Mast Cells Exert Anti-Inflammatory Effects in an IL10-/- Model of Spontaneous Colitis.

Mast cells are well established as divergent modulators of inflammation and immunosuppression, but their role in inflammatory bowel disease (IBD) remains to be fully defined. While previous studies have demonstrated a proinflammatory role for mast cells in acute models of chemical colitis, more recent investigations have shown that mast cell deficiency can exacerbate inflammation in spontaneous colitis models, thus suggesting a potential anti-inflammatory role of mast cells in IBD. Here, we tested the hypothesis that in chronic, spontaneous colitis, mast cells are protective. We compared colitis and intestinal barrier function in IL10-/- mice to mast cell deficient/IL10-/- (double knockout (DKO): KitWsh/Wsh × IL10-/-) mice. Compared with IL10-/- mice, DKO mice exhibited more severe colitis as assessed by increased colitis scores, mucosal hypertrophy, intestinal permeability, and colonic cytokine production. PCR array analyses demonstrated enhanced expression of numerous cytokine and chemokine genes and downregulation of anti-inflammatory genes (e.g., Tgfb2, Bmp2, Bmp4, Bmp6, and Bmp7) in the colonic mucosa of DKO mice. Systemic reconstitution of DKO mice with bone marrow-derived mast cells resulted in significant amelioration of IL10-/--mediated colitis and intestinal barrier injury. Together, the results presented here demonstrate that mast cells exert anti-inflammatory properties in an established model of chronic, spontaneous IBD. Given the previously established proinflammatory role of mast cells in acute chemical colitis models, the present findings provide new insight into the divergent roles of mast cells in modulating inflammation during different stages of colitis. Further investigation of the mechanism of the anti-inflammatory role of the mast cells may elucidate novel therapies.

Urine sodium concentrations are predictive of hypoadrenocorticism in hyponatraemic dogs: a retrospective pilot study.

OBJECTIVES: To determine if a urine sodium concentration could be used to rule out hypoadrenocorticism in hyponatraemic dogs. MATERIALS AND METHODS: Medical records were reviewed for hyponatraemic dogs (serum sodium<135 mmol/L) that had recorded urine sodium concentrations. Twenty hyponatraemic dogs were included: 11 diagnosed with classical hypoadrenocorticism and nine with non-adrenal causes of hyponatraemia. A Wilcoxon rank-sum test was used to compare results between groups. RESULTS: No dog with hypoadrenocorticism had a urine sodium concentration less than 30 mmol/L. Urine sodium concentration in dogs with hypoadrenocorticism was significantly higher (median 103 mmol/L, range: 41 to 225) than in dogs with non-adrenal illness (median 10 mmol/L, range: 2 to 86) (P<0·0005). Serum sodium concentrations were not significantly different between dogs with hypoadrenocorticism and dogs with non-adrenal illness. CLINICAL SIGNIFICANCE: These results suggest that urine sodium concentrations can be used to prioritise a differential diagnosis of hypoadrenocorticism in hyponatraemic dogs. A urine sodium concentration less than 30 mmol/L in a hyponatraemic dog makes classical hypoadrenocorticism an unlikely cause of the hyponatraemia. Nevertheless, because of the small sample size our results should be interpreted with caution and a larger follow-up study would be valuable.

Hypercoagulability in dogs with protein-losing nephropathy as assessed by thromboelastography.

BACKGROUND: Dogs with protein-losing nephropathy (PLN) are at risk of thromboembolic disease, but the mechanism leading to hypercoagulability and the population of dogs at risk are unknown. OBJECTIVES: To characterize thromboelastography (TEG) and its association with serum albumin (SALB), UPC, and antithrombin activity in dogs with PLN. ANIMALS: Twenty-eight client-owned dogs with PLN (urine protein:creatinine ratio [UPC] > 2.0) and 8 control dogs were prospectively enrolled in this observational study. METHODS: TEG parameters, antithrombin activity, serum biochemical profiles, and UPC were measured. TEG analyses were run in duplicate with kaolin activation; reaction time (R), clot formation time (K), α-angle (α), maximal amplitude (MA), and global clot strength (G) were analyzed. RESULTS: Dogs with PLN had lower K (P = .004), and higher α (P = .001), MA (P < .001), and G (P < .001) values than controls. No significant correlation between TEG parameters and UPC, SALB, or antithrombin was noted. Twelve PLN dogs (42.8%) were azotemic and 19 (67.8%) were hypoalbuminemic (SALB < 3.0 g/dL); 11 had SALB < 2.5 g/dL. CONCLUSIONS AND CLINICAL IMPORTANCE: These results indicate that dogs with PLN have TEG values that demonstrate hypercoagulability compared with a control population but that antithrombin, SALB, or UPC cannot be used in isolation to predict this result. A comprehensive evaluation of the coagulation system in individual patients may be necessary to predict the point at which anti-thrombotic therapy is indicated.

