Dense monocular depth estimation for stereoscopic vision based on pyramid transformer and multi-scale feature fusion

Stereoscopic display technology plays a significant role in industries, such as film, television and autonomous driving. The accuracy of depth estimation is crucial for achieving high-quality and realistic stereoscopic display effects. In addressing the inherent challenges of applying Transformers to depth estimation, the Stereoscopic Pyramid Transformer-Depth (SPT-Depth) is introduced. This method utilizes stepwise downsampling to acquire both shallow and deep semantic information, which are subsequently fused. The training process is divided into fine and coarse convergence stages, employing distinct training strategies and hyperparameters, resulting in a substantial reduction in both training and validation losses. In the training strategy, a shift and scale-invariant mean square error function is employed to compensate for the lack of translational invariance in the Transformers. Additionally, an edge-smoothing function is applied to reduce noise in the depth map, enhancing the model's robustness. The SPT-Depth achieves a global receptive field while effectively reducing time complexity. In comparison with the baseline method, with the New York University Depth V2 (NYU Depth V2) dataset, there is a 10% reduction in Absolute Relative Error (Abs Rel) and a 36% decrease in Root Mean Square Error (RMSE). When compared with the state-of-the-art methods, there is a 17% reduction in RMSE.

Laparoscopic and open liver resection for hepatocellular carcinoma with Child-Pugh B cirrhosis: multicentre propensity score-matched study

BACKGROUND

Laparoscopic liver resection for hepatocellular carcinoma (HCC) in Child-Pugh A cirrhosis has been demonstrated as beneficial. However, the role of laparoscopy in Child-Pugh B cirrhosis is undetermined. The aim of this retrospective cohort study was to compare open and laparoscopic resection for HCC with Child-Pugh B cirrhosis.

METHODS

Data on liver resections were gathered from 17 centres. A 1 : 1 propensity score matching was performed according to 17 predefined variables.

RESULTS

Of 382 available liver resections, 100 laparoscopic and 100 open resections were matched and analysed. The 90-day postoperative mortality rate was similar in open and laparoscopic groups (4.0 versus 2.0 per cent respectively; P = 0.687). Laparoscopy was associated with lower blood loss (median 110 ml versus 400 ml in the open group; P = 0.004), less morbidity (38.0 versus 51.0 per cent respectively; P = 0.041) and fewer major complications (7.0 versus 21.0 per cent; P = 0.010), and ascites was lower on postoperative days 1, 3 and 5. For laparoscopic resections, patients with portal hypertension developed more complications than those without (26 versus 12 per cent respectively; P = 0.002), and patients with a Child-Pugh B9 score had higher morbidity rates than those with B8 and B7 (7 of 8, 10 of 16 and 21 of 76 respectively; P < 0.001). Median hospital stay was 7.5 (range 2-243) days for laparoscopic liver resection and 18 (3-104) days for the open approach (P = 0.058). The 5-year overall survival rate was 47 per cent for open and 65 per cent for laparoscopic resection (P = 0.142). The 5-year disease-free survival rate was 32 and 37 per cent respectively (P = 0.742).

CONCLUSION

Patients without preoperative portal hypertension and Child-Pugh B7 cirrhosis may benefit most from laparoscopic liver surgery.

Using δ13C of Levoglucosan As a Chemical Clock

Compound specific carbon isotopic measurements (δ¹³C) of levoglucosan were carried out for ambient aerosol sampled during an intensive biomass burning period at different sites in Guangdong province, China. The δ¹³C of ambient levoglucosan was found to be noticeably heavier than the average δ¹³C of levoglucosan found in source C3-plant-combustion samples. To estimate the photochemical age of sampled ambient levoglucosan, back trajectory analyses were done. The origin and pathways of the probed air masses were determined, using the Lagrangian-particle-dispersion-model FLEXPART and ECMWF meteorological data. On the other hand, the isotopic hydrocarbon clock concept was applied to relate the changes in the field-measured stable carbon isotopic composition to the extent of chemical processing during transport. Comparison of the photochemical age derived using these two independent approaches shows on average good agreement, despite a substantial scatter of the individual data pairs. These analyses demonstrate that the degree of oxidative aging of particulate levoglucosan can be quantified by combining laboratory KIE studies, observed δ¹³C at the source and in the field, as well as back trajectory analyses. In this study, the chemical loss of levoglucosan was found to exceed 50% in one-fifth of the analyzed samples. Consequently, the use of levoglucosan as a stable molecular tracer may underestimate the contribution of biomass burning to air pollution.

Survey on examining prevalence of paternal anxiety and its risk factors in perinatal period in Hong Kong: a longitudinal study

BACKGROUND

There is emerging evidence of the significance of paternal mental health problems among the expectant fathers during the antenatal and postnatal period. The present study aims at determining the prevalence of paternal perinatal anxiety and identifying its risk factors among the fathers.

METHODS

A total of 622 expectant fathers were recruited in Hong Kong. The expectant fathers were assessed using standardized and validated psychological instruments on three time points including early pregnancy, late pregnancy and 6 week postnatal. Independent samples t-test, one way ANOVA, Pearson's correlation and multiple linear regression were used to examine the effect of hypothesized risk factors. Hierarchical multiple regression and mixed effect model were also conducted with potential confounding factors controlled for.

RESULTS

Results showed that a significant proportion of expectant fathers experienced anxiety during the perinatal period. Low self-esteem and poor social support were found to be risk factors of paternal anxiety across pregnancy to postnatal period. Work-family conflict could significantly predict paternal anxiety in the pregnancy period.

CONCLUSIONS

The present study points to the need for greater research and clinical attention to paternal anxiety, given that it is a highly prevalent problem and could be detrimental to their partner's well-being and children development. The present findings contributes to the theoretical understanding of the prevalence and risk factors of paternal perinatal anxiety and have implications for the design of effective identification, prevention, and interventions of these clinical problems.

