MR vascular imaging with a fast gradient refocusing pulse sequence and reformatted images from transaxial sections

The authors present a method for obtaining magnetic resonance (MR) images of intra- and extracranial vessels from thin contiguous transaxial sections. A section-selective gradient refocusing pulse sequence with a short repetition time caused flow-related enhancement from spins that flowed perpendicular to the transaxial sections. The signal was further enhanced by means of flow compensation gradients to rephase any phase shifts resulting from moving spins in the presence of the imaging gradients. Coronal and sagittal sections, reformatted from multiple transaxial sections, are shown to have excellent vessel contrast without the use of contrast material. These images were obtained in 12 minutes of acquisition time from as many as 60 sections of 3-mm thickness. Such a technique shows significant promise for MR angiography.     

Do the daily experiences of healthy men and women vary according to occupational prestige and work strain?

OBJECTIVE: This study evaluated the influence of occupational prestige and work strain on mood, the occurrence of interpersonal conflict, and ambulatory blood pressure and heart rate. METHODS: Participants were 50 men and 50 women matched for occupational prestige who were healthy and middle-aged and who completed measures of mood and conflict simultaneously with measures of ambulatory blood pressure and heart rate recorded every 30 minutes during waking hours of two workdays and one nonworkday; at the end of each day, overall ratings were made. Work strain was assessed by the Work Section of the Self-Evaluation and Social Support Interview Schedule. Multiple level random regression coefficients analyses were conducted. RESULTS: Men and women with low-prestige occupations experienced more interpersonal conflict, b = -0.03, p = .04, and higher ambulatory heart rate, b = -4.83, p = .004, throughout the three days of the study. Relative to those with low work strain, those reporting high work strain experienced negative emotion, b = -0.41, p < .0001, and boredom, b = -0.17, p < .0004. End of the day ratings of negative mood were more influenced by work strain among men than among women. No effects of occupational prestige or work strain were obtained for ambulatory blood pressure readings after adjustment for physical activity, posture, and location. CONCLUSIONS: Individuals in low-prestige occupations experience greater exposure to interpersonal conflict and arousal as indexed by heart rate, which might increase risk for stress-related illnesses often associated with social class. Individuals who report work strain experience negative mood and boredom, both at work and at home. The absence of work effects on ambulatory blood pressure may be due to the participants being healthy.     

Life course socioeconomic conditions and adult psychosocial functioning

BACKGROUND: Various psychosocial factors have been linked to adult physical health and are also associated with socioeconomic position in adulthood. We evaluated the effect of socioeconomic conditions over the life course on measures of psychosocial functioning in adulthood. METHODS: Life course socioeconomic position was assessed by retrospective recall of parents' education and occupation when the respondent was age 10, and the respondents' education, occupation, and income in 2585 men from eastern Finland aged 42, 48, 54, and 60 years. Measures of psychosocial functioning were derived from scales measuring cynical hostility, hopelessness, and depressive symptoms. RESULTS: Men with both parents who had less than a primary school education or who both had unskilled manual jobs had higher age-adjusted levels of cynical hostility, hopelessness, and depressive symptoms in adulthood. Mutually adjusted analyses showed that parents' education and the respondents' education, occupation, and income all had statistically independent effects on adult levels of cynical hostility and hopelessness. For instance, men for whom neither parent had completed primary education had a 0.15 standard deviation (P = 0.006) higher cynical hostility score, and a 0.20 standard deviation (P = 0.00018) higher hopelessness score, after adjustment for education, occupation and income. In contrast, depressive symptoms in adulthood were only associated with the respondent's occupation and income. CONCLUSIONS: Childhood socioeconomic position was associated with adult psychosocial functioning, but these effects were specific to some aspects of adult psychosocial functioning--cynical hostility and hopelessness, but not depressive symptoms. Adult occupation and income were associated with all measures of psychosocial functioning. In addition to the impact of adult socioeconomic position, some aspects of poor psychosocial functioning in adulthood may also have socioeconomic roots early in life.     

