Embryo mortality in Holstein x Limousine embryos

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1,082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO x HO) or Limousine semen (HO x LM), to compare pregnancy loss from 28-35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO x HO embryo vs. HO x LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO x HO embryos had greater LEM (15.16%) than HO x LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; however, within no-summertime, LEM (%) was higher in HO x HO than HO x LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO x HO than in the HO x LM (P=0.023) group; however, the concentration of P4 was not different between groups (P > 0.05).

The association of prepartum urine pH, plasma total calcium concentration at calving and postpartum diseases in Holstein dairy cattle

The use of anionic salts to prevent milk fever in dairy cattle has been an effective nutritional strategy; however, the degree of acidification that determines the most acceptable productive responses and well-being of the cow is still a controversial topic. The objective of this study was to assess urine pH in prepartum Holstein cows fed anionic diets and determine its association with plasma total Ca, Mg, P, β-hydroxyl-butyrate (BHB) concentrations at parturition and the occurrence of peripartum disorders. This investigation consisted of 2 studies. Study 1 was conducted on a grazing dairy. Between February and May 2019, 60 prepartum multiparous cows were tested for urine pH and plasma metabolite concentration at parturition. Total Ca, P, Mg and BHB at day 1 in milk (DIM) were assessed and statistically analyzed by ANOVA (models for polynomial regression). Study 2 was conducted on a drylot dairy farm. Between July 2018 and January 2019, 203 cows were evaluated for urine pH and followed-up for 30 DIM to obtain the incidence of dystocia, stillbirths, milk fever, retained fetal membranes, metritis, clinical mastitis and ketosis. Cows were categorized based on their last urine pH as group 1: pH > 7.0 (n = 135); group 2: pH between 6.0 and 7.0 (n = 46) and group 3: pH < 6.0 (n = 22). A logistic regression model for each health event was conducted considering urine pH group as the main effect. Urine sample was collected at 2.71 ± 2.84 days before parturition. In study 1, there was a quadratic effect of urine pH on total Ca. Total Ca concentration was higher between urine pH 6.0 and 7.0, while decreasing below pH 6.0 and above pH 7.0. There was a trend (P = 0.11) for a quadratic effect of urine pH on the concentration of plasma BHB at parturition. β-Hydroxyl-butyrate was lower approximately between urine pH 6.5 and 7.5. In study 2, the odds for a stillborn in cows with urine pH < 6.0 was 2.39 (95% CI = 1.06-5.40) times the odds for a stillborn in cows with urine pH ≥ 7.0. There was no association between urine pH and the other diseases. In conclusion, cows with prepartum urine pH < 6.0 and >7.0 had lower concentration of plasma total Ca and tended to have a higher concentration of BHB. Cows with urine pH < 6.0 had a higher incidence of stillbirths than cows with urine pH > 7.0.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

Association between milk production and treatment response of ovarian cysts in lactating dairy cows using the Ovsynch protocol

The objective of this study was to evaluate the association between the level of milk production on the day of diagnosis of ovarian cysts and treatment response using the Ovsynch protocol. On the day of cyst diagnosis (Day 0), 260 lactating dairy cows with ovarian cysts were treated with gonadotropin-releasing hormone (GnRH), PGF2alpha on Day 7, GnRH on Day 9, and timed inseminated 16-20 h later (Ovsynch protocol). Pregnancy was determined (by transrectal palpation) between 42 and 49 days after insemination. On Day 0, data for milk production (kg/day), parity, days in milk (DIM), and body condition score (BCS) were recorded. Using the median value for milk production on the day of diagnosis, cows were classified as high producers (>28.5 kg) and low producers (<or=28.5 kg). Cows were classified as primiparous (first lactation) or multiparous (second or more lactations). Data for conception rate (CR) were analyzed using logistic regression accounting for milk production on the day of diagnosis, parity, DIM, and BCS. The CR for low and high producers was 6 and 16%, respectively. There was no association between DIM and BCS with the other variables (P>or=0.05). Primiparous cows were more likely (adjusted odds ratio: AOR=3.63; 95% CI: 95% confidence intervals=1.28-10.30; P<or=0.01) to become pregnant than multiparous cows, and low producers were less likely (AOR=0.31; 95% CI=0.11-0.85; P<or=0.02) to become pregnant than high producers. It was concluded that cows with high milk production on the day of cyst diagnosis were more likely to become pregnant following treatment than cows with low milk production. It appears paradoxical that high milk production predisposes to the occurrence of ovarian cysts, but that high-producing cows respond better to treatment compared to low-producing cows. It is hypothesized that the level of milk production on the day of cyst diagnosis could be an additional potential predictor of success to treatment of lactating cows with ovarian cysts using the Ovsynch protocol.