Early life stress triggers persistent colonic barrier dysfunction and exacerbates colitis in adult IL-10-/- mice.

BACKGROUND: It has become increasingly evident that disease flares in the human inflammatory bowel diseases are influenced by life stress. It is known that life stress can trigger disturbances in intestinal barrier function and activate proinflammatory signaling pathways, which are important contributors to intestinal inflammation and clinical disease; however, the exact mechanisms of stress-induced inflammatory bowel disease exacerbations remain to be elucidated. Here, we presented a model of early life stress-induced exacerbation of colitis in interleukin (IL)-10 mice. METHODS: C57Bl/6 wild-type and IL-10 mice were exposed to neonatal maternal separation (NMS) stress on postnatal days 1 to 18 and reared under normal conditions until 10 to 12 weeks of age. At this time, histopathology, colitis scores, intestinal barrier function, proinflammatory cytokine expression, and mast cell activity were evaluated. RESULTS: NMS increased the severity of colitis IL-10 mice indicated by greater colitis scores and colonic proinflammatory cytokine concentrations. NMS and IL-10 increased colonic permeability; however, NMS alone did not induce colitis. Increased mast cell activation and colonic tryptase release were observed in IL-10 mice exposed to NMS, indicating mast cell activation. CONCLUSIONS: This study demonstrates that colitis in IL-10 mice can be exacerbated by NMS stress. The precise mechanisms of enhanced colitis severity in NMS IL10 mice are unclear but persistent defects in intestinal barrier function likely play a contributing role. NMS serves as a novel model to investigate the mechanisms by which early life stress influences the development and course of inflammatory bowel disease in adulthood.

Effects of prostaglandin E and F receptor agonists in vivo on luteal function in ewes.

Loss of progesterone secretion at the end of the estrous cycle is via uterine PGF(2alpha) secretion; however, uterine PGF(2alpha) is not decreased during early pregnancy in ewes to prevent luteolysis. Instead the embryo imparts resistance to PGF(2alpha)-induced luteolysis, which is via the 2-fold increase in prostaglandins E(1) and E(2) (PGE(1), PGE(2); PGE) in the endometrium during early pregnancy. Chronic intrauterine infusion of PGE(1) or PGE(2) prevents spontaneous or an estradiol-17beta, IUD, or PGF(2alpha)-induced luteolysis. Four PGE receptor subtypes (EP(1), EP(2), EP(3), and EP(4)) and an FP receptor specific for PGF(2alpha) have been identified. The objective of this experiment was to determine the effects of EP(1), EP(2), EP(3), or FP receptor agonists in vivo on luteal mRNA for LH receptors, occupied and unoccupied LH receptors, and circulating progesterone in ewes. Ewes received a single treatment of 17-phenyl-tri-Nor-PGE(2) (EP(1), EP(3)), butaprost (EP(2)), 19-(R)-OH-PGE(2) (EP(2)), sulprostone (EP(1), EP(3)), or PGF(2alpha) (FP) receptor agonists into the interstitial tissue of the ovarian vascular pedicle adjacent to the luteal-containing ovary. 17-Phenlyl-tri-Nor-PGE(2) had no effect (P> or =0.05) on any parameter analyzed. Butaprost and 19-(R)-OH-PGE(2) increased (P< or =0.05) mRNA for LH receptors, occupied and unoccupied LH receptors, and circulating progesterone. Both sulprostone and PGF(2alpha) decreased (P< or =0.05) mRNA for LH receptors, occupied and unoccupied LH receptors, and circulating progesterone. It is concluded that both EP(3) and FP receptors may be involved in luteolysis. In addition, EP(2) receptors may mediate prevention of luteolysis via regulation of luteal mRNA for LH receptors to prevent loss of occupied and unoccupied LH receptors and therefore to sustaining luteal function.

