Sensitivity of Sniffer Dogs for a Diagnosis of Parkinson's Disease: A Diagnostic Accuracy Study

BACKGROUND

The diagnostic criteria for Parkinson's disease (PD) remain complex, which is especially problematic for nonmovement disorder experts. A test is required to establish a diagnosis of PD with improved accuracy and reproducibility.

OBJECTIVE

The study aimed to investigate the sensitivity and specificity of tests using sniffer dogs to diagnose PD.

METHODS

A prospective, diagnostic case-control study was conducted in four tertiary medical centers in China to evaluate the accuracy of sniffer dogs to distinguish between 109 clinically established medicated patients with PD, 654 subjects without PD, 37 drug-naïve patients with PD, and 185 non-PD controls. The primary outcomes were sensitivity and specificity of sniffer dog's identification.

RESULTS

In the study with patients who were medicated, when two or all three sniffer dogs yielded positive detection results in a sample tested, the index test sensitivity, specificity, and positive and negative likelihood ratios were 91% (95% CI: 84%-96%), 95% (95% CI: 93%-97%), and 19.16 (95% CI: 13.52-27.16) and 0.10 (95% CI: 0.05-0.17), respectively. The corresponding sensitivity, specificity, and positive and negative likelihood ratios in patients who were drug-naïve were 89% (95% CI: 75%-96%), 86% (95% CI: 81%-91%), and 6.6 (95% CI: 4.51-9.66) and 0.13 (95% CI: 0.05-0.32), respectively.

CONCLUSIONS

Tests using sniffer dogs may be a useful, noninvasive, fast, and cost-effective method to identify patients with PD in community screening and health prevention checkups as well as in neurological practice. © 2022 International Parkinson and Movement Disorder Society.

Different iron deposition patterns in akinetic/rigid-dominant and tremor-dominant Parkinson's disease

OBJECTIVE

The loss of dopaminergic cells and excessive iron deposition in some deep brain nuclei are associated with the pathophysiology of PD, and different clinical subtypes may indicate different pathological processes. This study was designed to investigate the relationships between regional iron in the cardinal subcortical nuclei and different clinical subtypes.

PATIENTS AND METHODS

Nine Arkinetic/Rigid-dominant Parkinson's disease (PDAR) patients, eight Tremor-dominant (PDTD)patients and 10 matched healthy controls were recruited for this study. The iron content in 8 cardinal subcortical nuclei was measured through SWI sequence scanning (3.0 T), and different patterns of iron deposition were analyzed not only between the PD patients and HC groups but also between the different clinical subtypes.

RESULTS

Compared with the healthy controls, the iron content in the substantia nigra pars compacta(SNc), substantia nigra pars reticulata(SNr) from both the severe and milder side in PD groups were significantly increased (P < 0.01 and P < 0.02 for SNc; both P < 0.01 for SNr), and the iron content in the GP of both the severe and milder side of the PDAR patients was significantly increased compared with the PDTD patients (P < 0.01 and P = 0.02, respectively) CONCLUSION: SWI is a very good technique for the in vivo assessment of subcortical nucleus iron content, and abnormal deposition of iron in the SNc and SNr is an obvious characteristic in PD patients. Furthermore, our data indicates that PDAR patients have higher iron content in the GP than PDTD patients and HCs, indicating that abnormal iron deposition in GP is related to the phenotype of Akinetic/Rigid in PD patients.

GCH1 variants contribute to the risk and earlier age-at-onset of Parkinson's disease: a two-cohort case-control study

Background

Common and rare variants of guanosine triphosphate cyclohydrolase 1 (GCH1) gene may play important roles in Parkinson’s disease (PD). However, there is a lack of comprehensive analysis of GCH1 genotypes, especially in non-coding regions. The aim of this study was to explore the genetic characteristics of GCH1, including rare and common variants in coding and non-coding regions, in a large population of PD patients in Chinese mainland, as well as the phenotypic characteristics of GCH1 variant carriers.

