Sporadic Patients Research Articles

Models of dental care for people experiencing homelessness in the UK: a scoping review of the literature.

Background People who experience homelessness have poor oral health and face barriers to accessing care. Recommendations have been outlined for health services to address their needs, termed 'inclusion health'. The Smile4Life report recommended three 'tiers' of dental service: emergency, ad hoc and routine care. Other medical services have developed into different models of care, for example mainstream practices with enhanced services for people who experience homelessness. There is little understanding of how inclusion health recommendations have been implemented across dental settings.Aims To describe and compare dental services that exist for people who experience homelessness in the UK.Methods Two Medline searches were performed in October 2020 to assess the models of dental care for people who experience homelessness in the UK.Results Nine dental services in the UK were identified who treated people who experience homelessness. Most did not explore definitions of homelessness. There were a mixture of models, including using blended approaches, such as different sites and appointment types, to flex to the needs of their population.Conclusion Many services that are dedicated to treat this population are based in the community dental services which allows for flexible models of care due to sporadic patient attendance, high treatment requirements and complex needs. More research is required to determine how other settings can accommodate these patients, as well as understanding how more rural populations access dental care.

Gender-specific association of uric acid and survival in sporadic amyotrophic lateral sclerosis patients

ObjectiveTo investigate the relationship between serum uric acid (UA) and survival in sporadic amyotrophic lateral sclerosis (sALS) patients. MethodA total of 801 sporadic amyotrophic lateral sclerosis (sALS) patients fulfilled the revised El Escorial criteria were enrolled and followed up in the study. Baseline clinical data and laboratory variables including gender, age, age of onset, site of onset, disease duration, body mass index (BMI), uric acid (UA), creatinine (Cr), and creatine kinase (CK) were collected during enrollment. Multivariate Cox regression models were used to evaluate the survival-related factors after adjustment for confounders. ResultsThe serum UA level was significantly lower in female patients than that in male patients (243.5 vs 314.9 μmol/L, p < 0.001). Gender, BMI, Cr, CK were significantly associated with the level of uric acid according to the linear regression analysis. In the multivariate Cox regression analysis, higher serum UA level (>268.0 μmol/L) was an independent protective factor for prolonged survival among female patients (HR = 0.69, P = 0.042) after adjustment for confounders. ConclusionThe present study provided further support that higher UA was a protective factor for survival in sALS patients, especially in female.

Verification of propagation hypothesis in patients with sporadic hand onset amyotrophic lateral sclerosis.

If lesions in sporadic amyotrophic lateral sclerosis (ALS) originate from a single focal onset site and spread contiguously by prion-like cell-to-cell propagation at a constant speed, the lesion spread time should be proportional to the anatomical distance. We verify this model in the patients. In 29 sporadic ALS patients with hand onset followed by spread to shoulder and leg, we retrospectively evaluated the inter/intra-regional spread time ratio: time interval of symptoms from hand-to-leg divided by that from hand-to-shoulder. We also obtained the corresponding inter-/intra-regional distance ratios of spinal cord from magnetic resonance imaging of 12 patients, and those of primary motor cortex from coordinates using neuroimaging software. Inter-/intra-regional spread time ratios ranged from 0.29 to 6.00 (median 1.20). Distance ratios ranged from 1.85 to 2.86 in primary motor cortex and from 5.79 to 8.67 in spinal cord. Taken together with clinical manifestations, of 27 patients with the requisite information available, lesion spreading was consistent with the model in primary motor cortex in 4 (14.8%) patients, and in spinal cord in only 1 (3.7%) patient. However, in more patients (12 of 29 patients: 41.4%), the inter-regional spread times in a long anatomical distance of hand-to-leg were shorter than or equal to the intra-regional spread times in a short anatomical distance of hand-to-shoulder. Contiguous cell-to-cell propagation at a constant speed might not play a major role at least in distant lesion spreading of ALS. Several mechanisms can be responsible for progression in ALS.

