Discovery of photosynthesis genes through whole-genome sequencing of acetate-requiring mutants of Chlamydomonas reinhardtii.

Large-scale mutant libraries have been indispensable for genetic studies, and the development of next-generation genome sequencing technologies has greatly advanced efforts to analyze mutants. In this work, we sequenced the genomes of 660 Chlamydomonas reinhardtii acetate-requiring mutants, part of a larger photosynthesis mutant collection previously generated by insertional mutagenesis with a linearized plasmid. We identified 554 insertion events from 509 mutants by mapping the plasmid insertion sites through paired-end sequences, in which one end aligned to the plasmid and the other to a chromosomal location. Nearly all (96%) of the events were associated with deletions, duplications, or more complex rearrangements of genomic DNA at the sites of plasmid insertion, and together with deletions that were unassociated with a plasmid insertion, 1470 genes were identified to be affected. Functional annotations of these genes were enriched in those related to photosynthesis, signaling, and tetrapyrrole synthesis as would be expected from a library enriched for photosynthesis mutants. Systematic manual analysis of the disrupted genes for each mutant generated a list of 253 higher-confidence candidate photosynthesis genes, and we experimentally validated two genes that are essential for photoautotrophic growth, CrLPA3 and CrPSBP4. The inventory of candidate genes includes 53 genes from a phylogenomically defined set of conserved genes in green algae and plants. Altogether, 70 candidate genes encode proteins with previously characterized functions in photosynthesis in Chlamydomonas, land plants, and/or cyanobacteria; 14 genes encode proteins previously shown to have functions unrelated to photosynthesis. Among the remaining 169 uncharacterized genes, 38 genes encode proteins without any functional annotation, signifying that our results connect a function related to photosynthesis to these previously unknown proteins. This mutant library, with genome sequences that reveal the molecular extent of the chromosomal lesions and resulting higher-confidence candidate genes, will aid in advancing gene discovery and protein functional analysis in photosynthesis.

Disparities in insecurity, social support, and family relationships in association with poor mental health among US adults during the COVID-19 pandemic.

The COVID-19 pandemic has had a significant impact on mental health. Identifying risk factors and susceptible subgroups will guide efforts to address mental health concerns during the pandemic and long-term management and monitoring after the pandemic. We aimed to examine associations of insecurity (concerns about food, health insurance, and/or money), social support, and change in family relationships with poor mental health and to explore disparities in these associations. An online survey was collected from 3952 US adults between May and August 2020. Symptoms of anxiety, depression, stress, and trauma-related disorders were assessed by the Generalized Anxiety Disorder 7-item scale, the Patient Health Questionnaire-9, the Perceived Stress Scale-4, and the Primary Care Post-Traumatic Stress Disorder Screen, respectively. Social support was measured by the Oslo Social Support Scale. Logistic regression was used and stratified analyses by age, race/ethnicity, and sex were performed. We found a higher prevalence of poor mental health among those who were younger, female, with lower socioeconomic status, and racial/ethnic minorities. Participants who were worried about money, health insurance, or food had higher odds of symptoms of anxiety (OR = 3.74, 95% CI: 3.06-4.56), depression (OR = 3.20, 95% CI: 2.67-3.84), stress (OR = 3.08, 95% CI: 2.67-3.57), and trauma-related disorders (OR = 2.93, 95% CI: 2.42-3.55) compared to those who were not. Compared to poor social support, moderate and strong social support was associated with lower odds of all four symptoms. Participants who had changes in relationships with parents, children, or significant others had worse mental health. Our findings identified groups at higher risk for poor mental health, which offers insights for implementing targeted interventions.

Dietary Inflammatory Nutrients and Esophageal Squamous Cell Carcinoma Risk: A Case-Control Study.

We conducted a case-control study (532 cases and 532 control) in Chinese adults to investigate the independent and interactive effects of dietary nutrients (pro- or anti-inflammation) on Esophageal Squamous Cell Carcinoma (ESCC) risk. Dietary data were collected using a food questionnaire survey that included 171 items. Two algorithms, the Least Absolute Shrinkage and Selector Operation (LASSO) and Bayesian Kernel Machine Regression (BKMR) were employed to select indicators and evaluate the interactive effect of nutrients' mixture on ESCC risk. Thirteen nutrients were selected, including three pro-inflammatory nutrients (protein, fat and carbohydrate) and ten anti-inflammatory nutrients (fiber, Vitamin A, riboflavin, niacin, Vitamin C, Fe, Se, MUFA, n-3 PUFA and n-6 PUFA). Single-exposure effects of fat, carbohydrate and fiber significantly contributed to ESCC risk. The pro-inflammatory nutrients' submodel discovered that the combined effect was statistically associated with increased ESCC risk. In addition, a higher fat level was significantly associated with ESCC risk. On the contrary, for fiber and riboflavin, the anti-inflammatory nutrients' submodel delineated a significant negative effect on the risk of ESCC. Our result implies that dietary nutrients and their inflammatory traits significantly impacted ESCC occurrence. Additional studies are warranted to verify our findings.

