Pre-emergent indaziflam can enhance forest seed germination in direct seeding?

Pre-emergent herbicides can contribute to the control of weed competition in direct seeding restoration, however it is necessary to evaluate their effects on seeds of native tropical forest species. The aim of the study was to assess the potential impact of the herbicide indaziflam on the germination of 17 forest species. For this, a dosage of 180 mL of the product in 200L of water was compared to the control without herbicide. The degree of sensitivity of each species was calculated by a ratio between the percentage of germination with herbicide (GH) and the control without herbicide (GC) classifying them as: extremely sensitive (ES= (GH/GC) <0.25), sensitive (S=0.25< (GH/GC) <0.50), low sensitivity (LS=0.50< (GH/GC) <0.75), indifferent (I=0.75< (GH/GC) <1.0) and potentiated (P= (GH/GC) >1). The herbicide promoted a significant reduction in mean germination in 35% (n=6) of the species and 59% (n = 10) were sensitive or extremely sensitive to indaziflam, and only three did not germinate. On the other hand, 29.4% (n=5) showed low sensitivity or indifference to the herbicide, while seed germination was slightly increased by indaziflam to 11.7% (n=2). Pre-emergent indaziflam can be recommended in direct seeding restoration, as only 17.6% (n=3) of the species were inhibited by pre-emergent. However, the effect of indaziflam varies by species and requires further studies to support large-scale use in direct seeding.

18F-FDG PET/CT images defined the true extent of a urothelial bladder carcinoma

A patient was referred, after neoadjuvant chemotherapy, for pre-surgical evaluation of urothelial bladder carcinoma (single lesion). Two thickenings in the left ureter wall identified on the CT scan were equivocal for malignancy. 18F-FDG PET/CT with delayed pelvic images, hyperhydration, and furosemide showed hypermetabolic ureteral metastases and multifocal bladder tumors. There were no lymph nodes or distant metastases. These 18F-FDG PET/CT findings completely altered the surgical treatment. The patient underwent left nephroureterectomy, radical cystoprostatectomy, and lymphadenectomy, followed by a urinary transit reconstruction. Histopathology confirmed multifocal high-grade urothelial carcinoma in the bladder walls and left ureter and benign lymph nodes.

Relative frequency of known causes of multiple mtDNA deletions: two novel POLG mutations

Diseases affecting mtDNA stability, termed nuclear-mitochondrial intergenomic communication disorders, are caused by a primary nuclear gene defect resulting in multiple mtDNA deletions. The aim of this study was to estimate the frequency of known etiologies and the spectrum of mutations in a cohort of 21 patients harboring multiple mtDNA deletions in skeletal muscle. We showed that 10 cases (48%) display mutations in POLG, including eight previously reported variants and two novel mutations (namely, p.Trp585X and p.Arg1081Gln). The novel mutations affect evolutionary conserved residues and were absent in a large set of control chromosomes. These findings expand the array of mutations associated with multiple rearranged mtDNA attributed to mutations in POLG. The relatively high diagnostic yield (about one in two cases) supports the notion that it is recommended to test POLG routinely in diagnostic laboratories whenever multiple mtDNA deletions are present, regardless of the age of onset of patients and their clinical phenotype.

