Worldwide prevalence of suicidal ideation and suicide plan among people with schizophrenia: a meta-analysis and systematic review of epidemiological surveys

Schizophrenia is a severe psychiatric disorder with high premature mortality rates. This is a meta-analysis and systematic review of the prevalence of suicidal ideation (SI) and suicide plan (SP) among people with schizophrenia. PubMed, Web of Science, Embase, and PsycINFO were systematically searched from their respective inception to October 10, 2020. Data on prevalence of SI and/or SP were synthesized using the random effects model. Twenty-six studies covering 5079 people with schizophrenia were included for meta-analysis. The lifetime and point prevalence of SI were 34.5% (95% CI: 28.2-40.9%), and 29.9% (95% CI: 24.2-35.6%), respectively. The lifetime prevalence of SP was 44.3% and the point prevalence of SP ranged between 6.4 and 13%. Subgroup and meta-regression analyses revealed that source of patients, survey countries, and sample size were significantly associated with the point prevalence of SI, while male proportion and quality assessment scores were significantly associated with the lifetime and point prevalence of SI. Survey time and mean age were significantly associated with lifetime prevalence of SI. Both SI and SP are common in people living with schizophrenia, especially in males and inpatients. Routine screening and effective interventions for SI and SP should be implemented in this population.

Nomogram to Predict the Benefit of Intensive Treatment for Locoregionally Advanced Head and Neck Cancer

PURPOSE

Previous studies indicate that the benefit of therapy depends on patients' risk for cancer recurrence relative to noncancer mortality (ω ratio). We sought to test the hypothesis that patients with head and neck cancer (HNC) with a higher ω ratio selectively benefit from intensive therapy.

EXPERIMENTAL DESIGN

We analyzed 2,688 patients with stage III-IVB HNC undergoing primary radiotherapy (RT) with or without systemic therapy on three phase III trials (RTOG 9003, RTOG 0129, and RTOG 0522). We used generalized competing event regression to stratify patients according to ω ratio and compared the effectiveness of intensive therapy as a function of predicted ω ratio (i.e., ω score). Intensive therapy was defined as treatment on an experimental arm with altered fractionation and/or multiagent concurrent systemic therapy. A nomogram was developed to predict patients' ω score on the basis of tumor, demographic, and health factors. Analysis was by intention to treat.

RESULTS

Decreasing age, improved performance status, higher body mass index, node-positive status, P16-negative status, and oral cavity primary predicted a higher ω ratio. Patients with ω score ≥0.80 were more likely to benefit from intensive treatment [5-year overall survival (OS), 70.0% vs. 56.6%; HR of 0.73, 95% confidence interval (CI): 0.57-0.94; P = 0.016] than those with ω score <0.80 (5-year OS, 46.7% vs. 45.3%; HR of 1.02, 95% CI: 0.92-1.14; P = 0.69; P = 0.019 for interaction). In contrast, the effectiveness of intensive therapy did not depend on risk of progression.

CONCLUSIONS

Patients with HNC with a higher ω score selectively benefit from intensive treatment. A nomogram was developed to help select patients for intensive therapy.

Generalized Competing Event Models Can Reduce Cost and Duration of Cancer Clinical Trials

PURPOSE

Generalized competing event (GCE) models improve stratification of patients according to their risk of cancer events relative to competing causes of mortality. The potential impact of such methods on clinical trial power and cost, however, is uncertain. We sought to test the hypothesis that GCE models can reduce estimated clinical trial cost in elderly patients with cancer.

METHODS

Patients with nonmetastatic head and neck (n = 9,677), breast (n = 22,929), or prostate cancer (n = 51,713) were sampled from the SEER-Medicare database. Using multivariable Cox proportional hazards models, we compared risk scores for all-cause mortality (ACM) and cancer-specific mortality (CSM) with GCE-based risk scores for each disease. We applied a cost function to estimate the cost and duration of clinical trials with a primary end point of overall survival in each population and in high-risk subpopulations. We conducted sensitivity analyses to examine model uncertainty.