Methods

In the first cohort of this case-control study, we performed whole-exome sequencing in 1555 patients with early-onset or familial PD and 2234 healthy controls; then in the second cohort, whole-genome sequencing was performed in sporadic late-onset PD samples (1962 patients), as well as 1279 controls. Variants at target GCH1 regions were extracted, and then genetic and detailed phenotypic data were analyzed using regression models and the sequence kernel association test. We also performed a meta-analysis to correlate deleterious GCH1 variants with age at onset (AAO) in PD patients.

Results

For coding variants, we identified a significant burden of GCH1 deleterious variants in early-onset or familial PD cases compared to controls (1.2% vs 0.1%, P < 0.0001). In the analysis of possible regulatory variants in GCH1 non-coding regions, rs12323905 (P = 0.001, odds ratio = 1.19, 95%CI 1.07–1.32) was significantly associated with PD, and variant sets in untranslated regions and intron regions, GCH1 brain-specific expression quantitative trait loci, and two possible promoter/enhancer (GH14J054857 and GH14J054880) were suggestively associated with PD. Genotype-phenotype correlation analysis revealed that the carriers of GCH1 deleterious variants manifested younger AAO (P < 0.0001), and had milder motor symptoms, milder fatigue symptoms and more autonomic nervous dysfunctions. Meta-analysis of six studies demonstrated 6.4-year earlier onset in GCH1 deleterious variant carriers (P = 0.0009).

Conclusions

The results highlight the importance of deleterious variants and non-coding variants of GCH1 in PD in Chinese mainland and suggest that GCH1 mutation can influence the PD phenotype, which may help design experimental studies to elucidate the mechanisms of GCH1 in the pathogenesis of PD.

Expansion of GGC repeat in the human-specific NOTCH2NLC gene is associated with essential tremor

Essential tremor is one of the most common movement disorders. Despite its high prevalence and heritability, the genetic aetiology of essential tremor remains elusive. Up to now, only a few genes/loci have been identified, but these genes have not been replicated in other essential tremor families or cohorts. Here we report a genetic study in a cohort of 197 Chinese pedigrees clinically diagnosed with essential tremor. Using a comprehensive strategy combining linkage analysis, whole-exome sequencing, long-read whole-genome sequencing, repeat-primed polymerase chain reaction and GC-rich polymerase chain reaction, we identified an abnormal GGC repeat expansion in the 5′ region of the NOTCH2NLC gene that co-segregated with disease in 11 essential tremor families (5.58%) from our cohort. Clinically, probands that had an abnormal GGC repeat expansion were found to have more severe tremor phenotypes, lower activities of daily living ability. Obvious genetic anticipation was also detected in these 11 essential tremor-positive families. These results indicate that abnormal GGC repeat expansion in the 5′ region of NOTCH2NLC gene is associated with essential tremor, and provide strong evidence that essential tremor is a family of diseases with high clinical and genetic heterogeneities.

[Effect of intravenous injection of intravenous injection of chlorine on blood oxygen saturation in patients with nasal endoscopic surgery]

Objective:To observe the effect of intravenous injection of chlorine on postoperative analgesia and blood oxygen saturation in patients with nasal endoscopic surgery.Method:According to the standard of American Society of anesthesiologists(ASA) grading assessment for Ⅰ-Ⅱ, undergoing nasal endoscopic surgery of 120 patients were randomly divided into two groups, 60 cases in each group. Control group dezocine 0.8 g/kg+ physiological saline to 100 ml; on the basis of the experimental group with flurbiprofen 2 mg/kg+ physiological saline to 100 ml. Respectively in the postoperative recovery and postoperative 2, 4, 12, 24 and 48 h recording vital signs, pain scores(visual analogue score, VAS) and sedation score(Ramsay score) and observe the adverse reaction rate and patient surveys on the satisfaction of postoperative analgesia.Result:The two groups compared test of TKA group after 4, 8, 12, 24, 36 h, 48 h, 72 h resting VAS score and postoperative 24 h, 48 h, 72 h activities of VAS score were lower than the control group, the difference is statistically significant (F=1 873.26, P< 0.05). After 2 h, 6 h, 2 groups of pH, PaO₂, PaCO₂, SpO₂ compared statistically significant (P> 0.05). After 24h, 48h after test group, PaO₂, PaCO₂, SpO₂ is better than that of the control group(P< 0.05); after 6 h, 24 h, 48 h after the test group patients Ramsay Sedation score than the control group, the difference is statistically significant(F=1 031.35, P< 0.05). The experimental group after TKA patients of pain control education satisfaction and to control or reduce pain method of satisfaction were superior to the control group, the difference significant (χ²=11.02, P< 0.05;χ²=9.33, P< 0.05).Conclusion:The application of intravenous injection of intravenous injection of chlorine in the postoperative pain of nasal endoscopic surgery can significantly improve the analgesic effect, improve the blood gas analysis, improve the analgesic effect, it is worthy of popularization and application.

