Illustrated larval key to lepidopteran pests of rice in Malaysia.

Here we provide an illustrated key to lepidopteran larvae that occur as pests on rice (Oryza) in Malaysia. We are unaware of a published key for this region for this vital commercial crop, and hence provide one based on easily observable features that could be useful for identification, early detection, and pest management by specialists and non-specialists alike (see discussion in Mukerji & Singh 1951, Sri et al. 2010, Timm et al. 2007, Tillmon et al. 2000, Wagener et al. 2004).

Characterization of Coconut cadang-cadang viroid variants from oil palm affected by orange spotting disease in Malaysia.

A 246-nt variant of Coconut cadang-cadang viroid (CCCVd) has been identified and described from oil palms with orange spotting symptoms in Malaysia. Compared with the 246-nt form of CCCVd from coconut, the oil palm variant substituted C(31)→U in the pathogenicity domain and G(70)→C in the central conserved domain. This is the first sequence reported for a 246-nt variant of CCCVd in oil palms expressing orange spotting symptoms.

Multinodular reticular schwannoma in the head and neck region: a potential diagnostic pitfall.

Reticular/microcystic schwannoma is a recently described morphologic variant of schwannoma that occurs predominantly in visceral organs, most commonly the gastrointestinal tract. This report describes a case occurring in the masticator space, accompanied by focal erosion of the orbital floor, clinically and radiologically worrisome for malignancy. The 26-year-old man presented with facial swelling for 3 month. The tumor shows a multinodular appearance, with dense lymphoplasmacytic infiltrates in the fibrous septa. The tumor nodules are composed of plump spindle cells disposed in a reticular pattern. The diagnosis is confirmed by strong positive staining for S100 protein. The differential diagnoses of reticular schwannoma in the soft tissues of head and neck region are different from those in the gastrointestinal tract.

Factors contributing to the efficacy of concurrent-adjuvant chemotherapy for locoregionally advanced nasopharyngeal carcinoma: combined analyses of NPC-9901 and NPC-9902 Trials.

BACKGROUND: The current standard treatment for locoregionally advanced nasopharyngeal carcinoma (NPC) was conventional-fractionation radiotherapy plus concurrent-adjuvant chemotherapy as recommended by the Intergroup-0099 Study. This combined analysis of the NPC-9901 and the NPC-9902 Trials aims to provide more comprehensive data to evaluate the efficacy of the Intergroup-0099 regimen and the contributing factors. METHODS: Eligible patients with stage III-IVB non-keratinizing NPC were randomly assigned to radiotherapy-alone (RT(i) group: 218 patients) or chemoradiotherapy (CRT(i) group: 223 patients) using cisplatin (100mg/m(2)) for three cycles in concurrence with radiotherapy, followed by cisplatin (80 mg/m(2)) plus fluorouracil (1000 mg/m(2)/day for 4 days) for three cycles. The median follow-up was 6.1 years. FINDINGS: Comparison by intention-to-treat showed that the CRT(i) group achieved significant improvement in overall failure-free rate (FFR), locoregional-FFR and cancer-specific survival (p ≤ 0.019); but the improvements for distant-FFR and overall survival (OS) were statistically insignificant (p ≥ 0.14). Further exploratory studies based on actual treatment showed that an additional improvement achieved was a significant gain in OS (CRT(a) versus RT(a) group: 72% versus 63% at 5-year, p=0.037). Multivariate analyses showed that the dose of cisplatin during the concurrent phase had significant impact on locoregional-FFR and OS, while that of fluorouracil during the adjuvant phase was significant for distant-FFR. The 5-year locoregional-FFR for patients who received 0-1, 2 and 3 concurrent cycles were 79%, 88% and 88%, respectively; the corresponding distant-FFR by adjuvant cycles were 68%, 78% and 77%, respectively. INTERPRETATION: Our results support the current practice of adding concurrent cisplatin plus adjuvant cisplatin-fluorouracil to radiotherapy for treating patients with locoregionally advanced NPC. The concurrent phase is important for locoregional control and survival, cisplatin 200mg/m(2) in two concurrent cycles might be adequate. Additional chemotherapy using fluorouracil-containing combination contributed to improving distant control.