RESULTS

For the purpose of enriching subpopulations, GCE models reduced estimated clinical trial cost compared with Cox models of ACM and CSM in all disease sites. The relative cost reductions with GCE models compared with ACM and CSM models, respectively, were -68.4% and -14.4% in prostate cancer, -38.8% and -18.3% in breast cancer, and -17.1% and -4.1% in head and neck cancer. Cost savings in breast and prostate cancers were on the order of millions of dollars. The GCE model also reduced relative clinical trial duration compared with CSM and ACM models for all disease sites. The optimal risk score cutoff for clinical trial enrollment occurred near the top tertile for all disease sites.

CONCLUSION

GCE models have significant potential to improve clinical trial efficiency and reduce cost, with a potentially large impact in prostate and breast cancers.

Integrated phase II/III clinical trials in oncology: a case study

BACKGROUND

Integrated phase II/III trial designs implement the phase II and phase III aspects of oncology studies into a single trial. Despite a body of literature discussing the merits of integrated phase II/III clinical trial designs within the past two decades, implementation of this design has been limited in oncology studies.

PURPOSE

We provide a brief discussion of the potential advantages and disadvantages of integrated phase II/III clinical trial designs in oncology and provide an example of the operating characteristics of a Radiation Therapy Oncology Group (RTOG) trial.

METHODS

We review the differences among proposed integrated phase II/III designs. Then, we illustrate the use of the design in a brain tumor trial to be conducted by the RTOG and examine the impact of association between endpoints on design performance in terms of type I error, power, study duration, and expected sample size.

RESULTS

Although integrated phase II/III designs should not be used in all situations, under appropriate conditions, significant gains can be achieved when using integrated phase II/III designs, including smaller sample size, time and resources savings, and shorter study duration.

LIMITATIONS

Data submission without delay and sufficient evaluation of intermediate endpoints are assumed.

CONCLUSIONS

Although there are potential benefits in using phase II/III designs, there also may be disadvantages. We recommend running design simulations incorporating theoretical and practical issues before implementing an integrated phase II/III design.

First Report of Cochliobolus sativus Causing Leaf Spot on Paper Mulberry in China

Paper mulberry, Broussonetia papyrifera (L.) Vent., is a highly adaptable, fast-growing tree that is native to eastern Asia. Its ability to absorb pollutants makes it ideal for ornamental landscapes, especially in industrial and mining areas. During the summer of 2010, brown lesions were observed on leaves of paper mulberry in Baiwangshan Forest Park, Beijing, China. These lesions were ovoid to fusiform and 4 to 9 × 2 to 4 mm with dark brown centers and light brown irregular edges. Spots on severely infected leaves sometimes coalesced to form long stripes with gray centers. To isolate the causal agent of the lesions, 4-mm2 pieces of diseased leaf tissue from 12 leaves were collected at the lesion margins and surface disinfected in 0.5% NaOCl for 3 min, rinsed three times with sterile water, plated on water agar, and incubated at 25°C with a 12-h photoperiod. After 5 days, the cultures, which became dark brown to black, were observed. Conidiophores (120 to 220 × 4 to 7 μm) were solitary or in groups of two to five, straight or flexuous with swollen bases, and light or dark brown. Conidia were dark olive brown, spindle- or oval-shaped with truncated ends (60 to 120 × 15 to 30 μm), slightly curved, and containing 3 to 12 distoseptate (mostly 6 to 10). Pseudothecia, produced after 14 days in culture, were dark brown to black and flask shaped (420 to 530 μm in diameter with 85 to 100 × 75 to 90 μm ostiolar beaks). Asci were cylindrical (100 to 220 × 30 to 40 μm) and contained eight ascospores. Ascospores were filiform, (150 to 360 × 6 to 9 μm), hyaline, with 6 to 11 septations. Isolates were identified as Cochliobolus sativus (Ito & Kurib.) Drechsler & Dastur (anamorph Bipolaris sorokiniana (Sacc. & Sorok.) Shoem.) on the basis of culture color and dimensions and colors of pseudothecia, asci, ascospores, conidiophores, and conidia (2,3). The identity of one isolate was confirmed by ITS1-5.8S-ITS2 rDNA sequence (GenBank Accession No. HQ 654781) analysis that showed 100% homology to C. sativus listed in Berbee et al. (1). Koch's postulates were performed with six potted 3-month-old paper mulberry plants. An isolate was grown on potato dextrose agar for 14 days to obtain conidia for a conidial suspension (3 × 10⁴ conidia/ml). Three of the potted plants were sprayed with the conidial suspension and three were sprayed with sterile water as controls. Each plant was covered with a plastic bag for 24 h to maintain high humidity and incubated at 25°C with a 12-h photoperiod. After 7 days, the inoculated plants showed leaf symptoms identical to those previously observed on paper mulberry trees in the Baiwangshan Forest Park, while control trees remained symptom free. Reisolation of the fungus from the inoculated plants confirmed that the causal agent was C. sativus. C. sativus is widely distributed worldwide causing a variety of cereal diseases. Wheat and barley are the most economically important hosts. To our knowledge, this is the first report of C. sativus as a pathogen causing leaf spot of paper mulberry in China. References: (1) M. L. Berbee et al. Mycologia 91:964, 1999. (2) M. B. Ellis. Dematiaceous Hyphomycetes. CABI, Oxon, UK, 1971. (3) A. Sivanesan et al. No.701 in: Descriptions of Pathogenic Fungi and Bacteria. CAB, Kew, Surrey, U.K., 1981.

