The stoned age: Sex differences in the effects of adolescent cannabinoid exposure on prefrontal cortex structure and function in animal models.

Cannabis is the most used drug during adolescence, which is a period of enhanced cortical plasticity and synaptic remodeling that supports behavioral, cognitive, and emotional maturity. In this chapter, we review preclinical studies indicating that adolescent exposure to cannabinoids has lasting effects on the morphology and synaptic organization of the prefrontal cortex and associated circuitry, which may lead to cognitive dysfunction later in life. Additionally, we reviewed sex differences in the effects of adolescent cannabinoid exposure with a focus on brain systems that support cognitive functioning. The body of evidence indicates enduring sex-specific effects in behavior and organization of corticolimbic circuitry, which appears to be influenced by species, strain, drug, route of administration, and window/pattern of drug exposure. Caution should be exercised when extrapolating these results to humans. Adopting models that more closely resemble human cannabis use will provide more translationally relevant data concerning the long-term effects of cannabis use on the adolescent brain.

Chronobiology of sleep in humans.

Periodic circadian (24-h) cycles play an important role in daily hormonal and behavioural rhythms. Usually our sleep/wake cycle, temperature and melatonin rhythms are internally synchronized with a stable phase relationship. When there is a desynchrony between the sleep/wake cycle and circadian rhythm, sleep disorders such as advanced and delayed sleep phase syndrome can arise as well as transient chronobiologic disturbances, for example from jet lag and shift work. Appropriately timed bright light is effective in re-timing the circadian rhythm and sleep pattern to a more desired time, ameliorating these disturbances. Other less potent retiming effects may also be obtained from the judicious use of melatonin and exercise.

Light emitting diodes can be used to phase delay the melatonin rhythm.

Two portable light sources, comprising light emitting diodes (LEDs) of two different wavelengths, were compared to a standard light box in suppressing and phase shifting nocturnal salivary melatonin. All light sources were equated for illuminance of 2000 lux. Sixty-six volunteers participated in the 2-day study and were randomly allocated to one of four conditions; light box, white LED, blue/green LED, or no light control group. Light was administered to the experimental groups from midnight to 02.00 hr on the first night. Half-hourly saliva samples were collected from 19.00 to 02.00 hr on night 1 and until 01.00 hr on night 2. Percent melatonin suppression on night 1 and dim light melatonin onset (DLMO) for each night were calculated. The experimental groups showed significant melatonin suppression during light stimulation, with the blue/green LEDs producing the greatest (70%) suppression. There was no significant difference between the light box at 63% and white LED at 50% suppression. Similarly, the blue/green LED had a significantly greater DLMO delay of 42 min and no difference between the light box of 23 min and the white LED of 22 min. These data suggest the portable LED light source is an effective way of delivering light to phase shift the melatonin rhythm, with the blue/green LED being the more effective of the two LEDs.

Effect of light wavelength on suppression and phase delay of the melatonin rhythm.

Different wavelengths of light were compared for melatonin suppression and phase shifting of the salivary melatonin rhythm. The wavelengths compared were 660 nm (red), 595 nm (amber), 525 nm (green), 497 nm (blue/green), and 470 nm (blue). They were administered with light-emitting diodes equated for irradiance of 130 muW/cm2. Fifteen volunteers participated in all five wavelength conditions and a no light control condition, with each condition conducted over two consecutive evenings. Half-hourly saliva sam ples were collected from 19:00 to 02:00 on night 1 and until 01:00 on night 2. Light was administered for the experimental conditions on the first night only from midnight to 02:00. Percentage melatonin suppression on night 1 and dim light melatonin onset (DLMO) for each night were calculated. The shorter wavelengths of 470, 497, and 525 nm showed the greatest melatonin suppression, 65% to 81%. The shorter wavelengths also showed the greatest DLMO delay on night 2, ranging from 27 to 36 min. The results were consistent with the involvement of a scotopic mechanism in the regulation of circadian phase.

The scientific basis of surgical glove selection in an in vitro fertilization laboratory.

Mouse embryos and human sperm are used as quality control bioassays in human in vitro fertilization (IVF) laboratories. These two models can reveal the cytotoxicty of items commonly used in IVF, such as surgical gloves. The literature published in this area points to the cytotoxicity of both glove powders and glove products.

Asymptomatic jaundice after fasting: a diagnostic dilemma.

An 18-year-old female with asymptomatic jaundice presented to the emergency department after fasting. She was referred to the regional medical center for evaluation and treatment. The diagnosis of Gilbert's syndrome was made by fractionation of serum unconjugated and conjugated bilirubin fraction by alkaline methanolysis, followed by thin-layer chromatography and analysis of fasting-state levels of cholyl conjugated bile acids. Methods for diagnosing this disorder are discussed.

A new silver sulfadiazine water soluble gel.

Silver sulfadiazine is the most commonly used topical antibacterial agent for the treatment of burn wounds. It has many clinical advantages, including a broad spectrum of antimicrobial activity, low toxicity, and minimal pain on application. The current formulation of silver sulfadiazine contains a lipid soluble carrier, polypropylene glycol, that has certain disadvantages, including pseudo-eschar formation and the need for twice daily application. The purpose of this investigation was to describe a new formulation of silver sulfadiazine in a water soluble gel, poloxamer 188. The antibacterial activity of this new gel has been compared to that of the commercially available silver sulfadiazine cream by in vitro and in vivo testing. The results of the in vitro antibacterial testing of these two different agents demonstrated the superiority of the new gel formulation. In experimental wounds, the antibacterial activity of the gel and the commercially available silver sulfadiazine cream were not significantly different when applied once a day. The antibacterial activity of the gel when applied once a day was comparable to that encountered by twice daily applications of the silver sulfadiazine cream by experimental wounds. The major advantage of this gel was its ease of application and removal that is attributed to its water solubility.

Industrial high-voltage electrical burn of the skull, a preventable injury.

Deep burns of the scalp and skull are often caused by high-voltage electrical injuries. Patients with such injuries should be referred to regional burn centers that are prepared to excise necrotic burn tissue and cover the devitalized bone with a well-vascularized flap. Strategies for prevention of these electrical burns are discussed.

Accidental hypothermia: a potential life-threatening hazard of automobile platform lifts.

The wheelchair/scooter of a patient with a relapsing-remitting form of multiple sclerosis was immobilized after inadvertent slippage of the rear wheels of his scooter off an automobile platform lift during travel. While waiting 45 min for the rescue squad, he developed mild hypothermia that responded to passive external rewarming techniques. This potentially life-threatening injury could have been prevented by using a platform lift equipped with full inboard and outboard roll-stop barriers on the platform.

Potential toxicity of retrograde uterine passage of particulate matter.

Dusting powders are commonly used on surgical gloves, examination gloves, and condoms. In addition, they are used in diaphragms, sanitary napkins, and toiletries. These dusting powders can gain access to the abdominal cavity through the vagina or through surgical intervention. The toxicity of these dusting powders in the abdominal cavity can be divided into acute and chronic complications that may be life-threatening. The use of medical and surgical products without dusting powders is strongly recommended.