Monitoring macroplastics in aquatic and terrestrial ecosystems: Expert survey reveals visual and drone-based census as most effective techniques.

Anthropogenic litter, such as plastic, is investigated by the global scientific community from various fields employing diverse techniques. The goal is to assess and finally mitigate the pollutants' impacts on the natural environment. Plastic litter can accumulate in different matrices of aquatic and terrestrial ecosystems, impacting both biota and ecosystem functioning. Detection and quantification of macroplastics, and other litter, can be realized by jointly using visual census and remote sensing techniques. The primary objective of this research was to identify the most effective approach for monitoring macroplastic litter in riverine and marine environments through a comprehensive survey based on the experiences of the scientific community. Researchers involved in plastic pollution evaluated four litter occurrence and flux investigation methods (visual census, drone-based surveys, satellite imagery, and GPS/GNSS trackers) through a questionnaire. Traditional visual census and drone deployment were deemed as the most popular approaches among the 46 surveyed researchers, while satellite imagery and GPS/GNSS trackers received lower scores due to limited field validation and short performance ranges, respectively. On a scale from 0 to 5, visual census and drone-based surveys obtained 3.5 and 2.0, respectively, whereas satellite imagery and alternative solutions received scores lower than 1.2. Visual and drone censuses were used in high, medium and low-income countries, while satellite census and GPS/GNSS trackers were mostly used in high-income countries. This work provides an overview of the advantages and drawbacks of litter investigation techniques, contributing i) to the global harmonization of macroplastic litter monitoring and ii) providing a starting point for researchers and water managers approaching this topic. This work supports the selection and design of reliable and cost-effective monitoring approaches to mitigate the ambiguity in macroplastic data collection, contributing to the global harmonization of macroplastic litter monitoring protocols.

Sympathetic skin response and heart rate variability in patients with Huntington disease.

OBJECTIVE: To examine the autonomic nervous system functions in patients with Huntington disease. BACKGROUND: Although patients with Huntington disease frequently experience vegetative symptoms, it is not clear if there is dysfunction of the autonomic nervous system. METHODS: Sympathetic skin response (SSR) latency and amplitude from both palms and soles and R-R (heart rate) interval variation (RRIV) at rest and during the Valsalva maneuver were examined in 22 patients and 21 age-matched controls. Unified Huntington's Disease Rating Scale scores were determined in all the patients. RESULTS: Our data are reported as means +/- SEMs. The SSR latencies in patients (mean palm latency, 1835.8+/-110.7 milliseconds; mean sole latency, 2625.3+/-226.9 milliseconds) were prolonged compared with controls (mean palm latency, 1359.5+/-28 milliseconds [P<.01]); mean sole latency, 2038.1+/-44.9 milliseconds [P<.01]) and amplitudes in patients (mean amplitude, 1063.1+/-237.7 microV) were smaller compared with controls (mean amplitude, 1846.3+/-251.2 microV [P<.05]). The RRIV in patients both at rest (mean RRIV in patients, 3.7%+/-0.4% vs. controls, 9.7%+/-0.6% [P<.01]) and during the Valsalva maneuver (mean RRIV in patients, 6.3%+/-1.6% vs. controls, 14.5%+/-1.2% [P<.01]) was lower compared with controls. Furthermore, the prolonged SSR latencies, smaller amplitudes, and lower RRIV in patients compared with controls closely correlated with the various components of the Unified Huntington's Disease Rating Scale scores (total behavior score and SSR latency, R = 0.6 [P<.01]; total behavior score and SSR amplitude, R = -0.5 [P<.05]; total behavior score and RRIV, R = -0.4 [P<.05]; verbal fluency and SSR latency, R = -0.5 [P<.05]; verbal fluency and SSR amplitude, R = 0.5 [P<.05], verbal fluency and RRIV, R = 0.5 [P<.05]; total functional capacity and SSR latency, R = -0.6 [P<.01]; total functional capacity and SSR amplitude, R = 0.5 [P<.05]). CONCLUSION: These results suggest that there is autonomic nervous system dysfunction in patients with Huntington disease.

