Investigating silent pauses in connected speech: integrating linguistic, neuropsychological, and neuroanatomical perspectives across narrative tasks in post-stroke aphasia

Introduction

Silent pauses are regarded as integral components of the temporal organization of speech. However, it has also been hypothesized that they serve as markers for internal cognitive processes, including word access, monitoring, planning, and memory functions. Although existing evidence across various pathological populations underscores the importance of investigating silent pauses' characteristics, particularly in terms of frequency and duration, there is a scarcity of data within the domain of post-stroke aphasia.

Methods

The primary objective of the present study is to scrutinize the frequency and duration of silent pauses in two distinct narrative tasks within a cohort of 32 patients with chronic post-stroke aphasia, in comparison with a control group of healthy speakers. Subsequently, we investigate potential correlation patterns between silent pause measures, i.e., frequency and duration, across the two narrative tasks within the patient group, their performance in neuropsychological assessments, and lesion data.

Results

Our findings showed that patients exhibited a higher frequency of longer-duration pauses in both narrative tasks compared to healthy speakers. Furthermore, within-group comparisons revealed that patients tended to pause more frequently and for longer durations in the picture description task, while healthy participants exhibited the opposite trend. With regard to our second research question, a marginally significant interaction emerged between performance in semantic verbal fluency and the narrative task, in relation to the location of silent pauses-whether between or within clauses-predicting the duration of silent pauses in the patient group. However, no significant results were observed for the frequency of silent pauses. Lastly, our study identified that the duration of silent pauses could be predicted by distinct Regions of Interest (ROIs) in spared tissue within the left hemisphere, as a function of the narrative task.

Discussion

Overall, this study follows an integrative approach of linguistic, neuropsychological and neuroanatomical data to define silent pauses in connected speech, and illustrates interrelations between cognitive components, temporal aspects of speech, and anatomical indices, while it further highlights the importance of studying connected speech indices using different narrative tasks.

First clinical study of a novel complete metal-free ceramic total knee replacement system

Background

The aim of the study was to evaluate the safety and efficacy of a novel metal-free ceramic total knee replacement system.

Methods

Thirty-eight primary total knee arthroplasties (TKAs) were performed on 34 patients using the metal-free BPK-S ceramic total knee replacement system with both the femoral and tibial components of an alumina/zirconia ceramic composite. The clinical outcome was evaluated pre- and postoperatively at 3 (n = 32 TKA) and 12 months (n = 32 TKA) using the Knee Society Score (KSS), the Oxford Knee Score and the EQ-5D. Safety analysis was performed by radiological examination and assessment of adverse events.

Results

Postoperatively, the KSS, Oxford Knee Score and EQ-5D improved significantly at 3 and 12 months (p < 0.001). Non-progressive partial radiolucent lines were observed in six cases, but there was no osteolysis and no implant loosening. Induction or exacerbation of allergies did not occur during the follow-up.

Conclusions

The metal-free BPK-S ceramic total knee replacement system proved to be a safe and clinically efficient alternative to metal implants in this short-term follow-up study.

Randomised clinical trial: mesalazine (Salofalk granules) for uncomplicated diverticular disease of the colon--a placebo-controlled study

BACKGROUND

Robust evidence regarding medical intervention for symptomatic uncomplicated colonic diverticular disease (DD) is sparse.

AIM

To investigate mesalazine (Salofalk granules) in this setting.

METHODS

In a double-blind, placebo-controlled, multicentre, 6-week trial, patients were randomised to mesalazine 1000 mg three times daily or placebo. Primary efficacy endpoint was change in lower abdominal pain to week 4 (baseline defined using pain score from 7 days pre-treatment).