Tiapride is more effective and causes fewer adverse effects than risperidone in the treatment of senile dementia

OBJECTIVE

We wanted to compare the effects of tiapride and risperidone in treating behavioral and psychological symptoms of senile dementia.

PATIENTS AND METHODS

108 patients with senile dementia received respective treatments (54 patients per treatment, either with 100 mg/day risperidone or 2.0 mg tiapride/day) for 2 months. Outcomes included the positive and negative syndrome scale (PANSS) scores, the curative rate of senile dementia, and prevalence of adverse effects (somnolence, headache, loss of weight, extrapyramidal system response, irritation and insomnia).

RESULTS

PANSS scores before treatment were comparable between treatment groups. On days 7, 15, 30, and 60 of the treatment, the differences between two treatment groups became evident. Thus, curative rates in patients treated with risperidone were 74.1% and in those treated with tiapride 88.9% (p < 0.05). Prevalence of adverse reactions was significantly lower in the latter group (9.3% vs. 25.9% in patients treated with risperidone; p < 0.05).

CONCLUSIONS

Tiapride is more effective in improving clinical symptoms of senile dementia and causes fewer adverse effects.

Safety and efficacy of valproic acid treatment in SCA3/MJD patients

BACKGROUND

Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is one of 10 known polyglutamine (polyQ) diseases. In Drosophila and rat models of polyQ diseases, histone deacetylation (HDAC) inhibitors improved locomotor function and survival time by increasing histone acetylation levels and modulating gene expression. Valproic acid (VPA) is a pan-HDAC inhibitor used clinically to treat bipolar and seizure disorders. We evaluated the clinical safety and efficacy of VPA treatment for SCA3/MJD patients.

METHODS

First, a randomized, open-label, dose-escalation method was used to evaluate tolerance to single-dose VPA administration in 12 SCA3/MJD patients. Patients were randomly assigned to three groups of four subjects, each with an oral dosage of 400 mg, 600 mg, or 800 mg (twice daily (bid) for one day). VPA was well-tolerated for one-dose by all patient groups. Second, a randomized, double-blind, placebo-controlled, dose-controlled study evaluated the safety and efficacy of multi-dose VPA (oral administration, twice daily (bid) for 12 weeks) in 36 SCA3/MJD patients. Patients received either low-dose VPA (800 mg/day), high-dose VPA (1200 mg/day), or placebo (n = 12 subjects per group). Symptoms were evaluated using the Scale for Assessment and Rating of Ataxia (SARA).

RESULTS

Multi-dose VPA treatment improved SARA measures of locomotor function. Major adverse effects included dizziness and loss of appetite.

CONCLUSIONS

VPA is a potentially beneficial agent for the treatment of SCA3/MJD. These results also provide insight into possible future therapeutics for polyQ diseases.