MR imaging and localized proton spectroscopy of the precentral gyrus in amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: In the search for a diagnostic test for amyotrophic lateral sclerosis (ALS), especially upper motor neuron (UMN) involvement, MR imaging and proton spectroscopy techniques have each received attention, but their findings have not been correlated. The purpose of this study was to identify relationships among the results of current techniques, taking into account the severity of clinical UMN disease, so that objective measures of the pathogenesis of ALS may be established. METHODS: Eighteen subjects with clinically diagnosed ALS and 12 healthy volunteers underwent MR imaging of the brain and localized proton MR spectroscopy. Water-suppressed spectra from the left precentral gyrus and from the left cuneus gyrus were analyzed with the LCModel method, yielding concentrations for N-acetyl (NA), total creatine (Cr), choline (Cho), glutamate (Glu), glutamine (Gin), and myo-inositol (Ins) metabolic substrates. Signal intensities of the precentral gyrus on T2-weighted images were assessed qualitatively in a blinded fashion. RESULTS: For the precentral gyrus, mean Cho (1.3 mM) and Ins (3.25 mM) for the ALS group were significantly increased. After adjustment for Cr covariance, mean Glu (5.08 mM) and NA (6.31 mM) were decreased. For the cuneus gyrus, no difference in metabolite concentrations between groups was observed. Trend analysis of the precentral gyrus metabolite concentrations revealed significant increases in Cho and Ins and decreases in NA and Glu with respect to the severity of clinical UMN signs. Metabolic changes were greater in the subset of ALS patients with precentral gyrus signal changes on imaging, and significantly increased Ins was associated with cortical hypointensity on fast spin-echo images. CONCLUSION: Mean metabolite concentrations determined from precentral gyrus spectra reflect clinical and pathologic changes that occur in ALS. Imaging findings, while related to the spectral and clinical results, are not specific to ALS.

Skull base metastases causing acute bilateral hypoglossal nerve palsy.

Acute bilateral tongue palsy is a rare clinical presentation. We report one such case caused by skull base metastases from prostate cancer. There were no other cranial nerves involved or associated neurological deficit. Mild improvement was seen following radiation therapy. We review the anatomy of the nerve and differential diagnosis of its disfunction.

1H-magnetic resonance spectroscopy in amyotrophic lateral sclerosis.

1H-magnetic resonance spectroscopy (MRS) is potentially a powerful tool for the investigation of the chemicals of the brain in vivo in health and disease. Levels of N-acetyl-aspartate (NAA) in the motor cortex and brainstem of patients with amyotrophic lateral sclerosis (ALS) have been reported to be reduced by up to 68%, and in one report the level of glutamate in the brainstem was increased by 58%. We studied levels of metabolites in the cerebral cortex and brainstem of 20 ALS patients and 14 age-matched controls with a 1.5 Tesla Picker magnet using MRS. We used the same spectra for determining both the area of the metabolite peaks expressed as a ratio of the area of the creatine (Cr) peak, and the absolute concentrations using the Provencher LC model. These produced different results. With the LC model, the NAA content of the motor cortex of ALS patients was reduced by 7.7% (P=0.015), and that of the brainstem was reduced by 21.5% (P=0.035), compared with controls. The degree of reduction of NAA was related to the severity of upper motor neuron abnormalities. No effect of treatment with anti-glutamate agents on NAA concentration could be detected. Concentrations of other metabolites were not affected in ALS. It appears that MRS is a technique that is still in development, and that further refinement is required before it can be used to understand disease mechanisms and investigate treatment in ALS.

The spectrum of chronic inflammatory demyelinating polyneuropathy.