RESULTS

Median change in lower abdominal pain with mesalazine vs. placebo was -37 (n = 56) vs. -33 (n = 61) [P = 0.374; 95% CI (-11; 4)] in the intent-to-treat (ITT) population, and -41 (n = 40) vs. -33 (n = 51) [P = 0.053; 95% CI (-18; 0)] in the per-protocol (PP) population, i.e. the primary endpoint was not significantly different. Post hoc adjustment for confounding factors ('baseline pain intensity', 'baseline symptom score (Brodribb)', and 'localisation of diverticula in the descending colon') resulted in P = 0.111 [ITT, 95% CI (-15.4; 1.6)] and P = 0.005 [PP, 95% CI (-19.7; -3.5)]. Between-group differences increased using pain score on day 1 as baseline, and reached significance for the PP population [mesalazine -42, placebo -26, P = 0.010; 95% CI (-25; -3)]. Median change in combined symptom score from baseline to week 4 was 257 mm with mesalazine vs. 198 mm with placebo [P = 0.064; 95% CI (-3; 105)]. More placebo-treated patients received analgesic/spasmolytic concomitant medication (34.4% vs. mesalazine 21.4%), indicating improved pain relief with mesalazine (P = 0.119). Safety was comparable.

CONCLUSIONS

A daily dose of 3.0 g mesalazine may relieve pain during a symptomatic flare of uncomplicated DD. In this, the first placebo-controlled double-blind trial in acute uncomplicated DD, mesalazine showed promising therapeutic efficacy.

Glucagon and a glucagon-GLP-1 dual-agonist increases cardiac performance with different metabolic effects in insulin-resistant hearts

BACKGROUND AND PURPOSE

The prevalence of heart disease continues to rise, particularly in subjects with insulin resistance (IR), and improved therapies for these patients is an important challenge. In this study we evaluated cardiac function and energy metabolism in IR JCR:LA-cp rat hearts before and after treatment with an inotropic compound (glucagon), a glucagon-like peptide-1 (GLP-1) receptor agonist (ZP131) or a glucagon-GLP-1 dual-agonist (ZP2495).

EXPERIMENTAL APPROACH

Hearts from IR and lean JCR:LA rats were isolated and perfused in the working heart mode for measurement of cardiac function and metabolism before and after addition of vehicle, glucagon, ZP131 or ZP2495. Subsequently, cardiac levels of nucleotides and short-chain CoA esters were measured by HPLC.

KEY RESULTS

Hearts from IR rats showed decreased rates of glycolysis and glucose oxidation, plus increased palmitate oxidation rates, although cardiac function and energy state (measured by ATP/AMP ratios) was normal compared with control rats. Glucagon increased glucose oxidation and glycolytic rates in control and IR hearts, but the increase was not enough to avoid AMP and ADP accumulation in IR hearts. ZP131 had no significant metabolic or functional effects in either IR or control hearts. In contrast, ZP2495 increased glucose oxidation and glycolytic rates in IR hearts to a similar extent to that of glucagon but with no concomitant accumulation of AMP or ADP.

CONCLUSION AND IMPLICATIONS

Whereas glucagon compromised the energetic state of IR hearts, glucagon-GLP-1 dual-agonist ZP2495 appeared to preserve it. Therefore, a glucagon-GLP-1 dual-agonist may be beneficial compared with glucagon alone in the treatment of severe heart failure or cardiogenic shock in subjects with IR.

The product of ORF III in cauliflower mosaic virus interacts with the viral coat protein through its C-terminal proline rich domain

Using the yeast two-hybrid system, we show that the ORF III product of cauliflower mosaic virus (pIII) interacts through its C-terminus with the viral coat protein. The last five amino acids of pIII were essential for the interaction and virus infectivity. Deletion of the last three amino acids or the mutation F129A decreased the strength of the interaction by 90%. We further show that pIII is closely associated with virus particles found in the inclusion bodies of infected plants but not in viral particles released from the inclusion bodies by urea treatment.