Comparison of synchronization of ovulation with timed insemination and exogenous progesterone as therapeutic strategies for ovarian cysts in lactating dairy cows

The objective of this study was to compare the effectiveness of the Ovsynch and controlled internal drug releasing (CIDR) protocols under commercial conditions for the treatment of cystic ovarian disease in dairy cattle. A total of 401 lactating dairy cows with ovarian cysts were alternatively allocated to two treatment groups on the day of diagnosis. Cows in the Ovsynch group were treated with GnRH on Day 0, PGF2alpha on Day 7, GnRH on Day 9, with timed insemination 16-20 h later. Cows in the CIDR group were treated with a CIDR insert on Day 0 for 7 days; on Day 7, the CIDR was removed, and cows were treated with PGF2alpha. All cows in the CIDR group were observed for estrus and cows exhibiting estrus within 7 days following removal of the CIDR and PGF2alpha administration were inseminated. The outcomes of interest for this experiment were the likelihood to be inseminated, return to cyclicity (determined by a CL on Day 21), conception and pregnancy rates. Data for these variables were analyzed using logistic regression. The percentage of cows inseminated in the Ovsynch and CIDR groups were 82 and 44%, respectively. Cows in the Ovsynch group were 5.8 times more likely to be inseminated than cows in the CIDR group. Cows with a low BCS were 0.48 times less likely to be inseminated than cows with a high BCS. The percentage of cows with a CL on Day 21 for the Ovsynch and CIDR groups was 83 and 79%, respectively (P > 0.05). Cows with a low BCS were 0.49 times less likely to have CL on Day 21 than cows with a high BCS. Conception and pregnancy rates for cows in the Ovsynch group were 18.3 and 14.4%, respectively. Conception and pregnancy rates for cows in the CIDR group were 23.1 and 9.5%, respectively. There was no significant differences between conception or pregnancy rates in cows in both groups. Primiparous cows were 2.6 times more likely to conceive than multiparous cows. In conclusion, the results of this study suggested that fertility was not different between cows with ovarian cysts treated with either the Ovsynch or the CIDR protocols in this dairy herd. In addition, primiparous cows had an increased likelihood for conception compared to multiparous cows, and cows with a low BCS were less likely to be inseminated or have a CL on Day 21, regardless of treatment.

Hepatitis C virus core protein down-regulates transcription of interferon-induced antiviral genes

BACKGROUND

Hepatitis C virus (HCV) proteins interfere with the interferon (IFN)-alpha-induced Jak/signal transducer and activator of transcription (STAT) pathway. Which protein is responsible for this effect and whether this interference results in down-regulation of IFN-induced genes remain controversial. We analyzed the effect of HCV core (HCV-Co) protein on expression of IFN-induced antiviral genes.

METHODS

HepG2 cells were transfected with the plasmid pHCV-Co, and, after treatment with IFN-alpha , levels of MxA, protein kinase R (PKR), and 2'-5' oligoadenylate synthetase (2'-5'OAS) mRNA were determined. Chloramphenycol acethyl transferase (CAT) analysis was performed on cells cotransfected with pHCV-Co and pMx4CAT (containing the MxA gene promoter) and treated with IFN. Electrophoretic mobility shift assays were used, and Western-blot analysis of STAT 1 and 2 was performed.