Hand, foot and mouth disease in an immunocompetent adult due to Coxsackievirus A6

Hand, foot and mouth disease most commonly occurs in children less than 10 years old, but can occur in immunocompetent adults. We describe a 37-year-old immunocompetent man who presented with multiple painful papules and vesicles on his palms and feet together with vesicles inside the mouth. Real-time polymerase chain reaction revealed Coxsackievirus A6 in the vesicle fluid from the feet, throat swab, and rectal swab. Since the disease is highly contagious, to contain the infection it is prudent to recognise that hand, foot and mouth disease can occur in immunocompetent adults.

Study of coupling efficiency of molecules to surface plasmon polaritons in surface-enhanced Raman scattering (SERS)

Studying the interaction between molecules and surface plasmon polaritons (SPPs) is of great important in understanding surface-enhanced Raman scattering (SERS). While it is known that SERS consists of excitation and emission enhancements, each of them is manifested by several sub-steps which individually also deserve attention. For example, for emission enhancement, the energy from the excited molecules is first coupled to SPPs, which then radiatively scatter to far-field. To understand these two sequential processes completely, differentiating them one by one is necessary. Here, we decouple them and determine the coupling efficiency of molecules to SPPs by using a phenomenological rate equation model. We find the coupling efficiency, defined as the ratio of the coupling rate from molecules to SPPs to the direct Raman decay rate, can be expressed as the SERS intensity ratio and the SPP absorption and radiative decay rates, which all can be determined by polarization- and angle-dependent Raman and reflectivity spectroscopy. As a demonstration, the coupling efficiencies of 6-mercaptopurine to SPPs propagating in Γ-X direction on Ag nanohole array are measured for several Raman emission wavelengths.

The prevalence of six species of Mycoplasmataceae in an HIV/AIDS population in Jiangsu Province, China

This study employed culture and polymerase chain reaction (PCR) to examine the prevalence of Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium, Mycoplasma fermentans, Mycoplasma penetrans and Mycoplasma pirum in 210 HIV/AIDS patients, 455 sexually transmitted infection (STI) clinic attendees and 245 healthy volunteers from first-void urine specimens for men and endocervical swabs for women. U. urealyticum and M. hominis were detected in 107 (51.0%) and 69 (32.9%) patients in the HIV/AIDS group. At least one of the other four organisms was detected in 34 (16.2%) HIV/AIDS patients, 29 (6.4%) STI clinic attendees and six (2.5%) healthy volunteers. This study showed that U. urealyticum, M. hominis and M. fermentans were significantly more prevalent in HIV/AIDS patients, as were other mycoplasmas. Our results suggest a possible role for co-infection.

Using percutaneous transhepatic cholangioscopic lithotripsy for intrahepatic calculus in hostile abdomen

BACKGROUND

Hepatolithiasis is a challenging condition to treat especially in patients with previous hepatobiliary surgery. Percutaneous Transhepatic Cholangioscopic Lithotripsy (PTCSL) is an attractive salvage option for the treatment of recurrent hepatolithiasis. We reviewed our experience using PTCSL in treating 4 patients with previous complex abdominal surgery.

METHODS

We studied the 4 patients who underwent PTCSL from October 2007 to July 2009. We reviewed the operative procedures, workflow of performing PTCSL in our institution and the outcome of the procedure. PTCSL was performed in our institution using 3 mm cholangioscope (Dornier MedTech(®)) and Holmium laser with setting at 0.8 J, 20 Hz and 16 W. This was performed through a Percutaneous Transhepatic Cholangio-catheter inserted by interventional radiologists.

RESULTS

There were 4 patients with a median age of 50 (43-69) years. The median duration of the condition prior to PTCSL was 102 (60-156) months. Three patients had recurrent pyogenic cholangitis (RPC) with recurrent intrahepatic stone. They all had prior complex hepatobiliary operations. The median duration of surgery was 130 (125-180) min. There was minimal intra-operative blood loss. The first procedure was performed under local anaesthesia and sedation, however, with experience the subsequent 3 patients had the procedure performed under general anaesthesia. The median size of bile duct was 18 (15-20) mm prior to the procedure. The number of stones ranged from one to three with the largest size of stone comparable to the size of bile duct. The median follow up was 18 (10-24) months. All patients were symptom free with neither stone recurrence or cholangitis at the last follow up.

CONCLUSION

PTCSL is a feasible and an effective treatment method for patients with recurrent biliary stone following complex abdominal surgery as the success rates from open surgery and endoscopic procedures are limited. Excellent results can be expected with this minimally invasive technique.

Is pancreaticoduodenectomy justified in elderly patients?

BACKGROUND

Although mortality & morbidity for pancreaticoduodenectomy (PD) have improved significantly over the last two decades, the concern for elderly undergoing PD remains. This study examines the outcome of the elderly patients who had pancreaticoduodenectomy in our institution.

METHODS

A prospective database comprising 69 patients who underwent pancreaticoduodenectomy between 2001 and May 2008 was analyzed. Using WHO definition, elderly patient is defined as age 65 and above in this study. Two groups of patients were compared [Group 1: Age ≤65 & Group 2: Age >65].

RESULTS

The mean age of our patients was 62 ± 11 years. There were 37 (54%) patients in Group 1 and 32 (46%) patients in Group 2. There was no statistical difference between the two groups in terms of gender and race. However, there were more patients in the Group 2 with >2 comorbidities (p = 0.03). The median duration of operation was significantly longer in Group 2 (550 min vs 471 min, p = 0.04). Morbidity rate in Group 2 was higher (56% vs. 44%, p = 0.04). There was higher proportion of post-operative pancreatic fistula (POPF) in the elderly group (37.5% vs. 16.7%, p = 0.05). Majority of them are Grade A POPF according to the ISG definition. The median post-operative length-of-stay (LOS) in hospital was 9 days longer in Group 2 (p = 0.01). Mortality rate between the 2 groups of patients was comparable (0% vs. 3%, p = 0.28).

CONCLUSION

Elderly patients are at increased risk of morbidity in pancreatocoduodenectomy, in particular POPF. However, morbidity and mortality rates are acceptable. It is therefore justified to offer PD to elderly patients who do not have significant cardiopulmonary comorbidities.

