Low neutralizing antibody responses in WM,CLL and NHL patients after the first dose of the BNT162b2 and AZD1222 vaccine

Clinical and Experimental Medicine - Vaccination against SARS-CoV-2 is considered as the most important preventive strategy against COVID-19, but its efficacy in patients with hematological...     

Phosphinic acids: current status and potential for drug discovery

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ALS-linked TDP-43 mutations produce aberrant RNA splicing and adult-onset motor neuron disease without aggregation or loss of nuclear TDP-43

Transactivating response region DNA binding protein (TDP-43) is the major protein component of ubiquitinated inclusions found in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitinated inclusions. Two ALS-causing mutants (TDP-43^Q331K and TDP-43^M337V), but not wild-type human TDP-43, are shown here to provoke age-dependent, mutant-dependent, progressive motor axon degeneration and motor neuron death when expressed in mice at levels and in a cell type-selective pattern similar to endogenous TDP-43. Mutant TDP-43-dependent degeneration of lower motor neurons occurs without: (i) loss of TDP-43 from the corresponding nuclei, (ii) accumulation of TDP-43 aggregates, and (iii) accumulation of insoluble TDP-43. Computational analysis using splicing-sensitive microarrays demonstrates alterations of endogenous TDP-43–dependent alternative splicing events conferred by both human wild-type and mutant TDP-43^Q331K, but with high levels of mutant TDP-43 preferentially enhancing exon exclusion of some target pre-mRNAs affecting genes involved in neurological transmission and function. Comparison with splicing alterations following TDP-43 depletion demonstrates that TDP-43^Q331K enhances normal TDP-43 splicing function for some RNA targets but loss-of-function for others. Thus, adult-onset motor neuron disease does not require aggregation or loss of nuclear TDP-43, with ALS-linked mutants producing loss and gain of splicing function of selected RNA targets at an early disease stage.Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-U) are progressive, adult-onset neurodegenerative diseases with overlapping clinical and pathological features (1–3). ALS is characterized by the selective loss of upper and lower motor neurons, leading to progressive fatal paralysis and muscle atrophy. A large majority (∼90%) of ALS and FTLD-U cases are without a known genetic cause. Importantly, in these sporadic cases, the appearance of ubiquitinated inclusions within the affected neurons of the nervous system characterizes both ALS and FTLD-U patients, suggesting an overlapping mechanism underlying both diseases. Biochemical characterization of brains and spinal cords from ALS and FTLD-U patients identified transactivating response region (TAR) DNA binding protein (TDP-43) as the major protein component of these ubiquitinated inclusions (4, 5). The discovery of ALS-linked mutations in the glycine-rich C-terminal domain of TDP-43 (6-8) demonstrated a pathological role of TDP-43 in both diseases. The subsequent identification of mutations in a structurally and functionally related nucleic acid binding protein, FUS/TLS (fused in sarcoma/translocated in liposarcoma) (9, 10), further implicated defects in RNA processing in ALS pathogenesis.TDP-43 is a multifunctional nucleic acid binding protein. Within the nervous system, TDP-43 binds to >6,000 pre-mRNAs and affects the levels of ∼600 mRNAs and the splicing patterns of another 950 (11). Structurally, the 414-aa protein consists of two RNA recognition motifs (RRM1 and RRM2) (12, 13), nuclear import and export signal (14), and a glycine-rich region implicated in protein–protein interactions (15, 16) that include components of the RNA splicing machinery (17, 18).Disruption in mice of the highly conserved Tardbp gene is embryonically lethal (19–22). Similarly, postnatal inactivation of Tardbp (by Cre recombinase-mediated gene excision encoded by a ubiquitously-expressed CAG-Cre transgene) results in rapid postnatal death accompanied by defects in fat metabolism (22). TDP-43 autoregulates its own RNA level (11, 23) at least in part by stimulating excision of an intron in its 3′ untranslated region, thereby making the spliced RNA a substrate for nonsense-mediated RNA degradation (11). Furthermore, transgenic rodent models have been used to demonstrate that overriding the autoregulatory mechanism by overexpression of unregulated wild-type (24–28) or disease-linked mutant (26, 28–35) TDP-43 transgenes can produce neurodegeneration in mice.ALS and FTLD-U patient brain and spinal cord samples are characterized by the accumulation of cytoplasmic TDP-43 aggregates accompanied by a distinct clearing of nuclear TDP-43 within affected neurons and glia (36, 37), implicating possible loss of nuclear TDP-43 function in disease pathogenesis. In human disease, TDP-43 has been reported to be abnormally phosphorylated, ubiquitinated, and cleaved to produce C-terminal fragments (4, 5, 38, 39). Ectopic expression of these C-terminal fragments in cell-culture models (40–42) has shown that they are aggregation-prone and confer an intrinsic toxicity. However, the extent of the contribution of these C-terminal fragments to disease pathogenesis is undetermined. Indeed, double-immunofluorescent labeling of ALS patient spinal cords using N-terminal–specific and C-terminal–specific antibodies suggests that inclusions in spinal cord motor neurons are comprised primarily of full-length TDP-43 (37). Importantly, retention of ability to bind RNA by full-length TDP-43 has been demonstrated to be required for toxicity in yeast, fly, and Caenorhabditis elegans models (43–46).Nevertheless, it remains unresolved whether toxicity to motor neurons from mutations in TDP-43 is mediated through a gain of toxic property, loss-of-function, or a combination of both. By generation of transgenic mice encoding levels of wild-type or mutant human TDP-43 comparable to endogenous TDP-43, we demonstrate mutant-dependent, age-dependent motor neuron disease from ALS-linked TDP-43 mutants in the absence of overexpression, cytoplasmic accumulation of a 35 kDa TDP-43 fragment, or insoluble TDP-43 aggregates. Accompanying autoregulation-mediated reduction of endogenous wild-type TDP-43 are splicing alterations previously identified to be TDP-43–dependent (11). Additional splicing alterations are identified by systematic genome-wide analyses of alternative splicing that are indicative of both enhancement and loss-of-function by the TDP-43 mutants for individual RNA substrates, from which we conclude that ALS-linked mutations confer both loss- and gain-of-function properties to TDP-43, and that these act intranuclearly to induce splicing alterations that may underlie age-dependent motor neuron disease.     