RESULTS

Levels of MxA mRNA in pHCV-Co-transfected cells decreased in a dose-dependent manner, by down-regulation of the MxA gene promoter. HCV-Co protein inhibits binding of IFN-stimulated gene factor 3 (ISGF3) to the IFN-stimulated response element (ISRE). Intracellular distribution of STAT 1 and 2 was not modified after treatment with IFN. Expression of HCV-Co protein also results in down-regulation of expression of PKR and 2'-5'OAS genes.

CONCLUSION

HCV-Co protein inhibits IFN-alpha-induced transcription of antiviral genes by decreasing binding of ISGF3 to the ISRE.

Uterine Involution and Fertility of Holstein Cows Subsequent to Early Postpartum PGF2α Treatment for Acute Puerperal Metritis

The objective was to evaluate the effect of 2 doses of PGF(2alpha) injected early postpartum on uterine involution, serum concentration of acute phase proteins at 12 d postpartum, and fertility in Holstein cows with acute puerperal metritis. Only cows diagnosed with retained fetal membranes and metritis and treated with ceftiofur hydrochloride for 5 d were used in the study. Two hundred cows were assigned randomly to be treated (n = 100) or to serve as controls (n = 100). Treatment consisted of 2 i.m. injections of PGF(2alpha) 8 h apart on d 8 postpartum. A subsample of 90 cows was selected randomly (45 treated cows; 45 controls) to evaluate uterine diameter using ultrasonography, uterine score, and serum concentrations of acute phase proteins at 12 d postpartum. The outcome variable for all cows was conception rate at first service. Postpartum, primiparous, treated cows had smaller uterine diameters and lower uterine scores than controls. Cows with a uterine diameter <5.1 cm at 12 d postpartum were 5.5 times more likely to conceive at first service than cows with larger uterine horn diameter. Treatment significantly reduced the concentrations of serum alpha1-acid glycoprotein. Within primiparous cows, treatment also increased conception at first service by 17%. It was concluded that 2 doses of PGF(2alpha) 8 h apart at 8 d postpartum in primiparous cows with acute puerperal metritis decreased the diameter of uterine horns and serum concentration of alpha1-acid glycoprotein at 12 d postpartum and increased the conception rate at first service.

Effect of pretreatment with bovine somatotropin (bST) and/or gonadotropin-releasing hormone (GnRH) on conception rate of dairy cows with ovarian cysts subjected to synchronization of ovulation and timed insemination

The objective of this study was to determine the effect of pretreatment with bovine somatotropin (bST) and/or gonadotropin-releasing hormone (GnRH) 7 days prior to initiation of a protocol for synchronization of ovulation and timed insemination (Ovsynch) on conception rate (CR) of cows with ovarian cysts. A total of 254 lactating dairy cows with ovarian cysts was divided into four groups (Day 0). On Day 0, cows in Group 1 (n = 61) were pretreated with 500 mg bST, s.q., and 100 microg GnRH, i.m.; cows in Group 2 (n = 73) were pretreated with 100 microg GnRH, i.m.; cows in Group 3 (n = 59) were pretreated with 500 mg bST, s.q.; and cows in Group 4 (n = 61) received no pretreatment. All cows were subjected to the Ovsynch protocol 7 days later. All cows previously received routine bST treatment every 14 days until milk production decreased to a minimum level established by the management of the herd. CR was assessed using logistic regression after adjusting for timing of concurrent bST treatment relative to Day 0, parity, season at time of insemination, and days in milk (DIM) on Day 0. CR for cows in Group 3 (12%) was significantly lower (P < 0.05) than that for cows in Group 4 (27%), and CR for cows in Group 1 (18%) and Group 2 (15%) tended to be lower (P < 0.10) than that for cows in Group 4 (27%). From the results of this study, it was concluded that bST pretreatment decreased CR, and pretreatment with GnRH, and GnRH with bST tended to decrease CR in lactating dairy cows with ovarian cysts concurrently treated with bST and subjected to the Ovsynch protocol.