Research criteria for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) were proposed by an Ad Hoc Subcommittee of the American Academy of Neurology (AAN) in 1991, and since then these criteria have been widely used in clinical studies. We have been impressed by the frequent finding of electrophysiological changes of a demyelinating neuropathy in patients whose clinical presentation does not conform to the usually accepted clinical phenotype of CIDP. To determine the clinical spectrum of CIDP, we conducted a retrospective review of patients of the peripheral electrophysiology laboratory of the University of Miami-Jackson Memorial Medical Center. Diagnostic criteria for acquired demyelination of an individual nerve were adapted from the AAN research criteria for the diagnosis of CIDP (1991). Patients were accepted for inclusion when such evidence was demonstrated in at least one motor nerve or at least two sensory nerves. We then reviewed the clinical phenotype and the underlying etiology of the neuropathy in these cases. Eighty-seven patients, 63 male and 24 female, age of onset 4-84 (mean 49.3) years, met these inclusion criteria. Forty-seven patients (54%) had distinct features outside the usual clinical presentation of CIDP. Of these, 15 (17%) had predominantly distal features, 13 (15%) had exclusively sensory polyneuropathy; seven (8%) had markedly asymmetric disease, seven (8%) had associated CNS demyelination, four (5%) had predominant cranial nerve involvement, and one (1%) had only the restless legs syndrome. An associated medical condition that may have been responsible for the acquired demyelinating neuropathy was present in 60% of the patients. We conclude that spectrum of CIDP is broader than would be indicated by the strict application of the AAN research criteria, and that many of the cases meeting more liberal criteria frequently respond to immunosuppressive therapy.

Early undernutrition blocks the effect of naltrexone on rat exploratory behavior.

1. Young rats were undernourished by feeding their dams an 8% protein diet (w/w) from birth until weaning (21 days); the dams of control rats were fed a 20% protein diet (w/w) until weaning. All offspring were fed a 20% protein diet from 21 to 120-150 days of age, when they were tested. 2. The involvement of endogenous opioids in the exploratory activity (rearing response and crossing frequency in a 2-compartment open-field test) was evaluated by examining the effects of a single injection of naltrexone (0.75 mg/kg, ip) 6 min prior to testing. 3. Naltrexone decreased exploratory activity (rearing) by approximately 50% in normal rats but had no effect on undernourished rats. 4. These data provide additional evidence for an alteration in the opioid system of undernourished rats.

Lateral sinus thrombosis and cervical abscess complicating cholesteatoma in children: case report and review.

To call attention to complications of chronic otitis media, the case of a patient who simultaneously developed lateral sinus thrombosis and Bezold's abscess is reported. A 7 year old boy presented with fever, drowsiness, cervical mass and otorrhea not responding to medical management. Work-up revealed lateral sinus thrombosis and cervical abscess secondary to right ear cholesteatoma. After treatment with surgery and antibiotics, he had a favorable outcome. We review the literature regarding the diagnosis and management of these complications and concluded that although less frequent they remain a clinical challenge.

Early diagnosis of carpal tunnel syndrome: comparison of digit 1 with wrist and distoproximal ratio.

Our objective in this study was to compare the sensitivity and specificity of the median sensory nerve conduction velocity (SNCV) from digit 1 to wrist with those of the distoproximal (D/P) ratio of the median SNCV from palm to digit 3/palm to wrist in the diagnosis of mild carpal tunnel syndrome (CTS) by using a receiver operating characteristic (ROC) curve. To achieve this objective, we studied prospectively (January 1997-October 1998) 370 patients referred for CTS. One hundred forty-two patients (38.4%) with moderate to severe CTS and 15 patients (4.1%) with multiple (> or = 3) compressive neuropathies in upper limbs with subclinical peripheral neuropathy were excluded. The remaining 213 patients (302 hands with mild CTS; 167 women; mean age, 50 y +/- 12 y) and 38 controls (71 hands; 25 women; mean age, 47 y +/- 13 y) had median and ulnar nerve conduction studies. ROC curves were constructed for median SNCV digit 1 to wrist and median SNCV D/P ratio from the patients' and controls' data. The median SNCV at < or = 45.9 m/s, corresponding to an optimal cutoff point on ROC curve, discriminated 89.5% of mild CTS from controls with specificity of 98.6%. The median D/P ratio at > or = 1.12, corresponding to an optimal cutoff point on ROC curve, discriminated 67.2% of mild CTS from controls with specificity of 97.2%. Of the 10.3% (31/302) of hands in which digit 1 to wrist was within normal limits at the selected optimal cutoff value (< or = 45.9 ms), 7% (21/302) had an abnormal D/P ratio (> or = 1.12), and 3.3% (10/302) had a normal electrophysiologic examination. The likelihood ratio (true-positive ratio to false-positive ratio, assessing the discriminative power of a test) of the median SNCV digit 1 to wrist, at an optimal point on ROC curve (63.9), was higher than that of the median SNCV D/P ratio (23.9, chi2 = 36.9, P < .001). These findings suggest that the median SNCV digit 1 to wrist is more sensitive than the median SNCV D/P ratio in the diagnosis of mild CTS.

