Finger dexterity measured by the Grooved Pegboard test indexes Parkinson's motor severity in a tremor-independent manner

Fine motor impairments are frequent complaints in people with Parkinson's disease (PD). While they may develop at an early stage of the disease, they become more problematic as the disease progresses. Tremors and fine motor symptoms may seem related, but evidence suggests two distinct phenomena. The purpose of our study was to investigate the relationships between fine motor skills and clinical characteristics of PD patients. We hypothesized worse fine motor skills to be associated with greater motor severity that is independent of tremor. We measured fine motor abilities using the Grooved Pegboard test (GPT) in each hand separately and collected clinical and demographics data in a cohort of 82 persons with PD. We performed regression analyses between GPT scores and a range of outcomes: motor severity, time from diagnosis, age and tremors. We also explored similar associations using finger and hand dexterity scores from a standardized PD rating scale. Our results indicate that scores on the GPT for each hand, as measures of manual dexterity, are associated with motor severity and time from diagnosis. The presence of tremors was not a confounding factor, as hypothesized, but age was associated with GPT scores for the dominant hand. Motor severity was also associated with hand and finger dexterity as measured by single items from the clinical Parkinson's rating scale. These findings suggest that the GPT to be useful tool for motor severity assessments of people with PD.

A Study Protocol for an Open-Label Feasibility Treatment Trial of Visual Snow Syndrome With Transcranial Magnetic Stimulation

Background: Visual Snow (VS) syndrome is believed to be due to aberrant central visual processing. Positron Emission Tomography (PET) brain imaging and visual evoked potential studies provide evidence for excessive neuronal activity in the medial temporal lobe, specifically the lingual gyrus, and suggest the VS syndrome is a hyperexcitability syndrome. These data provide the basis for consideration of repetitive transcranial magnetic stimulation (rTMS) as a potential treatment for the VS syndrome.

Objective: To publish the study protocol for a pilot study underway at the University of Colorado School of Medicine to investigate the use of rTMS intervention to improve symptoms and visual dysfunction associated with VS. The study aims to determine the adverse events and drop-out rate, evaluate performance of outcome measures, including a novel VS symptom scale, and describe changes in outcomes associated with treatment.

Methods and Design: Up to 10 participants meeting criteria for VS syndrome, age 19–65 years, will undergo an open-label intervention consisting of 10 rTMS sessions, occurring 5 days a week over a 2-week period. Participants will complete pre-treatment and post-treatment assessments that include: the Colorado Visual Snow Scale (CVSS), the National Eye Institute Visual Functional Questionnaire—25 (VFQ-25), the General Anxiety Disorder—7 scale (GAD-7), and three psychophysical visual processing tasks.

Discussion: Knowledge gained from this pilot study will inform future study planning and provide valuable lessons for future investigation of rTMS for the VS syndrome. An overview of study proceedings thus far demonstrates recruitment challenges associated with the COVID-19 pandemic, and additional challenges that are unique to the VS syndrome and to treatment schedules associated with TMS.

Registration: This study has been approved by the Colorado Multiple Institutional Review Board. ClinicalTrials.gov Identifier: NCT04925232.

Randomized controlled trial of neurologic music therapy in Parkinson's disease: research rehabilitation protocols for mechanistic and clinical investigations

Background

Presently available medications and surgical treatments for Parkinson’s disease have limited effects on fine motor problems and often leave patients with significant fine motor disability. Standard of care occupational therapy (OT) yields low efficacy, potentially due to a lack of standard protocols. Neurologic music therapy (NMT) techniques, especially rhythmic auditory stimulation which relies on interaction between rhythm and movement, have shown to be effective in PD gait rehabilitation possibly through their reliance on neural pathways that are not affected by PD. Therapeutic instrumental music performance (TIMP) is one other NMT technique that holds promise but which mode of action and efficacy has not been investigated in PD yet.

Methods

One hundred PD participants will be randomly assigned to receive 15 sessions of either TIMP with rhythm or TIMP without rhythm, standard of care OT, or to be waitlisted (control) over 5 consecutive weeks. Brain oscillatory responses will be collected using magnetoencephalography during an auditory-motor task to understand the underlying mechanisms. The Grooved Pegboard, the UPDRS III finger tap, and the finger-thumb opposition will be assessed to investigate clinical changes related to fine motor function. This project will also serve to confirm or refute our pilot data findings suggesting NMT relies on compensatory brain networks utilized by the PD brain to bypass the dysfunctional basal ganglia.

Discussion

This study aims to use standardized TIMP and OT research protocols for investigating the neuronal pathways utilized by each intervention and possibly study their efficacy with respect to fine motor rehabilitation via a randomized control trial in the PD population.

Trial registration

ClinicalTrials.gov NCT03049033. Registered on September 29, 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05560-7.