Randomized trial of radiotherapy plus concurrent-adjuvant chemotherapy vs radiotherapy alone for regionally advanced nasopharyngeal carcinoma.

BACKGROUND: Current practice of adding concurrent-adjuvant chemotherapy to radiotherapy (CRT) for treating advanced nasopharyngeal carcinoma is based on the Intergroup-0099 Study published in 1998. However, the outcome for the radiotherapy-alone (RT) group in that trial was substantially poorer than those in other trials, and there were no data on late toxicities. Verification of the long-term therapeutic index of this regimen is needed. METHODS: Patients with nonkeratinizing nasopharyngeal carcinoma staged T1-4N2-3M0 were randomly assigned to RT (176 patients) or to CRT (172 patients) using cisplatin (100 mg/m(2)) every 3 weeks for three cycles in concurrence with radiotherapy, followed by cisplatin (80 mg/m(2)) plus fluorouracil (1000 mg per m(2) per day for 4 days) every 4 weeks for three cycles. Primary endpoints included overall failure-free rate (FFR) (the time to first failure at any site) and progression-free survival. Secondary endpoints included overall survival, locoregional FFR, distant FFR, and acute and late toxicity rates. All statistical tests were two-sided. RESULTS: The two treatment groups were well balanced in all patient characteristics, tumor factors, and radiotherapy parameters. Adding chemotherapy statistically significantly improved the 5-year FFR (CRT vs RT: 67% vs 55%; P = .014) and 5-year progression-free survival (CRT vs RT: 62% vs 53%; P = .035). Cumulative incidence of acute toxicity increased with chemotherapy by 30% (CRT vs RT: 83% vs 53%; P < .001), but the 5-year late toxicity rate did not increase statistically significantly (CRT vs RT: 30% vs 24%; P = .30). Deaths because of disease progression were reduced statistically significantly by 14% (CRT vs RT: 38% vs 24%; P = .008), but 5-year overall survival was similar (CRT vs RT: 68% vs 64%; P = .22; hazard ratio of CRT = 0.81, 95% confidence interval = 0.58 to 1.13) because deaths due to toxicity or incidental causes increased by 7% (CRT vs RT: 1.7% vs 0, and 8.1% vs 3.4%, respectively; P = .015). CONCLUSIONS: Adding concurrent-adjuvant chemotherapy statistically significantly reduced failure and cancer-specific deaths when compared with radiotherapy alone. Although there was no statistically significant increase in major late toxicity, increase in noncancer deaths narrowed the resultant gain in overall survival.

Carcinoid tumour of the kidney in a Chinese woman presenting with loin pain.

Renal carcinoid tumours are uncommon. The aetiology is not yet fully understood and there is still no useful diagnostic tool for detecting them. We report our experience managing a Chinese woman with a primary renal carcinoid tumour.

Generating spin currents in semiconductors with the spin Hall effect.

We investigate electrically induced spin currents generated by the spin Hall effect in GaAs structures that distinguish edge effects from spin transport. Using Kerr rotation microscopy to image the spin polarization, we demonstrate that the observed spin accumulation is due to a transverse bulk electron spin current, which can drive spin polarization nearly 40 microns into a region in which there is minimal electric field. Using a model that incorporates the effects of spin drift, we determine the transverse spin drift velocity from the magnetic field dependence of the spin polarization.

Preliminary results of a randomized study on therapeutic gain by concurrent chemotherapy for regionally-advanced nasopharyngeal carcinoma: NPC-9901 Trial by the Hong Kong Nasopharyngeal Cancer Study Group.