Modulation of epileptiform discharges in the rat limbic system in vitro by noradrenergic agents

Application of bicuculline (20 microm) in a horizontal slice preparation of the rat limbic system induced epileptiform discharges ('bursts') that spread from the hippocampus to the entorhinal cortex (EC) and the basolateral amygdala (BLA). These bursts were time locked, with the CA3-CA2 regions discharging first at a 0.1+/-0. 008Hz (n=30 slices) frequency, followed after 27+/-3 ms by the superficial layers of the EC and after 44.3+/-3 ms by the BLA. Application of 50 microM noradrenaline (NA) for 4 min reduced the burst frequency to 40% of its initial value. Pharmacological study of NA action on burst frequency revealed that it consisted of a beta adrenoreceptor-mediated increase and an alpha(2) adrenoreceptor-mediated decrease of epileptiform bursting frequency.

Molecular characterization and chromosomal localization of mouse Puralpha gene

Puralpha is a 39-kDa sequence-specific single-stranded DNA/RNA binding protein with the ability to modulate transcription of several genes containing the Pur element in their promoter region. Human and mouse Puralpha exhibit an extraordinary degree of conservation with only two changes at amino acid residues 49 and 306. A 15-kb genomic clone encompassing the mouse Puralpha gene was isolated by screening the mouse genomic library, using a PCR-amplified fragment from human Puralpha cDNA. Results from sequencing analysis confirmed the isolated genomic clone to be Puralpha and not the other members of the Pur family, including Purbeta. Characterization of the mouse Puralpha gene by restriction analysis/Southern blotting and sequencing revealed that the Puralpha gene contains only one intron within the 5' UTR and the open reading frame was intact. Using chromosomal markers, the Puralpha gene was mapped to chromosome 18 in mouse and rat.

New (sulfonyloxy)piperazinyldibenzazepines as potential atypical antipsychotics: chemistry and pharmacological evaluation

A series of 2- or 8-trifluoromethylsulfonyloxy (TfO) and 2- or 8-methylsulfonyloxy (MsO) 11-piperazinyldibenzodiazepines, -oxazepines, and -thiazepines were synthesized and evaluated in pharmacological models for their potential clozapine-like properties. In receptor binding assays, the 2-TfO analogues (18a, GMC2-83; 24, GMC3-06; and previously reported GMC1-169, 9a) of the dibenzazepines have profiles comparable to that of clozapine, acting on a variety of CNS receptors except they lack M1 receptor affinity. Introduction of 2-TfO to clozapine leads to compound 9e (GMC61-39) which has a similar binding profile as that of clozapine including having M1 receptor affinity. Interestingly, the MsO analogues, as well as the 8-TfO analogues, have no or weak dopaminergic and serotonergic affinities, but all 8-sulfonyloxy analogues do have M1 affinities. In behavioral studies performed to indicate the potential antipsychotic efficacy and the propensity to induce EPS, 2-TfO analogues blocked effectively the apomorphine-induced climbing in mice in a dose-dependent manner with ED50 values (mg/kg) of 2.1 sc for 9a, 1.3 po for 18a, 2.6 sc for 24, and 8.2 sc for 9e. On the other hand, they showed a clear dose separation with regard to their ED50 values (mg/kg) for indicating catalepsy in rats (>44 sc for 9a, 28 po for 18a, 30 sc for 24, and >50 sc for 9e, respectively), thus implicating a more favorable therapeutic ratio (K/A, ED50 climbing/ED50 catalepsy) in comparison with typical neuroleptics such as haloperidol and isoclozapine. Furthermore, compound 18a was also demonstrated to be an orally potent DA antagonist with an ED50 value of 0.7 mg/kg po in the ex vivo L-DOPA accumulation model. The present study contributes to the SAR of 11-piperazinyldibenzazepines, and the 2-TfO analogues of 11-piperazinyldibenzazepines are promising candidates as clozapine-like atypical antipsychotics with low propensity to induce EPS.