The association between lameness, ovarian cysts and fertility in lactating dairy cows

The objective of this observational study was to evaluate the association between lameness, ovarian cysts, and fertility in lactating dairy cows. Data analysis of historical records from a 3000 Holstein farm was conducted. Sixty-five cows that became lame within 30 days postpartum were used as cases, and 130 nonlame cows served as controls. The outcome variables were incidence of ovarian cysts (OC, %), conception rate at first service (CRFS, %), overall pregnancy rate (PR, %), and calving to first service interval (CFSI, day), Incidence of OC and CRFS were analyzed by logistic regression, PR by survival analysis and CFSI by ANOVA. Lame cows had a lower CRFS (17.5% versus 42.6%) and higher incidence of OC (25.0% versus 11.1%) than controls (P<or=0.05). Calving to first service interval was not different between lame and control cows (P>0.05). There was a multicollinearity relationship between lameness and ovarian cysts. The results show that cows that became lame within the first 30 days postpartum were associated with a higher incidence of ovarian cysts, a lower likelihood of pregnancy, and lower fertility than control cows. Because this is an observational study it is not possible to conclude a cause-effect relationship.

Regulation of embryo survival in cattle

Evidence is presented that bovine somatotrophin (bST) treatment of lactating dairy cows enhances both expression of oviductal insulin-like growth factor II (IGF-II) mRNA and endometrial insulin-like growth factor binding protein 3 (IGFBP-3) mRNA between day 3 and day 7 of the oestrous cycle. mRNA encoding growth hormone (GH) receptor in endometrial tissues increased between day 3 and day 7 of the oestrous cycle. The changes induced by bST treatment may contribute to stimulation of embryo development and increase pregnancy rates in lactating dairy cows. Additive effects of bST and rb interferon tau (rbIFN-tau) to inhibit phorbol ester induction of prostaglandin F2alpha secretion in immortalized bovine endometrial cells indicates that there is interplay between their signal transduction pathways. Non-lactating dairy cows were killed at day 17 after oestrus to evaluate the effects of pregnancy status (cyclic versus pregnant) and bST (bST versus control) treatment on endometrial gene expression. Distinctly different mRNA and protein responses were detected between cyclic and pregnant cows that were related to luteolytic-antiluteolytic drive (that is expression of progesterone receptor, oxytocin receptor, oestradiol receptor alpha and prostaglandin GH synthase 2 (PGHS-2)). The bST-induced changes in PGHS-2 protein (+), oxytocin receptor mRNA (+) and oestrogen receptor alpha protein (+) may potentially affect the mechanisms associated with maintenance of pregnancy. Two experiments were conducted to evaluate whether ovarian follicular suppression induced by biodegradable deslorelin implants would reduce either early or late embryo losses. A 450 microg deslorelin implant used to induce ovulation in a timed insemination programme decreased subsequent follicular development and tended to reduce early embryo losses, whereas a 2.1 mg deslorelin implant failed to reduce late embryonic losses when inserted on day 27 of pregnancy.