First Report of Black Spot Caused by Colletotrichum gloeosporioides on Paper Mulberry in China

Paper mulberry, Broussonetia papyrifera (L.) Venten. (family Moraceae), is a fast-growing tree with luxuriant branches and leaves. Because of strong adaptability and tolerance to unfavorable environmental conditions, it is an important tree species for shade or shelter and reforestation in mined areas and on hillsides. During the summer of 2010, brown-to-black spots were observed on leaves of paper mulberry in Baiwangshan Forest Park in Beijing, China. Early symptoms were round or elliptic, light brown, small lesions that later extended to round or irregular spots (4 to 6 × 4 to 8 mm) that were dark brown or black in the center with brown or light brown margins. Several dozen spots were found on severely infected leaves. Leaf tissues (2 × 2 mm), cut from the margins of lesions, were surface disinfected in 0.5% NaOCl solution for 3 min, rinsed three times with sterile water, plated on potato dextrose agar (PDA) and incubated at 25°C with a 12-h light and 12-h dark period. Numerous waxy subepidermal acervuli with setae were observed after 3 days. Acervuli were brown or black, round or elongate, and 100 to 250 μm in diameter. Setae were dark brown, erect straight or slightly curved, and 60 to 74 × 4 to 8 μm with one to two septa. Conidiophores were hyaline or light brown, short with no branches, and cylindrical with dimensions of 12 to 21 × 4 to 5 μm. Conidia were 11 to 21 × 3 to 6 μm, hyaline, aseptate, and cylindrical. Mycelia on PDA were off white-to-dark gray on the reverse side of the colony. Six isolates (BP21-1 to BP21-6) were obtained from different infected leaves and identified as Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (teleomorph Glomerella cingulata (Stonem.) Spaulding & Schrenk) on the basis of reverse colony color, dimensions and colors of acervuli, conidiophores, and conidia (3). ITS1-5.8S-ITS2 rDNA sequence analysis was performed on all six isolates. The resultant sequences were identical (GenBank Accession No. HQ 654780) and revealed 99% similarity (100% coverage) with C. gloeosporioides isolates in the GenBank (Accession Nos. EU371022.1 and AY376532.1) (2). Pathogenicity was demonstrated using six potted 3-month-old paper mulberry trees. Isolate BP21-2 was grown on PDA for 14 days and conidia were harvested to prepare a suspension of 10⁶ conidia/ml. Three plants were sprayed with the conidial suspension and three were sprayed with sterile water. All trees were covered with plastic bags for 24 h to maintain high humidity and incubated at 25°C for 6 days. All conidia-inoculated trees showed identical symptoms as the infected leaves in the park, while the control trees remained symptom free. Reisolation of the fungus confirmed that the causal agent was C. gloeosporioides. C. gloeosporioides is distributed worldwide causing anthracnose on a wide variety of plants including members of mulberry family Moraceae, e.g., mortality of stem cuttings and death of saplings on mulberry (Morus alba L.) in India (1). To our knowledge, this is the first report of C. gloeosporioides causing black spots on paper mulberry in China. References: (1) V. P. Gupta et al. Indian Phytopathol. 50:402, 1997. (2) K. D. Hyde et al. Fungal Divers. 39:147, 2009. (3) J. E. M. Mordue. No. 315 in: Descriptions of Pathogenic Fungi and Bacteria. CMI. Kew, Surrey, UK, 1971.

