Effects of chronic stress on plasma corticosterone, ACTH and prolactin

Rats were placed in a stressful environment for 24 hr per day and levels of plasma hormones were measured after varying numbers of days in the environment. Rats were habituated to operant chambers placed in sound-attenuated enclosures. Food pellets were available by lever press on a FR1 schedule. After 3 days of habituation, rats in the “stressed” group were trained to pull a ceiling chain to avoid or escape shock. Following training, stress trials, consisting of a consecutive sequence of 5 sec each of a warning light, warning tone and 0.16, 0.32, 0.65, 1.3 and 2.6 mA of footshock, occurred approximately once per 5 min around-the-clock. For the first day, the sequence was terminated when the ceiling chain was pulled. On subsequent days, 90% of all shock presentations could be avoided or escaped by chain pull; the remaining 10% of trials were inescapable and the entire sequence was presented. Control rats lived in identical chambers without presentation of shock. Rats were sacrificed after 1, 2, 3, 4, 7 or 14 days in this environment and levels of plasma corticosterone, ACTH and prolactin were determined. Levels of plasma corticosterone were elevated during the first 7 days in the stressful environment, but returned to control values by day 14. Levels of plasma ACTH and prolactin were similar in stressed and control rats at all time points measured. These data suggest that stress-induced changes in glucocorticoids but not in ACTH or prolactin might mediate some of the physiological changes that occur as the result of chronic stress.     

25-Hydroxyvitamin D3 metabolism in a human leukemia cell line

Summary 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) is a potent inducer of monocytic differentiation of the human promyelocytic leukemia cell line, HL-60. We have noted that 25-hydroxyvitamin D₃ (25(OH)D₃) in high doses is also capable of promoting monocytic differentiation of this cell line. To test the possibility that the latter activity is due to conversion of 25OHD₃ to 1,25(OH)₂D₃ by HL-60, we exposed HL-60 cells to 25OHD₃ and analyzed the products by HPLC and radioreceptor assay. When chromatographed in the traditional solvent system (isopropanol-hexane), a new peak appears which migrates with authentic 1,25(OH)₂D₃. However, in a solvent system containing dichloromethane, 90% of the peak migrates with another metabolite, 19-Nor-10-Keto-25OHD₃ (19-Nor-25OHD₃). Production of this metabolite is enhanced by living cells and is synthesized by both virgin HL-60 and those which have undergone differentiation. We next determined if authentic 19-Nor-25OHD₃ also promotes differentiation of this cell. As assessed by appearance of the monocyte-specific surface antigen (63D3) and macrophage-specific esterase activity, we find that this metabolite does, in fact, induce monocytic differentiation of HL-60 with a potency of approximately 1/200 that of 1,25(OH)₂D₃ and similar to that of 25OHD₃. In agreement with the effect upon cell maturation, 19-Nor-25OHD₃ displaces³H-1,25(OH)₂D₃ from its HL-60 receptor with an efficiency comparable to 25OHD₃. Hence, HL-60 cells convert 25OHD₃ to 19-Nor-25OHD₃, and 19-Nor-25OHD₃ induces monocytic differentiation of HL-60 with comparable efficiency to its precursor, 25OHD₃.     

Local fibrinolysis for superior mesenteric artery thromboembolism

A 66-year-old man with atrial fibrillation was referred soon after developing left lower limb and abdominal pain with rectal bleeding. An immediate flush aortogram showed embolic occlusion of the left distal superficial femoral artery and superior mesenteric artery (SMA), 3 cm from its ostium. Recombinant tissue plasminogen activitor (rtPA) 40 mg was selectively in stilled in the SMA in two boluses. Abdominal symptoms resolved within 48 h, and complete recanalization of the SMA was shown on angiography. Exploratory laparotomy after 72 h showed a normal small bowel and right colon, and was completed by femoropopliteal embolectomy. Six months later, the patient remained asymptomatic.     

Atributable risk of breast,prostate, and lung cancer in Hawaii due to saturated fat

The dietary data from case-control studies of breast, prostate, and lung cancer in Hawaii revealed that saturated fat was a risk factor for these malignancies. The dietary intakes from the three studies were used to calculate the attributable risk (AR) due to saturated fat. For all ethnic groups combined, the ARs for the highest quartiles of intake were 14.9 percent for female breast cancer, 13.0 percent for prostate cancer, and 23.1 percent for male lung cancer. Our results suggested that a reduction of saturated fat to the lowest quartiles of intake could result in a 10 to 20 percent decrease in risk for these three cancers in Hawaii. We also examined the ethnic-specific risks associated with saturated fat consumption among the Japanese and the Caucasians in the three studies. The ARs for the highest quartiles of intake were notably higher among the Caucasians than the Japanese, primarily due to the difference in their dietary patterns. Although the calculated AR due to saturated fat was higher among the Caucasians than among the Japanese, all persons in the population would derive considerable benefit by reducing their intake of this nutrient.Authors are with the Epidemiology Program, Cancer Research Center of Hawaii, University of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813, USA. Address correspondence to Dr Hankin. This study was supported in part by NIH Grant PO1 CA 33619.     

Simultaneous occurrence of acute myelogenous leukemia and seminoma of the testis

Summary Simultaneous tumors are rarely encountered during the course of acute leukemias. We report on a case of seminoma of the testis that occurred during the evolution of acute myelogenous leukemia. To our knowledge, this stimultaneous association has not previously been described, but a causal relationship was not apparent in the present case. The likelihood of a common carcinogenesis existed, but direct exposure to carcinogens could not be established. Although the results of a physical examination and echography were normal at the time of diagnosis, we cannot exclude the presence of microscopic cancer of the testis. Since the dissemination pattern of seminoma is usually slower than that observed in this case and the disease remains limited to the lymph nodes for long periods following dissemination, the rapid development of the present case might have been attributable to the immunosuppression and the scrotal sepsis that occurred during the induction therapy. Immunosuppression might have stimulated the progression of a primary microscopic seminoma and the development of metastasis, whereas the scrotal sepsis and inflammation might have favored the occurrence of metastasis through bypass of the lymphatic barrier.     

Longitudinal Evaluation of an Enhanced Alcohol Misuse Prevention Study (AMPS) Curriculum for Grades Six-Eight

ABSTRACT: For students progressing from sixth to eighth grade, an enhanced Alcohol Misuse Prevention Study (AMPS) curriculum that emphasized social pressure resistance training, peer support, and norm-setting was developed, implemented, and evaluated. Schools were randomly assigned within communities to curriculum or control groups. Students were pretested early in sixth grade before the intervention and posttested at the end of sixth, seventh, and eighth grades. Results indicated the curriculum was effective in increasing students' knowledge of curriculum material, and among the subgroup of students who had used alcohol unsupervised by adults before the pretest, in reducing the rate of increase of alcohol misuse. The findings result from a replication of the analytic approach used with the initial AMPS cohort data.