The effect of interval from day of administration of bovine somatotropin (bST) to synchronization of ovulation and timed-insemination on conception rate of dairy cows with and without ovarian cysts

The objective of this study is to evaluate the effect of the interval from the day of administration of bovine somatotropin (bST) to the day of initiation of synchronization of ovulation (Day 0 and 7) and timed-insemination (TAI) on conception rate (CR) of dairy cows with and without ovarian cysts, respectively. Lactating dairy cows (n = 359) were divided into two groups. Cows in Group 1 (n = 238, without ovarian cysts) were treated with 100 microg, i.m. GnRH on Day 0; 25 mg, i.m. PGF2a on Day 8. 100 mirog. i.m. GnRH on Day 10; and inseminated 16 h later without detection of estrus. Cows in Group 2 (n = 121, with ovarian cysts) were treated with 100 microg, i.m. GnRH on Day 0; 100 microg, i.m. GnRH on Day 7; 25 mg, i.m. PGF2alpha on Day 14, 100 ug, i.m. GnRH on Day 16; and inseminated 16 h later without detection of estrus. Between 60 and 63 days postpartum, all cows in the herd were given bST every 14 days for the duration of the study. Logistic regression was used to assess the risk of nonpregnancy associated with interval from bST treatment to Day 0 for cows without ovarian cysts. and both Day 0 and 7 for cows with ovarian cysts adjusting for parity and days in milk. The CR for cows in Group 1 was significantly higher when the interval from last treatment with bST to Day 0 was between 1 and 3 days (28%) compared to 4-6 days (14%). In addition, the risk of nonpregnancy was 2.19 times greater in cows 4-6 days after bST treatment compared to 1-3 days after adjusting for parity and days in milk. The CR for cows in Group 2 was not significantly different when the interval from last treatment with bST to both Day 0 and 7 was between 1 and 3, 4 and 6, and 7 and 14 days. In conclusion, the results of this study suggested bST treatment closer to Day 0 had a positive effect on CR of cows without ovarian cysts, but bST treatment closer to both Day 0 and 7 had no effect on CR of cows with ovarian cysts. This was interpreted to mean that bST had a beneficial effect on either, or both, the preovulatory follicle and the oocyte in dairy cows without ovarian cysts, but not in dairy cows with ovarian cysts.

Efficacy of prolonged interferon-alpha treatment in chronic hepatitis B patients with HBeAb: comparison between 6 and 12 months of therapy

We compared the response and the relapse rates of HBeAb-positive patients treated with interferon-alpha for 6 or 12 months. Thirty-eight HBeAb-positive patients which chronic hepatitis B were randomly allocated into two groups: Group I (19 patients receiving 10 MU of recombinant interferon-alpha 2b three times a week for 2 months, followed by 5 MU three times a week for 2 months and then 3 MU three times a week for 2 months); Group II (19 patients receiving 10 MU of recombinant interferon-alpha 2b three times a week for 2 months, followed by 5 MU three times a week for 2 months and then 3 MU three times a week for 8 months). At the end of treatment, alanine aminotransferase normalization was higher but not more significant in Group I than in II (53% vs 26%), while hepatitis B virus DNA clearance was similar in both groups (21% in Group I vs 26% in Group II). However, at 12 months of follow-up, biochemical relapses occurred only in Group I (60% vs 0% in Groups I and II, respectively). Five complete responders cleared hepatitis B surface antigen at that time. In conclusion, prolonged treatment of HBeAb patients is efficient in reducing the biochemical relapse.

Analysis of hepatitis B virus precore variants in hepatitis B e antibody-positive patients treated with prednisone plus interferon

To assess the effects of prednisone and interferon on the distribution of hepatitis B virus (HBV) precore mutants, nine hepatitis B e antibody (HBeAb)-positive patients with HBV chronic infection were studied. Patients were treated with prednisone (30 mg day-1 for 4 weeks, followed by 20 mg day-1 for 2 weeks and by 10 mg day-1 for 1 week), followed by recombinant interferon-alpha (15 MU thrice per week) for 6 months, without a clearance period. The HBV precore region was amplified by polymerase chain reaction (PCR) and distribution of the precore mutants was determined by hybridization of PCR products. Moreover, the glucocorticoid-responsive element (GRE) was sequenced to determine whether changes in the sequence were produced at the end of prednisone treatment. During prednisone treatment, changes in alanine transaminase (ALT) were observed in only two patients, in who ALT decreased to nearly normal values. In three patients ALT normalized at the end of interferon treatment. At baseline, wild-type HBV alone was detected in one patient, while seven patients were infected by a mixture of wild-type and precore mutants, predominantly wild type. At the end of prednisone treatment, two patients were infected by only wild-type HBV. The proportion of precore mutants decreased in three cases, while no changes were observed in three. At the end of interferon treatment, the precore mutant proportion decreased in the three responders, while tending to increase or remain unchanged in the rest. No significant changes in GRE sequence were found as a result of prednisone treatment. Our results would appear to confirm the role of the immune system in the selection of precore mutants.