The implementation of an end-of-life integrated care pathway in a Chinese population

The integrated care pathway is used in end-of-life care to improve quality of care; the Liverpool Care Pathway (LCP) has been used in Europe and North America. Tuen Mun Hospital is a regional hospital in Hong Kong, China. The End-of-life Care Pathway (ECP) based on the concepts used in the Liverpool Care Pathway, was developed, with modification to suit the local condition. Criteria for entry onto the ECP were that the multidisciplinary team agreed the patient was dying, and was at least two of the following: bedbound; semi-comatose; only able to take sips of fluid; no longer able to take tablets. The ECP template replaced all other inpatient documents. The ECP was implemented in the palliative care unit for terminal cancer patients. An audit was performed to review the result. Fifty-one Chinese patients were included in the audit with mean age 64. The median duration of ECP use was 24 hours. All patients had current medication assessed and non-essential drugs were discontinued. The audit result suggested integrated care pathway in end-of-life care could be implemented successfully in an Oriental culture. The acceptance of using the ECP as a standard clinical practice takes time and education. Appropriate template design and supervision are the keys to success.

Starting a laparoscopic hepatectomy programme

INTRODUCTION

Laparoscopic hepatectomy has been performed in many overseas centres. By avoiding long incisions associated with open hepatectomies, patients suffer less pain, recover faster and enjoy a shorter hospital stay. In Singapore, many centres have recently embarked on this approach. We believe that careful patient selection can facilitate scaling the learning curve. The aim of this study was to review our centre's initial outcome with laparoscopic anatomical liver resection when stringent selection criteria were applied.

METHODS

For our initial experience, we based our patient selection on criteria recommended by centres more experienced with laparoscopic hepatectomy. We selected only patients with small lesions confined to Couinaud's liver segments of II, III, IVB, V and VI. The surgical technique was similar in all cases, including intraoperative ultrasonography for localisation, ultrasonic shears and surgical staplers for parenchymal transection, and delivery of the specimen via a Pfannenstiel incision. No hand ports were used. Patients' records were retrospectively reviewed.

RESULTS

Between July 2006 and August 2007, we had five consecutive patients. Their median age was 50 (range 36-66) years. Four of these patients had hepatocellular carcinomas and one had a liver abscess. The median operation time was 275 (range 250-290) minutes, and median intraoperative blood loss was 400 (range 200-700) ml. The median hospital stay was four days.

CONCLUSION

At the initial stages of a laparoscopic hepatectomy programme, we propose that a stringent patient selection criteria coupled with the proper surgical expertise can ensure favourable outcomes, comparable to more established centres.

Comprehensive characterization of indoor airborne bacterial profile

This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens. These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.

Photocatalytic disinfection of marine bacteria using fluorescent light

Photocatalytic oxidation (PCO) using fluorescent light was used to disinfect two marine bacteria: Alteromonas alvinellae and Photobacterium phosphoreum. Results showed that P. phosphoreum exhibited a lower susceptibility towards PCO than A. alvinellae, which was related to their fatty acid profiles and levels of superoxide dismutase (SOD) and catalase (CAT). Results also revealed that CAT and SOD levels would be triggered by PCO reaction. In addition, PCO disinfection efficiency could be enhanced by acidic pH levels and increased temperatures, while different growth phases demonstrated diverse effects to the studied bacteria, probably due to their morphological difference or change in physiological state. Lastly intracellular leakage of potassium ion (K(+)), in line with the loss of cell viability, was observed during PCO. Mineralization of bacteria by PCO was monitored by total organic carbon analysis. From the regrowth study, the tested strains failed to reactivate within 96h after PCO treatment, indicating PCO caused irreversible bacterial inactivation.

Neutral zinc(II) O,O-di-alkyldithiopho- sphates-variable temperature 31P NMR and quantum chemical study of the ZDDP monomer-dimer equilibrium

A full line-shape analysis of the VT 31P NMR spectra was carried out for the monomer-dimer equilibrium of neutral ZDDP. The energy surface and the energetics of the monomer-dimer equilibrium (DeltaH degrees , DeltaG degrees , Ea, DeltaH(not equal), and DeltaG(not equal)) are reported for three variants wherein the alkyl groups in the ZDDP are 2-ethylhexyl, isopropyl, and isobutyl. We explored a reaction pathway between the monomer and dimer form by means of density functional theory (DFT). The linear combination of atomic orbitals (LCAO) code DMol3 was used together with a synchronous transient method to effectively locate transition states. Vibrational eigenmodes of all intermediates were computed to capture finite temperature effects. Methyl and ethyl were considered as alkyl groups. Two novel intermediates were located-a four-membered ring and a six-membered ring intermediate along the reaction coordinate. Comparison of the experimentally derived and computed energy surfaces was carried out.

Hybrid pulmonary artery conduit angioplasty for heterotopic heart transplantation

Heterotopic heart transplantation is rare in clinical practices. It carries technical difficulty not only during transplantation procedures, but also in the postoperative surveillance. We report two cases of heterotopic heart transplantation, which were complicated by pulmonary artery conduit stenosis within 2 years. We applied a less invasive approach combining cardiovascular surgeons with an interventional cardiologist. Through the donor heart right ventricular outflow tract, we performed balloon angioplasty and stent deployment. An excellent angiographic result with minimal residual pressure gradient was achieved in both patients.

Magnetic resonance imaging for the detection of nasopharyngeal carcinoma

BACKGROUND

Endoscopic guided biopsy (EGB) is performed after an initial endoscopy for the investigation of patients with suspected nasopharyngeal carcinoma (NPC). The aim of the study was to determine whether MR imaging has the potential to replace invasive EGB in patients with a normal endoscopy.

PATIENTS AND METHODS

Data from 2 groups of patients was reviewed, group 1 with proved NPC for MR staging (n = 456) and group 2 with suspected NPC (n = 77). The sensitivity was calculated for group 1 and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for group 2.