PURPOSE: This randomized study compared the results achieved by concurrent chemoradiotherapy (CRT) versus radiotherapy (RT) alone for nasopharyngeal carcinoma (NPC) with advanced nodal disease. PATIENTS AND METHODS: Patients with nonkeratinizing/undifferentiated NPC staged T1-4N2-3M0 were randomized to CRT or RT. Both arms were treated with the same RT technique and dose fractionation. The CRT patients were given cisplatin 100 mg/m2 on days 1, 22, and 43, followed by cisplatin 80 mg/m2 and fluorouracil 1,000 mg/m2/d for 96 hours starting on days 71, 99, and 127. RESULTS: From 1999 to January 2004, 348 eligible patients were randomly assigned; the median follow-up was 2.3 years. The two arms were well-balanced in all prognostic factors and RT parameters. The CRT arm achieved significantly higher failure-free survival (72% v 62% at 3-year, P = .027), mostly as a result of an improvement in locoregional control (92% v 82%, P = .005). However, distant control did not improve significantly (76% v 73%, P = .47), and the overall survival rates were almost identical (78% v 78%, P = .97). In addition, the CRT arm had significantly more acute toxicities (84% v 53%, P < .001) and late toxicities (28% v 13% at 3-year, P = .024). CONCLUSION: Preliminary results confirmed that CRT could significantly improve tumor control, particularly at locoregional sites. However, there was significant increase in the risk of toxicities and no early gain in overall survival. Longer follow-up is needed to confirm the ultimate therapeutic ratio.

Overall survival after concurrent cisplatin-radiotherapy compared with radiotherapy alone in locoregionally advanced nasopharyngeal carcinoma.

This phase III randomized study compared concurrent cisplatin-radiotherapy (CRT) versus radiotherapy (RT) alone in patients with locoregionally advanced nasopharyngeal carcinoma. A total of 350 patients were randomly assigned to receive external RT alone or concurrently with cisplatin at a dosage of 40 mg/m(2) weekly. The primary endpoint was overall survival, and the median follow-up was 5.5 years. The 5-year overall survival was 58.6% (95% confidence interval [CI] = 50.9% to 66.2%) for the RT arm and 70.3% (95% CI = 63.4% to 77.3%) for the CRT arm. In Cox regression analysis adjusted for T stage, age, and overall stage, the difference in overall survival was statistically significantly in favor of concurrent CRT (P = .049, hazard ratio [HR] = 0.71 [95% CI = 0.5 to 1.0]). Subgroup analysis demonstrated that there was no difference between overall survival in the arms for T1/T2 stage (P = .74, HR = 0.93 [95% CI = 0.59 to 1.4]), whereas there was a difference between the arms for T3/T4 stage (P = .013, HR = 0.51 [95% CI = 0.3 to 0.88]), favoring the CRT arm. The regimen of weekly concurrent CRT is a promising standard treatment strategy for locoregionally advanced nasopharyngeal carcinoma patients.

Treatment results for nasopharyngeal carcinoma in the modern era: the Hong Kong experience.

PURPOSE: To analyze the treatment results achievable for nasopharyngeal carcinoma in the modern era to identify the key failures for future improvement and to provide an updated baseline for future trials. METHODS AND MATERIALS: The results of 2687 consecutive patients treated at all public oncology centers in Hong Kong during 1996-2000 were retrospectively analyzed. The stage distribution (by American Joint Committee on Cancer and International Union Against Cancer staging system, 1997) was 7% Stage I, 41% Stage II, 25% Stage III, and 28% Stage IVA-B. All patients were irradiated with 6-MV photons and the median total dose was 66 Gy. Only 23% of patients had additional treatment with chemotherapy. RESULTS: The 5-year local, nodal, and distant failure-free rates were 85%, 94%, and 81%, respectively; patients with local failure had significantly higher risk of nodal and distant failures. The 5-year progression-free, overall, and cancer-specific survival rates were 63%, 75%, and 80%, respectively. The presenting stage was the most important prognostic factor for all endpoints: with overall survival decreasing from 90% for Stage I to 58% for Stage IVA-B. The results achieved by the 2070 patients treated by radiotherapy alone were almost identical to that of the whole series, the distant failure-free rate among patients with locoregional control was 89% for Stage I-II and 75% for Stage III-IVB. The 860 patients (32%) staged with magnetic resonance imaging achieved significantly better results than those staged by computed tomography, the overall survival being 93% vs. 83% for Stages I-II, and 72% vs. 63% for Stages III-IVB (p = 0.001). CONCLUSIONS: Treatment results for nasopharyngeal carcinoma have substantially improved in the modern era; future trials should be based on updated baseline results. Further reduction of distant failure is important for future breakthrough, particularly for patients with advanced disease.

Core-shell nanorods for efficient photoelectrochemical hydrogen production.