Synthesis and muscarinic receptor pharmacology of a series of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridine bioisosteres of arecoline

A series of O- and ring-alkylated derivatives of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridin-3-ol was synthesized via treatment of appropriately substituted 4-benzylamino-1,2,5,6-tetrahydropyridine-3-carboxamides with hydrogen sulfide and subsequent ring closure by oxidation with bromine. The muscarinic receptor affinity as well as estimated relative efficacy and subtype selectivity of this series of bicyclic arecoline bioisosteres were determined using rat brain membranes and a number of tritiated muscarinic receptor ligands. The effects at the five cloned human muscarinic receptor subtypes of a selected series of chiral analogues, with established absolute stereochemistry, were studied using receptor selection and amplification technology (R-SAT). The potency, relative efficacy, and receptor subtype selectivity of these compounds were related to the structure of the O-substituents and the position and stereochemical orientation of the piperidine ring methyl substituents.

Assaying for structural variation in the parvovirus capsid and its role in infection

The capsid of canine parvovirus (CPV) was assayed for susceptibility to proteases and for structural variation. The natural cleavage of VP2 to VP3 in CPV full (DNA containing) particles recovered from tissue culture occurred within the sequence Arg-Asn-Glu-Arg Ala-Thr. Trypsin, chymotrypsin, bromelain, and cathepsin B all cleaved >90% of the VP2 to VP3 in full but not in empty capsids and did not digest the capsid further. Digestion with proteinase K, Pronase, papain, or subtilisin cleaved the VP2 to VP3 and also cleaved at additional internal sites, causing particle disintegration and protein degradation. Several partial digestion products produced by proteinase K or subtilisin were approximately 31-32.5 kDa, indicating cleavage within loop 3 of the capsid protein as well as other sites. Protease treatment of capsids at pH 5.5 or 7.5 did not significantly alter their susceptibility to digestion. The isoelectric point of CPV empty capsids was pH 5.3, and full capsids were 0.3 pH more acidic, but after proteolysis of VP2 to VP3, the pI of the full capsids became the same as that of the empty capsids. Antibodies against various capsid protein sequences showed the amino termini of most VP2 molecules were on the outside of full but not empty particles, that the VP1-unique sequence was internal, and that the capsid could be disintegrated by heat or urea treatment to expose the internal sequences. Capsids added to cells were localized within the cell cytoplasm in vesicles that appeared to be lysosomes. Microinjected capsids remained primarily in the cytoplasm, although a small proportion was observed to be in the nucleus after 2 h. After CPV capsids labeled with [35S]methionine were bound to cells at 0 degrees C and the cells warmed, little cleavage of VP1 or VP2 was observed even after prolonged incubation. Inoculation of cells with virus in the presence of proteinase inhibitors did not significantly reduce the infection.

Cure of autoimmune gastritis by Helicobacter pylori eradication in a 21-year-old male

BACKGROUND

More recent investigations have shown that in some patients Helicobacter pylori (Hp) antibodies can act as antigastric antibodies and lead to atrophic autoimmune gastritis of the oxyntic mucosa. The question thus arises as to whether this form of autoimmune gastritis can be healed by eradicating Hp.

METHODS

Case history of a 21-year-old man with active autoimmune gastritis of the oxyntic mucosa with lymphocytic infiltration of the entire lamina propria, foci of lymphocytic destruction of a number of glands, and hypertrophy of the preserved parietal cells, but no signs of Hp in the Warthin Starry stain. The search for parietal cell antibodies and intrinsic factor antibodies proved negative, while the level of the gastrin in the serum was slightly elevated. Since the presence of Hp IgG antibodies (243 U/ml) was confirmed. Hp eradication therapy was carried out.

RESULTS

15 months after Hp treatment the Hp IgG antibody titre had decreased to 11 U/ml. The autoimmune gastritis had healed, and autoaggressive inflammatory infiltrates with focal destruction of corpus glands and hypertrophy of the parietal cells were no longer detectable.

CONCLUSIONS

Autoimmune gastritis induced by Hp may possibly be cured with Hp eradication treatment; to confirm this, further controlled prospective studies are needed.