Long-term Recurrence Rates After Surgery in Primary Hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia, yet long-term (5- and 10-year) recurrence rates after curative surgery have been unclear. To perform the first systematic review and meta-analysis investigating the long-term recurrence rates of sporadic PHPT after successful parathyroidectomy. A comprehensive search of multiple databases (including PubMed, EMBASE, Cochrane, EBSCO-CINHAL, EMBASE, Ovid, Scopus, and Google Scholar) was performed from each database's inception to January 18, 2023. Observational studies reporting at least 5 years of follow-up data after surgical resection were included. Two reviewers independently screened articles for relevance. Of 5769 articles initially identified, 242 were examined in full-text review and 34 were deemed eligible for inclusion. Two authors independently performed data extraction and study appraisal, using the National Institutes of Health study quality assessment tools. Of 30 658 participants, 350 patients (1.1%) experienced recurrence after resection. A meta-analysis of proportions was performed to obtain the pooled recurrence rates. The pooled estimate for overall recurrence rate was 1.56% (95% CI 0.96-2.28%; I2 = 91%). The pooled estimates for 5- and 10-year recurrence rate after resection were 0.23% (0.04-0.53%, 19 studies; I2 = 66%) and 1.03% (0.45-1.80%, 14 studies; I2 = 89%), respectively. Sensitivity analyses did not find a statistically significant difference when adjusting for study size, diagnosis, or surgical approach. Approximately 1.56% of sporadic PHPT patients eventually develop recurrence following parathyroidectomy. The initial diagnosis and procedure type does not influence recurrence rates. Consistent long-term follow-up is warranted to help identify recurrent disease.

Tumor immune environment in colitis-associated colorectal cancers: Comparison with sporadic colorectal cancers.

e15531 Background: Persistent inflammatory diseases such as ulcerative colitis (UC) and Crohn’s disease (CD) contribute to the tumor initiation and progression in colitis-associated cancers (CAC). Intestinal damage caused by persistent inflammation promotes clonal expansion of somatic and epithelial cells and alters the immune microenvironment. A comprehensive investigation in comparing the tumor immune environment in CAC with sporadic colorectal cancers (CRC) will provide more clinical usefulness of immunoprofiling in CRC. Methods: Thirteen patients with CAC (6 with UC and 7 with CD) and 10 patients with sporadic colorectal cancer from our hospital were enrolled in the study. FFPE samples from patients were analyzed for the tumor infiltrating lymphocytes [PD-L1+, CD3+, CD4+, CD8+, CD20+, CD68+, CD163+] by multiplex immunofluorescence technique. The core and peritumor areas annotated by pathologists on images. Then artificial intelligence (AI) algorithms delineated the tumor-enriched segments and stroma, and calculated the density and percentage of each marker in two regions. A nonparametric approach (Kruskal–Wallis) was used to compare the density and percentage of immune cells between CAC and sporadic colorectal cancer groups. Results: In the stroma area, the density (counts per mm2) of PD-L1+CD68+ cells in patients with CAC were significantly higher than those in sporadic cancer patients (p &lt; 0.05). However, the density of PD-L1+CD68+ did not show significant differences related to disease types (CAC or sporadic CRC) in the tumor-enriched segments. Significantly, the density of CD3+CD4+ cells and the percentage of CD68+CD163- cells in patients with CAC showed a trend of higher density than those in sporadic cancer patients in the stroma area (all, 0.05 &lt; p &lt; 0.1). The density and the percentage of CD20+ cells in CAC patients had a higher density tendency than those in sporadic cancer patients both in the tumor-enriched segments and stroma (all, 0.05 &lt; p &lt; 0.1). Other indicators in tumor-enriched segments and stroma, such as CD3+, CD4+, CD8+, CD68+CD163+ and PD-L1+, had no significant difference between CAC and sporadic CRC patients, regardless of the percentage or the density. Conclusions: We identified that the tumor immune environment of CAC was different from that of sporadic CRC. Some tumor infiltrating lymphocytes such as PD-L1+CD68+ cells infiltrated more in CAC than those in sporadic cancer, suggesting that CAC may respond better to immunotherapy than sporadic CRC. However, this hypothesis requires a further validation with a larger sample size.

Analysis of the CHD7 gene mutations in patients of congenital heart disease with extracardiac malformations.