We propose core-shell InP-CdS and InP-ZnTe nanorods as photoelectrodes in the efficient photoelectrochemical hydrogen production. On the basis of our systematic study using strain-dependent k.p theory, we find that in these heterostructures both energies and wave function distributions of electrons and holes can be favorably tailored to a considerable extent by exploiting the interplay between quantum confinement and strain. Consequently, these core-shell nanorods with proper dimensions (height, core radius, and shell thickness) can simultaneously satisfy all criteria for effective photoelectrodes in solar-based hydrogen production.

Staging of nasopharyngeal carcinoma: suggestions for improving the current UICC/AJCC Staging System.

AIMS: To evaluate the current UICC/AJCC Staging System for nasopharyngeal carcinoma and to search for ways of improving the system. MATERIALS AND METHODS: This is a retrospective analysis of 2687 consecutive patients treated in five public centres in Hong Kong during the period 1996-2000. All patients were staged by computed tomography, magnetic resonance imaging, or both. The prognostic significance of the current stage assignment on various aspects of tumour control was evaluated. RESULTS: T-category, N-category and stage-group were all significant prognostic factors for major end points (P < 0.01). However, the distinction of prognosis between Stage I and II was insignificant (5-year cancer-specific survival being 92% vs 95%; P = 0.13). Multivariate analyses (corrected for age and sex) revealed lack of significance between T2a and T1 in hazards of local and distant failures, N3a and N2 in distant failure and subgroups of T1-2N0 in cancer-specific deaths. Corresponding down-staging of T2a to T1, N3a to N2, and subgroup T2N0 to stage I, resulted in more even and orderly increase in the hazard ratio of cancer-specific deaths (from 1 for stage I to 1.98 for II, 3.5 for III, 6.08 for IVA and 8.62 for IVB), better hazard consistency among subgroups of the same stage and more balanced stage distribution. CONCLUSIONS: The current UICC/AJCC Staging System could be further improved by the modifications suggested; validation of the current proposal by external data is urgently awaited.

High temperature gate control of quantum well spin memory.

Time-resolved optical measurements in (110)-oriented GaAs/AlGaAs quantum wells show a tenfold increase of the spin-relaxation rate as a function of applied electric field from 20 to 80 kV cm(-1) at 170 K and indicate a similar variation at 300 K, in agreement with calculations based on the Rashba effect. Spin relaxation is almost field independent below 20 kV cm(-1) reflecting quantum well interface asymmetry. The results indicate the achievability of a voltage-gateable spin-memory time longer than 3 ns simultaneously with a high electron mobility.

Changes in clinical presentation, management and outcome in 1348 patients with differentiated thyroid carcinoma: experience in a single institute in Hong Kong, 1960-2000.

The clinical features, management and outcome of 1348 patients diagnosed with differentiated thyroid carcinoma in Queen Elizabeth Hospital, Hong Kong, were analysed according to the period of diagnosis: A (before 1980), B (1981-1990) and C (1991-2000). As time advanced, ratio of papillary carcinoma (PTC) to follicular carcinoma (FTC) increased (A:B:C = 1.6: 3.1: 7.2). The mean size of the primary tumour decreased (A:B:C = 3.5 cm: 2.8 cm: 2.5 cm), with a greater percentage of microcarcinoma of 1 cm or less (A:B:C = 5.1%: 16.1%: 21.7%). At presentation, the incidence of lymph-node metastasis decreased (A:B:C = 32.7%: 31.6%: 24.8%) and that of distant metastasis decreased (A:B:C = 9%: 6.1%: 5.3%). Bilateral surgical resection was more commonly used (A:B:C = 62.8%: 89.1%: 94.8%) than lobectomy (A:B:C = 26.3%: 2.8%: 1.8%). Radiation treatment, radioactive iodine (131I; RAI) and external radiotherapy (EXT), was more commonly used (A:B:C = 53.2%: 74.7%: 85.1%). RAI was used in 84.3% (A:B:C = 50%: 71.2%: 84.3%) and EXT in 14.5% of patients in the past decade (A:B:C = 10.9%: 8.7%: 14.5%). The proportion of patients who adopted a bilateral surgery and RAI treatment increased gradually with time (A:B:C = 33%: 68%: 83.8%). The 5-year cause-specific survival (A:B:C = 90.2%: 93.7%: 95.7%), locoregional failure-free survival (A:B:C = 72.6%: 82.9%: 91.6%) and distant metastasis failure-free survival (A:B:C = 84.5%: 89.1%: 92.6%) were improved. However, the period of diagnosis was not found to be an important explanatory variable (i.e. P > 0.05) in Cox regression after adjusting for other factors, indicating that the improvement was probably related to the temporal trend of other factors: presentation at earlier stage, increased ratio of PTC:FTC and more aggressive management by bilateral surgery and radiation therapy.