Using next-generation sequencing as a genetic diagnostic tool in rare autosomal recessive neurologic Mendelian disorders

Next-generation sequencing was used to investigate 9 rare Chinese pedigrees with rare autosomal recessive neurologic Mendelian disorders. Five probands with ataxia-telangectasia and 1 proband with chorea-acanthocytosis were analyzed by targeted gene sequencing. Whole-exome sequencing was used to investigate 3 affected individuals with Joubert syndrome, nemaline myopathy, or spastic ataxia Charlevoix-Saguenay type. A list of known and novel candidate variants was identified for each causative gene. All variants were genetically verified by Sanger sequencing or quantitative polymerase chain reaction with the strategy of disease segregation in related pedigrees and healthy controls. The advantages of using next-generation sequencing to diagnose rare autosomal recessive neurologic Mendelian disorders characterized by genetic and phenotypic heterogeneity are demonstrated. A genetic diagnostic strategy combining the use of targeted gene sequencing and whole-exome sequencing with the aid of next-generation sequencing platforms has shown great promise for improving the diagnosis of neurologic Mendelian disorders.

SUMO-1 modification on K166 of polyQ-expanded ataxin-3 strengthens its stability and increases its cytotoxicity

Post-translational modification by SUMO was proposed to modulate the pathogenesis of several neurodegenerative diseases. Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is an autosomal dominant neurodegenerative disease caused by polyQ-expanded ataxin-3. We have previously shown that ataxin-3 was a new target of SUMOylation in vitro and in vivo. Here we identified that the major SUMO-1 binding site was located on lysine 166. SUMOylation did not influence the subcellular localization, ubiquitination or aggregates formation of mutant-type ataxin-3, but partially increased its stability and the cell apoptosis. Our findings revealed the role of ataxin-3 SUMOylation in SCA3/MJD pathogenesis.

Simple and sensitive determination of sparfloxacin in pharmaceuticals and biological samples by immunoassay

Plasma quinolone concentrations are not routinely measured in clinical practice. However, in order to optimize quinolone treatment, monitoring of plasma concentrations could sometimes be useful particularly in critically ill patients. In this study, anti-sparfloxacin antibody was obtained by immunizing rabbits with sparfloxacin conjugated with bovine serum albumin using isobutyl chloroformate method. After the assay procedure was optimized, the standard curve of sparfloxacin was established. The practical measuring range of the competitive ELISA extended from 5 ng/mL to 2 μg/mL. The recovery rates and coefficients of variation for rat plasma, urine and tissues were 87.7-106.2% and 4.8-15.3%, respectively. To demonstrate the potential of the ELISA, a preliminary pharmacokinetics and tissue distribution study of sparfloxacin in rats and quantitative analysis of sparfloxacin in several pharmaceuticals were performed and compared with high-performance liquid chromatography (HPLC). The experimental data indicated that the proposed method would be a valuable tool in therapeutic drug monitoring (TDM) for sparfloxacin.

[Effect of gossypol on the proliferation of rat prostate cells studies in vivo and in vitro]

The effect of gossypol on prostate cells of rat was studied both in vitro and in vivo. For in vivo study, mature male Sprague Dawley rats were given gossypol orally, 5 mg/day, 5 times a week for one month. Then the prostates were examined histologically. By adding gossypol to the culture system directly, NbE-1 cells were used in vitro study. Several parameters, including histological structure, cell growth, DNA synthesis and mitotic cycle of cells were measured by different methods. The prostate size and weight in experimental rats decreased and significant differences between acini in controls and gossypol treated animals were noted. Acini of control prostate were full of protruding folds constituted by columnar epithelial cells, whereas, the most of the acini in treated animals were composing of cubic or square epithelial cells and epithelial folds were rarely seen. Thus, acini with normal appearance were about 14% less than that in controls. In the in vitro experiments, both cell proliferation and DNA synthesis decreased from 0 to 80% and from 0 to 90% respectively, when the concentrations of gossypol were increased from 0 to 20 micrograms/ml. It seems that 10 micrograms/ml of gossypol could cause the most significant inhibition in these two cellular functions. The cell mitotic assay showed that in treated groups, the cell number of S phase was decreased from 43 to 31%, this fact indicated that the inhibition on cell proliferation caused by gossypol might be due to preventing cells to enter S phase. Besides, inhibition effect on the proliferation of prostatic epithelial cells was dosage dependent and related to the duration of treatment.