Evidence of subtype-specific antibodies to antigenic epitopes in the NS5 region of hepatitis C virus in the circulation of patients with chronic hepatitis C

The antigenicity of the NS5 region of type 1 hepatitis C virus (HCV) was investigated by epitope mapping of the region spanning amino acids 2530 to 2723 of the HCV polyprotein. Six antigenic regions were recognized by anti-HCV positive sera from individuals with chronic hepatitis C in a modified enzyme-linked immunosorbent assay with synthetic oligopeptides. Five of these regions demonstrated intra-type 1 sequence variations defining subtype 1a and 1b HCV sequences. The region between amino acids 2623 and 2634 allowed testing of subtype-specific anti-NS5 antibodies; serological reactivity to subtypes 1a and 1b was observed in 27 and 61%, respectively, of 150 cases with chronic hepatitis C. Simultaneous reactivity to subtypes 1a and 1b was found in 23% of the patients. Detection of subtype-specific anti-NS5 antibody correlated in more than 80% of the cases with the HCV genotype (subtypes 1a and 1b) analyzed by PCR amplification of the NS5 sequence. These data provide evidence of the existence of a subtype-specific anti-NS5 response in the circulation of patients with chronic hepatitis C.

Effects of rHuEPO on Q-EEG and event-related potentials in chronic renal failure

Quantitative electroencephalography is a powerful tool to evaluate brain function, and preliminary data have shown its usefulness in the evaluation of patients with chronic renal failure (CRF). In this study, baseline values of different quantitative EEG variables, as well as data from the P300 component of the visual event-related potential, in 43 patients with chronic renal failure, were compared with those of a group of healthy subjects and with the results obtained after 3, 6, 9 and 12 months of treatment of these patients with rHuEPO. Baseline total power was much lower in patients with CRF than in healthy subjects, and the distribution of power among the frequency bands was also abnormal. rHuEPO promptly normalized total power and progressively improved power distribution, although full normality was not achieved. Mean dominant frequencies in brain areas were abnormal in patients with CRF, and progressive improvement was seen along the study. The latency of P300, which was increased before treatment, decreased in all subjects, but normal values were not reached. The same applies to the hypomanic and psychopathic scores of psychological tests. Altogether, brain dysfunction of CRF seems to substantially improve by treatment of the anemia with rHuEPO.

Pilot study of recombinant human granulocyte-macrophage colony-stimulating factor in the treatment of chronic hepatitis B

Recombinant human granulocyte-macrophage colony-stimulating factor is being used to improve the immunological function of patients with various diseases and to ameliorate hematological disorders. We investigated the tolerance and possible antiviral effect of the administration of daily doses of recombinant human granulocyte-macrophage colony-stimulating factor (3, 1 or 0.5 micrograms/kg body wt) to nine patients with chronic hepatitis B, alone or in combination with 5 MU interferon-alpha 2b. Recombinant human GM-CSF reduced significantly (p < 0.02) hepatitis B virus DNA levels. The three doses used were equally effective. Of the eight patients who completed the study, four became negative for HBV DNA and HBeAg; two of them seroconverted to HBe antibody. These four patients showed improvement in the histological activity of their liver disease. Ultimately, two patients regained normal ALT values. 2',5'-Oligoadenylate synthetase activity increased significantly (p < 0.01) in cell lysates of mononuclear cells cultured in vitro, coinciding with the reductions in hepatitis B virus DNA levels. Recombinant human granulocyte-macrophage colony-stimulating factor was well tolerated but produced a dose-dependent increase in white blood cell counts. It became intolerable at doses of 3 micrograms (and was reduced to 1.5 microgram); this effect was reversible after cessation of recombinant human granulocyte-macrophage colony-stimulating factor treatment. No remarkable variations occurred in other parameters. In conclusion, recombinant human granulocyte-macrophage colony-stimulating factor administration is safe and tolerable at doses of 0.5 to 1 microgram/kg body wt and may exert an antiviral effect in chronic hepatitis B.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulin M antibody to hepatitis C virus during interferon therapy for chronic hepatitis C