Autologous stem cell transplantation for nasal NK/T-cell lymphoma: a progress report on its value.

Nasal NK/T-cell lymphoma is an Epstein-Barr virus-related, highly aggressive but localized disease in Orientals. The median survival is <1 year. Here, we update our experience on 18 patients treated with autologous stem cell transplantation (ASCT). Two patients died of mucositis and septicemia during ASCT. Relapse occurred in nine cases, including six local relapses. Compared with patients treated in remission, all patients treated in active or disseminated disease died of early relapse. Within this cohort, there was no significant survival difference between patients treated in first (CR1, n = 7) or second (CR2, n = 5) complete remissions. However, among consecutive cases analyzed, the patients receiving ASCT at CR1 showed a trend towards better overall survival compared with historical matched controls (P = 0.064). Disease relapse beyond 6 months was not seen after ASCT. Our retrospective data suggest that ASCT in CR1 is a viable consolidation therapy for local-stage NK/T lymphoma, but a randomized trial is needed to prove any definite survival benefit. For patients with relapsed, refractory or extranasal disease, early consideration for allogeneic transplantation and alternative therapy may be warranted.

Economic analysis of celecoxib versus diclofenac plus omeprazole for the treatment of arthritis in patients at risk of ulcer disease.

AIM: To evaluate the economic impact of celecoxib therapy vs. diclofenac plus omeprazole therapy for the treatment of arthritis in Chinese patients with a high risk of bleeding, from the perspective of a public health organization in Hong Kong. METHODS: The medical records of 287 Chinese arthritic patients with a history of bleeding ulcers who had previously participated in a randomised study of celecoxib 200 mg twice daily and extended-release diclofenac 75 mg twice daily plus 20 mg of omeprazole daily for 6 months were reviewed. RESULTS: Compared to the diclofenac plus omeprazole group, the average total direct cost per patient in the celecoxib group showed a significant reduction of 11%, from HK 10,915 (range HK dollars 10,915-57,899) to HK dollars 9714 (range HK dollars 9714-89,770) (P<0.0001) (1 US dollars=7.8 HK dollars). The median direct medical cost for routine management in the celecoxib group was significantly lower (11%) than that for the diclofenac plus omeprazole group [HK dollars 10,915 (range 10,915-28,048) vs. HK dollars 9714 (range HK dollars 6946-26,179) (P<0.0001)]. In patients who experienced recurrent bleeding, the celecoxib group showed a significantly higher median cost of management of recurrent bleeding than the diclofenac plus omeprazole group [HK dollars 8466 (range 572-29,851) vs. HK dollars 23,210 (range HK dollars 12,318-65,823)] (P=0.036). CONCLUSIONS: Celecoxib therapy appears to cost less compared with diclofenac plus omeprazole for treatment of arthritis in Chinese patients with a high risk of bleeding.

Diffuse sclerosing variant of papillary thyroid carcinoma--clinical features and outcome.

