Visual search and eye movements in patients with chronic solvent-induced toxic encephalopathy

Various aspects of visual perception have been found to be impaired in patients with occupational chronic solvent-induced toxic encephalopathy (CSE). The purpose of the study was to characterise the changes in eye movements and visual search performance in CSE patients. We measured eye movements of 13 CSE patients and 22 healthy controls during dynamic visual search task by using a fast video eye tracker. The task was to search for and identify a target letter among numerals presented in a rectangular stimulus matrix (3 × 3–10 × 10 items). Threshold search time, i.e. the duration of stimulus presentation required for identifying the target with a given probability was determined by using a psychophysical staircase method. The visual search times of the CSE patients were clearly longer, and they needed considerably more eye fixations than healthy controls to find the target. Thus, their reduced performance in this task was mainly related to the reduction in the number of items which could be processed during a single eye fixation (perceptual span). This reduction probably reflects a limited capacity of visual attention, since visual acuity, contrast sensitivity, and the oculomotor saccade velocity were found to be normal. The results suggest that motor slowness or low-level visual factors do not explain the poor performance of CSE patients in visual search tasks. The results are also discussed with respect to the effects of education, and compared to the performance in the widely used neuropsychological Trail Making Test, which uses similar stimuli and requires visual search.     

Association of cord blood platelet characteristics and hematopoietic progenitor cells

BACKGROUND: Total nucleated cell (TNC) dose is associated with neutrophil and platelet (PLT) engraftment after cord blood (CB) transplantation and thus is used for selection of CB for banking. The goal of this study was to evaluate the internal relationships of CB PLT characteristics, TNC, and the hematopoietic progenitor cell (HPC) content of CB units. STUDY DESIGN AND METHODS: HPC and TNC counts of 167 CB units processed with an automated cell separation system were compared with CB PLT count and mean PLT volume (MPV). Megakaryocyte progenitors (CFU-MK) were cultured from a subset of units (n = 24). RESULTS: PLT concentration correlated with MPV (r = -0.39), which was also associated with both TNC and total CD34+ cells before and after processing (r = 0.37 and 0.35 and r = 0.41 and 0.42, respectively). In addition, MPV was associated with HPC counts in the CB unit. The p value was less than 0.001 for all associations. PLT count was inversely associated with markers of hematopoietic potential. Median removal of PLTs during processing was 62 percent (range, 40%-84%). All 24 CB units of the subset exhibited CFU-MK growth. In multivariate linear regression analysis, MPV improved prediction of the HPC content of the CB unit compared to prediction with CB volume and nucleated cell concentration only. CONCLUSION: Mean PLT volume correlated with current markers of CB hematopoietic potential and is potentially useful for evaluating CB collections for banking. The question of the clinical significance of PLT characteristics in CB transplantation remains unanswered.     

P300 of auditory event related potentials in occupational chronic solvent encephalopathy

This retrospective study characterized the P300 component of the auditory event related potential (ERP) and assessed its diagnostic value in occupational chronic solvent encephalopathy (CSE). The P300 was recorded on 86 CSE patients by the classical oddball paradigm. In addition to the laboratory's reference values, we used an age and education matched control group that consisted of 104 blue-collar workers with no known occupational solvent exposure. The association of P300 values with solvent exposure indices, major depression, alcohol consumption, and neuropsychological parameters was studied. The P300 amplitude was lower in CSE patients (mean 7.5 microV; S.D. 3.6) compared to laboratory controls (mean 11.8 microV; S.D. 4.1; F(1,167)=24.4; p<0.001, 95% CI -4.4 to -1.8) and to matched controls (mean 9.0 microV; S.D. 4.0; p=0.007, 95% CI -2.6 to -0.4). The P300 latency was longer in the CSE patients (mean 358 ms; S.D. 28) compared to laboratory controls (mean 339 ms; S.D. 19, F(1,167)=7.6, p=0.006, 95% CI 3.12-18.7) but did not differ from matched controls (mean 358 ms; S.D. 22; p=0.947, 95% CI -7.4 to 6.9). The solvent exposure indices, major depression, or alcohol consumption did not associate with the P300 values. The P300 amplitude correlated positively with the Digit Symbol test. All the amplitude values in the patient group and in the matched control group were classified as normal (i.e. age corrected mean+/-2.5S.D.) against the laboratory's reference values. Thirty percent of the latencies in the CSE patient group and 26% in the matched control group were classified as abnormal. At group level, the decreased P300 amplitudes in CSE patients may reflect solvent-related pathophysiology. However, the P300 measured with the classical oddball paradigm does not seem to be sensitive at individual level or useful in clinical practice.     