Prostaglandin E1 (PGE1), but not prostaglandin E2 (PGE2), alters luteal and endometrial luteinizing hormone (LH) occupied and unoccupied LH receptors and mRNA for LH receptors in ovine luteal tissue to prevent luteolysis.

Loss of luteal progesterone secretion at the end of the ovine estrous cycle is via uterine PGF(2)alpha secretion. However, uterine PGF(2)alpha secretion is not decreased during early pregnancy in ewes. Instead, the embryo imparts a resistance to PGF(2)alpha. Prostaglandins E (PGE; PGE(1)+PGE(2)) are increased in endometrium and uterine venous blood during early pregnancy in ewes to prevent luteolysis. Chronic intrauterine infusion of PGE(1) or PGE(2) prevents spontaneous or IUD, estradiol-17beta, or PGF(2)alpha-induced premature luteolysis in nonbred ewes. The objective was to determine whether chronic intrauterine infusion of PGE(1) or PGE(2) affected mRNA for LH receptors, occupied and unoccupied receptors for LH in luteal and caruncular endometrium, and luteal function. Ewes received Vehicle, PGE(1), or PGE(2) every 4h from days 10 to 16 of the estrous cycle via a cathether installed in the uterine lumen ipsilateral to the luteal-containing ovary. Jugular venous blood was collected daily for analysis of progesterone and uterine venous blood was collected on day-16 for analysis of PGF(2)alpha and PGE. Corpora lutea and caruncular endometrium were collected from day-10 preluteolytic control ewes and day-16 ewes treated with Vehicle, PGE(1) or PGE(2) for analysis of the mRNA for LH receptors and occupied and unoccupied receptors for LH. Luteal weights on day-16 in ewes treated with PGE(1) or PGE(2) and day-10 control ewes were similar (P>or=0.05), but were greater (PPGE(2)>Vehicle-treated ewes. Concentrations of PGF(2)alpha and PGE in uterine venous plasma on day-16 were similar (P>or=0.05) in the three treatment groups. Luteal mRNA for LH receptors and unoccupied and occupied LH receptors were similar (P>or=0.05) in day-10 control ewes and day-16 ewes treated with PGE(2) and were lower (P

Is endothelin-1 luteolytic or antiluteolytic in ewes?

Endothelin-1 (ET-1) has been reported to mediate prostaglandin (PG) F(2)alpha (PGF(2)alpha)-induced luteolysis. Prostaglandins E (PGE; PGE(1)+PGE(2)) are associated with implantation, maternal recognition of pregnancy, and are antiluteolytic and luteotropic in vitro and in vivo. ET-1 increased PGE secretion by bovine luteal tissue in vitro from cows where estrus was not synchronized or when estrus was synchronized with lutalyse and did not affect luteal PGF(2)alpha or progesterone secretion, which does not support the concept that ET-1 is luteolytic or mediates PGF(2)alpha luteolysis. Therefore, the objective of this experiment was to determine whether ET-1 infused every 6h from 2400 h on day 10-1800 h on day 18 of the ovine estrous cycle either into the interstitial tissue of the ovarian vascular pedicle (IP) or intrauterine (IU) adjacent to the luteal-containing ovary was luteolytic in ewes. Treatments were: Vehicle-IP; Vehicle-IU; ET-1-IP; or ET-1-IU. Weights of corpora lutea differed (P< or = 0.05) among treatment groups. Weights of corpora lutea at 1800 h on day 18 were: VEH-IP-247+/-38 mg; VEH-IU-195+/-31 mg; ET-1-IP-626+/-74 mg; and ET-1-IU-542+/-69 mg. Luteal weights on day 18 in ET-1-IP or ET-1-IU-treated ewes did not differ (P> or =0.05), but were heavier (P< or =0.05) than in the Vehicle-IP or Vehicle-IU treatment groups which did not differ (P> or =0.05). Profiles of progesterone in jugular venous plasma of both control groups treated with Vehicle-IP or Vehicle-IU were lower (P< or =0.05) than in ewes treated with ET-1-IP or ET-1-IU, which did not differ (P> or =0.05) between ET-1-IP or ET-1-IU treatment groups. Treatment with ET-1-IP or ET-1-IU increased (P< or =0.05) the PGE:PGF(2)alpha ratio when compared to the Vehicle-IP or Vehicle-IU treatment groups, which did not differ (P> or =0.05) between each other. In summary, ET-1 prevented the decrease in luteal weights and the decline in progesterone, but increased the PGE:PGF(2)alpha ratio when compared to controls. Therefore, it is concluded that ET-1 is not luteolytic in ewes, but instead may be luteotropic or antiluteolytic by altering uterine secretion of the PGE:PGF(2)alpha ratio, since PGE(1) or PGE(2) are luteotropic in vitro and in vivo, PGE(1) or PGE(2) prevent PGF(2)alpha-induced luteolysis in vitro and in vivo, and PGE(1) and PGE(2) increase two-fold in ewe endometrium to prevent luteolysis during early pregnancy.