Congenital heart disease (CHD) is a common birth defect, and is frequently accompanied with extracardiac malformations (ECM). Uncovering the genetic etiology of CHD may have a meaningful impact on disease management. De novo variants have been proven to be associated with CHD. Whole exome sequencing was performed for 4 unrelated CHD families with extracardiac malformations, candidate genes were screened by using stringent bioinformatics analysis, and the obtained variants were confirmed by Sanger sequencing. RT-PCR and Sanger sequencing were used to investigate the influence of a splice variant on pre-mRNA splicing. Further targeted sequencing was conducted to investigate the association of CHD7 variants with sporadic CHD. Four novel heterozygous loss-of-function CHD7 mutations were found by using stringent bioinformatics analysis: the frameshift mutation c.1951_1952delAAinsT (p.L651X) in family #1, the nonsense mutations c.2913C>G (p.Y971X) in family #2 and c.3106C>T (pA1036X) in family #3, and the splicing mutation c.4353+4_4353+12delinsGCCCA in family #4. Sanger sequencing confirmed that these were all de novo mutations and were absent in the healthy parents and siblings of the probands. Further studies revealed that the splice mutation c.4353+4_4353+12delinsGCCCA influenced CHD7 mRNA splicing in vivo. Targeted sequencing found 23 rare mutations in 1,155 sporadic CHD patients. The findings here confirm that de novo loss-of-function variants of the CHD7 gene are the genetic cause of familial CHD with extracardiac malformations and the spectrum of pathogenic CHD7 variants in sporadic CHD is expanded.

Hemiplegic Migraine in Children and Adolescents.

Only a few studies have focused on hemiplegic migraine (HM) in children despite its early age of onset. The aim of this review is to describe the peculiar characteristics of pediatric HM. This is a narrative review based on 14 studies on pediatric HM selected from 262 papers. Different from HM in adults, pediatric HM affects both genders equally. Early transient neurological symptoms (prolonged aphasia during a febrile episode, isolated seizures, transient hemiparesis, and prolonged clumsiness after minor head trauma) can precede HM long before its onset. The prevalence of non-motor auras among children is lower than it is in adults. Pediatric sporadic HM patients have longer and more severe attacks compared to familial cases, especially during the initial years after disease onset, while familial HM cases tend to have the disease for longer. During follow-up, the frequency, intensity, and duration of HM attacks often decrease. The outcome is favorable in most patients; however, neurological conditions and comorbidities can be associated. Further studies are needed to better define the clinical phenotype and the natural history of pediatric HM and to refine genotype-phenotype correlations in order to improve the knowledge on HM physiopathology, diagnosis, and outcome.

Gene Panel Sequencing Analysis Revealed a Strong Contribution of Rare Coding Variants to the Risk of Parkinson's Disease in Sporadic Moroccan Patients.

Parkinson's disease (PD) is a neurodegenerative movement disorder which can be either familial or sporadic. While it is well known that monogenic mutations are not a very common cause of PD, GWAS studies have shown that an additional fraction of the PD heritability could be explained by rare or common variants. To identify the rare variants that could influence the risk of PD in the Moroccan population, a cohort of 94 sporadic PD patients negative for the LRRK2 G2019S mutation was subjected to NGS gene panel sequencing, and gene dosage using the MLPA method. Mean age of onset at enrollment was 51.7 ± 11.51years, and 60% of patients were men. We identified 70 rare variants under 0.5% of frequency in 16 of the 20 genes analyzed, of which 7 were novel. Biallelic disease-causing variants in genes with recessive inheritance were found in 5 PD cases (5.31%), whereas 13 patients (13.8%) carried likely pathogenic variants in genes with dominant inheritance. Moreover, 8 patients (8.5%) carried a single variant in MAPT or POLG, whereas co-occurrence of rare variants involving more than one gene was observed in 28 patients (30%). PD patients with variants in recessive genes had a younger mean age at onset than patients with dominant ones (33.40 (12.77) vs. 53.15 (6.63), p < 0.001), while their clinical features were similar. However, patients with rare variants in the risk factor genes or in more than one gene tended to have less resting tremor (p < 0.04), but more dystonia (p < 0.006) and dementia (p < 0.002) than those without any rare variants in known PD-associated genes. Our results showed a significant enrichment of rare variants particularly in LRRK2, VPS13C, POLG, and MAPT and underline their impact on the risk of sporadic form of the disease.

PINK1-Dependent Mitophagy Inhibits Elevated Ubiquitin Phosphorylation Caused by Mitochondrial Damage.