Patient participation in decision making about care.

The purpose of this study was to find out how cancer patients perceive patient participation in decision-making and to see which factors in their view facilitate and restrict participation. Data were collected in focus group interviews with 25 patients, most of whom had breast cancer. Data interpretation was based on the method of qualitative content analysis. The results showed that patients, nurses and physicians all play a part in terms of how patients participate in decision-making. Patients defined participation in decision-making in terms of asking questions, obtaining/providing information and choosing from/presenting different alternatives. Among the factors that were thought to promote participation in decision-making were the patient's activity, the presence of a primary nurse/physician, the encouragement of nurses and physicians to participate, the treatment of patients as equals, and nurses and physicians having enough time for patients. As for factors hindering participation in decision-making, reference was made to patient ignorance, physical and mental imbalance and shyness on the part of the patient. Obstacles to participating in decision-making that originated in the nurses and physicians were the tendency for them to treat patients as objects, to fall in a routine, problems with information dissemination and lack of time.     

Pt-grown carbon nanofibers for enzymatic glutamate biosensors and assessment of their biocompatibility

Application-specific carbon nanofibers grown from Pt-catalyst layers have been shown to be a promising material for biosensor development. Here we demonstrate immobilization of glutamate oxidase on them and their use for amperometric detection of glutamate at two different potentials. At −0.15 V vs. Ag/AgCl at concentrations higher than 100 μM the oxygen reduction reaction severely interferes with the enzymatic production of H₂O₂ and consequently affects the detection of glutamate. On the other hand, at 0.6 V vs. Ag/AgCl enzyme saturation starts to affect the measurement above a glutamate concentration of 100 μM. Moreover, we suggest here that glutamate itself might foul Pt surfaces to some degree, which should be taken into account when designing Pt-based sensors operating at high anodic potentials. Finally, the Pt-grown and Ni-grown carbon nanofibers were shown to be biocompatible. However, the cells on Pt-grown carbon nanofibers had different morphology and formation of filopodia compared to those on Ni-grown carbon nanofibers. The effect was expected to be caused rather by the different fiber dimensions between the samples than the catalyst metal itself. Further experiments are required to find the optimal dimensions of CNFs for biological purposes.

Pt-grown carbon nanofibers were utilized for the fabrication of glutamate biosensors and in addition their biocompatibility was assessed.     