Pyoderma gangrenosum: a review of clinical features and outcomes of 23 cases requiring inpatient management.

Pyoderma gangrenosum (PG) is a rare dermatological disorder characterised by the rapid progression of a painful, necrolytic ulcer. This study retrospectively identified patients who were admitted and treated for PG during a 10-year period (2003-2013). Twenty-three patients were included in this study, 16 women and seven men. The mean age at initial admission was 62.8 years (range 30 to 89 years). Lesions were localised to lower limb in 13 patients, peristomal region in four, breast in three, and upper limb in one, and two patients had PG at multiple sites. The variants of PG noted were ulcerative (18), bullous (2), vegetative (2), and pustular (1). Associated systemic diseases were observed in 11 patients (47.8%). Systemic therapies were initiated in 21 patients while two patients received topical treatments. The mean length of hospital stay was 47 days (range 5 to 243 days) and five patients died during their admissions. Seven patients required readmissions for exacerbations of their PG. Our study showed that patients admitted for treatment of PG had high morbidity and mortality. This study also highlights the importance of early and aggressive treatment of patients admitted with PG as well as treating associated systemic diseases and wound infections.

A 10 year retrospective study of surgical outcomes of adult intracranial pilocytic astrocytoma.

Pilocytic astrocytomas (PA) are benign neoplasms commonly located in the cerebellum with a peak incidence in the first two decades of life. PA occurrence in adults is rare and very little information is available in the literature about tumour characteristics in this population. This study retrospectively identified 20 adults with PA. The characteristics of the tumour, treatment modalities and patient outcomes are discussed, as well as identifying factors that may be associated with worse prognosis. The mean age at diagnosis was 27 years. The majority of PA were located in the posterior fossa. Other tumour locations included the cerebral hemispheres, brainstem, tectal plate and optochiasmatic region (optic chiasm, hypothalamus and third ventricle). All patients in this study underwent surgery, two received adjuvant chemotherapy and one received adjuvant radiotherapy. Tumour recurrence occurred in six patients and two eventually died from the disease. When achieved, complete tumour resection was found to be curative. Tumour location affects extent of surgical resection; tumours in inaccessible locations were associated with higher rates of recurrence. Overall survival and progression free survival rates were 87% and 60% respectively. The degree of surgical resection and tumour location were found to affect prognosis. Unfavourable outcomes were observed in these adults with PA compared to those expected for a younger population, suggesting a possible association between age and outcome.

Tenosynovial giant cell tumour of brachial plexus.

Tenosynovial giant cell tumours (TGT) are benign tumours that arise in the synovial lining of joints, tendon sheaths and bursae. Tumours arising from the vertebral column are extremely rare, with few cases reported. In this article, we describe an unusual case of an extra-articular TGT of the brachial plexus, arising from the synovium of the vertebral facet joint. To our knowledge and after a review of the literature, this is the first patient with a TGT involving the brachial plexus. The clinical, radiological and histological features of this tumour are described together with a brief discussion of management options.

A challenging diagnosis: case report of extensive pyoderma gangrenosum at multiple sites.

BACKGROUND: Pyoderma gangrenosum (PG) is a rare dermatological condition characterized by the rapid progression of a painful, necrolytic ulcer with an irregular, undermined border and commonly affects the lower extremities, mainly in the pretibial area. The diagnosis of PG is not easy. Due to lack of diagnostic laboratory test and histopathological findings indicative of PG, it is often misdiagnosed as an infection. This results in delayed or inappropriate treatment of the condition, which leads to devastating consequences such as limb amputation and death. MAIN OBSERVATIONS: We report a rare case of a 51-year-old female who was initially diagnosed as having infected ulcers and underwent serial debridements, which resulted in extensive PG at three different sites (abdominal, left thigh, and sacral). CONCLUSION: This case highlights the challenges in diagnosing PG, emphasizes the key clinical features to aid diagnosis, and the clinical consequences of delayed or misdiagnosis of this condition.

Gliomatosis cerebri in a patient with Ollier disease.

Gliomatosis cerebri (GC) is an uncommon brain tumour defined as a diffuse neoplastic glial cell infiltration of the brain, involving more than two cerebral lobes and, occasionally, the infratentorial structures or the spinal cord. GC of the oligodendroglial phenotype is extremely rare, especially in the paediatric setting. We describe an unusual case of oligodendroglial GC diagnosed in a 16-year-old boy with Ollier disease. To our knowledge this is the first case of GC reported in a child with Ollier disease.