Postpartum evolution of cervical squamous intraepithelial lesions with respect to the route of delivery

OBJECTIVE.: To analyze the effect of the mode of delivery on the evolution of cervical squamous intraepithelial lesions. MATERIALS AND METHODS.: A chart review was performed of all pregnant women referred to the Northwestern Memorial Hospital Colposcopy Clinic between January 1990 and December 1998. Postpartum changes in the Pap smear and in a combined cytologic, histologic, and colposcopic impression of cervical status were evaluated. Data were analyzed using the chi, Fisher exact test, or Student t test. RESULTS.: Antepartum cytology was atypical squamous cells of undetermined significance in 23 women (7.1%), low-grade squamous intraepithelial lesions in 226 women (69.3%), and high-grade squamous intraepithelial lesions in 77 women (23.6%). Vaginal delivery occurred in 300 women (92.0%); 6 women (1.8%) had an elective cesarean section, and 20 women (6.1%) underwent a cesarean section after laboring. Of 306 women who had postpartum Pap smears, 37.9% had no change, 58.8% had improvement, and 3.3% had worsening of their cervical cytology. The rates of improvement of postpartum Pap smears were 164/285 (57.5%) following a vaginal delivery and 16/21 (76.2%) after a cesarean section (p = .81). Similarly, using a combined histologic, colposcopic, and cytologic evaluation of the cervix, the route of delivery did not affect postpartum cervical status (p = .68). CONCLUSION.: The route of delivery did not appear to influence the evolution of cervical squamous intraepithelial lesions during pregnancy and the puerperium.     

The DNA of annexin V-binding apoptotic cells is highly fragmented

Jurkat leukemia cells induced to undergo apoptosis by treatment with an antibody against the Fas receptor have two annexin V (AV)-binding subpopulations: (a) single-positive cells that bind AV but not propidium iodide (PI); and (b) double-positive cells that bind AV and PI. The single-positive population is thought to represent an early stage of apoptosis. We have examined the relationship between AV binding and a classical characteristic of apoptosis, DNA fragmentation. Time course studies with Jurkat cells treated for 1, 2, or 4 h with anti-Fas indicated that the proportion of AV-binding cells was increased after 2 h. A significant increase in DNA fragmentation was observed only at 4 h as measured by the mean tail moment determined with the alkaline single cell gel electrophoresis (comet) assay. This correlation suggests a temporal relationship between the two parameters, but does not provide direct evidence of what happens in individual cells. We developed a method to measure fluorescent markers of cellular structure or function with a laser scanning cytometer and then perform the comet assay on the same cells. Cells in each AV-binding subpopulation were re-examined before and after electrophoresis. Most AV-/PI- cells had no DNA damage, although a few cells showed a pattern of damage characteristic for apoptosis. Double-positive cells all had damaged DNA; approximately half had the apoptotic pattern, and the rest had a pattern typical for necrosis. Nearly all of the single-positive cells had damaged DNA with the apoptotic pattern. Both AV-positive populations contained cells with little or no detectable DNA after electrophoresis, indicating that the DNA was highly fragmented. These results indicate that AV binding is an excellent marker for apoptotic cells, but that these cells already have fragmented DNA.     

谷氨酸脱羧酶抑制剂L-苹果酸对小鼠学习记忆的影响

跳台法和Y迷宫法试验表明,小鼠po L-苹果酸600mg·kg^-1连续5d后对记忆的获得、巩固和再现均有明显的改善作用,并能促进空间辨别学习能力;L-苹果酸改善记忆的作用能被NMDA受体拮抗剂氯胺酮所拮抗。脑内游离氨基酸测定显示,L-苹果酸可明显降低小鼠脑内GABA水平,提高Glu/GABA比值。实验结果表明,脑内GABA水平下降,Glu/GABA比值升高对学习记忆有正性调节作用。