The emergent relationship between temporoparietal junction and anosognosia in Alzheimer's disease

Anosognosia and impairment of insight are characteristic features of Alzheimer's disease (AD), which can lead to delays in appropriate medical care and significant family discord. The default mode network (DMN), a distributed but highly connected network of brain regions more active during rest than during task, is integrally involved in awareness. DMN dysfunction is common in AD, and disrupted communication between memory-related and self-related DMN networks is associated with anosognosia in AD patients. In addition, the temporoparietal junction (TPJ) is a key region of the "social brain" and also contributes to representations of the self. The exact classification of the TPJ within the DMN is unclear, though connections between the TPJ and DMN have been highlighted in multiple avenues of research. Here we discuss the relationship between the TPJ, DMN, and AD, as well as the potential involvement of the TPJ in anosognosia in AD. We review past and present findings to raise attention to the TPJ, with a specific emphasis on neuroimaging technologies which suggest a pivotal role of the TPJ within large-scale brain networks linked to anosognosia in AD.

Epigenetic status of argininosuccinate synthetase and argininosuccinate lyase modulates autophagy and cell death in glioblastoma

Arginine deprivation, either by nutritional starvation or exposure to ADI-PEG20, induces adaptive transcriptional upregulation of ASS1 and ASL in glioblastoma multiforme ex vivo cultures and cell lines. This adaptive transcriptional upregulation is blocked by neoplasia-specific CpG island methylation in either gene, causing arginine auxotrophy and cell death. In cells with methylated ASS1 or ASL CpG islands, ADI-PEG20 initially induces a protective autophagic response, but abrogation of this by chloroquine accelerates and potentiates cytotoxicity. Concomitant methylation in the CpG islands of both ASS1 and ASL, observed in a subset of cases, confers hypersensitivity to ADI-PEG20. Cancer stem cells positive for CD133 and methylation in the ASL CpG island retain sensitivity to ADI-PEG20. Our results show for the first time that epigenetic changes occur in both of the two key genes of arginine biosynthesis in human cancer and confer sensitivity to therapeutic arginine deprivation. We demonstrate that methylation status of the CpG islands, rather than expression levels per se of the genes, predicts sensitivity to arginine deprivation. Our results suggest a novel therapeutic strategy for this invariably fatal central nervous system neoplasm for which we have identified robust biomarkers and which overcomes the limitations to conventional chemotherapy imposed by the blood/brain barrier.

The collagen prolyl hydroxylases are novel transcriptionally silenced genes in lymphoma

BACKGROUND

Prolyl hydroxylation is a post-translational modification that affects the structure, stability and function of proteins including collagen by catalysing hydroxylation of proline to hydroxyproline through action of collagen prolyl hydroxylases3 (C-P3H) and 4 (C-P4H). Three C-P3Hs (nomenclature was amended according to approval by the HGNC symbols and names at http://www.genenames.org/ and Entrez database at http://www.ncbi.nlm.nih.gov/gene) leucineproline-enriched proteoglycan (leprecan) 1 (Lepre1), leprecan-like 1 (Leprel1), leprecan-like 2 (Leprel2) and two paralogs Cartilage-Related Protein (CRTAP) and leprecan-like 4 (Leprel4) are found in humans. The C-P4Hs are tetrameric proteins comprising a variable α subunit, encoded by the P4HA1, P4HA2 and P4HA3 genes and a constant β subunit encoded by P4HB.

METHODS

We used RT-PCR, qPCR, pyrosequencing, methylation-specific PCR, western blotting and immunohistochemistry to investigate expression and regulation of the C-P3H and C-P4H genes in B lymphomas and normal bone marrow.

RESULTS

C-P3H and C-P4H are downregulated in lymphoma. Down-regulation is associated with methylation in the CpG islands and is detected in almost all common types of B-cell lymphoma, but the CpG islands are unmethylated or methylated at lower levels in DNA isolated from normal bone marrow and lymphoblastoid cell lines. Methylation of multiple C-P3H and C-P4H genes is present in some lymphomas, particularly Burkitt's lymphoma.

CONCLUSIONS

Methylation of C-P3H and C-P4H is common in B lymphomas and may have utility in differentiating disease subtypes.

NT5E CpG island methylation is a favourable breast cancer biomarker

BACKGROUND

Relapse risk assessment and individual treatment recommendations remain suboptimal for breast cancer patients. In the light of existing preclinical and clinical data, we studied NT5E (5'-nucleotidase, ecto) expression and NT5E CpG island methylation in breast cancer.

METHODS

We used RT-PCR, qPCR, methylation-specific PCR and pyrosequencing to analyse NT5E in breast carcinoma cell lines and primary and breast carcinomas.

