Variation in xylem structure from tropics to tundra: Evidence from vestured pits

Bordered pits play an important role in permitting water flow among adjacent tracheary elements in flowering plants. Variation in the bordered pit structure is suggested to be adaptive in optimally balancing the conflict between hydraulic efficiency (conductivity) and safety from air entry at the pit membrane (air seeding). The possible function of vestured pits, which are bordered pits with protuberances from the secondary cell wall of the pit chamber, could be increased hydraulic resistance or minimized vulnerability to air seeding. These functional hypotheses have to be harmonized with the notion that the vestured or nonvestured nature of pits contains strong phylogenetic signals (i.e., often characterize large species-rich clades with broad ecological ranges). A literature survey of 11,843 species covering 6,428 genera from diverse climates indicates that the incidence of vestured pits considerably decreases from tropics to tundra. The highest frequencies of vestured pits occur in deserts and tropical seasonal woodlands. Moreover, a distinctly developed network of branched vestures is mainly restricted to warm habitats in both mesic and dry (sub)tropical lowlands, whereas vestures in woody plants from cold and boreal arctic environments are usually minute and simple. A similar survey of the frequency of exclusively scalariform perforation plates illustrates that the major ecological trend of this feature is opposite that of vestured pits. These findings provide previously undescribed insights suggesting that vessels with vestured pits and simple perforation plates function as an efficient hydraulic system in plants growing in warm environments with periodical or continuous drought stress. NaturalisPlant science

Comparative wood anatomy of the blueberry tribe (Vaccinieae, Ericaceae s.l)

Wood samples of 111 Vaccinieae specimens (Vaccinioideae, Ericaceae s.l.) representing 98 species and 26 genera are investigated with light microscopy and scanning electron microscopy. The wood structure of Vaccinieae delivers taxonomically important characters that can be used to define some subclades within the tribe. The wood of the large polyphyletic genus Vaccinium strongly resembles non-vaccinioid members of the family, which are characterized by bordered vessel-ray pits and relatively narrow (2- to 4-seriate) and low multiseriate rays (often less than 1000 m) with exclusively or mainly procumbent body ray cells. The East Malesian clade, Meso-American/Caribbean clade, and the Andean clade show a combination of wood anatomical features that is lacking in other representatives of the family. These features include scalariform vessel-ray pits with strongly reduced borders, a high portion of upright body ray cells, wide (4- to 14-seriate) and high multiseriate rays (often more than 3000 m), and prismatic crystals in chambered ray cells (although absent in Symphysia racemosa). The presence of secretory ducts in the primary xylem and in the pith tissue may represent a synapomorphy for the Andean clade. Furthermore, the presence of undivided axial parenchyma cells, usually ranging from 500 to 900 m, seems to be unique in the subfamily.  FWN – Publicaties zonder aanstelling Universiteit Leide

Reestablishment of the smile after hypoglossal-facial nerve transfer: what can we learn

Objective The aim of this study was to assess the ability to smile following a hypoglossal-facial nerve transfer (N12-N7).Design This is a retrospective chart review.Setting National tertiary referral center for skull base pathology.Participants Seventeen patients.Main Outcome Measures The ability to smile following an N12-N7 transfer was assessed by five medical doctors on photographs of the whole face and frontal, orbital, and oral segments. The (segmented) photographs were scored for the symmetry, asymmetry, and correct or incorrect assessment of the affected side.Results Seventeen patients were analyzed by 5 assessors providing 85 assessments. The whole face at rest was judged symmetrical in 26% of the cases and mildly asymmetrical in 56%. Frontal, orbital, and oral segments were symmetrical in 63, 20, and 35%, respectively. The affected side was correctly identified in 76%. When smiling, the whole face was symmetrical in 6% and mildly asymmetric in 59%. The affected side was correctly identified in 94%. The frontal, orbital, and oral segments during smiling were symmetrical in 67, 15, and 6%, respectively. The affected side of the frontal, orbital, and buccal facial segments during smiling was correctly identified in 89, 89, and 96%, respectively. Interobserver variability with Fleiss' kappa analysis showed that the strength of the agreement during smile of the total face was good (0.771)Conclusions Following an N12-N7 transfer, a good facial symmetry at rest can be achieved. During smiling, almost all patients showed asymmetry of the face, which was predominantly determined by the orbital and oral segments. To improve the ability to smile after an N12-N7 transfer, additional procedures are needed.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