Processing sites are different in the generation of HLA-A2.1-restricted, T cell reactive tumor antigen epitopes and viral epitopes

In order to improve the processing efficiency of T cell tumor antigen epitopes, this bioinformatic study compares proteolytic sites in the generation of 47 experimentally identified HLA-A2.1-restricted immunodominant tumor antigen epitopes to those of 52 documented HLA-A2.1-restricted immunodominant viral antigen epitopes. Our results show that the amino acid frequencies in the C-terminal cleavage sites of the tumor antigen epitopes, as well as several positions within the 10 amino acid (aa) flanking regions, are significantly different from those of the viral antigen epitopes. In the 9 amino acid epitope region, frequencies differed somewhat in the secondary-anchored amino acid residues on E3 (the third aa of the epitope), E4, E6, E7 and E8; however, frequencies in the primary-anchored positions, on E2 and E9, for binding in the HLA-A2.1 groove, remained almost identical. The most frequently occurring amino acid pairs in both N-terminal and C-terminal cleavage sites in the generation of tumor antigen epitopes were different from those of the viral antigen epitopes. Our findings demonstrate for the first time that these two groups of epitopes may be cleaved by distinct sets of proteasomes and peptidases or similar enzymes with lower efficiencies for tumor epitopes. In the future, in order to more effectively generate tumor antigen epitopes, targeted activation of the immunoproteasomes and peptidases that mediate the cleavage of viral epitopes could be achieved, thus enhancing our potential for antigen-specific tumor immunotherapy.

Parity Alternation of Ground-State Pn- and Pn+ (n = 3−15) Phosphorus Clusters

The ground-state structures of neutral, cationic, and anionic phosphorus clusters P(n), P(n)(+), and P(n)(-) (n = 3-15) have been calculated using the B3LYP/6-311+G* density functional method. The P(n)(+) and P(n)(-) (n = 3-15) clusters with odd n were found to be more stable than those with even n, and we provide a satisfactory explanation for such trends based on concepts of energy difference, ionization potential, electron affinity, and incremental binding energy. The result of odd/even alternations is in good accord with the relative intensities of cationic and anionic phosphorus clusters observed in mass spectrometric studies.

A Density Functional Study on Beryllium-Doped Carbon Dianion Clusters CnBe2- (n = 4−14)

Making use of the software of molecular graphics, we designed numerous models of C(n)()Be(2-) (n = 4-14). We carried out geometry optimization and calculation on vibration frequency by means of the B3LYP density functional method. After comparison of structure stability, we found that the ground-state isomers of C(n)()Be(2-) (n = 4-14) are linear with the beryllium atom located inside the C(n)() chain. When a side carbon chain is with an even number of carbon atoms, it is polyacetylene-like, whereas when a side chain is with an odd number of carbon atoms, it is cumulene-like. The C(n)Be(2-) (n = 4-14) clusters with an even number of carbon atoms are more stable than that with an odd number of carbon atoms, matching the peak pattern observed in accelerator mass spectrometry (AMS) and Coulomb Explosion Imaging (CEI) investigations of C(n)()Be(2-) (n = 4-14). The trend of such odd/even alternation is explained based on concepts of bonding characteristics, electronic configuration, electron detachment, and incremental binding energy.

Investigation of Lyme disease in Xinjiang

From April through July 1988, an epidemiological investigation on Lyme disease was carried out in Nalati Xanyuan, Xinjiang Uygur Autonomous Region, China. Of 150 Ixodes persulcatus ticks examined by darkfield microscopy, 42 (28%) were found to have spirochetes. Two strains of spirochetes were isolated from I. persulcatus with BSK medium. Rabbits inoculated with the spirochetes showed erythema chronicum migrans at the sites of inoculation and the spirochetes were found in the cerebrospinal fluid by darkfield microscopy. Serum samples from 63 patients were examined for antibodies to B. burgdorferi by IFA test and 11 of them were positive with a titer of 1:64. Upon these results, it may be concluded that natural focus of Lyme disease exists in Xinjiang, China.