Screening and prioritization of nano- and microplastic particle toxicity studies for evaluating human health risks – development and application of a toxicity study assessment tool

Concern regarding the human health implications that exposure to nano- and microplastic particles (NMPs) potentially represents is increasing. While there have been several years of research reporting on the ecotoxicological effects of NMPs, human health toxicology studies have only recently emerged. The available human health hazard data are thus limited, with potential concern regarding the relevance and reliability for understanding the potential human health implications. In this study we develop and apply a NMP toxicity screening assessment tool (NMP-TSAT) for evaluating human health effects studies against a suite of quality assurance and quality control (QA/QC) criteria for both in vivo and in vitro studies. A total of 74 studies representing either inhalation or oral exposure pathways were identified and evaluated. Assessment categories include particle characterization, experimental design, and applicability for risk assessment; with critical and non-critical criteria organized to allow screening and prioritization. It is observed that the majority of studies evaluated using the NMP-TSAT have been performed on monodisperse particles, predominately spheres (≈60%), consisting of polystyrene (≈46%). The majority of studies have tested particles < 5 μm, with a minimal particle size of 10 nm and a maximum particle size of about 200 μm. The total assessment score (TAS) possible for in vivo studies is 52, whereas for in vitro studies it is 46, which is based on receiving a maximum score of 2 against 26 and 23 criteria, respectively. The evaluated TAS ranged from between 12 and 44 and 16–34, for in vivo and in vitro studies, respectively. Given the challenges associated with prioritizing studies based on ranking them according to their TAS we propose a Tiered approach, whereby studies are initially screened based on how they score against various critical criteria, which have been defined for their relevance for assessing the hazards and risks for human health. In this instance, studies that score a minimum of ‘1’ against each of the critical criteria, regardless of how they rank according to their TAS, are prioritized as part of a Tier 1 screening and prioritization phase, which would then be followed by an expert evaluation, representing a Tier 2 level of assessment. Using this approach we identify 10 oral ingestion and 2 inhalation studies that score at least 1 against all critical criteria. Lastly, several key observations for strengthening future effects studies are identified, these include a need for the generation and access to standard reference materials representative of human exposure to NMPs for use in toxicity test systems and/or the improved characterization and verification of test particle characteristics, and the adoption of study design guidance, such as recommended by OECD, when conducting either in vivo inhalation or oral ingestion toxicity tests.

Salbutamol Toxicity in a Newborn Due to Unintentional Oral Ingestion of Inhalation Respules—A Case Report

Cases of salbutamol toxicity by oral ingestion and inhalation are rarely reported in the pediatric age group and have never been reported in neonates. We report a case of salbutamol toxicity by unintentional oral ingestion of inhalation respules in a newborn, which led to tachycardia and QT prolongation requiring medical management. The importance of breastfeeding, identifying similar looking medications, and keeping them separately at home are discussed.

Severe brimonidine eye drop intoxication in a neonate as an accidental oral ingestion

Brimonidine tartrate eye drops are a topical agent used to treat glaucoma in children over 2 years of age and adults. It is banned for children younger than 2 years of age because post-marketing studies have shown serious side effects. Colic is common in infants, which worries parents. And parents often use herbal and chemical medicines to solve this problem. We present a 12-day-old newborn with brimonidine eye drop intoxication, in which the drug was mistakenly administered orally to treat the colic problem.

Effects of oral ingestion of hyoscyamine from Daturastramonium seeds on the hippocampus in adult Wistar rats (Rattusnorvegicus)

The study aimed to evaluate the effects of oral ingestion of hyoscyamine fraction of Daturastramonium seeds on the hippocampus in adult Wistar rats. Fresh seeds of D. stramonium were procured and fractionated using high-performance liquid chromatography (HPLC). Twenty-four healthy adult Wistar rats weighed 230±0.50 grams, were procured and divided equally into four groups for the experiment. The group one received an equivalent bodyweight of normal saline, while three other groups received 200, 400 and 800 mg/kgbwt of hyoscyamine fraction of D. stramonium respectively for three weeks. At the end of the experiment, the animals were subjected to memory test using Morris water maze (MWM) and Novel object recognition test (NORT) test paradigms. The data obtained were expressed as mean ± SEM and repeated measures ANOVA with Fisher’s multiple comparisons post-hoc tests were used to obtain mean differences using Minitab 17 (LLC., U.K.) statistical package software. P < 0.05 was considered statistically significant. There was a statistically significant increase in the exploration time (p = 0.031) and escape latency period (p < 0.001) in the novel object recognition and Morris water maze test between the groups in the treated compared to the control group. The CA3 region of the treated group showed significant neuronal lesions, cytoplasmic vacuolations, pyknosis and necrosis. . In conclusion, exposure to hyoscyamine fraction of D.stramonium at adulthood impaired memory in Wistar rats.