RESULTS

NT5E CpG island methylation was inversely associated with NT5E expression in breast carcinoma cell lines. In clinical series, patients whose primary tumours had NT5E CpG island methylation were less likely to develop metastasis (P=0.003, OR=0.34, 95% CI: 0.17-0.69). In 3/4 paired samples, NT5E was methylated in primary tumours and demethylated in CNS metastases. Patients progressing to non-visceral as compared with visceral metastases were more likely to have NT5E CpG island methylation in primary tumours (P=0.01, OR=11.8). Patients with tumours lacking detectable methylation had shorter disease-free survival (DFS) (P=0.001, HR=2.7) and overall survival (OS) (P=0.001, HR=3). The favourable prognostic value of NT5E methylation was confirmed in oestrogen receptor negative (P=0.011, HR=3.27, 95% CI: 1.31-8.12) and in triple negative cases (P=0.004; HR=6.2, 95% CI: 1.9-20). Moreover, we observed a more favourable outcome to adjuvant chemotherapy in patients whose tumours were positive for NT5E CpG island methylation: DFS (P=0.0016, HR=5.1, 95% CI: 1.8-14.37) and OS (P=0.0005, HR=7.4, 95% CI: 2.416-23.08).

CONCLUSION

NT5E CpG island methylation is a promising breast cancer biomarker.

High frequency of complex TP53 mutations in CNS metastases from breast cancer

Background:

Brain metastasis from breast cancer is usually associated with a poor prognosis and early death. Alteration of p53 may contribute to malignant progression by abrogation of apoptosis induced by oncogene activation and by acquisition of gain-of-function properties, which promote tumour aggression. Mutation in TP53 occurs at high frequency in carcinomas of the lung and gastro-intestinal tract, but is much less frequent, at 25%, in primary breast cancer. The frequency of TP53 alteration in the central nervous system (CNS) metastatic breast cancer is not known.

Methods:

In all, 23 cases of histologically confirmed CNS metastatic breast cancer were identified and the coding sequence of TP53 determined. TP53 was also sequenced in two control series of primary breast carcinomas from independent clinical centres.

Results:

We demonstrate a strikingly high frequency of TP53 mutation in the CNS metastatic lesions with an over-representation of complex mutations (non-sense/deletions/insertions). Complex mutations occur in metastatic lesions in both triple-negative breast cancer and hormone receptor/HER2-positive cases. Analysis of paired primary carcinomas and brain metastatic lesions revealed evidence for both clonal selection and generation of new mutations (missense and complex) in progression from a primary breast carcinoma to brain metastasis.

Conclusion:

Mutation in TP53 is the most common genetic alteration reported during metastasis to the brain in breast cancer.

Zinc content of red and white blood cells in aboriginal children

Studies were carried out on erythrocyte, granulocyte and lymphocyte zinc content of aboriginal children at the La Grange settlement in the north-west area of the Kimberley. Forty-eight children, 34 boys and 14 girls between 6 and 13 years were studied. Only the boys were investigated for white blood cell (WBC) zinc. Twenty-five Caucasian children volunteered to give blood for control studies. Two approaches were made concerning zinc analyses, atomic absorption spectroscopy and proton induced x-ray emission. It was found that lymphocyte, granulocyte and erythrocyte zinc content were significantly reduced in aboriginal boys aged 6 to 13 years. Since the turnover of white blood cells is relatively fast, it follows that the zinc content of these cells may be a true index of current zinc status confirming previous observations.

Optimized liquid-chromatographic determination of metronidazole and its metabolites in plasma

Metronidazole and its known metabolites in plasma can be rapidly separated by a "high-pressure" liquid-chromatographic method that can also be adapted for rapid determination of tinidazole. Samples deproteinized with trichloroacetic acid (50 g/L final concentration) undergo isocratic separation on a reversed-phase C18 column eluted with an 8/92 (by vol) mixture of acetonitrile/KH2PO4 (5 mmol/L, pH 3.0). The method is sensitive, reliably detecting as little as 25 micrograms of metronidazole and (or) its metabolites per milliliter of plasma. The detector response varied linearly with concentration for all compounds tested over a wide range (25-500 micrograms/L). Within-day and between-day variation was generally less than 2.5% for all concentrations of all compounds tested. Various other antibiotics tested did not interfere.

Optimized liquid-chromatographic determination of metronidazole and its metabolites in plasma

Metronidazole and its known metabolites in plasma can be rapidly separated by a "high-pressure" liquid-chromatographic method that can also be adapted for rapid determination of tinidazole. Samples deproteinized with trichloroacetic acid (50 g/L final concentration) undergo isocratic separation on a reversed-phase C18 column eluted with an 8/92 (by vol) mixture of acetonitrile/KH2PO4 (5 mmol/L, pH 3.0). The method is sensitive, reliably detecting as little as 25 micrograms of metronidazole and (or) its metabolites per milliliter of plasma. The detector response varied linearly with concentration for all compounds tested over a wide range (25-500 micrograms/L). Within-day and between-day variation was generally less than 2.5% for all concentrations of all compounds tested. Various other antibiotics tested did not interfere.