Mapping the dynamic transfer functions of eukaryotic gene regulation.

Biological information can be encoded within the dynamics of signaling components, which has been implicated in a broad range of physiological processes including stress response, oncogenesis, and stem cell differentiation. To study the complexity of information transfer across the eukaryotic promoter, we screened 119 dynamic conditions-modulating the pulse frequency, amplitude, and pulse width of light-regulating the binding of an epigenome editor to a fluorescent reporter. This system revealed tunable gene expression and filtering behaviors and provided a quantification of the limit to the amount of information that can be reliably transferred across a single promoter as ∼1.7 bits. Using a library of over 100 orthogonal chromatin regulators, we further determined that chromatin state could be used to tune mutual information and expression levels, as well as completely alter the input-output transfer function of the promoter. This system unlocks the information-rich content of eukaryotic gene regulation.

Current status of nitrous oxide as a behavior management practice routine in pediatric dentistry.

Nitrous oxide (N(2)O) as a behavioral management intervention in children has attained an excellent safety record and is, therefore, used widely. As is true of any diagnostic or therapeutic dental intervention, however, its usage merits periodic review, even if-or particularly when-it is routinely applied. For example, when N(2)O is used in combination with other sedatives, such polypharmacy can produce potentially serious side effects. There are also bioenvironmental risks to patients and staff if ambient air is not properly monitored. Using historical publications, current empirical articles, professional usage policies, and educational textbooks, the purpose of this article was to review indications and contraindications of N(2)O and discuss various factors that should or should not be considered about its use in the United States. Even though today's parents may be more accepting of pharmacologic approaches such as N(2)O, the choice to use it should always be made with the child's best interest in mind.

Ethical considerations in the use of nitrous oxide in pediatric dentistry.

Nitrous oxide (N2O) has become a routine intervention in contemporary American dental practice, especially in the management of children. However, routines translate to confidence which in turn may lead to overconfidence, such that possible risks and misuses are insufficiently acknowledged. This article ethically evaluates the use of nitrous oxide as a practice routine in treating children. Nitrous oxide administration is analyzed in reference to three internationally acknowledged principles of dental ethics: nonmaleficence, beneficence, and patient autonomy. In reference to the principle of nonmaleficence, the potential for adverse effects of N2O is discussed, particularly when it is administered in conjunction with other sedatives and anesthetics. The importance of abiding by clinical protocols is emphasized. Next, in reference to the principle of beneficence, the authors address the problematic application of N2O for the benefit of individuals other than the patient (e.g., dentists and parents). Finally, the importance of respecting patient autonomy is discussed, specifically the need to obtain explicit consent for N2O. The article supports the continued use of nitrous oxide but advises greater attention to how and why it is administered. Four recommendations are offered for an ethically sound usage.

Extirpation of the primary canine tooth follicles: a form of infant oral mutilation.

BACKGROUND: Ebinyo is a form of infant oral mutilation (IOM), widely practiced in rural areas of eastern Africa, in which traditional healers and other village elders extirpate the primary canine tooth follicles of infants by using crude, often unsterilized, instruments or utensils. Traditional folklore suggests that the underlying tooth follicles, thought to resemble worms, are the cause of high temperature, vomiting, loss of appetite and diarrhea in infants. In addition to the serious and potentially fatal immediate postsurgical complications, many of those who undergo this practice exhibit characteristic long-term adverse dentoalveolar effects. Children in these families also may be at greater risk of undergoing other mutilation rituals because of their cultural background. CASE DESCRIPTION: We report on the clinical and radiographic findings in five siblings who apparently were subjected to IOM as infants before immigrating to the United States. CLINICAL IMPLICATIONS: Although the practice of IOM is believed to be exceedingly rare in developed countries, it is important that dentists and allied dental personnel who treat refugees from areas of the world in which IOM is endemic be aware of the social factors behind this practice as well as be able to recognize its dental and psychological sequelae.