Marked improvement of severe polyneuropathy associated with multifocal osteosclerotic myeloma following surgery, radiation, and chemotherapy.

We describe a patient with a 3 year history of progressive polyneuropathy that rendered him severely quadriparetic and bedridden. Work up revealed an IgG lambda monoclonal spike and multifocal osteosclerotic myeloma. Remarkable improvement followed combined treatment with surgical excision, radiation therapy, and chemotherapy using chlorambucil, danazol, and hydrocortisone. Hence, we believe that aggressive local therapy associated with systemic chemotherapy should be considered in severely affected patients with multifocal osteosclerotic myeloma and peripheral neuropathy.

Undernutrition during suckling and latent learning ability of rehabilitated adult male rats.

The present report investigates the effects of early undernutrition on the latent learning ability of rehabilitated adult male rats in a simple maze task. Rats were undernourished during suckling by feeding their dams an 8% casein diet. Well-nourished dams received a 25% casein diet during the same period. Rats were weaned at 21 days of age and nutritionally rehabilitated until they became adults, when behavioral task was conducted. Under a nonappetitive condition, rats were exposed either to an open field or to a maze apparatus. They were thereafter deprived of water and tested in the maze apparatus. Both well-nourished and undernourished rats that had been previously exposed to the maze performed better than those exposed to the open field. Nutritional treatment had no effect on performance of either the latent learning or of the open-field groups. These results suggest that rehabilitated adult rats are able to learn about the environment when no immediate reinforcement is involved. The discrepancy between our findings and results reported by others may be due to differences in task complexity and/or perhaps to the fact that nutritional rehabilitation also plays a role in reversing some of the deleterious effects of early undernutrition on learning ability of rats.

Relapses in the Guillain-Barré syndrome after treatment with intravenous immune globulin or plasma exchange.

To clarify the question of whether Guillain-Barré syndrome (GBS) patients treated with intravenous immune globulin (i.v.IG) relapse at a higher frequency than those treated with plasma exchange (PE), 54 patients with GBS were studied retrospectively. A higher frequency of relapses was noted in the PE-treated patients than in those receiving i.v.IG. The presence of an associated medical condition correlated with an increased risk of relapses, while earlier onset of treatment resulted in a decrease of relapses of GBS. This study found no support for prior suggestions of increased relapses in patients with GBS treated with i.v.IG as opposed to those treated with PE.

Chronic use of benzodiazepines and cognitive deficit complaints: a risk factor study.

Benzodiazepines produce an anterograde amnesia after acute administration but whether their chronic use is hazardous to memory processes remains unclear. The present study analyses the risk of increasing cognitive complaints with chronic benzodiazepine use. Subjects seeking medical assistance at the General Internal Medicine Outpatient Clinic of Hospital de Clinicas de Porto Alegre, were interviewed before seeing physicians. They were asked about use of benzodiazepines, history of neurological and psychiatric diseases, use of alcohol, and deficits in remembering and learning as well as age, sex and level of education. Age (over 51 years), low level of education, a history of neurological and psychiatric diseases and use of benzodiazepines showed significant associations with cognitive complaints. After a conditional logistic regression analysis, benzodiazepine use lost its association with memory complaints. These data support the hypothesis that the chronic use of benzodiazepines does not carry a risk for cognitive deficits complaints.