Modifying one’s hand’s trajectory when a moving target’s orientation changes

The path that the hand takes to intercept an elongated moving target depends on the target’s orientation. How quickly do people respond to changes in the moving target’s orientation? In the present study, participants were asked to intercept moving targets that sometimes abruptly changed orientation shortly after they started moving. It took the participants slightly more than 150 ms to adjust their hands’ paths to a change in target orientation. This is about 50 ms longer than it took them to respond to a 5-mm jump in the moving target’s position. It is only slightly shorter than it took them to initiate the movement. We propose that responses to changes in visually perceived orientation are not exceptionally fast, because there is no relationship between target orientation and direction of hand movement that is sufficiently general in everyday life for one to risk making an inappropriate response in order to respond faster.     

Felty’s Syndrome

Felty's syndrome is a complication of rheumatoid arthritis whereby patients develop neutropenia of varying severity. Although the main clinical concern is the development of serious infections, often patients remain asymptomatic or continue with clinical problems related to the rheumatoid arthritis and not to the neutropenia. There is now considerable clinical experience with the use of the recombinant human haemopoietic growth factors granulocyte and granulocyte-macrophage colony-stimulating factors (G-CSF and GM-CSF) in the treatment of patients with Felty's syndrome. The only indication for the use of either growth factor for Felty's syndrome is the onset of infectious complications, which may be recurrent and serious. In general, when this occurs, the neutropenia is severe (<10(8) cells/L). The mechanism(s) underlying development of the neutropenia in Felty's syndrome is similar to that in other forms of immune-mediated neutropenia, and in general is associated with a terminal defect in neutrophil maturation. It is likely that the maturational defect is a consequence of ;immune based' inhibition, although we lack detailed understanding of this inhibitory process. Growth factor therapy does not relieve the defect in terminal maturation, but in general may induce a significant improvement in the peripheral white cell count. Instances where growth factor therapy does not work appear to be due to an inability to overcome the maturational defect. Thus, the level of granulopoietic inhibition mediated by the rheumatoid process varies in severity among patients. To date, treatment options for Felty's syndrome have included disease-modifying antirheumatic drugs, corticosteroids and splenectomy. The addition of growth factor therapy is a welcome addition to these less than optimal treatment options. However, all of the above therapies fail on occasion. Moreover, the dosage and frequency of growth factors must be titrated to keep the white blood cell count <5 x 10(9) cells/L, since overshoot may result in complications, the most common being exacerbation of the rheumatoid arthritis. Another mechanism by which these drugs may exacerbate rheumatoid arthritis is through activation of neutrophils. The addition of disease-modifying drugs may relieve the maturational defect, improve the peripheral white cell count and minimise disease exacerbation by limiting neutrophil exposure to the administered haemopoietic growth factor. However, long term monotherapy with G-CSF has been successfully employed without requiring disease-modifying therapy.     

Non-Hodgkin’s Lymphoma

Non-Hodgkin's lymphomas (NHL) represent a heterogenous group of diseases including low, intermediate and high grade histological subtypes. Most entities are sensitive to chemotherapy and radiotherapy. However, most relapsed patients are incurable with conventional treatment. The major reason for unsatisfactory long-term results in NHL is tumour cells that persist after standard treatment. New sensitive techniques have been developed to detect occult lymphoma cells. These cells might be eradicated by new immunotherapeutic agents with different modes of action, such as cytokines or antibody-based agents. In NHL, most experience has been accumulated with interferon-alpha, which seems to be effective against minimal residual disease (MRD). The experience with interleukin-2 and interleukin-3 is less convincing. Monoclonal antibodies have been used in their native form, or conjugated with radioisotopes or toxins to selectively destroy lymphoma cells. Such immunotoxins and radioisotope-coupled antibodies have shown promising results in early clinical trials, and are now being evaluated in patients with smaller tumour burdens.     

Acrel’s ganglion

No data exists in the extant literature regarding the distal swelling of the posterior interosseous nerve (Acrel’s ganglion). To further elucidate this ganglion, ten adult cadavers (20 sides) underwent dissection and histological examination of this structure. No inflammatory response was noted in these histologically normal peripheral nerve structures. No neuronal cell bodies were identified. Although the etiology of such swellings is unclear, the term “ganglia” should not be applied to these enlargements of the distal posterior interosseous nerve.     