RESULTS

In group 1, which included 118 of 456 (26%) with stage 1 disease, cancer was detected in all patients, giving a sensitivity of 100%. In group 2, MR imaging was negative for NPC in 70 (91%) patients, and no cancer has been detected on follow-up (follow-up range, 1-90 months; mean, 36 months). MR imaging was positive for NPC in 7 (9%) patients and NPC was confirmed by biopsy in 3 (4%). Two of these 3 patients had undergone negative endoscopy and biopsy before the MR imaging. NPC was not present in the remaining 4 patients, 2 of whom were found to have lymphoid hyperplasia. MR imaging had a sensitivity of 100%, specificity of 95%, NPV of 100%, PPV of 43%, and accuracy of 95%.

CONCLUSION

MR imaging has the potential to screen healthy patients who do not require EGB and direct the site of biopsy in small cancers that may be missed by endoscopy. On the basis of these results, a prospective study is planned.

Comparison of an aprepitant regimen with a multiple-day ondansetron regimen, both with dexamethasone, for antiemetic efficacy in high-dose cisplatin treatment

BACKGROUND

We compared an aprepitant regimen with a control regimen of ondansetron + dexamethasone given for 4 days.

PATIENTS AND METHODS

Patients scheduled to receive cisplatin > or =70 mg/m(2) were randomized to either the aprepitant regimen (aprepitant, ondansetron and dexamethasone on day 1; aprepitant and dexamethasone on days 2-3; dexamethasone on day 4) or control regimen (ondansetron + dexamethasone on days 1-4). Patients recorded vomiting, nausea and rescue therapy use. The primary end point was complete response (no vomiting and no use of rescue therapy) in the overall phase (days 1-5 post-cisplatin).

RESULTS

Complete response rates were higher in the aprepitant than control group in the overall (72% versus 61%; P = 0.003), acute (day 1; 88% versus 79%; P = 0.005) and delayed phases (days 2-5; 74% versus 63%; P = 0.004), as were rates of no vomiting (overall 77% versus 62%, P < or = 0.001; acute 89% versus 81%, P = 0.004; delayed 79% versus 64%, P < or = 0.001). Rates of no rescue therapy were similar between groups.

CONCLUSIONS

Compared with an antiemetic regimen in which ondansetron + dexamethasone were given for 4 days, the aprepitant regimen was superior in the acute, delayed and overall phases of chemotherapy-induced nausea and vomiting. The aprepitant regimen should be considered a new standard of antiemetic therapy for cisplatin-treated patients. www.ClinicalTrials.gov Identifier: NTC00090207.

Pulmonary artery thrombosis in a patient with severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) is an emerging infectious disease with both pulmonary and extra-pulmonary manifestations. Although coagulation abnormalities are common in these patients, clinically overt thromboembolic events are rarely reported. This report describes the first case of pulmonary artery thrombosis in a patient with laboratory confirmed SARS.

Bowel colonization with resistant gram-negative bacilli after antimicrobial therapy of intra-abdominal infections: observations from two randomized comparative clinical trials of ertapenem therapy

The selection of resistant gram-negative bacilli by broad-spectrum antibiotic use is a major issue in infection control. The aim of this comparative study was to assess the impact of different antimicrobial regimens commonly used to treat intra-abdominal infections on the susceptibility patterns of gram-negative bowel flora after completion of therapy. In two international randomized open-label trials with laboratory blinding, adults with complicated intra-abdominal infection requiring surgery received piperacillin-tazobactam (OASIS 1) or ceftriaxone/metronidazole (OASIS II) versus ertapenem for 4-14 days. Rectal swabs were obtained at baseline, end of therapy, and 2 weeks post-therapy. Escherichia coli and Klebsiella spp. were tested for production of extended-spectrum beta-lactamase (ESBL). Enterobacteriaceae resistant to the agent used were recovered from 19 of 156 (12.2%) piperacillin-tazobactam recipients at the end of therapy compared to 1 (0.6%) patient at baseline (p<0.001) in OASIS I, and from 33 of 193 (17.1%) ceftriaxone/metronidazole recipients at the end of therapy compared to 5 (2.6%) patients at baseline (p<0.001) in OASIS II. Ertapenem-resistant Enterobacteriaceae were recovered from 1 of 155 and 1 of 196 ertapenem recipients at the end of therapy versus 0 and 1 ertapenem recipients at baseline in OASIS I and II, respectively. Resistant Enterobacteriaceae emerged significantly less often during treatment with ertapenem than with the comparator in both OASIS I (p<0.001) and OASIS II (p<0.001). The prevalence of ESBL-producers increased significantly during therapy in OASIS II among 193 ceftriaxone/metronidazole recipients (from 4 [2.1%] to 18 [9.3%]) (p<0.001), whereas no ertapenem recipient was colonized with an ESBL-producer at the end of therapy in either study. Selection for imipenem-resistant Pseudomonas aeruginosa was uncommon in all treatment groups. In these studies, the frequency of bowel colonization with resistant Enterobacteriaceae substantially increased in patients treated with either piperacillin-tazobactam or ceftriaxone/metronidazole, but not in patients treated with ertapenem.

Interfacial Study of Cubic Boron Nitride Films Deposited on Diamond

We have studied the nucleation and growth of cubic boron nitride (cBN) films deposited on silicon and diamond-coated silicon substrates using fluorine-assisted chemical vapor deposition (CVD). These comparative studies substantiate that the incubation amorphous/turbostratic BN layers, essential for the cBN nucleation on silicon, are not vital precursors for cBN nucleation on diamond, and they are inherently eliminated. At vastly reduced critical bias voltage, down to -10 V, cBN growth is still maintained on diamond surfaces, and cBN and underlying diamond crystallites exhibit an epitaxial relationship. However, the epitaxial growth is associated with stress in the cBN-diamond interfacial region. In addition, some twinning of crystallites and small-angle grain boundaries are observed between the cBN and diamond crystallites because of the slight lattice mismatch of 1.36%. The small-angle grain boundaries could be eliminated by imposing a little higher bias voltage during the initial growth stage. The heteroepitaxial growth of cBN films on different substrate materials are discussed in the view of lattice matching, surface-energy compatibility, and stability of the substrate against ion irradiation.

