High-dose pentoxifylline in patients with AIDS: inhibition of tumor necrosis factor production. National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group.

Tumor necrosis factor-alpha (TNF) may activate human immunodeficiency virus (HIV), antagonize zidovudine activity, and contribute to AIDS wasting syndrome. Pentoxifylline decreases TNF production. In cell culture, pentoxifylline decreases HIV replication and gene expression. Since an AIDS Clinical Trial Group study suggested that pentoxifylline (400 mg thrice daily) is safe in AIDS patients and decreases TNF mRNA levels in peripheral blood mononuclear cells (PBMC), a second cohort received 800 mg thrice daily for 8 weeks. During treatment, the median decrease in TNF production by PBMC cultured with 0.1 microgram/mL lipopolysaccharide (LPS) was 40%. The median change in TNF mRNA was a 34% decrease. Pentoxifylline did not affect HIV levels as detected by quantitative microculture or serum p24 antigen measurements, nor did it alter zidovudine pharmacokinetics. The most common toxicity was gastrointestinal. Pentoxifylline at dosages of less than thrice-daily 800 mg is well tolerated and may decrease TNF mRNA levels and LPS-induced TNF production.

Effects of induction of low plasma progesterone concentrations with a progesterone-releasing intravaginal device on follicular turnover and fertility in cattle.

The effects of concentration of progesterone in plasma on development and fertility of the first wave dominant follicle were studied in cattle. To identify a source of exogenous progesterone that would permit extension of the first wave dominant follicle, nonlactating Holstein cows (n = 6) received on day 8 of two successive oestrous cycles an injection of PGF2 alpha (25 mg) and a new (1.9 g of progesterone (Period 1)) or used (approximately 1.2 g of progesterone (Period 2)) CIDR-B device that was removed on day 17. Control cows (n = 6) received a new CIDR-B device on day 8 that was removed on day 17 and a PGF2 alpha injection (25 mg) on day 17. Ultrasonography and collection of blood samples were performed on alternate days throughout the experiment. Plasma concentrations of progesterone and oestradiol were different between treatments (P < 0.0001 and P < 0.05, respectively). The dominant follicle was maintained until day 17 and ovulated upon removal of the intravaginal device in 1 of 6, 6 of 6 and 0 of 6 in new CIDR-B, used CIDR-B and control groups, respectively (P < 0.01). The preovulatory dominant follicles were 14.2 +/- 1.6 mm, 20 +/- 1.3 mm and 10 +/- 1.3 mm, respectively (P < 0.001) on day 17. There were fewer 5-9 mm follicles in cows having a persistent dominant follicle (P < 0.01). The interval to onset of oestrus was negatively correlated with size of the dominant follicle on day 17 (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Will the first dominant follicle of the estrous cycle of heifers ovulate following luteolysis on day 7?

The pattern of turnover of dominant follicles involves the sequential growth and regression of two to three dominant follicles during the estrous cycle. The dominant follicle that ovulates is the one that develops concomitantly with the regression of the corpus luteum. The aim of this paper was to determine if the first dominant follicle would ovulate following induction of luteolysis with prostaglandin F2 alpha analogues (PGF) on Day 7 of the cycle. Heifers (n = 43) were checked for estrus (Day 0); their ovaries were scanned daily from Day 6 of the cycle for one week, and the fate of the first dominant follicle was determined. Luteolysis was induced on Day 7 with PGF analogues, and blood samples were taken daily for progesterone and estradiol measurement and at 3-h intervals for 33 h for luteinizing hormone (LH) measurement. Of the 43 heifers given PGF, complete luteolysis occurred in 40 animals. Of these, the first dominant follicle ovulated in 37 heifers; the dominant follicle was not the ovulatory follicle in 2 heifers and the dominant follicle became cystic in one heifer.