Mechanism whereby nitric oxide (NO) infused chronically intrauterine in ewes is antiluteolytic rather than being luteolytic.

Nitric oxide (NO) has been reported to be luteolytic in vitro and in vivo in cows. However, an NO donor reversed PGF2alpha-induced inhibition of rat luteal progesterone secretion in vitro and an NO donor or endothelin-1 stimulated bovine luteal tissue secretion of prostaglandins E (PGE; PGE1, PGE2) in vitro without affecting progesterone or PGF2alpha secretion. In addition, chronic infusion of an NO donor into the interstitial tissue of the ovarian vascular pedicle adjacent the luteal-containing ovary prevented the decline in circulating progesterone, while a nitric oxide synthase (NOS) inhibitor did not affect luteolysis. The objective of this experiment was to determine whether an NO donor or NOS inhibitor infused chronically intrauterine adjacent to the luteal-containing ovary during the ovine estrous cycle was luteolytic or antiluteolytic. Ewes were treated either with vehicle (N=5), diethylenetriamine (DETA-control for DETANONOate; N=5), (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETANONOate-long acting NO donor; N=6), l-arginine (N=5), l-nitro-arginine methyl ester (l-NAME-NOS inhibitor; N=6), or NG-monomethyl-l-arginine acetate (l-NMMA; NOS inhibitor; N=5) every 6h from 2400h (0h) on day 8 through 1800h on day 18 of the estrous cycle. Jugular venous blood and inferior vena cava plasma via a saphenous vein cathether 5cm anterior to the juncture of the ovarian vein and inferior vena cava were collected every 6h for analysis for progesterone and PGF2alpha and PGE, respectively, by RIA. Corpora lutea were collected at 1800h on day 18 and weighed. Weights of corpora lutea were heavier (P< or =0.05) in DETANONOate-treated ewes when compared to vehicle, DETA, l-arginine, l-NAME, or l-NMMA-treated ewes, l-arginine luteal weights were heavier than vehicle, DETA, l-arginine, l-NAME, or l-NMMA-treated ewes, and luteal weights of vehicle, DETA, l-NAME, or l-NMMA-treated ewes did not differ amongst each other (P> or =0.05). Profiles of progesterone in jugular venous blood on days 8-18 differed (P< or =0.05) in DETANONOate-treated ewes when compared to vehicle, DETA, l-arginine, l-NMMA or l-NAME-treated ewes, which did not differ (P> or =0.05) amongst each other. The PGE:PGF2alpha ratio profile in inferior vena cava plasma of DETANONOate-treated ewes was increased (P< or =0.05) when compared to all other treatment groups. In a second experiment, conversion of [3H PGE2] to [3H PGF2alpha] by day 15 ovine caruncular endometrium in vitro was determined in vehicle, DETA, or DETANONOate-treatment groups. Conversion of [3H PGE2] to [3H PGF2alpha] was decreased (P< or =0.05) only by DETANONOate. It is concluded that NO is not luteolytic during the ovine estrous cycle, but may instead be antiluteolytic and prevent luteolysis by altering the PGE:PGF2alpha ratio secreted by the uterus.

Chlortetracycline supplementation of yearling dairy heifers.