A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults

BACKGROUND

The incidence and severity of herpes zoster and postherpetic neuralgia increase with age in association with a progressive decline in cell-mediated immunity to varicella-zoster virus (VZV). We tested the hypothesis that vaccination against VZV would decrease the incidence, severity, or both of herpes zoster and postherpetic neuralgia among older adults.

METHODS

We enrolled 38,546 adults 60 years of age or older in a randomized, double-blind, placebo-controlled trial of an investigational live attenuated Oka/Merck VZV vaccine ("zoster vaccine"). Herpes zoster was diagnosed according to clinical and laboratory criteria. The pain and discomfort associated with herpes zoster were measured repeatedly for six months. The primary end point was the burden of illness due to herpes zoster, a measure affected by the incidence, severity, and duration of the associated pain and discomfort. The secondary end point was the incidence of postherpetic neuralgia.

RESULTS

More than 95 percent of the subjects continued in the study to its completion, with a median of 3.12 years of surveillance for herpes zoster. A total of 957 confirmed cases of herpes zoster (315 among vaccine recipients and 642 among placebo recipients) and 107 cases of postherpetic neuralgia (27 among vaccine recipients and 80 among placebo recipients) were included in the efficacy analysis. The use of the zoster vaccine reduced the burden of illness due to herpes zoster by 61.1 percent (P<0.001), reduced the incidence of postherpetic neuralgia by 66.5 percent (P<0.001), and reduced the incidence of herpes zoster by 51.3 percent (P<0.001). Reactions at the injection site were more frequent among vaccine recipients but were generally mild.

CONCLUSIONS

The zoster vaccine markedly reduced morbidity from herpes zoster and postherpetic neuralgia among older adults.

Diverse bitter stimuli elicit highly similar patterns of Fos-like immunoreactivity in the nucleus of the solitary tract

Previous studies have demonstrated that oral stimulation with quinine elicits Fos-like immunoreactivity in the first-order gustatory nucleus, the NST, with a different topographic distribution than sucrose or citric acid. However, it is unknown whether the quinine pattern is unique to this alkaloid or common across bitter stimuli with different chemical structures. Indeed, recent physiological experiments suggest that taste receptor cells and primary afferent neurons may exhibit selectivity for various bitter tastants. The present investigation compared the distribution of FLI in NST following stimulation with three bitter chemicals: QHCl, denatonium and propylthiouracil, stimuli that evoked Ca(2+) currents in almost entirely different sets of receptor cells. The results demonstrate that the quinine pattern is not idiosyncratic but instead generalizes to the other two tastants. Although it remains possible that intermingled but different NST neurons are activated by these stimuli, these data suggest that a specialized region in the NST is preferentially involved in processing a common aspect of bitter tastants. In contrast to citric acid, quinine, denatonium and propylthiouracil all elicited vigorous oromotor rejection responses, consistent with our earlier hypothesis that the medial third of the NST may be an afferent trigger zone for oromotor rejection.

Mirizzi syndrome: a diagnostic and operative challenge

INTRODUCTION

Mirizzi syndrome (MS) is an unusual complication of gallstone disease. The majority of cases are not identified pre-operatively, despite advances in imaging techniques.

MATERIALS AND METHODS

Eighteen cases of MS were treated between January 1997 and April 2002. The clinical presentation, modes of investigation, surgical management and outcome are retrospectively reviewed.

RESULTS

There were 13 female and 5 male patients, with a mean age of 60 years. Seven patients presented with the classical Charcot's triad. Ultrasonography (US) was the first imaging investigation in 13 patients and computerised tomography (CT) in the other five cases. Eleven patients had a successful endoscopic retrograde cholangio-pancreatography (ERCP) carried out. Diagnosis of MS was arrived at in seven patients following pre-operative imagings. Overall, 11 patients had Type 1 and seven patients had Type 2 MS. In the group with Type 1 MS, nine patients underwent open cholecystectomy, of whom six had concomitant common bile duct (CBD) exploration for stones and one patient with biliary stenosis had a hepaticojejunostomy bypass. Laparoscopic cholecystectomy was attempted in two patients, with successful completion in one case. In the group with Type 2 MS, four fistulas were closed surgically, the other three had biliary bypass procedures.

CONCLUSION

Mirizzi syndrome is an unusual condition that poses diagnostic and operative challenges to the surgeon. With a judicious approach during dissection and early recognition of its presence, bile duct injury can be avoided. Good outcome can be achieved with an appropriate surgical procedure.

Treatment of atrazine by integrating photocatalytic and biological processes

This research examines the degradation of atrazine by photocatalytic oxidation (PCO) under different experimental conditions. Deisopropylatrazine, deethylatrazine and deethyldeisopropylatrazine were formed as major intermediates based on gas chromatography-mass spectrometry. The reaction mixture was found to be toxic towards two bioassays, i.e. the Microtox and amphipods survival tests even when atrazine was completely degraded by PCO within 2 h under optimized conditions. The results indicate that adding H2O2 could significantly enhance the degradation of atrazine by PCO. Ammeline, ammelide and cyanuric acid (CA) became the major intermediates/products as detected by high performance liquid chromatography from 6th to the 40th h of PCO treatment. After 72 h PCO treatment, only CA was detectable in the reaction mixture. Further degradation of CA was carried out by a newly isolated CA-degrading bacterium, Sphingomonas capsulata. The photochemical pretreatment integrated with microbial degradation lead to the complete degradation and detoxification of atrazine.

Matrix metalloproteinase-8 in sera and from polymorphonuclear leucocytes in rheumatoid arthritis: in vitro characterization and correlation with disease activity

OBJECTIVES

To determine matrix metalloproteinase-8 (MMP-8) secretion from rheumatoid arthritis (RA) peripheral blood polymorphonuclear leucocytes (PMNs), in response to immune complexes (IC), cytokines and their combinations, and to study correlation of serum MMP-8 with disease activity.

METHODS

PMNs from RA patients and controls were stimulated in vitro with interleukin-15 (IL-15), IL-18, adherent immune complexes, rabbit anti-human immunoglobulin G (anti-HIgG), human immunoglobulin G (HIgG), and their F (ab') 2 prongs, phorbol myristate acetate (PMA) or combinations of above. Supernatants from these experiments and sera from both groups were assayed for MMP-8 using ELISA and correlated with disease activity measures in patients.