Ubiquitin phosphorylation by the mitochondrial protein kinase PTEN-induced kinase 1 (PINK1), upon mitochondrial depolarization, is an important intermediate step in the recycling of damaged mitochondria via mitophagy. As mutations in PINK1 can cause early-onset Parkinson's disease (PD), there has been a growing interest in small-molecule activators of PINK1-mediated mitophagy as potential PD treatments. Herein, we show that N6-substituted adenosines, such as N6-(2-furanylmethyl)adenosine (known as kinetin riboside) and N6-benzyladenosine, activate PINK1 in HeLa cells and induce PINK1-dependent mitophagy in primary mouse fibroblasts. Interestingly, pre-treatment of HeLa cells and astrocytes with these compounds inhibited elevated ubiquitin phosphorylation that is induced by established mitochondrial depolarizing agents, carbonyl cyanide m-chlorophenyl-hydrazine and niclosamide. Together, this highlights N6-substituted adenosines as progenitor PINK1 activators that could potentially be developed, in the future, as treatments for aged and sporadic PD patients who have elevated phosphorylated ubiquitin levels in the brain.

The incidence rate of allergic reactions induced by oxaliplatin is higher in patients with rectal cancer compared with colon cancer

Aim To explore the diverse profiles of adverse reactions caused by oxaliplatin between colon and rectal cancer, we investigated the toxicity of oxaliplatin in patients with colon and rectal cancer. Methods From January 2017 to December 2021, 200 cases of sporadic CRC patients with adverse reactions after oxaliplatin were collected from Harbin Medical University Cancer Hospital, Harbin, China. All patients received a chemotherapy regimen containing oxaliplatin (100 colon cancer and 100 rectal cancer). We reviewed the adverse reactions induced by oxaliplatin in patients with colon and rectal cancer. Results We found there was no significant difference in gastrointestinal toxicity, hematotoxicity, neurotoxicity, hepatotoxicity, respiratory toxicity, and cardiotoxicity caused by oxaliplatin between patients with colon cancer and patients with rectal cancer, but patients with rectal cancer were more prone to allergic reactions than patients with colon cancer after oxaliplatin. In addition, we found neutrophil-to-lymphocyte ratios (NLR) and platelet-to-lymphocyte ratios (PLR) were higher in patients with colon cancer than in patients with rectal cancer. This may reflect differences in immune status and inflammatory responses between colon cancer and rectal cancer, which might be the reason for more allergic reactions caused by oxaliplatin in colon cancer patients compared to rectal cancer patients. Conclusion Except for a higher incidence of allergic reactions in patients with rectal cancer, no significant difference in the incidence of adverse drug reactions associated with oxaliplatin was noted between patients with colon cancer and rectal cancer. Our results suggested more attention should be paid to the allergic reaction caused by oxaliplatin in patients with colon cancer.

Pathways Related to Colon Inflammation Are Associated with Colorectal Carcinoma: A Transcriptome- and Methylome-Wide Study.

The association of chronic inflammation with colorectal carcinoma (CRC) development is well known in ulcerative colitis (UC). However, the role of inflammatory changes in sporadic CRC pathogenesis is less widely appreciated. In this study, in the first step using RNA-seq, we identified gene-pathway-level changes in UC-associated CRC (UC CRC, n = 10) and used the changes as a proxy for inflammation in human colon to ask if there were associations of inflammatory pathway dysregulations in sporadic CRC pathogenesis (n = 8). We found down-regulations of several inflammation-related metabolic pathways (nitrogen metabolism, sulfur metabolism) and other pathways (bile secretion, fatty acid degradation) in sporadic CRC. Non-inflammation-related changes included up-regulation of the proteasome pathway. In the next step, from a larger number of paired samples from sporadic CRC patients (n = 71) from a geographically and ethnically different population and using a different platform (microarray), we asked if the inflammation-CRC association could be replicated. The associations were significant even after stratification by sex, tumor stage, grade, MSI status, and KRAS mutation status. Our findings have important implications to widen our understanding of inflammatory pathogenesis of sporadic CRC. Furthermore, targeting of several of these dysregulated pathways could provide the basis for improved therapies for CRC.

Identification and functional analyses of a novel FOXL2 pathogenic variant causing blepharophimosis, ptosis, and epicanthus inversus syndrome.

To discover the molecular pathogenic basis of the blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES), and to predict the clinical subtype according to in vitro experiments, which is significant to the prognosis. A 3-year-old sporadic female patient with typical clinical manifestations of BPES was enrolled. The coding region of forkhead box L2 (FOXL2) gene was sequenced, and the functional assays were performed in vitro by Western blotting, subcellular localization experiment, luciferase reporter assay, and quantitative real-time polymerase chain reaction. A novel FOXL2 point pathogenic variant (c.274G>T) was detected, resulting in a truncated protein (p.E92*). Functional studies demonstrated that the FOXL2 pathogenic variant induced the subcellular mislocalization and the abnormal transcriptional activity on promoters of the steroidogenic acute regulatory protein (StAR or STARD1) gene and the odd-skipped related 2 transcription factor (OSR2) gene. A novel pathogenic variant is identified to expand the spectrum of the known FOXL2 mutations. The in vitro experiments provide reference data and more insights to the molecular pathogenesis of BPES. The predicted high risk of ovarian insufficiency makes it significant for the patient enrolled to have further follow-up and therapy concerning female endocrinology.