Wright’s与Giemsa’s联合染色法染神经元尼氏体

Wright’s与Giemsa’s联合染色法是血涂片的常用方法，本人将其用于神经组织的染色，发现其染神经元尼氏体的染色效果非常好，并且易保存、不褪色。现介绍如下：     

Anorectal Crohn’s Disease

In some patients with Crohn's disease the anorectal complications are the major cause of symptoms and morbidity. Anorectal Crohn's disease may be present in patients with intestinal Crohn's disease, may be the initial manifestation of the disease, or rarely occurs without involvement of Crohn's disease elsewhere in the intestinal tract. The pathogenesis of these anorectal complications remains to be clarified. The anorectal examination is very important in the assessment of patients with suspected or documented inflammatory bowel disease. Meticulous physical examination, examination under anaesthesia and radiological imaging modalities may be utilised to specifically identify the location of abscesses and fistulae. Treatment strategy should be directed toward symptomatic relief; the most important symptom is pain. In most patients this pain will be attributable to an incompletely drained rectal abscess. Simple incision and drainage procedures are often all that is required as initial treatment of anorectal abscesses. Treatment of the anorectal fistulae that occur secondary to Crohn's disease requires combined medical and surgical therapy. Drug therapy is more often initiated for Crohn's disease that involves other areas of the gastrointestinal tract. The anorectal manifestations often respond to these same medications. Lay-open procedures (fistulotomies) are often all that is required surgically for simple (low) anorectal fistulae. High (complex) fistulae that involve large portions of the anorectal muscular ring are more difficult to treat. Patients with these fistulae must be treated on an individual basis, usually local surgical therapy combined with a medical regimen. Many surgical procedures are performed and many classes of medications are utilised on patients with these complex anorectal fistulae. Choosing the appropriate surgical and medical interventions is often quite difficult. Although sulfasalazine, mesalazine and corticosteroids have no lasting or maintenance value for fistulae, the immunosuppressive agents mercaptopurine, azathioprine and cyclosporin, the antibacterial metronidazole and the anti-tumour necrosis factor-alpha monoclonal antibody infliximab have varying degrees of effect. The goal of the combined regimen is to cure the fistula, or at least make it minimally symptomatic, without altering the patient's continence.     

Does Parkinson’s disease affect judgement about another person’s action?

The observer’s motor system has been shown to be involved in observing the actions of another person. Recent findings suggest that people with Parkinson’s disease do not show the same motor facilitatory effects when observing the actions of another person. We studied whether Parkinson’s patients were able to make unspeeded judgements about another person’s action. Participants were asked to watch video clips of an actor lifting a box containing different weights (100, 200, 300 or 400 g) and to guess the weight that was being lifted on a 9-point scale. We compared the performance of 16 patients with PD with 16 healthy age-matched controls. Both groups were able to do the task, showing a significant relationship between the real weight and the guessed weight, albeit with a tendency to overestimate the lowest weight and underestimate the heaviest weight. The PD patients, however, showed a reduced slope value. These results show that despite their own motor deficits, PD patients are still able to judge the weight being lifted by another person, albeit with a slight reduction in accuracy. Further research will be required to determine whether PD patients use a motor simulation or a visual compensatory strategy to achieve this.     

Comparing movement patterns associated with Huntington’s chorea and Parkinson’s dyskinesia

Involuntary movements such as levodopa-induced dyskinesia in Parkinson’s disease (PD) and chorea in Huntington’s disease (HD) are the consequence of two distinct basal ganglia dysfunctions. Yet, their clinical manifestations seem to resemble each other. We seek to determine how to detect PD dyskinesia and HD chorea during quiet stance using healthy control subjects’ postural sway as a base measure and identify means to distinguish mathematically HD chorea from PD dyskinesia. Movements were recorded using a magnetic tracker system with fifteen sensors placed strategically to capture whole-body displacement. Choreic and dyskinetic patients as well as healthy controls were asked to stand with arms stretched horizontally in front of them for 60 s. We examined amplitude, frequency dispersion, proportional energy, sample entropy, kurtosis, skewness, amplitude fluctuation, maximum coherency between 44 pairs of body segments. The choreic and dyskinetic movements revealed similar patterns of sample entropy, amplitude fluctuation, and coherencies between body segments. However, skewness and kurtosis for velocity of movements were found to be higher in HD chorea than in PD dyskinesia, reflecting rapid movements in HD patients. There was also a tendency for the frequency composition of PD dyskinesia to be more concentrated in the 1.0–1.5 Hz range. Our results show that despite their similarities in apparent randomness and lack of coordination, dyskinesia associated with treatment of PD and chorea in HD each have their own distinctive characteristics which may be related to their specific pathophysiology.     

Parkinson’s disease and Alzheimer’s disease: a Mendelian randomization study

Background

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the top two common neurodegenerative diseases in elderly. Recent studies found the α-synuclein have a key role in AD. Although many clinical and pathological features between AD and PD are shared, the genetic association between them remains unclear, especially whether α-synuclein in PD genetically alters AD risk.

Results

We did not obtain any significant result (OR?=?0.918, 95% CI: 0.782–1.076, P?=?0.291) in MR analysis between PD and AD risk. In MR between α-synuclein in PD with AD risk, we only extracted rs356182 as the IV through a strict screening process. The result indicated a significant association based on IVW method (OR?=?0.638, 95% CI: 0.485–0.838, P?=?1.20E-03). In order to examine the robustness of the IVW method, we used other three complementary analytical methods and also obtained consistent results.

Conclusion

The overall PD genetic risk factors did not predict AD risk, but the α-synuclein susceptibility genetic variants in PD reduce the AD risk. We believe that our findings may help to understand the association between them, which may be useful for future genetic studies for both diseases.