Reducing the risk of fatal and disabling hypoglycaemia: a comparison of arterial blood sampling systems.

BACKGROUND: In 2008, the National Patient Safety Agency (NPSA) published a report after 42 incidents and two deaths where glucose-containing flush solutions were attached to the arterial line. The molar concentration of 5% glucose is 277 mmol litre(-1). Only a tiny amount of sample contamination will lead to an artificially high glucose. As the NPSA sought a solution, a bench model was constructed to compare the performance of three open and three closed arterial line systems in limiting sample contamination. METHODS: All arterial line systems were set up in a standard manner and pressurized to 300 mm Hg with 5% glucose used as the flush solution. This was connected to the 'radial artery' using an 18 G needle representing the radial cannula. The radial artery was simulated using a wide-bore extension set with 'blood' flow at 60 ml min(-1). Blood was simulated by the addition of red dye to Hartmann's solution. Increasing multiples of arterial line dead space were aspirated and discarded. Blood samples were then obtained and glucose concentration was measured. RESULTS: Significant glucose contamination (3 mmol litre(-1) +/-3.4) was detected in all open arterial line systems up to an aspiration volume of five times the dead space. No samples from the closed systems recorded glucose concentration >1 mmol litre(-1). CONCLUSIONS: Recommended minimal discard volumes are inadequate in the presence of glucose as the flush solution and can lead to high blood glucose readings, inappropriate insulin use, and iatrogenic neuroglycopaenia. Our study demonstrates that the closed-loop arterial sampling system could be the universal solution sought by the NPSA.

Initial deficit and recovery of function after MDMA preexposure in rats.

RATIONALE: 3,4-methylenedioxymethamphetamine (MDMA) exposure was reported to result in deficits in serotonergic neurotransmission with concomitant behavioral suppression and tolerance to MDMA. Some data have also suggested that the neurochemical deficits recover over time, raising the question as to whether behavioral suppression would show a similar recovery. OBJECTIVES: The possibility of recovery of behavioral deficits was examined in the present study. Rats were administered an MDMA pretreatment regimen that was shown to produce numerous serotonergic deficits and behavioral suppression 2 weeks thereafter. The full expression of MDMA-produced hyperactivity was dependent upon serotonergic integrity, therefore, the present study aimed to determine whether MDMA pretreated rats were tolerant to MDMA 2 weeks after exposure. Further, because serotonergic deficits have shown recovery over time, similar behavioral tests were conducted at a later time point to determine whether functional recovery was evident. METHODS: MDMA-produced hyperactivity was measured at different withdrawal periods (2 and 12 weeks) to determine initial effects and the possibility of recovery of function. RESULTS: In saline-pretreated control rats, +/-MDMA (0.0-10.0 mg/kg) produced a dose-dependent increase in locomotor activity. Rats that had received prior exposure to MDMA (4 x 10 mg/kg MDMA injections administered at 2 h intervals) demonstrated tolerance when the activity was measured 2 weeks after pretreatment. For these rats, there was a downward shift in the dose-effect curve for MDMA-produced hyperactivity. MDMA-produced hyperactivity in rats that were tested 12 weeks after pretreatment was, however, comparable to controls, suggesting recovery of function. CONCLUSION: These data are consistent with the idea that high dose MDMA exposure produces neuroadaptations that exhibit recovery with extended abstinence from the drug.

An item response theory analysis of self-report measures of adult attachment.

Self-report measures of adult attachment are typically scored in ways (e.g., averaging or summing items) that can lead to erroneous inferences about important theoretical issues, such as the degree of continuity in attachment security and the differential stability of insecure attachment patterns. To determine whether existing attachment scales suffer from scaling problems, the authors conducted an item response theory (IRT) analysis of 4 commonly used self-report inventories: Experiences in Close Relationships scales (K. A. Brennan, C. L. Clark, & P. R. Shaver, 1998), Adult Attachment Scales (N. L. Collins & S. J. Read, 1990), Relationship Styles Questionnaire (D. W. Griffin & K. Bartholomew, 1994) and J. Simpson's (1990) attachment scales. Data from 1,085 individuals were analyzed using F. Samejima's (1969) graded response model. The authors' findings indicate that commonly used attachment scales can be improved in a number of important ways. Accordingly, the authors show how IRT techniques can be used to develop new attachment scales with desirable psychometric properties.

Practicing dentistry in the age of telemedicine.

BACKGROUND: This article examines teledentistry and some of its current legal issues. Topics include licensure, malpractice, technology and ethics. General recommendations for the dental practitioner are included. The literature review includes state and federal laws, the Telemedicine Report to Congress and numerous articles (both printed and electronic) associated with the topic. Sources were selected for timeliness and relevance to legal issues and implications of telemedicine/teledentistry for the dental practitioner. CONCLUSIONS: Numerous issues require resolution before telemedicine and teledentistry will truly realize their enormous potential to increase access to health care while decreasing health care costs. These issues include interstate licensure, jurisdiction and malpractice, as well as technological, security and ethical questions. PRACTICE IMPLICATIONS: Telemedicine and teledentistry are relatively new to the dental field. Many of the legal issues reviewed have yet to be resolved by the legislature or the courts. Furthermore, technology has not yet progressed to the point where the practitioner can be certain that no technological failure will occur during a teledental consultation. In spite of these problems, the potential of telemedicine and teledentistry is tremendous. Improvement in accessibility of health care and lowered health care costs are only two of the many advantages that will emerge as telemedicine and teledentistry become integrated with, and fundamentally change, the practice of medicine and dentistry.