The epidemiological and clinical characteristics of patients with young-onset genetic Creutzfeldt-Jakob disease

ABSTRACT Objectives The onset of Creutzfeldt-Jakob disease (CJD) is usually around the age of 60, but younger patients have been described as well. Our study characterizes the demographic and clinical features of young-onset CJD patients. Methods The CJD Israeli National Database was reviewed, and the patients were divided into groups of young (<40-year-old) (Y|) and older disease onset (>40-year-old) (O). Each group was further divided into sporadic (sCJD) and genetic (gCJD) patients. Clinical and demographic parameters were compared between the groups Results The study included 731 patients (Y- 18 patients, O- 713 patients). MRI showed classical features more often in the older population (O-76.9%, Y-36%, p = 0.006). Rapidly progressive dementia as a presenting feature was more common in the older group (O = 58%, Y = 27.7%, p = 0.019) whereas cerebellar onset (gait instability, dysarthria) was more common in the younger group (O = 6.7%, Y = 27.7%, p = 0.036)). Among gCJD patients, rapidly progressive dementia was commonly seen in older patients (O = 54%, Y = 21% p = 0.008) whereas cerebellar symptoms were seen in young patients (O = 7%, Y = 30% p = 0.01) Typical MRI findings were seen in 37% of young people compared to 87% of older patients (p = 0.002). No significant differences were between young and older patients in the sCJD group. Conclusion Young-onset gCJD patients have unique disease features including less typical brain MRI changes, a lower prevalence of dementia, and a higher prevalence of cerebellar signs at disease onset.

Unexpected phenotypic and molecular changes of combined glucocerebrosidase and acid sphingomyelinase deficiency.

Heterozygous variants in GBA1, encoding glucocerebrosidase (GCase), are the most common genetic risk factor for Parkinson's disease (PD). Moreover, sporadic PD patients also have a substantial reduction of GCase activity. Genetic variants of SMPD1 are also overrepresented in PD cohorts, whereas a reduction of its encoded enzyme (acid sphingomyelinase or ASM) activity is linked to an earlier age of PD onset. Despite both converging on the ceramide pathway, how the combined deficiencies of both enzymes might interact to modulate PD has yet to be explored. Therefore, we created a double-knockout (DKO) zebrafish line for both gba1 (or gba) and smpd1 to test for an interaction in vivo, hypothesising an exacerbation of phenotypes in the DKO line compared to those for single mutants. Unexpectedly, DKO zebrafish maintained conventional swimming behaviour and had normalised neuronal gene expression signatures compared to those of single mutants. We further identified rescue of mitochondrial Complexes I and IV in DKO zebrafish. Despite having an unexpected rescue effect, our results confirm ASM as a modifier of GBA1 deficiency in vivo. Our study highlights the need for validating how genetic variants and enzymatic deficiencies may interact in vivo.

Colitis-Associated Colorectal Cancer Survival is Comparable to Sporadic Cases after Surgery: a Matched-Pair Analysis

BackgroundInflammatory bowel disease (IBD) confers an increased lifetime risk of colorectal cancer (CRC). The pathogenesis of colitis-associated CRC is considered distinct from sporadic CRC, but existing is mixed on long-term oncologic outcomes. This study aims to compare clinicopathological characteristics and survival between colitis-associated and sporadic CRC. MethodsData was retrospectively extracted and analyzed from a single institutional database of patients with surgically resected CRC between 2004 and 2015. Patients with IBD were identified as having colitis-associated CRC. The remainder were classified as sporadic CRC. Propensity score matching was performed. Univariate and survival analyses were carried out to estimate the differences between the two groups. ResultsOf 2275 patients included in this analysis, 65 carried a diagnosis of IBD (2.9%, 33 Crohn’s disease, 29 ulcerative colitis, 3 indeterminate colitis). Average age at CRC diagnosis was 62 years for colitis-associated CRC and 65 for sporadic CRC. The final propensity score matched cohort consisted of 65 colitis-associated and 130 sporadic CRC cases. Patients with colitis-associated CRC were more likely to undergo total proctocolectomy (p < 0.01) and had higher incidence of locoregional recurrence (p = 0.026) compared to sporadic CRC patients. There were no significant differences in time to recurrence, tumor grade, extramural vascular invasion, perineural invasion, or rate of R0 resections. Overall survival and disease-free survival did not differ between groups. On multiple Cox regression, IBD diagnosis was not a significant predictor of survival. ConclusionsPatients with colitis-associated CRC who undergo surgical resection have comparable overall and disease-free survival to patients with sporadic CRC.