Chlortetracycline is an antibiotic that is used to increase weight gain, efficiency of gain, carcass grade, and conception rates. The objective of this experiment was to evaluate the effects of supplementation of 350 mg/d of chlortetracycline on ADG, G:F, BCS, thyroxine, and systemic glucose concentrations in yearling dairy heifers. Forty 12-mo-old Holstein heifers (initial BW = 363 +/- 21 kg) were housed in a free-stall barn with ad libitum access to feed and water for 104 d. A transition period was begun 14 d before the age of 12 mo to acclimate the heifers to the diet. The chlortetracycline-fed group (n = 20) consumed 328 +/- 8.2 mg of chlortetracycline/heifer daily. Measurements for BW, withers and hip heights, BCS, and health score were recorded weekly. Dry matter intake was measured daily. Blood was sampled every 4 d to determine plasma thyroxine and glucose concentrations and every 2 d to determine progesterone concentrations. Heifers were artificially inseminated on the first observed standing heat after 13 mo of age. There were no effects of chlortetracycline on ADG, G:F, withers and hip heights, BCS, blood glucose concentrations, peak progesterone concentrations, health, or conception rate. There was an interaction between treatment and time for chlortetracycline on serum thyroxine concentration. In the beginning of the experiment, serum thyroxine concentration was lower in heifers supplemented with chlortetracycline. There was no difference between treatments in thyroxine concentration at the end of the experiment. Chlortetracycline supplementation was not beneficial for yearling dairy heifers.

Is nitric oxide luteolytic or antiluteolytic?

Nitric oxide (NO) has been reported to be luteolytic based on treatment of cows in vivo with an inhibitor of nitric oxide synthase (NOS-produces NO), which delayed the decline in progesterone by two to three days [Jaroszewki J, Hansel, W. Intraluteal administration of a nitric oxide synthase blocker stimulates progesterone, oxytocin secretion and prolongs the life span of the bovine corpus luteum. Proc Soc Exptl Biol Med 2000;224:50-5; Skarzynski D, Jaroszewki J, Bah, M, et al. Administration of nitric oxide synthase inhibitor counteracts prostaglandin F(2alpha)-induced luteolysis in cattle. Biol Reprod 2003;68:1674-81]. The objective of this experiment was to determine the effect of a long acting NO donor or a NOS inhibitor infused chronically into the interstitial tissue of the ovarian vascular pedicle adjacent to the ovary with a corpus luteum on secretion of progesterone during the ovine estrous cycle. Ewes were treated either with Vehicle (N=5); Diethylenetriamine (DETA-control for DETA-NONOate; N=5); (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino]diazen-1-ium-1,2-diolate (DETA-NONOate-long acting NO donor; N=6); or l-nitro-arginine methyl ester (l-NAME-NOS inhibitor; N=6) every 6 h from 24:00 h (0 h) on day 8 through 18:00 h on day 18 of the estrous cycle. Jugular venous blood was collected every 6h for analysis for progesterone and corpora lutea were collected at 18:00 h on day 18 and weighed. Weights of corpora lutea were heavier (P< or =0.05) in DETA-NONOate-treated ewes when compared to Vehicle, DETA, or l-NAME-treated ewes, which did not differ amongst each other (P> or =0.05). Profiles of progesterone in jugular venous blood on days 8-18 differed (P< or =0.05) in DETA-NONOate-treated ewes when compared to Vehicle, DETA, or l-NAME-treated ewes did not differ (P> or =0.05) amongst each other. It is concluded that NO is not luteolytic during the ovine estrous cycle, but may instead be antiluteolytic and prevent luteolysis.

Alien limb syndrome and moya-moya disease.

We present the case of a 29-year-old woman with an alien limb and callosal disconnection syndrome who was diagnosed with moya-moya disease. We discuss the potential mechanisms responsible for the alien limb syndrome.

Plasmids of Pseudomonas cepacia strains of diverse origins.