RESULTS

MMP-8 secretion from stimulated PMNs was compared to unstimulated PMNs. Immune complexes elicited significant MMP-8 secretion (p = 0.006 and 0.001, control and RA respectively). Unlike HIgG and its F (ab')2 fragment, very high secretion was elicited by anti-HIgG (242.37 +/- 10.85 ng/ml) and its F (ab')2 prong (195.85 +/- 28.67 ng/ml). IL-15 did not elicit any secretion. IL-18 with PMA increased secretion significantly only from RA PMNs (p = 0.003). Serum MMP-8 correlated positively with serum CRP (p = 0.017) and not with disease activity score (p = 0.199).

CONCLUSIONS

We for the first time demonstrate that immune complexes elicit MMP-8 secretion from PMNs. Except for higher secretion from RA PMNs in response to combination of IL-18 and PMA, both control and RA PMNs respond similarly to various stimuli. Secretion by anti-HIgG occurs by a mechanism independent of Fc receptor. Correlation with CRP suggest that serum MMP-8 may be an indicator of acute inflammatory activity.

Homicide–suicide in Hong Kong, 1989–1998

This study provides the first systematic research of homicide-suicide (HS) in a Chinese society. Data were drawn from the HK Homicide Monitoring Data-base computer file derived from investigation and death reports held by the HK Police Force and the Coroner's Court. During the 10-year study period, 56 events involving 133 deaths were identified. The majority of offenders were males (75%) and most victims were female (64%). The mean age of offenders and victims were 41.9 and 32.3 years, respectively. Spouses and lovers comprised the majority of victims (46.4%) followed by child victims (36%). Most HS events were motivated by separation or termination of marital or sexual relations (39%), economic reasons (25%) and other domestic disputes (20%). The most frequent modes of killing were strangulation/suffocation (26%), stabbing/chopping (24%), followed by gassing/poisoning (14%) and falling from height (14%). The commonest of suicide was falling from height (48%). It was followed by gassing/poisoning (22%) and strangulation/suffocation (13%). Depression (18.3%) was found to be the commonest mental disorder. Most offenders were from low-socio-economic background. Two-third were unemployed and 76.6% had 9 or less years of education. HS in HK were distinguished from those reported in the western literature in respect to the high relevance of economic factors, the absence of mercy killing between old couples, a higher percentage of pedicide-suicides and the infrequent use of firearms.

Lack of detrimental effects of nitric oxide inhibition in bile duct-ligated rats with hepatic encephalopathy

BACKGROUND

The pathogenetic mechanisms of hepatic encephalopathy (HE) are not fully understood. Vasodilatation induced by nitric oxide (NO) may be involved in the development of HE. There is no comprehensive data concerning the effects of NO inhibition on HE in chronic liver disease.

METHODS

Male Sprague-Dawley rats weighing 240-270 g at the time of surgery were selected for experiments. Secondary biliary cirrhosis was induced by bile duct ligation (BDL). Counts of movements were compared between BDL rats and rats receiving a sham operation. In another series of experiments, BDL rats received either Nomega-nitro-L-arginine methyl ester (L-NAME, 25 mg kg-1 day-1 in tap water) or tap water (control) from the 36th to 42nd days after BDL. Besides motor activities, plasma levels of tumour necrosis factor (TNF)-alpha and nitrate/nitrite, liver biochemistry tests and haemodynamics were determined after treatment.

RESULTS

Compared with the sham-operated rats, the total, ambulatory and vertical movements were significantly decreased in the BDL rats (P </= 0.001). The L-NAME group had a significantly higher mean arterial pressure than that of the control group (119.0 +/- 2.5 mmHg vs. 97.3 +/- 2.8 mmHg, P = 0.002). However, the counts of motor activities, plasma levels of TNF-alpha and nitrate/nitrite, and serum biochemistry tests were not significantly different between the L-NAME and control groups.

CONCLUSIONS

Bile duct ligation may induce HE evidenced by a decrease in motor activities. However, chronic L-NAME administration did not have significantly detrimental or therapeutic effects on the severity of encephalopathy in BDL rats.

Homicide–suicide in Hong Kong, 1989–1998

This study provides the first systematic research of homicide-suicide (HS) in a Chinese society. Data were drawn from the HK Homicide Monitoring Data-base computer file derived from investigation and death reports held by the HK Police Force and the Coroner's Court. During the 10-year study period, 56 events involving 133 deaths were identified. The majority of offenders were males (75%) and most victims were female (64%). The mean age of offenders and victims were 41.9 and 32.3 years, respectively. Spouses and lovers comprised the majority of victims (46.4%) followed by child victims (36%). Most HS events were motivated by separation or termination of marital or sexual relations (39%), economic reasons (25%) and other domestic disputes (20%). The most frequent modes of killing were strangulation/suffocation (26%), stabbing/chopping (24%), followed by gassing/poisoning (14%) and falling from a height (14%). The commonest method of suicide was falling from a height (48%). It was followed by gassing/poisoning (22%) and strangulation/suffocation (13%). Depression (18.3%) was found to be the commonest mental disorder. Most offenders were from low-socio-economic background. Two-third were unemployed and 76.6% had 9 or less years of education. HS in HK were distinguished from those reported in the western literature in respect to the high relevance of economic factors, the absence of mercy killing between old couples, a higher percentage of pedicide-suicides and the infrequent use of firearms.

