Plasma leptin in men and women with seasonal affective disorder and in healthy matched controls.

Seasonal affective disorder (SAD) is a specific clinical entity characterized by recurrent episodes of depression, which typically occur during the winter with periods of remission during the spring and summer. These depression episodes are accompanied by hyperphagia with cravings for carbohydrates and moderate weight gain, and usually respond to light therapy. We examined potential relationships between leptin, a hormone known to affect appetite and weight regulation, and seasonal changes in mood and appetite by measuring plasma leptin, clinical severity of depression, appetite scores, and body mass index (BMI) in 19 women and 8 men with SAD and matched controls (20 women and 8 men) in the summer and winter. Plasma leptin was positively correlated with BMI in patients and controls during both seasons. Women and men with SAD both experienced depression in the winter, which was associated with increased appetite, caloric intake, and carbohydrate craving. Increased body weight during the winter in subjects with SAD was paralleled by a lack of concomitant changes in plasma leptin, which suggests that leptin sensitivity to changes in body weight may be influenced by seasons in subjects with SAD, similar to seasonal mammals.

The effects of seasons and light therapy on G protein levels in mononuclear leukocytes of patients with seasonal affective disorder.

BACKGROUND: Information-transducing heterotrimeric G proteins have been implicated previously in the mechanism of action of mood stabilizers and in the pathophysiology of mood disorders. Mononuclear leukocytes of patients with unipolar and bipolar depression have been characterized by reduced measures of the stimulatory and inhibitory G proteins. In this study, patients with seasonal affective disorder (SAD) were measured for mononuclear leukocyte G protein levels while depressed during the winter, following light therapy, and in remission during the summer. METHODS: Twenty-six patients with SAD and 28 healthy subjects were assessed in the study. The immunoreactivities of Gs alpha, Gi alpha, and Gbeta subunit proteins were determined by Western blot analysis of mononuclear leukocyte membranes with selective polyclonal antibodies for the various G subunit proteins, followed by densitometric quantitation using an image analysis system. RESULTS: Untreated patients with SAD and winter, atypical-type depression showed significantly reduced mononuclear leukocyte immunoreactive levels of Gs alpha and Gi alpha proteins, similar to previous observations in patients with nonseasonal major depression. The reduced G protein levels were normalized with 2 weeks of light therapy. The same patients while in remission during the summer had G protein levels that were similar to those of healthy subjects. CONCLUSIONS: G protein-immunoreactive measures in patients with SAD are suggested as a state marker for winter depression, which is normalized by light treatment and during the summer. We speculate that light may exert its effects via normalization of transducin (Gt protein) levels, which are thought to be reduced in winter depression.

Radiosensitizing effect of nicotinamide and carbogen combined in fractionated pions or x-rays in SCCVII tumors.

Well-known radiotherapeutic strategies for hypoxic cells include hypoxic radiosensitizers, heavy particles, and fractionated irradiation. This study attempted to obtain the ultimate effectiveness of these strategies by combining nicotinamide plus carbogen (N + C) as a hypoxic radiosensitizer with fractionated pions. In addition, the influence on the N + C effect of X-ray dose rate used as a reference radiation was evaluated. When SCCVII tumors in the dorsum of feet reached 50 mm3 in volume, they were irradiated with pions (0.2 Gy/min), the same dose rate (LDR; 0.2 Gy/min) X-rays, or high dose rate (HDR; 1.5 Gy/min) X-rays in 10 fractions over 11 days. Nicotinamide (0.5 mg/g) was administered i.p. one hour before irradiation, and normobaric carbogen (95% oxygen and 5% carbon dioxide) was breathed from 10 min before irradiation. The effect was evaluated by tumor growth time (TGT50) assay. The combination of N + C significantly enhanced the effect of 30 Gy LDR and 28 Gy HDR X-rays, with the effect corresponding to that of 39 Gy HDR X-rays: the enhancement ratios were 1.2 and 1.4, respectively. The effect of 20 Gy pions was equivalent to the effect of 33 Gy HDR X-rays (ratio of 1.65), or the effect of N + C combined with 28 Gy HDR X-rays. However, N + C did not enhance the effect of 20 Gy pions. This suggested that the fractionated pions had great biological effectiveness against hypoxic cells. In conclusion, N + C afforded no additional benefit with fractionated pions, but it was thought to be of value for fractionated X-rays, even in a dose rate of 0.2 Gy/min.

Inferior oblique muscle injury from local anesthesia for cataract surgery.

BACKGROUND: Vertical rectus muscle injury is commonly cited as a cause of strabismus after cataract surgery. Injury to the inferior oblique muscle or nerve as a complication of cataract surgery has not been described previously. METHODS: Four patients without pre-existing strabismus who had diplopia after cataract surgery were studied. Analysis included prism and cover testing, Lancaster red-green testing, and fundus torsion assessment. RESULTS: Three patients had a delayed-onset hypertropia with fundus extorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle overaction secondary to presumed contracture. The fourth patient had an immediate-onset hypotropia with fundus intorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle paresis. Damage to a vertical rectus muscle or "unmasking" of a pre-existing superior oblique muscle paresis could not explain the history and findings in this group of four patients. CONCLUSION: The inferior oblique muscle contracture observed in three patients may have been caused by local anesthetic myotoxicity, whereas the paresis observed in one patient may have been due to mechanical trauma or anesthetic toxicity directly to the nerve innervating the muscle. Inferior oblique muscle or nerve injury should be considered as another possible cause of postoperative strabismus, especially when significant fundus torsion accompanies a vertical deviation.

Nanogram level quantitation of oxycodone in human plasma by capillary gas chromatography using nitrogen-phosphorus selective detection.

A sensitive and specific capillary gas chromatographic assay is reported for the quantitation of oxycodone in human plasma. The technique involves a single extraction of oxycodone and internal standard (hydrocodone) from plasma by toluene containing 1% isopropanol. Separation is achieved on a methyl silicone (HP-1) fused-silica capillary column (25 m x 0.2 mm I.D., 0.33 microns film thickness) and detection is by nitrogen-phosphorus selective mode. The minimum quantifiable limit is 1.8 ng/ml using 2 ml of plasma. The method is applicable to characterize the plasma profile of oxycodone in humans after a single oral 5-mg oxycodone hydrochloride tablet.