AIM: Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is rare and occurs in young patients. This is a single institute retrospective analysis to report the clinical features and outcome of DSPC. METHOD: DSPC constituted 8 (0.74%) of 1086 papillary thyroid carcinomas (PTC) referred to the department of Clinical Oncology, Queen Elizabeth Hospital Hong Kong from 1960 to 2000. RESULTS: The mean follow-up was 8 years (range: 1.4 to 15.2 years). Six were females and two were males, with age ranging from 11 to 48 years. All were ethnic Chinese. Compared with the whole cohort of PTC followed in the same period, these patients showed younger age at presentation (mean 27.4 vs 45.3 years), larger tumor size (mean 6.9 cm vs 2.4 cm), higher incidence of lymph node metastasis (100% vs 32.4%), and more frequent presence of serum anti-thyroglobulin autoantibody (75% vs 11.3%). The patients were managed as for differentiated thyroid carcinoma according to the institute's protocol, including total thyroidectomy followed by radioiodine (RAI) treatment. External radiotherapy was given to two patients as primary treatment and one patient after regional relapse. One patient had distant metastases at presentation and she was successfully treated by surgery followed by RAI, remaining in complete remission at 12.1 years. One patient had lymph node recurrence after primary total thyroidectomy and RAI treatment and was successfully salvaged by surgery and external radiotherapy. At last follow-up, all eight patients were alive with no evidence of disease. CONCLUSIONS: Although DSPC is associated with some unfavourable features at presentation (such as large tumor size, extensive lymph node metastasis), the prognosis appears to be as good as classical PTC. After aggressive treatment by radical surgery, RAI ablation and/or external radiotherapy, the outcome and survival was excellent.

In-depth evaluation of the AJCC/UICC 1997 staging system of nasopharyngeal carcinoma: prognostic homogeneity and proposed refinements.

PURPOSE: To critically evaluate the American Joint Commission on Cancer (AJCC)/International Union Against Cancer (UICC) 1997 staging system and look back on its achievements by comparing it with the AJCC/UICC 1992 and Ho 1978 staging systems. To identify areas for additional refinement, we analyzed the prognostic heterogeneity within each stage in depth, which provided important clues for the addition or better categorization of the different defining criteria. METHODS AND MATERIALS: We performed a retrospective review of the data from 1294 consecutive biopsy-proven nonmetastatic nasopharyngeal carcinoma patients and staged the extent of disease according to the defining criteria of the three staging systems. All patients had undergone detailed pretreatment assessment by fiberoptic endoscopy and CT. Radical-intent radiotherapy was given using the Ho technique according to our standard protocol. RESULTS: The AJCC/UICC 1997 staging system was superior to the other two staging systems, because it assigned patients to more uniform-size stage groupings and correlated better with prognosis. Parapharyngeal space involvement was not an independent predictor for survival, local control, or metastasis. On the other hand, carotid space involvement correlated with a greater likelihood of metastasis. Prognostic heterogeneity was found. Those with orbit, cranial nerve, or intracranial involvement fared worse within Stage T4; those with a maximal lymph node size >3 cm fared worse within Stage N2; and those with bilateral lymph node metastasis fared worse within Stage N3. CONCLUSION: The prognostic accuracy of the AJCC/UICC 1997 staging system can be improved further by recategorization of the T, N, and group stage criteria.

Changing epidemiology of nasopharyngeal carcinoma in Hong Kong over a 20-year period (1980-99): an encouraging reduction in both incidence and mortality.

Epidemiological data from the Hong Kong Cancer Registry for the period 1980-99 were analyzed. Altogether 21,768 new cases of nasopharyngeal carcinoma (NPC) and 8,664 related deaths were registered. In both genders, the peak incidence occurred in the 50-59 years age group, and this age distribution pattern remained similar throughout. The age-standardized incidence rate steadily decreased from 28.5 in 1980-84 to 20.2 in 1995-99 per 100,000 males, and from 11.2-7.8 per 100,000 females, resulting in a total decrease of 29% for males and 30% for females over this 20-year period. The magnitude of total decrease in NPC mortality amounted to 43% and 50%, respectively, as the age-standardized mortality rate steadily decreased from 13.7 in 1980-84 to 7.8 in 1995-99 per 100,000 males, and from 4.5-2.2 per 100,000 females. The age-standardized mortality/incidence ratio also decreased from the peak of 0.48 in 1980-84 to 0.39 in 1995-99 for males, and from 0.40-0.29 for females. Females had significantly lower age-standardized incidence (male/female ratio 2.5-2.6, p < 0.01) and mortality (male/female ratio 3.0-3.5, p< 0.01) throughout the whole period. Furthermore, females had consistently lower mortality/incidence ratio: 0.29 vs. 0.39 in 1995-99. These data are highly suggestive of significant improvement in prevention and control of NPC in Hong Kong. Closer scrutiny of the differences in intrinsic and extrinsic factors between the genders might help to show important factors affecting oncogenesis and prognosis. Possible ways for further reduction of incidence and mortality are discussed.