Spatial relations of the angular vein, an important landmark in axillary nodal dissection

Helpful anatomy for the breast surgeon

Characterization of ambient volatile organic compounds at a landfill site in Guangzhou, South China

Ambient air monitoring was conducted at Datianshan landfill, Guangzhou, South China in 1998 to investigate the seasonal and horizontal variations of trace volatile organic compounds (VOCs). Twelve sampling points over the Datianshan landfill were selected and samples were collected simultaneously using Carbontrap(TM) adsorption tubes. Thirty eight VOCs were detected in the winter, whereas 60 were detected in the summer. The VOC levels measured in summer were alkanes, 0.5-6.5 microg/m(3); aromatics, 2.3-1667 microg/m(3); chlorinated species, 0.2-31 microg/m(3); terpines, 0.1-34 microg/m(3); carbonyl species, 0.3-5.6 microg/m(3) and naphthalene and its derivatives, 0.4-27 microg/m(3). Compared to the summer samples the VOC levels in winter were much lower (mostly 1-2 orders of magnitude lower). The aromatics are dominant VOCs in landfill air both in winter and summer. High levels of alkylbenzene and terpines such as methyl-isopropylbenzene (max 1667 microg/m(3)) and limonene (max 162 microg/m(3)) cause undesirable odor. The similar correlation coefficients of BTEX in summer and winter suggest VOCs emissions were from landfill site sources. The variation of BTEX ratio at landfill site is different from that in the urban area of Guangzhou. It shows that the ambient VOCs at landfill site were different from the urban areas.

Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage

The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images ( p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain.

Hepatolithiasis--a case series

INTRODUCTION

Hepatolithiasis is an uncommon entity in Singapore. We reviewed the cases presented to our institution (a 1200-bedded restructured hospital) over a 5-year period.

MATERIAL AND METHODS

Twelve cases of hepatolithiasis were treated between December 1995 and July 2000 representing 0.77% of gallstone disease operated on in the same period. The clinical presentation, investigations, treatment and subsequent progress are presented.

RESULTS

The patients' ages ranged from 28 to 82 years. There was a male to female ratio of 5:7. All patients had upper abdominal pain at presentation; 10 patients had clinical evidence of cholangitis. Ultrasound was the commonest first line investigation but additional investigations, such as computed tomographic (CT) scan and various forms of cholangiography, were frequently necessary for complete delineation of the biliary disease. The intrahepatic stones were located predominantly in the left lobe of the liver. Parenchymal atrophy was seen in 83% of patients. Two patients underwent a biliary bypass operation only, 5 had a hepatic resection only, and 5 had combined procedures. Follow-up ranged from 4 to 50 months. Postoperative recovery was generally unremarkable. Complications included subphrenic abscess (1 patient), recurrent stricture (1 patient) and recurrent stones (1 patient). One patient had an elevated serum CA 19-9 preoperatively; a small villous adenoma was noted at the biliary stricture in the resected left lateral segment of the liver. There was no operative mortality.

CONCLUSION

Hepatolithiasis is uncommon in Singapore. Complete diagnosis requires a combination of imaging modalities. Surgery remains the mainstay of definitive treatment. With adequate treatment, good outcome is possible.

Postantibiotic effects of antituberculosis agents alone and in combination

The postantibiotic effects (PAEs) of seven antimycobacterial agents, tested at their respective peak concentrations in serum alone and in different combinations, against Mycobacterium tuberculosis ATCC 27294 were studied with a radiometric culture system in parallel with the viable count method. Rifampin gave the longest PAE (67.8 h) among the drugs used alone, and combinations of first-line drugs generally gave PAEs longer than 120 h. The data obtained might help provide a better understanding of the scientific basis of intermittently administered antituberculosis chemotherapy.

Childhood vaccination against varicella: persistence of antibody, duration of protection, and vaccine efficacy

OBJECTIVE

To document the duration of protection afforded by Oka/Merck varicella vaccine over a 7-year period.

STUDY DESIGN

The subjects were healthy children 1 to 12 years of age originally enrolled in clinical studies to evaluate the primary immune response to varicella vaccine 6 weeks after vaccination. Each was monitored for antibody persistence, breakthrough infection, and household exposure to varicella to produce estimates of vaccine efficacy.

RESULTS

The 6-year cumulative varicella antibody persistence rate was 99.5% (95% CI: 98.9%, 100.0%). The annual breakthrough rate through 7 years ranged from 0.2% to 2.3% per year; the estimated cumulative event rate was 6.5%. Comparison of the observed average annual breakthrough rate with the age-adjusted expected annual incidence rate of varicella in unvaccinated children corresponded to an estimated vaccine efficacy of 93.8% to 94.6%. Eighty vaccinated children were exposed to varicella in the household, resulting in 8 (10%) cases of infection. When compared with the historical attack rate of 86.8% in unvaccinated susceptible persons exposed to varicella in the household, this yields an estimated vaccine efficacy of 88.5% (95% CI: 80.9%, 96.1%). Varicella cases in vaccinated children generally were mild.

CONCLUSION

The live attenuated varicella vaccine is highly effective in inducing persistent immunity and long-term protection against breakthrough varicella infection.

Immunization of HIV-infected children with varicella vaccine

OBJECTIVE

To determine the safety and immunogenicity of varicella vaccine in children with human immunodeficiency virus (HIV) infection. Children (n = 41) who were mildly affected by HIV (Centers for Disease Control and Prevention stage N1 or A1) and had no history or serum antibody indicative of prior varicella infection were immunized with two doses of live attenuated varicella vaccine.

RESULTS

A minority of the vaccine recipients had mild local or systemic reactions. Vaccination had no effect on the clinical stage of HIV or the HIV RNA plasma load. CD4 cell percentage and CD4 cell count were marginally decreased at week 4 after the first vaccination; this effect was no longer present at week 8 after vaccination. Two months after the second dose of vaccine, 60% of vaccine recipients had anti-varicella antibody in their serum, and 83% had a positive lymphocyte proliferation assay response to varicella antigen.

CONCLUSION

On the basis of its safety and immunogenicity, varicella vaccine should be considered in the childhood vaccines given to mildly affected HIV-infected children.

Laparoscopic fenestration of a simple hepatic cyst

Hepatic cysts are usually asymptomatic, most being detected incidentally during imaging. Distinction has to be made between a simple hepatic cyst from more sinister types such as a parasitic cyst and a cyst occurring as part of a neoplastic process. Intervention in a simple hepatic cyst is only indicated when they become symptomatic or when they grow at a rapid rate. Surgery is the mainstay of treatment, with laparoscopic intervention becoming more and more widely accepted. We present here the first case of laparoscopic fenestration of liver cyst performed in our hospital and also review the literature on this modality of treatment.

