Evidence of small microplastics (<100 µm) ingestion by Pacific oysters (Crassostrea gigas): A novel method of extraction, purification, and analysis using Micro-FTIR.

Microplastics (MPs) are present in fresh, brackish, or marine waters. Micro- and macroinvertebrates can mistake MPs or small microplastics (SMPs, <100 µm) to be food particles and easily ingest them according to the size of their mouthparts. SMPs may then block the passage of food through the intestinal tract (i.e. hepatopancreas), accumulate within the organism, and enter the food web. Pacific oysters (Crassostrea gigas) are allochthonous filter-feeding bivalve mollusks, which have been introduced in coastal seas around the world in both natural banks and farms. Considering their economic and ecological value, these bivalves have been chosen as a model to study the ingestion of SMPs. A novel method for the extraction and purification of SMPs in bivalves was developed. Quantification and simultaneous polymer identification of SMPs using Micro-FTIR (Fourier Transform Infrared Spectroscopy) were performed, with a limit of detection for the particle size of 5 µm.

Identifying and treating patients with suboptimal responses.

Multiple sclerosis (MS) is an immune-mediated neurologic disease in which acute inflammatory events early in the disease course contribute to subsequent neurologic disability. The early relapsing inflammatory phase is followed by a progressive degenerative phase in which the frequency of acute inflammatory attacks diminishes but progressive loss of neurologic function continues. Current immune therapies are most effective in suppressing the acute inflammatory events that characterize the earlier stages of disease. Optimal suppression of these inflammatory events is likely to have the best potential for delaying or preventing loss of axons and decline in neurologic function. In view of these considerations, and because MS is a heterogeneous disease and response to disease-modifying agents (DMA) varies across individuals, it is important to identify suboptimal responders as early as possible to allow therapeutic modification while the opportunity to avert future loss of function remains. At present, no criteria for identifying suboptimal responders have been validated. In January 2004, a group of neurologists from 16 MS centers in the United States met to develop a consensus on criteria for defining suboptimal response for use in compelling clinical situations and to prompt clinical studies to validate the efficacy of these criteria. Consensus criteria included relapse rates of either 1/year or unchanged from pretreatment rates, incomplete recovery from multiple attacks, evolution of polyregional neurologic involvement, recurrent brainstem or spinal cord lesions, and cumulative loss of neurologic function sufficient to disrupt daily activities. The panel then considered the use of mitoxantrone for patients with worsening MS and a suboptimal response to DMA therapy.

Membrane vesicles shed into the extracellular medium by human breast carcinoma cells carry tumor-associated surface antigens.

We have compared the pattern of surface antigen expression, as detected by monoclonal antibodies (mAbs), in plasma membranes vs shed membrane vesicles of two human breast carcinoma cell lines, MCF-7 and 8701-BC. Antigen expression was detected on cells by immunofluorescence (IF) analysis, whilst, due to their small dimensions, the same technique was not applicable to vesicles. For these structures dot-blot analysis and immunoelectron microscopy (IEM) were employed. When applicable, both cell membranes and membrane vesicles were immunoprecipitated and the precipitate (IP) was analyzed by SDS-PAGE. Cells of both lines expressed HLA class I antigens, epithelial cytokeratins, beta 1 integrins, CEA and the glycoprotein detected by mAb 19.9, but only MCF-7 cells expressed Lewis Y, episialin and globo-H antigens and only 8701-BC cells expressed folate receptor. Membrane vesicles of both cell lines appeared to be rich in beta 1, alpha 3 and alpha 5 integrin chains, expressed HLA class I antigens and carried most of the plasma membrane antigens found in the cell membranes. Overall we have analyzed 17 antigens on the two cell lines and on their vesicles. The results obtained for cells (IF and IP) and those for vesicles (dot-blot and IP) were generally concordantly positive or concordantly negative. We obtained a total of 26 clearly concordant combinations on 34 analyses. In three cases we found discordant results, whereas in the remaining combinations we observed slight reactivity and we found difficulties in determining concordance. Discordant results concerned the expression of the following antigens: folate receptors, which were clearly expressed in 8701-BC cells but not detected by dot-blot analysis or IEM on their shed membrane vesicles; neu (c-erb-B2) receptor found in MCF-7 cell membranes but not in their vesicles; and the globo-H antigen recognized by mAb MBr1, detected at low levels on 8701-BC plasma membranes but undetectable on their membrane vesicles. Like vesicles shed in vitro by cultured cells, the vesicles shed in vivo by human breast carcinoma cells could be tagged with several antibodies against tumor-associated antigens. The vesicles shed in vivo were found in association with a fiber network. Some of the fibers had the characteristic fibrin periodicity. These data suggest that tumor markers detected in the circulation of carcinoma patients, at least in part, are carried by shed membrane vesicles. Moreover the observation that membrane vesicles carry both tumor-associated antigens and HLA class I molecules indicate that these structures could in principle present antigens to the immune system.(ABSTRACT TRUNCATED AT 400 WORDS)

Immediate reproducibility of the tilt-table test in adults with unexplained syncope.

