De-Escalation by Reversing the Escalation with a Stronger Synergistic Package of Contact Tracing, Quarantine, Isolation and Personal Protection: Feasibility of Preventing a COVID-19 Rebound in Ontario, Canada, as a Case Study.

Since the beginning of the COVID-19 pandemic, most Canadian provinces have gone through four distinct phases of social distancing and enhanced testing. A transmission dynamics model fitted to the cumulative case time series data permits us to estimate the effectiveness of interventions implemented in terms of the contact rate, probability of transmission per contact, proportion of isolated contacts, and detection rate. This allows us to calculate the control reproduction number during different phases (which gradually decreased to less than one). From this, we derive the necessary conditions in terms of enhanced social distancing, personal protection, contact tracing, quarantine/isolation strength at each escalation phase for the disease control to avoid a rebound. From this, we quantify the conditions needed to prevent epidemic rebound during de-escalation by simply reversing the escalation process.

Pharmacokinetics of glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase and their blood glutamate-lowering activity in naïve rats.

Traumatic brain injury (TBI) and stroke lead to elevated levels of glutamate in the brain that negatively affect the neurological outcomes in both animals and humans. Intravenous administration of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) enzymes can be used to lower the blood glutamate levels and to improve the neurological outcome following TBI and stroke. The objective of this study was to analyze the pharmacokinetics and to determine the glutamate-lowering effects of GOT and GPT enzymes in naïve rats. We determined the time course of serum GOT, GPT, and glutamate levels following a single intravenous administration of two different doses of each one of the studied enzymes. Forty-six male rats were randomly assigned into one of 5 treatment groups: saline (control), human GOT at dose 0.03 and 0.06 mg/kg and porcine GPT at dose 0.6 and 1.2 mg/kg. Blood samples were collected at baseline, 5 min, and 2, 4, 8, 12, and 24 h after the drug injection and GOT, GPT and glutamate levels were determined. The pharmacokinetics of both GOT and GPT followed one-compartment model, and both enzymes exhibited substantial glutamate-lowering effects following intravenous administration. Analysis of the pharmacokinetic data indicated that both enzymes were distributed predominantly in the blood (central circulation) and did not permeate to the peripheral organs and tissues. Several-hour delay was present between the time course of the enzyme levels and the glutamate-lowering effects (leading to clock-wise hysteresis on concentration-effect curves), apparently due to the time that is required to affect the pool of serum glutamate. We conclude that the interaction between the systemically-administered enzymes (GOT and GPT) and the glutamate takes place in the central circulation. Thus, glutamate-lowering effects of GOT and GPT apparently lead to redistribution of the excess glutamate from the brain's extracellular fluid into the blood and can reduce secondary brain injury due to glutamate neurotoxicity. The outcomes of this study regarding the pharmacokinetic and pharmacodynamic properties of the GOT and GPT enzymes will be subsequently verified in clinical studies that can lead to design of effective neuroprotective treatment strategies in patients with traumatic brain diseases and stroke.

Mandibular fractures in children: analysis of 61 cases and review of the literature.

OBJECTIVE: The purpose was to evaluate the incidence, etiology, site and patterns, management and treatment methods, and outcome of pediatric patients with mandibular fractures. METHODS: Pediatric patients (1.5-16 years old) with mandibular fractures, treated at the Soroka University Medical Center were included in the study. Age, gender, etiology, site and type of fracture, associated injuries, mode of treatment, outcome, complications, and follow up were evaluated. The cases were divided into 3 age groups: Group A: 1.5-5 years, Group B: 6-11 years, and Group C: 12-16 years. RESULTS: Sixty one patients were included in the study. The male to female ratio was 2:1. Motor vehicle accident was the most common cause. Associated trauma was more common in young children. The condyle was involved in 54% of the fractures. Closed reduction and intermaxillary fixation was the most common treatment used. Complications were rare. CONCLUSION: Management of mandibular fracture in the pediatric age group is a challenge. The anatomical complexity of the developing mandible and teeth strongly suggest the use of surgical techniques that are different from those routinely used in adults. The conservative approach is recommended. Whenever possible closed reduction should be the treatment of choice.

Cystic lesions of the jaws in edentulous patients: analysis of 27 cases.

In this retrospective study we reviewed the distribution, characteristics, and treatment of 27 cystic jaw lesions in edentulous patients, and compared these with 242 cysts in dentate patients. The mean age was 60 years (range 46-74), and the male:female ratio 4.4:1. The maxilla was more affected than the mandible, with radicular/residual cysts being the most common. Patients were treated by marsupialisation, enucleation, or enucleation with bone grafting. Edentulous men were at higher risk than women of developing cystic lesions in the maxilla. Patients who are edentulous alert us to the possibility that their general health may be compromised, and this should be kept in mind when planning treatment.