Long-term quality of life of vestibular schwannoma patients: a longitudinal Analysia

Objective: Vestibular schwannoma management aims to maintain optimal quality of life (QoL) while preventing severe sequelae of the tumor or its treatment. This study assessed long-term QoL of patients with vestibular schwannoma in relation to treatment modality and decisional regret. Study Design:  A longitudinal study, in which clinical and QoL data were used that were cross-sectionally acquired in 2014 and again in 2020 from the same patient group. Setting: A tertiary expert center for vestibular schwannoma care in the Netherlands. Methods: QoL was measured by the Penn Acoustic Quality of Life (PANQOL) scale. Changes in time were assed using a linear mixed model. In addition, the Decision Regret Scale was analyzed. Results: Of 867 patients, 536 responded (62%), with a median follow-up of 11 years. All PANQOL subdomain scores remained stable over time and did not exceed minimal clinically important difference (MCID) levels. Time since treatment did not affect QoL. Patients had comparable average QoL scores and proportions of patients with changing QoL scores (ie, exceeding the MCID) over time, irrespective of the received initial treatment. Female patients and those who required salvage therapy (either by radiotherapy or surgery) reported a lower QoL. The latter patient group reported the highest decisional regret. Conclusion: On average, the long-term QoL of patients with vestibular schwannoma is comparable for patients under active surveillance and those who have received active treatment, and it remains stable over time. This suggests that, on average, preservation of QoL of patients with vestibular schwannoma is feasible when adequately managed.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

A prediction model for recurrence after translabyrinthine surgery for vestibular schwannoma: toward personalized postoperative surveillance

Purpose The aim of this study is to compute and validate a statistical predictive model for the risk of recurrence, defined as regrowth of tumor necessitating salvage treatment, after translabyrinthine removal of vestibular schwannomas to individualize postoperative surveillance. Methods The multivariable predictive model for risk of recurrence was based on retrospectively collected patient data between 1995 and 2017 at a tertiary referral center. To assess for internal validity of the prediction model tenfold cross-validation was performed. A 'low' calculated risk of recurrence in this study was set at < 1%, based on clinical criteria and expert opinion. Results A total of 596 patients with 33 recurrences (5.5%) were included for analysis. The final prediction model consisted of the predictors 'age at time of surgery', 'preoperative tumor growth' and 'first postoperative MRI outcome'. The area under the receiver operating curve of the prediction model was 89%, with a C-index of 0.686 (95% CI 0.614-0.796) after cross-validation. The predicted probability for risk of recurrence was low (< 1%) in 373 patients (63%). The earliest recurrence in these low-risk patients was detected at 46 months after surgery. Conclusion This study presents a well-performing prediction model for the risk of recurrence after translabyrinthine surgery for vestibular schwannoma. The prediction model can be used to tailor the postoperative surveillance to the estimated risk of recurrence of individual patients. It seems that especially in patients with an estimated low risk of recurrence, the interval between the first and second postoperative MRI can be safely prolonged.Otorhinolaryngolog

Prognostic factors for the outcome of translabyrinthine surgery for vestibular schwannomas

