex workers and 633 male clients recruited from Department of Health Social Hygiene Clinics between April and mid-May 1993. Frequency of condom use per 10 sexual contacts was rated as never, seldom (1-3), sometimes (4-6), often (7-9), or always. With paying male clients, these rates were 11,1%, 7.4%, 11.1%, 32.1%, and 37.9%, respectively. With non-paying sexual partners, however, these rates were 51.6%, 3.7%, 7.9%, and 18.4%. There was a significant difference in condom use rates with clients between sex workers over 30 years of age (64%) and their younger counterparts (87%). Among the male clients of prostitutes, condom use was as follows: never, 11.1%; seldom, 11.7%; sometimes, 9.6%; often, 17.5%; and always, 45.2%. The reasons most frequently cited by these men for non-use of condoms were: sexual partner considered reliable (46%), reduced sexual pleasure (26%), and lack of availability (22%). On the other hand, 86% indicated they would use a condom if convinced it would reduce the risk of HIV and other sexually transmitted diseases and 43% would use condoms if requested or provided by their partner. These findings suggest that the transmission of HIV by female sex workers could be substantially curtailed through the provision of free condoms to prostitutes, counseling to enable these women to take the initiative in insisting on condom use, and educational campaigns that emphasize the effectiveness of condoms in HIV prevention.

Treatment of pruritus of reactive perforating collagenosis using transcutaneous electrical nerve stimulation.

Reactive perforating collagenosis is a form of perforating dermatosis due to transepithelial elimination of collagen and characterized by itchy papulonodular eruptions frequently seen in patients with diabetes mellitus and end stage renal failure. Pruritus is often severe and treatment is difficult. Two adult Chinese diabetic patients with acquired reactive perforating collagenosis unresponsive to topical therapies and oral antihistamines, were treated with transcutaneous electrical nerve stimulation. There was a significant reduction of itch followed by gradual resolution of the skin lesions.

Treatment of vitiligo with autologous epidermal transplantation using the roofs of suction blisters.

We report our experience of autologous epidermal transplantation for three patients with vitiligo. The vitiligo in two patients was stable whereas that in the third was active. Autologous epidermal transplantation using suction blister roofs from normally pigmented skin was performed following the failure to repigment skin using topical steroid and/or psoralen-ultraviolet A treatment. Grafts were well taken in all three patients. Satisfactory repigmentation was noted in the two patients who had stable vitiligo; there were no complications except for mild hyperpigmentation at the donor areas. For the patient who had active vitiligo, depigmentation of the graft and concomitant Koebner's phenomenon at the donor site were observed 3 weeks after the procedure. We conclude that autologous epidermal transplantation using the roofs of suction blisters is an excellent and safe repigmenting procedure for stable, localised vitiligo and that active disease precludes transplantation.

Crusted (Norwegian) scabies in two old-age home residents.

Scabies is commonly seen in hospitals, where it frequently affects geriatric and convalescent patients. The clinical features of the classic form of scabies are well recognised. Crusted (Norwegian) scabies, which is a hyperinfestation variant of scabies, is very contagious and can present as other dermatoses, thus delaying the correct diagnosis and management. Two residents of different old-age homes presented with hyperkeratotic skin eruptions, which later proved to be crusted scabies. In both cases, the scabies was initially misdiagnosed as eczema. The delay in making a correct diagnosis led to an outbreak of scabies in the old-age home in which one of the patients was residing.

Porphyria cutanea tarda and melioidosis.

Porphyria cutanea tarda is a metabolic disorder in the haem biosynthetic pathway. It includes a heterogeneous group of conditions, which may be inherited or, more commonly, acquired. Although porphyria cutanea tarda presents with cutaneous lesions only, it is often associated with systemic disease. A 64-year-old Chinese patient, who developed sporadic porphyria cutanea tarda 1 year after the diagnosis of pulmonary melioidosis, is discussed. The patient presented with a history of recurrent photosensitive vesicles, blisters, and skin fragility on the sun-exposed areas of both forearms and hands, 6 months after commencing doxycycline and amoxycillin. Both the histological and biochemical findings were characteristic of porphyria cutanea tarda. All the lesions subsided after cessation of these antibiotics. The patient was free of further lesions at follow-up 6 months later. The association seen in this case between porphyria cutanea tarda and melioidosis is unlikely to be coincidental, because these two diseases are both very rare in Hong Kong. In addition, the temporal relationship between the antibiotic therapy and the clinical course of skin lesions in this patient suggests that the drugs were a trigger factor, precipitating their appearance.

An open non-comparative pilot study with azithromycin in the treatment of non-gonococcal urethritis in the sexually transmitted disease clinics in Hong Kong.

The aim of this study is to find out the efficacy and safety of azithromycin in the treatment of males with uncomplicated non-gonococcal urethritis. It is an open, non-comparative study carried out in the major sexually transmitted disease clinics in Hong Kong. The subjects were 45 male outpatients with clinical symptoms and signs of acute non-gonococcal urethritis. Patients presenting with acute urethritis were examined and non-gonococcal urethritis were examined and non-gonococcal urethritis was daignosed by the positive urethral smear for white blood cells but negative for gonococcus. They were given a single 1 gram oral dose of azithromycin at the clinic. Follow-ups after one and two weeks to examine for cure and adverse events were made. The result showed that 35 out of 42 evaluable patients were cleared of urethritis. Only 2 out of 22 chlamydial antigen positive patients still remained positive at the last visit. Adverse events were not uncommon but all were only mild. We concluded that 1 gram single dose of azithromycin was effective and well tolerated in the treatment of non-gonococcal urethritis in male patients.

Single-arc volumetric-modulated arc therapy can provide dose distributions equivalent to fixed-beam intensity-modulated radiation therapy for prostatic irradiation with seminal vesicle and/or lymph node involvement.

OBJECTIVES: Volumetric-modulated arc therapy (VMAT) is becoming an increasingly utilised modality for treating a variety of anatomical sites. However, the efficacy of single-arc VMAT to treat prostate cancer suspicious for extraprostatic extension was heretofore unknown. In this work, we report our institutional experience with single-arc VMAT and fixed-beam intensity-modulated radiation therapy (IMRT) for prostate cancer patients treated for seminal vesicle and/or lymph node involvement. METHODS: Single-arc VMAT and 7- or 9-field IMRT treatment plans were compared for 10 prostate cancer patients treated for seminal vesicle involvement and/or lymph node involvement. All treatment plans were constructed using the Philips Pinnacle treatment planning system (v.9.0, Fitchburg, WI) and delivered on an Elekta Infinity radiotherapy accelerator (Crawley, UK). Resulting plans were compared using metrics that characterised dosimetry and delivery efficiency. RESULTS: No statistically significant differences in target coverage, target homogeneity or normal tissue doses were noted between the plans (p>0.05). For prostate patients treated for seminal vesicle involvement, VMAT plans were delivered in 1.4±0.1 min (vs 9.5±2.4 min for fixed-beam IMRT) (p<0.01) and required approximately 20% fewer monitor units (p=0.01). For prostate patients treated for lymph node involvement, VMAT plans were delivered in 1.4±0.1 min (vs 11.7±1.3 min for fixed-beam IMRT) (p<0.01) and required approximately 45% fewer monitor units (p<0.01). CONCLUSION: Single-arc VMAT plans were dosimetrically equivalent to fixed-beam IMRT plans with significantly improved delivery efficiency.