There are few data regarding the immediate reproducibility of the tilt-table test (TTT). Therefore, the immediate reproducibility of the TTT was examined in 19 patients (11 men and 8 women; mean age 49 +/- 19 years) with syncope or presyncope. The mean number of episodes that patients had experienced was 14 +/- 25 (range 1 to 100). After baseline supine observation for 10 minutes, patients were placed in 80 degrees of head-up tilt until a positive response occurred or for a maximum of 10 minutes. Patients were then returned to the supine position for 5 minutes, followed by retilt for another 10 minutes. If the baseline tilt was negative, the study was repeated with intravenous isoproterenol, and immediate reproducibility was examined in the same manner. The 19 patients underwent a total of 31 TTTs (19 baseline and 12 follow-up on drug). The TTT was immediately reproducible in 24 of 31 tests performed (77%). Eight tests were reproducibly positive and 16 negative. The results of 7 TTTs (23%) (5 baseline and 2 follow-up on drug) were not reproducible. In 6 of these studies (86%), the positive result occurred first and the negative result second. The reproducibility of an initially negative TTT result (16 of 17; 94%) was much higher than that of an initially positive one (8 of 14; 57%). The immediate reproducibility of the TTT in adult patients with unexplained syncope is approximately 75%. In studies that are not reproducible, most (86%) are positive first and negative second. Therefore, in most patients it is not necessary to check immediate reproducibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic coil stimulation of the human lumbosacral vertebral column: site of stimulation and clinical application.

We describe the technique of magnetic coil (MC) stimulation of the lumbosacral roots and the possible site of stimulation in 22 control subjects, and the clinical usefulness of MC stimulation in 5 patients with low back pain. We observed 2 components in the compound muscle action potential of the soleus muscle following MC stimulation over the lumbosacral region. The second component had the physiological properties of the H reflex. The conduction time from the anterior horn cells of the lumbosacral spinal cord to the site of nerve root stimulation over the lumbosacral vertebral column was indirectly calculated as between 3.9 and 4.1 msec. Assuming a conduction velocity of 50 m/sec this would represent a distance of approximately 20 cm from the spinal motor neurons. Based on our control and patient data we conclude that the MC stimulation may be an useful technique for the diagnosis of lumbosacral radiculoplexopathy.

Propriospinal myoclonus: a neurophysiologic analysis.

We are reporting a neurophysiologic analysis of two patients presenting with thoracoabdominal spontaneous muscle jerks. Polymyographic recordings showed myoclonic bursts with onset in the upper rectus abdominis or lower intercostal muscles followed by rostral propagation to the upper intercostal and caudal propagation to the abdominal muscles by slowly conducting pathways. Jerk-locked back-averaging did not show time-locked cortical or premovement potentials. Peroneal somatosensory evoked response, C-reflex, and intercostal nerve conduction were normal. These findings suggest a generator for the myoclonus in the midthoracic region of the spinal cord with up and down propagation by slowly conducting pathways, such as propriospinal fibers. This type of spinal myoclonus may thus be termed "propriospinal myoclonus," as suggested by Brown et al.

Percutaneous magnetic coil stimulation of human cervical vertebral column: site of stimulation and clinical application.

In order to understand which neural elements are excited after percutaneous magnetic coil (MC) stimulation over the cervical vertebral column we have performed such study in 8 normal subjects and 4 patients. On moving the coil rostrocaudally up to 3 cm and horizontally up to 2 cm from the midline we found no change in the latencies of the compound muscle action potentials to biceps, deltoid, abductor pollicis brevis (APB) and abductor digiti minimi muscles indicating a fixed site of excitation of the spinal roots within the intervertebral foramina. F latencies to APB after stimulation of the median nerve at the wrist were always longer than the direct latencies obtained after cervical vertebral stimulation. The mean difference between indirect latency based on F technique and direct latency to APB was 0.45 msec which represented a distance of 2.7 cm distal to the anterior horn cells assuming a conduction velocity of 60 m/sec. MC stimulation in 2 patients suggested a diagnosis of cervical radiculopathy which was confirmed by imaging studies or operative findings. Both MC and needle root stimulation in one patient with diabetic brachial plexopathy and in another with diabetic polyneuropathy suggested that the needle stimulation occurred about 1.2-1.8 cm proximal to MC stimulation.

Determination of amniotic fluid IgM and IgA by hydroxyethylcellulose-agarose gel electroimmunodiffusion.

An electroimmunodiffusion method on hydroxyethylcellulose-agarose by which IgA and IgM concentrations down to 0.3 mg/dl can be measured in amniotic fluid is presented. Elevated Ig levels were found in both fetal infection and in congenital malformations. The potential value of Ig determination in amniotic fluid is discussed.