Role of NCKAP1 in the Defective Phagocytic Function of Microglia-Like Cells Derived from Rapidly Progressing Sporadic ALS

Microglia plays a key role in determining the progression of amyotrophic lateral sclerosis (ALS), yet their precise role in ALS has not been identified in humans. This study aimed to identify a key factor related to the functional characteristics of microglia in rapidly progressing sporadic ALS patients using the induced microglia model, although it is not identical to brain resident microglia. After confirming that microglia-like cells (iMGs) induced by human monocytes could recapitulate the main signatures of brain microglia, step-by-step comparative studies were conducted to delineate functional differences using iMGs from patients with slowly progressive ALS [ALS(S), n = 14] versus rapidly progressive ALS [ALS(R), n = 15]. Despite an absence of significant differences in the expression of microglial homeostatic genes, ALS(R)-iMGs preferentially showed defective phagocytosis and an exaggerated pro-inflammatory response to LPS stimuli compared to ALS(S)-iMGs. Transcriptome analysis revealed that the perturbed phagocytosis seen in ALS(R)-iMGs was closely associated with decreased NCKAP1 (NCK-associated protein 1)-mediated abnormal actin polymerization. NCKAP1 overexpression was sufficient to rescue impaired phagocytosis in ALS(R)-iMGs. Post-hoc analysis indicated that decreased NCKAP1 expression in iMGs was correlated with the progression of ALS. Our data suggest that microglial NCKAP1 may be an alternative therapeutic target in rapidly progressive sporadic ALS.

Octapeptide repeat alteration mutations of the prion protein gene in clinically diagnosed Alzheimer's disease and frontotemporal dementia.

Studies focusing on octapeptide repeat alteration mutations in PRNP in Alzheimer's disease (AD) and frontotemporal dementia (FTD) cohorts have been rare. We aim to screen sporadic AD and FTD patients with unknown etiology for the octapeptide repeat insertions and deletions in PRNP. Two hundred and six individuals were screened for alterations to the repeat region in the PRNP gene, including 146 sporadic AD and 60 sporadic FTD patients. Our study showed a 1.5% (3/206) occurrence of the octapeptide repeat alteration mutations in PRNP in a Chinese cohort of sporadic dementia. One late-onset FTD patient and one early-onset AD patient each had a two-octapeptide repeat deletion in PRNP, while one early-onset AD patient had a five-octapeptide repeat insertion mutation. PRNP octapeptide repeat alteration mutations are present in sporadic AD and FTD patients. The genetic investigation for PRNP octapeptide repeat alteration mutations in sporadic dementia patients should be carried out in future clinical studies.

Lattice Light-Sheet Microscopy as a Key Method for the Analysis of the Mislocalization of TDP-43 in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease) is a neurodegenerative disorder that is characterized by the progressive loss of motor neurons. Consequently, patients afflicted with this disease eventually lose the motor function associated with moving, speaking, eating, and even breathing. One neuroscience team identified a common mechanism in nearly all sporadic ALS patients in which transactive response DNA binding protein 43 kDa (TDP-43) was mislocalized from the nucleus to the cytoplasm. This suggests that the mislocalization of TDP-43 into the cytoplasm is central for the onset of ALS in patients, but the underlying factors that result in this process are not fully understood as there are no current laboratory methods to study the progression of TDP-43 mislocalization. However, the development and refinement of lattice light-sheet microscopy (LLSM) as a laboratory technique has significant potential in helping scientists elucidate the unknown processes behind ALS. This review discusses the implications of lattice light-sheet microscopy and its optimization methods as a solution to the issue and identifies LLSM as a key method that could be significant in the field of ALS research.

Spectrum and frequency of genetic variants in sporadic amyotrophic lateral sclerosis.