A prevalent pathogenic GAMT mutation (c.59G>C) in Portugal

Guanidinoacetate methyltransferase (GAMT) deficiency (MIM 601240), an autosomal recessive disorder of creatine biosynthesis, presents with mental retardation, extrapyramidal symptoms, autistic-like behavior and epilepsy. Other hallmarks are cerebral creatine deficiency, increased levels of guanidinoacetate in body fluids and mutations in the GAMT gene. Creatine supplementation partially restores cerebral creatine content. Worldwide, 29 patients have been identified and 15 different mutations have been reported in the GAMT gene. Ten out of these 29 patients are of Portuguese origin. Likely, a founder effect and a high carrier rate in Portugal exist, since in 17 out of the 20 Portuguese alleles the c.59G>C; p.Trp20Ser mutation was found. We investigated the carrier rate of the c.59G>C; p.Trp20Ser mutation in different regions of Portugal and confirmed the pathogenic nature of this missense mutation by transient transfections. Anonymous bloodspots (1002) were screened for the presence of the c.59G>C; p.Trp20Ser mutation by SNaPshot (Single Nucleotide Polymorphism Multiplex Kit). Eight carriers of c.59G>C; p.Trp20Ser were detected of which four are derived from the Archipelagos. This suggests that the carrier rate of the c.59G>C; p.Trp20Ser mutation is relatively high in these islands, as well as in other parts of Portugal. It also implies that newborn screening in these regions is warranted for this treatable disorder.

Overexpression of GAMT restores GAMT activity in primary GAMT-deficient fibroblasts

Guanidinoacetate methyltransferase deficiency (MIM 601240) is an autosomal recessive disorder of creatine biosynthesis. Patients present with mental retardation, extrapyramidal symptoms, autistic-like behavior, epilepsy, cerebral creatine deficiency and increased levels of guanidinoacetate. So far 15 mutations have been reported, including six missense variants that are highly likely to be pathogenic mutations. To prove that mutations in the GAMT gene are responsible for GAMT deficiency we overexpressed the GAMT open reading frame in GAMT-deficient fibroblasts by stable transfection. In addition, HeLa cells were transiently transfected with the same expression vector. In contrast to mock transfectants transfection of primary GAMT-deficient fibroblasts with wild-type GAMT results in the restoration of GAMT activity as measured by GC-MS using stable isotope labeled substrates. Moreover, the expression of the GAMT-EGFP fusion protein was analyzed by Western blot, confirming the presence of GAMT fusion protein, both in the stable as well as in the transient transfectants. Here, we prove that mutations in the GAMT gene are responsible for GAMT deficiency, since overexpression of the GAMT open reading frame restores GAMT activity in GAMT-deficient fibroblasts. Furthermore, the transient transfection of HeLa cells will be important for functional analysis of variants of unknown consequence (i.e., missense mutations).

Are cerebral creatine deficiency syndromes on the radar screen?

Cerebral creatine deficiency syndromes (CCDS) are responsible for a considerable proportion of the population affected with mental retardation. CCDS are caused by either an inborn error of the proteins involved in creatine biosynthesis or in the creatine transporter. Besides mental retardation, the clinical characteristics of CCDS are speech and language delay, epilepsy and features of autism. CCDS can be diagnosed by proton magnetic resonance spectroscopy of the brain and/or by biochemical and molecular analysis. Treatment of the defects in creatine biosynthesis has yielded favorable outcomes, while treatments for creatine transporter deficiency are still under investigation at this time. The relatively large contribution of the CCDS to the monogenic causes of mental retardation emphasizes the importance of including CCDS in the differential diagnosis of mental retardation of unknown etiology. Pathophysiology is not yet unravelled, although it is known that creatine plays an important role in energy storage and transmission. Moreover, in vitro data indicate that creatine acts as a neuromodulator in the brain.

Creatine and guanidinoacetate: diagnostic markers for inborn errors in creatine biosynthesis and transport

In this study, measurements of guanidinoacetate (GAA) and creatine (Cr) in urine, plasma, and cerebrospinal fluid (CSF) were performed using stable isotope dilution gas chromatography-mass spectrometry. Both compounds were analyzed in a single analysis. Reference values were established for GAA and Cr. These values were age dependent. No differences with gender were observed. Eight guanidinoacetate methyltransferase (GAMT) deficient patients and eight creatine transporter SLC6A8 deficient patients were investigated. In urine, plasma, and CSF of GAMT deficient patients increased levels of GAA are present. The SLC6A8 deficient patients all show increased creatine/creatinine (Cr/Crn) ratio in urine demonstrating the importance of the Cr/Crn ratio as a pathognomonic marker of the SLC6A8 deficiency.