A RANDOMIZED TRIAL OF ISOKINETIC VERSUS ISOTONIC REHABILITATION PROGRAM AFTER ARTHROSCOPIC MENISCECTOMY

Background:

Although both isotonic and isokinetic exercises are commonly used in the rehabilitation of patients after arthroscopic meniscectomy no studies have compared their effect on strength recovery and functional outcomes.

Purpose:

The purpose of this study was to investigate the effects of two rehabilitation programs (isotonic and isokinetic) on muscle strength and functional performance after partial knee meniscectomy. A secondary purpose was to assess the correlation between isokinetic strength deficits and hop test performance deficits.

Methods:

Twenty male patients who underwent arthroscopic partial meniscectomy volunteered for the study. Both isotonic and isokinetic training were performed with the same equipment thereby blinding subjects to the mode of exercise. Main outcome measures were collected on the 14th and 33rd postoperative days and included isokinetic strength of the knee extensors and flexors, functional performance (single, triple, and vertical hopping) and the Lysholm questionnaire. Multivariate and univariate analyses of variance were used to assess the effects of the independent variables on the isokinetic variables, functional tests, and Lysholm score. Pearson''s correlation was used to assess the relationship between isokinetic strength deficits and functional performance deficits.

Results:

Isokinetic measures, functional tests, and the Lysholm score all increased between initial and final assessment (p≤0.003). However, there were no group or group*time effects on any of the outcome variables (p≥0.33). Functional tests were better predictors of isokinetic deficits in the 14^th compared to the 33^rd postoperative day.

Conclusion:

No differences were found in the outcomes of patients treated using an isokinetic and an isotonic protocol for rehabilitation after arthroscopic meniscectomy. More than half of patients did not meet the 90% criterion in the hop tests for safe return to sports five weeks after meniscectomy. There were correlations between the hop tests and isokinetic deficits two weeks after meniscectomy but not at the fifth week.

Level of evidence:

1b     

Memory enhancing effects of saffron in aged mice are correlated with antioxidant protection

Brain aging is characterized by cognitive decline and memory deficits that could be the result of oxidative stress and impaired cholinergic function. In this study, the effects of a daily, 7-day, intraperitoneal administration of saffron on cognitive functions were examined in both healthy adult (4 months old) and aged (20 months old), male Balb-c mice (n=8/group), by passive avoidance test. Whole brain homogenates (minus cerebellum) were collected for examination of brain oxidative markers, caspase-3 and acetylcholinesterase (AChE) activity. Results showed that saffron-treated mice exhibited significant improvement in learning and memory, accompanied by reduced lipid peroxidation products, higher total brain antioxidant activity and reduced caspase-3 activity in both age groups of mice. Furthermore, salt- and detergent-soluble AChE activity was significantly decreased only in adult mice. Thus, we showed, for the first time, that the significant cognitive enhancement conferred by saffron administration in mice, is more closely related to the antioxidant reinforcement. Next, we compared the effect of saffron (1-250 μg/mL), crocetin and safranal (1-125 μM) on H(2)O(2)-induced toxicity in human neuroblastoma SH-SY5Y cells. Both saffron and crocetin provided strong protection in rescuing cell viability (MTT assay), repressing ROS production (DCF assay) and decreasing caspase-3 activation. These data, together with earlier studies suggest that crocetin is a unique and potent antioxidant, capable of mediating the in vivo effects of saffron.     

Leukocytoclastic vasculitis after long-term treatment with sunitinib: a case report

We report on a 63-year-old woman, previously in good health, who had undergone nephrectomy for clear cell renal cell carcinoma in 2002. Because of systemic relapse with multiple lung metastases in 2006, the patient was treated with sunitinib 50 mg daily on a 4-weeks on-/2-weeks off-schedule. After 3 years of treatment, she developed a purpuric rash on her feet and trunk. Biopsy revealed leukocytoclastic vasculitis. No other organ involvement was diagnosed. She was started on oral prednisone 30 mg daily with rapid resolution of the vasculitic skin lesions. Sunitinib was temporally discontinued and reintroduced at the same dose level. Reappearance of a less serious vasculitis after 2 cycles of re-treatment was resolved in the weeks off-treatment and by reducing the dose of sunitinib along with 5 mg of prednisone daily. One year after the diagnosis, the patient is still on this therapy. Oncology providers should be aware of this rare but potentially serious, possible adverse effect of sunitinib.