Prenatal treatment of severe fetomaternal alloimmune thrombocytopenia

Prenatal treatment of fetomaternal alloimmune thrombocytopenia (FMAIT) in previously affected families is of great clinical importance. We report here our experience in the prenatal treatment of 15 severely thrombocytopenic fetuses. Thrombocytopenia was in 13 cases due to immunization to HPA-1a, in one case to HPA-5b, and in one case to HPA-6b. Thirteen fetuses received altogether 34 intrauterine platelet transfusions, seven of them in combination with maternal-administered intravenous gammaglobulin (IVIG) and two in combination with IVIG and prednisone. Six of the 13 fetuses had only one transfusion just prior to delivery. In our experience, IVIG seemed to be less effective than reported; only two fetuses of eight treated initially with weekly maternal-administered IVIG responded, and these were the mildest affected cases in the study. On the other hand, owing to the short survival time, weekly platelet transfusions could only partly maintain a safe platelet count in the four fetuses treated with serial intrauterine platelet transfusions. The number of transfusions needed to be limited because of the high cumulative risk associated with repeated procedures. Three of 34 intrauterine platelet transfusions were associated with near-loss of three different fetuses due to prolonged fetal bradycardia after the transfusion. In conclusion, overall neonatal outcome was good, with no mortality; among the study group there was no intracranial haemorrhage (evaluated by postnatal ultrasonography) compared with one case in their untreated siblings. However, the problem of the optimal treatment of FMAIT remains to be solved. For the moment, the treatment of choice is a combination of maternal IVIG and platelet transfusions in severely affected cases. Serial fetal blood samplings (FBS) are needed in order to monitor the fetus with sufficient care.     

Neurofibromatosis type 2

Neurofibromatosis type 2 is an often devastating autosomal dominant disorder which, until relatively recently, was confused with its more common namesake neurofibromatosis type 1. Subjects who inherit a mutated allele of the NF2 gene inevitably develop schwannomas, affecting particularly the superior vestibular branch of the 8th cranial nerve, usually bilaterally. Meningiomas and other benign central nervous system tumours such as ependymomas are other common features. Much of the morbidity from these tumours results from their treatment. It is now possible to identify the NF2 mutation in most families, although about 20% of apparently sporadic cases are actually mosaic for their mutation. As a classical tumour suppressor, inactivation of the NF2 gene product, merlin/schwannomin, leads to the development of both NF2 associated and sporadic tumours. Merlin/schwannomin associates with proteins at the cell cytoskeleton near the plasma membrane and it inhibits cell proliferation, adhesion, and migration.     

Shoulder joint impairment among Finns aged 30 years or over: prevalence, risk factors and co-morbidity.

OBJECTIVES: To describe the prevalence, risk factors and consequences of shoulder joint impairment in the population. METHODS: A representative sample (n = 7217) of the Finnish population aged > or = 30 yr participated in a health examination survey (the Mini-Finland Health Survey). The design of the survey allowed an independent assessment of disability, reported shoulder pain, shoulder joint impairment and major chronic co-morbidity. RESULTS: Shoulder impairment was observed in 8.8%, while pain was reported by 30%. The prevalence of shoulder pain decreased among the elderly, whereas impairments increased up to 20% of those aged 75-80 yr. In addition to age, sex, previous injury to the shoulder joint and a history of physically heavy work, diabetes was associated with shoulder impairment (OR 1.6, 95% CI 1.2-2.1). Shoulder impairment was associated with disability (adjusted OR 2.0, CI 1.6-2.5). CONCLUSIONS: Shoulder impairment is an important component of ill health among the elderly, and cannot be reduced to reported pain alone.     

A manometric study of anorectal function after surgery for anal fistula, with special reference to incontinence

Anorectal function was manometrically studied in 199 adults on average 9 years after laying open of anal fistula, in order to determine the factors adversely affecting anal continence. Resting anal pressure, and especially squeeze and voluntary contraction pressures, were significantly reduced in the 67 patients with defective anal control. Maximal squeeze and contractile pressures were significantly lower in women than in men but, like maximal resting pressure, were uninfluenced by age. Fistula type significantly influenced maximal resting and squeeze pressures, with tendency to low pressures and high incidence of defective anal control after operation for high intermuscular fistula. Maximal contractile power was unrelated to extent of external sphincter division. Rectal sensation and activity of the rectoanal reflexes did not appreciably differ between the continent patients and the others. Digital assessment of sphincter tone at rest and at maximal contraction correlated well with the respective anal pressures, but was an unreliable indicator of anal continence. The manometric findings warrant maximal preservation of the anal sphincter musculature, but fistula healing must not be thereby endangered.