Thirty-seven strains of Pseudomonas cepacia from clinical, pharmaceutical-industrial, and environmental origins were analyzed for the presence of plasmid DNA by a modification of the rapid alkaline extraction method of Birnboim (H. C. Birnboim, Methods Enzymol. 100:243-255, 1983). Plasmids were present in 31 strains (84%) from all sources, with no one source showing less than 75% plasmid carriage among its strains. The plasmid profiles indicated that the presence of large plasmids (146 to 222 kb) was the norm. Those strains with greater antibiotic resistance were mainly in the clinical and pharmaceutical groups and carried large plasmids (222 kb) that appeared essentially identical by restriction digest analysis. The ability for conjugative transfer was shown with the broad-host-range plasmid R751 carrying the gene for resistance to trimethoprim, one of the few antimicrobial agents effective against P. cepacia. The plasmid was transferred from Pseudomonas aeruginosa to P. cepacia strains as well as from P. cepacia transconjugants to other P. cepacia strains.

A highly conserved repeated chromosomal sequence in the radioresistant bacterium Deinococcus radiodurans SARK.

A DNA fragment containing a portion of a DNA damage-inducible gene from Deinococcus radiodurans SARK hybridized to numerous fragments of SARK genomic DNA because of a highly conserved repetitive chromosomal element. The element is of variable length, ranging from 150 to 192 bp, depending on the absence or presence of one or two 21-bp sequences located internally. A putative translational start site of the damage-inducible gene is within the reiterated element. The element contains dyad symmetries that suggest modes of transcriptional and/or translational control.

Gene expression in Deinococcus radiodurans.

We previously reported that the Escherichia coli drug-resistance determinants aphA (kanamycin-resistance) and cat (chloramphenicol-resistance) could be introduced to Deinococcus radiodurans by transformation methods that produce duplication insertion. However, both determinants appeared to require dramatic chromosomal amplification for expression of resistance. Additional studies described here, confirming this requirement for extensive amplification, led us to the use of promoter-probe plasmids in which the E. coli promoter has been deleted, leaving only coding sequences for the marker gene. We find that the insertion of D. radiodurans sequences immediately upstream from the promoterless drug-resistance determinant produces drug-resistant transformants without significant chromosomal amplification. Furthermore, a series of stable E. coli-D. radiodurans shuttle plasmids was devised by inserting fragments of D. radiodurans plasmid pUE10 in an E. coli plasmid directly upstream from a promoterless cat gene. These constructions replicated in D. radiodurans by virtue of the pUE10 replicon and expressed the cat determinant because of D. radiodurans promoter sequences in the pUE10 fragment. Of three such constructions, none expressed the cat gene in E. coli. Similar results were obtained using a promoterless tet gene. Translational fusions were made between D. radiodurans genes and E. coli 5'-truncated lacZ. Three fusions that produced high levels of beta Gal in D. radiodurans were introduced into E. coli, but beta Gal was produced in only one. The results demonstrate that the E. coli genes cat, tet and lacZ can be efficiently expressed in D. radiodurans if a D. radiodurans promoter is provided, and that D. radiodurans promoters often do not function as promoters in E. coli.

Gene fusions with lacZ by duplication insertion in the radioresistant bacterium Deinococcus radiodurans.

Deinococcus radiodurans is the most-studied species of a eubacterial family characterized by extreme resistance to DNA damage. We have focused on developing molecular biological techniques to investigate the genetics of this organism. We report construction of lacZ gene fusions by a method involving both in vitro splicing and the natural transformation of D. radiodurans. Numerous fusion strains were identified by expression of beta-galactosidase. Among these fusion strains, several were inducible by exposure to the DNA-damaging agent mitomycin C, and four of the inducible fusion constructs were cloned in Escherichia coli. Hybridization studies indicate that one of the damage-inducible genes contains a sequence reiterated throughout the D. radiodurans chromosome. Survival measurements show that two of the fusion strains have increased sensitivity to mitomycin C, suggesting that the fusions within these strains inactivate repair functions.

Duplication insertion of drug resistance determinants in the radioresistant bacterium Deinococcus radiodurans.