Objective: To identify predictors of tumor recurrence and postoperative facial nerve function after translabyrinthine surgery for unilateral vestibular schwannomas. Study Design: Retrospective study. Setting: Tertiary referral center. Patients: Between 1996 and 2017 a total of 596 patients with unilateral vestibular schwannoma underwent translabyrinthine surgery. Pre- and postoperative clinical status, radiological, and surgical findings were evaluated. Intervention(s): Translabyrinthine surgery. Main Outcome Measure(s): Potential predictors for tumor recurrence and facial nerve outcome were analyzed using Cox regression and ordinal logistic regression, respectively. Results: The extent of tumor removal was total in 32%, near-total in 58%, and subtotal in 10%. In 5.5% (33/596) of patients the tumor recurred. Subtotal tumor resection (p = 0.004, hazard ratios [HR] = 10.66), a young age (p = 0.008, HR = 0.96), and tumor progression preoperatively (p = 0.042, HR = 2.32) significantly increased the risk of recurrence, whereas tumor size or histologic composition did not. A good postoperative facial nerve function (House-Brackmann grade 1-2) was achieved in 85%. The risk of postoperative facial nerve paresis or paralysis increased with tumor size (p < 0.001, OR = 1.52), but was not associated with the extent of tumor removal, histologic composition, or patient demographics. Conclusions: Translabyrinthine surgery is an effective treatment for vestibular schwannoma, with a good local control rate and facial nerve outcome. The extent of tumor removal is a clinically relevant predictor for tumor recurrence, as are young patient age and preoperative tumor progression. A large preoperative tumor size is associated with a higher risk of postoperative facial nerve paresis or paralysis.Development and application of statistical models for medical scientific researc

The impact of vestibular schwannoma and its management on employment

Background Employment is an important factor in quality of life. For vestibular schwannoma (VS) patients, employment is not self-evident, because of the sequelae of the disease or its treatment and their effects on daily life. Objectives This study assessed employment status, sick leave (absenteeism) and being less productive at work (presenteeism) in the long-term follow-up of VS patients, and evaluated the impact of treatment strategy (active surveillance, surgery or radiotherapy). Methods A cross-sectional survey study was performed in a tertiary university hospital in the Netherlands. Patients completed the iMTA-post productivity questionnaire (iPCQ). Employment status was compared to that of the general Dutch population. Employment, absenteeism and presenteeism were compared between patients under active surveillance, patients after radiotherapy and post-surgical patients. Result In total 239 patients participated, of which 67% were employed at the time of the study. Only 14% had a disability pension, which was comparable to the age-matched general Dutch population. The proportion of patients with absenteeism was 8%, resulting in a 4% reduction of working hours. Presenteeism was reported by 14% of patients, resulting in a 2% reduction of working hours. The median number of working hours per week was 36, and since the diagnosis, these hours had been reduced by 6%. There were no significant differences between treatment modalities. Conclusion On average, long-term employment status and working hours of VS patients are comparable to the age-matched general population. Treatment strategies do not seem to differentially impact on long-term employment of VS patients.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Germline DLST variants promote epigenetic modifications in pheochromocytoma-paraganglioma

Context: Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors in which altered central metabolism appears to be a major driver of tumorigenesis, and many PPGL genes encode proteins involved in the tricarboxylic acid (TCA) cycle.Objective/design: While about 40% of PPGL cases carry a variant in a known gene, many cases remain unexplained. In patients with unexplained PPGL showing clear evidence of a familial burden or multiple tumors, we aimed to identify causative factors using genetic analysis of patient DNA and functional analyses of identified DNA variants in patient tumor material and engineered cell lines.Patients and Setting: Patients with a likely familial cancer burden of pheochromocytomas and/or paragangliomas and under investigation in a clinical genetic and clinical research setting in university hospitals.Results: While investigating unexplained PPGL cases, we identified a novel variant, c.1151C>T, p.(Pro384Leu), in exon 14 of the gene encoding dihydrolipoamide S-succinyltransferase (DLST), a component of the multi-enzyme complex 2-oxoglutarate dehydrogenase. Targeted sequence analysis of further unexplained cases identified a patient carrying a tumor with compound heterozygous variants in DLST, consisting of a germline variant, c.1121G>A, p.(Gly374Glu), together with a somatic missense variant identified in tumor DNA, c.1147A>G, p.(Thr383Ala), both located in exon 14. Using a range of in silico and functional assays we show that these variants are predicted to be pathogenic, profoundly impact enzyme activity, and result in DNA hypermethylation.Conclusions: The identification and functional analysis of these DLST variants further validates DLST as an additional PPGL gene involved in the TCA cycle.MTG

Limited carbon and biodiversity co-benefits for tropical forest mammals and birds

The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi-objective conservation planning when fine scale data on wildlife are lacking