Early synapsids neurosensory diversity revealed by CT and synchrotron scanning.

Non-mammaliaform synapsids (NMS) represent the closest relatives of today's mammals among the early amniotes. Exploring their brain and nervous system is key to understanding how mammals evolved. Here, using CT and Synchrotron scanning, we document for the first time three extreme cases of neurosensory and behavioral adaptations that probe into the wide range of unexpected NMS paleoneurological diversity. First, we describe adaptations to low-frequency hearing and low-light conditions in the non-mammalian cynodont Cistecynodon parvus, supporting adaptations to an obligatory fossorial lifestyle. Second, we describe the uniquely complex and three-dimensional maxillary canal morphology of the biarmosuchian Pachydectes elsi, which suggests that it may have used its cranial bosses for display or low-energy combat. Finally, we introduce a paleopathology found in the skull of Moschognathus whaitsi. Since the specimen was not fully grown, this condition suggests the possibility that this species might have engaged in playful fighting as juveniles-a behavior that is both social and structured. Additionally, this paper discusses other evidence that could indicate that tapinocephalid dinocephalians were social animals, living and interacting closely with one another. Altogether, these examples evidence the wide range of diversity of neurological structures and complex behavior in NMS.

[Aminoglycoside treatment I. Administration of gentamicin once versus three times daily]. / Aminoglykosidbehandling I. Gentamicinbehandling én gang versus tre gange daglig.

Gentamicin is the most commonly used aminoglycoside in Danish hospitals. The aim of this study was to compare two dosage regimens, thrice-a-day (TID) and once-a-day (OD) with regard to efficacy, safety and tissue toxicity. Twenty-three patients were allocated to TID and 26 were allocated to OD gentamicin. Data from patients treated for more than 72 hours were evaluated. Efficacy was assessed by the rate at which body temperature fell to normal. Renal toxicity was judged by an increase in serum creatinine of more than 50 mumol/l and inner ear toxicity was clinically estimated daily during treatment, followed up by audiometry if positive signs occurred. Serum gentamicin was determined daily to estimate the size of next dose. A low frequency of dose adjustments was considered to reflect safety, as well as the absence of renal and inner ear affection. Results showed no significant differences between the two groups regarding efficacy, safety or tissue toxicity. Renal toxicity developed in two patients on TID regime and in one patient on OD regime. No inner ear toxicity was seen. The renal toxicity appeared unpredictably, both early and late in the treatment period and preceded by low or high values serum gentamicin. It is recommended that gentamicin be administered OD for reasons of economy and convenience and that kidney function be monitored daily throughout the treatment period.

[Aminoglycoside treatment II: Dosage regimes at the departments of internal medicine in Denmark]. / Aminoglykosidbehandling II. Dosisregimer på intern-medicinske afdelinger i Danmark.

The aim of this study was to get a general view of the habitual practice of the usage of aminoglycosides in Danish medical departments, regarding choice of drug, dosage regimen and monitoring of drug-related toxicity, as this antimicrobial agent is commonly used in Danish hospitals against severe infections in spite of the potential for nephro- and ototoxicity. The survey, taking place in 1991 and in 1994, showed that gentamicin and netfilmicin were preferred as first choice with an equal frequency in university and county hospital department, whereas in departments in small hospitals gentamicin was preferred twice as often. From 1991 to 1994 the dosage regimen most commonly used had altered from thrice-a-day to once-a-day. Monitoring of serum levels of the drug was performed on all treated patients in fifty-two of the seventy-nine departments questioned. Most of the departments also monitored the kidney function.