Therapy of motoneuron diseases entered a new phase with the use of intrathecal antisense oligonucleotide therapies treating patients with specific gene mutations predominantly in the context of familial amyotrophic lateral sclerosis. With the majority of cases being sporadic, we conducted a cohort study to describe the mutational landscape of sporadic amyotrophic lateral sclerosis. We analysed genetic variants in amyotrophic lateral sclerosis-associated genes to assess and potentially increase the number of patients eligible for gene-specific therapies. We screened 2340 sporadic amyotrophic lateral sclerosis patients from the German Network for motor neuron diseases for variants in 36 amyotrophic lateral sclerosis-associated genes using targeted next-generation sequencing and for the C9orf72 hexanucleotide repeat expansion. The genetic analysis could be completed on 2267 patients. Clinical data included age at onset, disease progression rate and survival. In this study, we found 79 likely pathogenic Class 4 variants and 10 pathogenic Class 5 variants (without the C9orf72 hexanucleotide repeat expansion) according to the American College of Medical Genetics and Genomics guidelines, of which 31 variants are novel. Thus, including C9orf72 hexanucleotide repeat expansion, Class 4, and Class 5 variants, 296 patients, corresponding to ∼13% of our cohort, could be genetically resolved. We detected 437 variants of unknown significance of which 103 are novel. Corroborating the theory of oligogenic causation in amyotrophic lateral sclerosis, we found a co-occurrence of pathogenic variants in 10 patients (0.4%) with 7 being C9orf72 hexanucleotide repeat expansion carriers. In a gene-wise survival analysis, we found a higher hazard ratio of 1.47 (95% confidence interval 1.02-2.1) for death from any cause for patients with the C9orf72 hexanucleotide repeat expansion and a lower hazard ratio of 0.33 (95% confidence interval 0.12-0.9) for patients with pathogenic SOD1 variants than for patients without a causal gene mutation. In summary, the high yield of 296 patients (∼13%) harbouring a pathogenic variant and oncoming gene-specific therapies for SOD1/FUS/C9orf72, which would apply to 227 patients (∼10%) in this cohort, corroborates that genetic testing should be made available to all sporadic amyotrophic lateral sclerosis patients after respective counselling.

Cathepsin B Deficiency Improves Memory Deficits and Reduces Amyloid-β in hAβPP Mouse Models Representing the Major Sporadic Alzheimer's Disease Condition.

The lysosomal cysteine protease cathepsin B (CTSB) has been suggested as a biomarker for Alzheimer's disease (AD) because elevated serum CTSB in AD patients has been found to correlate with cognitive dysfunction. Furthermore, CTSB gene knockout (KO) in non-transgenic and transgenic AD animal models showed that elimination of CTSB improved memory deficits. However, conflicting CTSB KO results on amyloid-β (Aβ) pathology in transgenic AD models have been reported. The conflict is resolved here as likely being due to the different hAβPP transgenes used in the different AD mouse models. CTSB gene KO reduced wild-type (Wt) β-secretase activity, brain Aβ, pyroglutamate-Aβ, amyloid plaque, and memory deficits in models that used cDNA transgenes expressing hAβPP isoform 695. But in models that used mutated mini transgenes expressing hAβPP isoforms 751 and 770, CTSB KO had no effect on Wt β-secretase activity and slightly increased brain Aβ. All models expressed the AβPP transgenes in neurons. These conflicting results in Wt β-secretase activity models can be explained by hAβPP isoform specific cellular expression, proteolysis, and subcellular processing. CTSB KO had no effect on Swedish mutant (Swe) β-secretase activity in hAβPP695 and hAβPP751/770 models. Different proteolytic sensitivities for hAβPP with Wt versus Swe β-secretase site sequences may explain the different CTSB β-secretase effects in hAβPP695 models. But since the vast majority of sporadic AD patients have Wt β-secretase activity, the CTSB effects on Swe β-secretase activity are of little importance to the general AD population. As neurons naturally produce and process hAβPP isoform 695 and not the 751 and 770 isoforms, only the hAβPP695 Wt models mimic the natural neuronal hAβPP processing and Aβ production occurring in most AD patients. Significantly, these CTSB KO findings in the hAβPP695 Wt models demonstrate that CTSB participates in memory deficits and production of pyroglutamate-Aβ (pyroglu-Aβ), which provide rationale for future investigation of CTSB inhibitors in AD therapeutics development.