An unusual cutaneous metastasis from hepatocellular carcinoma

Cutaneous metastases from hepatocellular carcinoma are rare. In this report we detail a case of hepatocellular carcinoma with the unusual manifestations of multiple skin metastases. A 49-year-old male, who had received surgical resection of hepatocellular carcinoma one year prior, presented with multiple reddish-blue, firm, painless and nonulcerative cutaneous papules and nodules over the fingers, palms, toes, soles and back. Pathology of the cutaneous nodules showed characteristic hepatocellular carcinoma with trabecular gland formation. These lesions grew very rapidly and developed to cauliflower appearances which had not been described previously in the literature. The patient died of respiratory failure secondary to lung metastasis two months after the first appearance of the skin lesions.

A minimal transverse incision with low median sternotomy for pediatric congenital heart surgery

OBJECTIVES

Median sternotomy is the incision of choice for most cardiac surgical procedures, but the full-length vertical skin incision generally leaves an unsightly scar. In certain patients undergoing short, low-risk procedures, cosmetic considerations are of relatively greater importance.

METHODS

A minimal transverse curvilinear skin incision with low median sternotomy is described which gives adequate exposure for selected open-heart procedures. Since September 1997, this approach has been used in 22 pediatric patients undergoing open-heart surgery including five cases of Fallot's tetralogy. We also compared the operation time and result with other approaches.

RESULTS

Using this modified method, the exposure of the heart was good enough, and there were no difficulties in cannulating the ascending aorta for cardiopulmonary bypass. Although it took a longer time to close the wound, the operation time was similar to the standard approach. The small transverse wound was not visible under conventional clothes.

CONCLUSIONS

A minimal transverse incision with low median sternotomy provides an alternative approach for small wound open-heart surgery in patients with a simple congenital cardiac defect. It is technically feasible and has a good cosmetic result.

Ruptured abdominal aortic aneurysms: a personal experience

Despite advances in surgical technique and peri-operative care, mortality from ruptured abdominal aortic aneurysm presenting to a hospital remains around 50%. This is in contrast to the mortality rate of < 5% for elective repair. In a two and a half year period,the principal surgeon operated on 10 patients with ruptured AAA, with a peri-operative and overall mortality of 30%. One of the ten patients had a ruptured mycotic aneurysm. We present our experience with these patients and also correlate this with recent publications.

Rapid identification of mycobacterium tuberculosis complex from Bactec 12B broth cultures originating from non-respiratory secretion specimens: comparison between Accuprobe and in-house polymerase chain reaction

The rapid identification of Mycobacterium tuberculosis complex from 161 consecutive positive Bactec 12B cultures originated from non-respiratory secretion specimens was evaluated by comparing Accuprobe and an in-house polymerase chain reaction method. Using conventional biochemical method as the gold standard, 85.7% of the isolates (n = 138) were identified as Mycobacterium tuberculosis. The sensitivities of Accuprobe and the in-house-polymerase chain reaction method in identifying Mycobacterium tuberculosis complex were 92.0% (127/138) and 93.5% (129/138), respectively. Specificities of both methods being 87.0% (20/23 for both tests). Using a batch system of performing identification once weekly, the average turnaround time for Accuprobe, from the time of primary inoculation, was 27 days, which was comparable with that of in-house polymerase chain reaction, which was 29 days. The average time required for a confirmatory result based on conventional biochemical identification method was 84 days. The estimated reagent cost of in-house polymerase chain reaction was only one-fifth of that of Accuprobe. Therefore, the choice of methodology will depend on the individual laboratory's availability of resources and clinical demand. In the event of discrepant results between rapid identification methods and conventional methods, histological examination and clinical assessment can provide guidance as to the nature of the infection.

The prognostic significance of p16(INK4a)/p14(ARF) locus deletion and MDM-2 protein expression in adult acute myelogenous leukemia

BACKGROUND

The p16(INK4a) locus encodes two distinct proteins, p16(INK4a) and p14(ARF). Although p16(INK4a) and p15(INK4b) are involved in the phosphorylation of the retinoblastoma (Rb) protein, p14(ARF) interacts with the MDM-2 oncoprotein antagonizing its function as a suppressor of p53. The role of deletions of p16(INK4a)/p14(ARF) and p15(INK4b) and expressions of MDM-2 in myeloid leukemias and its influence on prognosis remain unclear.

METHODS

The authors analyzed deletions of p16(INK4)/p14(ARF) and p15(INK4b) in 74 adults with acute myeloid leukemia (AML) by Southern blotting. Western blotting was used to determine Rb protein phosphorylation in patients with deletions of p16(INK4)/p14(ARF) and p15(INK4b). Then, they analyzed the levels of MDM-2 protein expression and correlated it with prognosis in an expanded population of 79 adults with AML by immunoblot analysis and solid-phase radioimmunoassay.

RESULTS

Deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) occurred in 4 of 74 patients (5%) (hemizygous in 3, homozygous in 1 patient). Although the complete remission (CR) rate was similar (79% vs. 50%; P = 0.187), CR duration (10 vs. 46 weeks; P < 0.001), event free survival rate (EFS; 6 vs. 85 weeks; P < 0.004) and overall survival rate (11 vs. 86 weeks; P = 0.001) were significantly shorter in patients with deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b). Thirty-seven (47%) of 79 patients studied for MDM-2 showed increased MDM-2 expression. These patients had a significantly shorter EFS rate (50 vs. 64 weeks; P = 0.023) and a trend for shorter CR duration (24 vs. 53 weeks; P = 0.07). Overall survival rate was not significantly different (50 vs. 84 weeks; P = 0.136).

CONCLUSIONS

The authors concluded that 1) deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) occur with low incidence in patients with AML; 2) patients with deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) have a significantly shorter CR duration, EFS rate, and overall survival rate than do patients without deletions; (3) overexpression of MDM-2 is common in AML and is associated with shorter CR duration and EFS rate. Mechanisms other than p14(ARF) deletion are responsible for MDM-2 overexpression, and this overexpression may play a role in the biology of the disease.