Escherichia coli drug resistance plasmids were introduced into Deinococcus radiodurans by cloning D. radiodurans DNA into the plasmids prior to transformation. The plasmids were integrated into the chromosome of the transformants and flanked by a direct repeat of the cloned D. radiodurans segment. The plasmid and one copy of the flanking chromosomal segment constituted a unit ("amplification unit") which was found repeated in tandem at the site of chromosomal integration. Up to 50 copies of the amplification unit were present per chromosome, accounting for approximately 10% of the genomic DNA. Circular forms of the amplification unit were also present in D. radiodurans transformants. These circles were introduced into E. coli, where they replicated as plasmids. The drug resistance determinants which have been introduced into D. radiodurans in this fashion are cat (from Tn9) and aphA (from Tn903). Transformation of D. radiodurans to drug resistance was efficient when the donor DNA was from D. radiodurans or E. coli, but was greatly reduced when the donor DNA was linearized with restriction enzymes prior to transformation. In the course of the study, a plasmid, pS16, was discovered in D. radiodurans R1, establishing that all Deinococcus strains so far examined contain plasmids.

The effect of age and smoking on vascular prostaglandin production in men and women.

6-Keto-PGF1 alpha, PGF2 alpha and PGE2 production by homogenates of aorta was unaffected by age, sex or smoking habits. Homogenates of saphenous vein from women aged 51-60 years produced greater and smaller amounts of 6-keto- PGF1 alpha and PGF2 alpha, respectively, than from women aged 41-50 and 61-70 years. In the 41-50 and 61-70 age groups, the amounts of 6-keto-PGF1 alpha and PGF2 alpha produced by homogenates of saphenous vein were smaller and greater, respectively, in women than in men. Cigarette smoking had no effect on PG production by homogenates of female saphenous vein. 6-Keto-PGF1 alpha production by homogenates of male saphenous vein was 20% lower in smokers and ex-smokers than in non-smokers, although this reduction was statistically significant only for ex-smokers. The amounts of PGE2 and PGF2 alpha produced by homogenates of male saphenous vein were smaller in smokers and ex-smokers, respectively, than in non-smokers. In spite of these changes in PG production by homogenates of saphenous vein, the basal outputs of PGs, particularly of 6-keto-PGF1 alpha, from the saphenous vein were little affected by age, sex or smoking habits.

Studies on the prostaglandin synthesizing capacity of several blood vessels from male and female rats.

Prostaglandin (PG) I2 (measured as 6-keto-PGF1 alpha) was the major PG synthesized by homogenates of the aorta from male rats, followed by lesser quantities of PGF2 alpha and PGE2. The amounts of 6-keto-PGF1 alpha synthesized by homogenates of the vena cava, mesenteric artery and femoral artery were much less than synthesized by the aorta, and were similar to the amounts of PGF2 alpha and PGE2 synthesized. The amounts of 6-keto-PGF1 alpha synthesized by homogenates of the aorta were 30% lower in female rats than in male rats. The amounts of 6-keto-PGF1 alpha and PGF2 alpha synthesized by homogenates of the aorta from female rats were similar, but the amounts of PGE2 synthesized were lower. The amounts of 6-keto-PGF1 alpha synthesized by homogenates of the aorta and femoral artery of female rats were similar, but the amounts of 6-keto-PGF1 alpha synthesized by homogenates of the mesenteric artery and vena cava were lower and were similar to the amounts of PGF2 alpha and PGE2 synthesized. The amounts of 6-keto-PGF1 alpha synthesized by the vena cava were significantly lower (P less than 0.05) and the amounts of 6-keto-PGF1 alpha and PGF2 alpha synthesized by the femoral artery and aorta, respectively, were significantly higher (P less than 0.05) in female rats than in male rats. The total amount of 6-keto-PGF1 alpha, PGF2 alpha and PGE2 synthesized by the aortae of male and female rats did not differ, indicating that the higher output of 6-keto-PGF1 alpha from the aorta of male rats compared to female rats is not due to a higher concentration of PGH2 synthetase in the aortic tissue of male rats. However, the shift in the relative amounts of 6-keto-PGF1 alpha and PGF2 alpha synthesized by the aorta of female rats in favour of PGF2 alpha may be responsible for the lower output of 6-keto-PGF1 alpha from the aorta of female rats. Oestradiol and progesterone had no effect on the amounts of 6-keto-PGF1 alpha, PGF2 alpha and PGE2 synthesized by homogenates of the aorta and vena cava from intact and ovariectomized, female rats. However, ovariectomy increased the amounts of 6-keto-PGF1 alpha and PGE2 synthesized by the aorta and vena cava, respectively, an effect not reversed by oestradiol and progesterone treatment.