Nicotinic receptors and stages of nicotine dependence.

Smoking is one of the leading causes of preventable death, where nicotine has been identified as the primary addictive constituent of tobacco. Consequently, there have been extensive investigations into the neuroadaptations that occur as nicotine dependence develops, where numerous neurological systems have been implicated. The focus of this review was on nicotinic acetylcholine receptor neuroadaptations that occur during the development of nicotine dependence. This focus was selected because (1) the nicotinic receptors are the primary binding sites for both nicotine and the most efficacious pharmacological smoking cessation treatments and (2) the receptors are located throughout the brain with considerable neuromodulatory ability. However, there was difficulty associated in outlining the role of nicotinic receptors in the development of nicotine dependence because it comprises a series of stages involving different neurological systems rather than a single state. To address this issue, the review adopts a novel approach and considers the role of nicotinic receptor subtypes at separate stages of the nicotine dependence cycle. This information was then used to examine the nicotinic receptor-related therapeutic mechanisms of three main pharmacological smoking cessation treatments.

Differential effects of maternal nutrient restriction through pregnancy on kidney development and later blood pressure control in the resulting offspring.

The mechanisms whereby maternal nutritional manipulation through pregnancy result in altered blood pressure in the offspring may include changes in fetal and newborn and adult renal prostaglandin (PG) synthesis, metabolism, and receptor expression. Since the postnatal effects of nutrient restriction on the renal PG synthesis and receptor system during nephrogenesis in conjunction with nephron numbers and blood pressure have not been evaluated in the rat, the present study examined the effect of reducing maternal food intake by 50% of ad libitum through pregnancy on young male rats. Six control-fed mothers and eight nutrient-restricted pregnant rats with single litter mates were used at each sampling time point, most of which occurred during nephrogenesis. Offspring of nutrient-restricted dams were lighter from birth to 3 days. This was accompanied by reduced PGE2, with smaller kidneys up to 14 days. Nutrient restriction also decreased mRNA expression of the PG synthesis enzyme, had little effect on the PG receptors, and increased mRNA expression of the degradation enzyme during nephrogenesis and the glucocorticoid receptor in the adult kidney. These mRNA changes were normally accompanied by similar changes in protein. Nephron number was also reduced from 7 days up to adulthood when blood pressure (measured by telemetry) did not increase as much as in control offspring during the dark, active period. In conclusion, maternal nutrient restriction suppressed renal PG concentrations in the offspring, and this was associated with suppressed kidney growth and development and decreased blood pressure.

Impact of maternal undernutrition and fetal number on glucocorticoid, growth hormone and insulin-like growth factor receptor mRNA abundance in the ovine fetal kidney.

Epidemiological and animal studies strongly indicate that the environment experienced in utero determines, in part, an individual's likelihood of developing cardiovascular disease in later life. This risk has been further linked to impaired kidney function, as a result of compromised development during fetal life. The present study therefore examined the influence of maternal nutrient restriction (NR), targeted at specific periods of kidney development during early to mid gestation, on the mRNA abundance of receptors for glucocorticoid (GCR), growth hormone (GHR) and insulin-like growth factors-I (IGF-IR) and -II (IGF-IIR), and the IGF-I and -II ligands. This was undertaken in both singleton and twin fetuses. At conception ewes were randomly allocated to either an adequately fed control group or one of four nutrient-restricted groups that were fed half the control amount from 0 to 30, 31 to 65, 66 to 110 or 0 to 110 days gestation. At 110 days gestation all ewes were humanely euthanased and fetal kidneys and surrounding adipose tissue sampled. There was no effect of NR or fetal number on kidney weight, shape or nephron number, but the surrounding fat mass was increased in singleton fetuses exposed to NR for 110 days. An increase in kidney mRNA abundance with NR only occurred in singleton fetuses where IGF-IR mRNA was enhanced with NR from 66-110 days gestation. In twin fetuses, NR had no effect on mRNA abundance. However, for all genes examined mRNA expression was lower in the kidneys of twin compared with singleton fetuses following NR, and the magnitude of the effect was dependent on the timing of NR. In conclusion, the abundance of mRNA for receptors which regulate fetal kidney development are lower in twin animals compared with singletons following periods of nutrient deficiency. This may impact on later kidney development and function.

Attachment styles and personality disorders: their connections to each other and to parental divorce, parental death, and perceptions of parental caregiving.

Attachment theory was explored as a means of understanding the origins of personality disorders. We investigated whether adult attachment styles and personality disorders share a common underlying structure, and how both kinds of variables relate to family background factors, including parental death, parental divorce, and current representations of childhood relationships with parents. A nonclinical group of 1407 individuals, mostly adolescents and young adults, were surveyed about their attachment styles, parental marital status, parental mortality status, perceptions of treatment by parents in childhood, and 13 personality disorders. Results indicated substantial overlap between attachment and personality-disorder measures. Two of the personality-disorder dimensions are related to the two dimensions of the attachment space; that is, there is a two-dimensional space in which both the attachment patterns and most of the personality disorders can be arrayed. The one personality-disorder factor that is unrelated to attachment appears akin to psychopathy. Both personality disorders and attachment styles were associated with family-of-origin variables. Results are discussed in terms of encouraging further research to test the idea that insecure attachment and most of the personality disorders share similar developmental antecedents.