Acute Poisoning Cases Presented to the Addis Ababa Burn, Emergency, and Trauma Hospital Emergency Department, Addis Ababa, Ethiopia: A Cross-Sectional Study

Background. Acute poisoning is a common reason for visits to the emergency room and hospitalization across the world, as well as a possible cause of morbidity and death. This study aimed to assess acute poisonings at Addis Ababa Burn, Emergency, and Trauma (AaBET) Hospital. Methodology. A one-year cross-sectional study was conducted at AaBET Hospital from February 1, 2018, to January 31, 2019. Data were collected using a structured and pretested questionnaire by the Emergency Medicine and Critical Care residents from acutely poisoned patients’ interviews and patient charts. Results. Data were collected from 98 acute poisoning cases, and 52% were males and 48% were females. 85 (86.7%) were less than 45 years. 52 (55.1%) were unemployed, and 33 (33.7%) were farmers. 96 (98%) cases were due to intentional poisoning, and 96 (98%) had oral ingestion. Organophosphates poisoning (27.5%) was the commonest cause, followed by 26.5% of unknown poisons and 16.3% prescribed drugs. Sixty-six percent of the patients presented to the hospital after 2 hours of ingestion. The case fatalities were 10.2% of which 40% of the cases were due to 2,4-dichlorophenoxyacetic (2, 4-D) poisoning, followed by aluminum phosphide (20%). Conclusion. This study showed farmers and the unemployed were more affected. The most common mode of poisoning was intentional poisoning, oral ingestion being the primary route. The common poisons used by the victims were organophosphates. 2, 4-D poisoning was the major cause of death.

Isolated Renal Hydatid Cyst in a 6-Year-Old Boy: A Case Report

Hydatid cyst (HC) is a parasitic infection transmitted by oral ingestion of Echinococcus granulosus eggs. Isolated kidney involvement is extremely rare. It is even less common in children. We present a case of isolated renal HC in a 6-year-old boy from Şanlıurfa, southeast Turkey who complained of abdominal pain and distension. Cystectomy was performed with a flank incision using the extraperitoneal approach. No recurrence was detected in the postoperative 6-month follow-up. There are not enough data about the efficacy of medical treatment in renal HC. Therefore, medical treatment should be considered pre- and post-operatively to prevent dissemination, rather than being used as a primary treatment. Kidney-sparing surgery should be the first choice in patients with isolated renal HC. However, nephrectomy is recommended for nonfunctioning kidneys, large cysts thought to be connected with the collecting system, and cysts with suspicious tumor. In societies where HC disease is endemic, renal HC should be considered in children with cysts located in kidney, even if the indirect hemagglutination test is negative.

Characterization of Individualized Glycemic Excursions during a Standardized Bout of Hypoglycemia-Inducing Exercise and Subsequent Hypoglycemia Treatment—A Pilot Study

The glycemic response to ingested glucose for the treatment of hypoglycemia following exercise in type 1 diabetes patients has never been studied. Therefore, we aimed to characterize glucose dynamics during a standardized bout of hypoglycemia-inducing exercise and the subsequent hypoglycemia treatment with the oral ingestion of glucose. Ten male patients with type 1 diabetes performed a standardized bout of cycling exercise using an electrically braked ergometer at a target heart rate (THR) of 50% of the individual heart rate reserve, determined using the Karvonen equation. Exercise was terminated when hypoglycemia was reached, followed by immediate hypoglycemia treatment with the oral ingestion of 20 g of glucose. Arterialized blood glucose (ABG) levels were monitored at 5 min intervals during exercise and for 60 min during recovery. During exercise, ABG decreased at a mean rate of 0.11 ± 0.03 mmol/L·min−1 (minimum: 0.07, maximum: 0.17 mmol/L·min−1). During recovery, ABG increased at a mean rate of 0.13 ± 0.05 mmol/L·min−1 (minimum: 0.06, maximum: 0.19 mmol/L·min−1). Moreover, 20 g of glucose maintained recovery from hypoglycemia throughout the 60 min postexercise observation window.

Association between Improvement of Oral Health, Swallowing Function, and Nutritional Intake Method in Acute Stroke Patients

Stroke and poor oral health are common in older people, and the brain injuries associated with stroke are often accompanied by a decline in oral function. In this study, we investigated the characteristics of stroke patients who could not recover oral ingestion until discharge and the association between improved oral health, swallowing function, and nutritional intake methods in acute care. The subjects were 216 consecutive stroke patients who were admitted to Tokyo Medical and Dental University hospital and received oral health management. Nutritional intake, dysphagia, and oral health were evaluated using the Functional Oral Intake Scale (FOIS), Dysphagia Severity Scale (DSS), and Oral Health Assessment Tool (OHAT), respectively. Patients in the tube feeding group (FOIS level 1–2, N = 68) tended to have a worse general condition, fewer functional teeth, and a worse DSS level than those in the oral nutrition group (FOIS level 3–7, N = 148). Multiple analysis with improvement in FOIS score as the dependent variable showed that number of functional teeth (odds ratio [OR]: 1.08, p = 0.04) and improved DSS (OR: 7.44, p < 0.001) and OHAT values (OR: 1.23, p = 0.048) were associated with improvement in nutritional intake methods in acute care. Therefore, recovery of swallowing function and oral health might be important for stroke patients to recover oral ingestion in acute care.