Testing for immunoglobulin (Ig) M antibody to hepatitis C virus (anti-HCV) as a predictive factor of therapeutic response to recombinant interferon alfa (rIFN-alpha) in chronic hepatitis C was evaluated in 122 patients with IgG anti-HCV. IgM anti-HCV was present in the pretreatment sample of 88% of patients who responded to treatment, including 20 of 21 (95%) long-term responders and 24 of 29 (83%) responders who had relapses after cessation of therapy. In contrast, IgM anti-HCV was present in only 23 of 39 (59%) nonresponders and 22 of 33 (66%) untreated controls (P less than 0.05). The number of cases with detectable IgM anti-HCV tended to decrease in responder patients, which was more evident for complete responders (42%) than for responders who relapsed (72%). During follow-up, the antibody became undetectable in the majority of long-term responders (28% were still IgM anti-HCV positive) but remained detectable in 69% of responders who relapsed (P less than 0.05). No special changes were noted in nonresponder or control patients. Thus, testing for IgM anti-HCV may help to identify a subset of patients who will benefit from rIFN-alpha therapy in chronic hepatitis C.

Long-term immunogenicity and efficacy of hepatitis B vaccine in hemodialysis patients

Although the efficacy of hepatitis B vaccines in patients under chronic hemodialysis treatment has been well documented, the persistence of immunity in this population remains largely unknown. In this study we have followed 60 hemodialysis patients up to 3 years after primary hepatitis B vaccination (four doses of recombinant hepatitis B vaccine; Engerix B, 20 mg/dose) to evaluate the persistence of immunity (as indicated by serum levels of antibody to hepatitis B surface antigen-anti-HBs-higher than or equal to 10 mIU/ml). Fourty-four (73%) patients developed anti-HBs levels above 10 mIU/ml after vaccination; the remaining 16 (27%) vaccinees were considered nonresponders and were given a booster dose that again failed to elicit an immunoresponse. After 3 years of follow-up, 18 out of 44 (41%) responders had no detectable anti-HBs levels in the serum (antibody loss occurring within 8 and 12 months in 3 cases, within 1 and 2 years in 13, and within 2 and 3 years in 2 other cases). When compared with the responders that lost their antibodies during the follow-up period, those who remained immunoreactive 3 years after vaccination was initiated were younger and had higher anti-HBs levels at 8 months of follow-up. Two hepatitis B virus infections were detected among nonresponders during the follow-up period. Based on these data, we conclude that patients undergoing chronic hemodialysis therapy not only have lower response rates to hepatitis B vaccination than healthy adults, but also that these are frequently transient.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticotropin-releasing factor concentrations exhibit an apparent diurnal rhythm in hypothalamic and extrahypothalamic brain regions: differential sensitivity to corticosterone

Regional brain concentrations of corticotropin-releasing factor (CRF) exhibited marked differences in a number of regions depending upon the time of day rats were sacrificed. When compared with animals killed at 09.00 h, CRF concentrations at 15.30 h were elevated in the median eminence, hypothalamus minus median eminence, preoptic area/suprachiasmatic nucleus, bed nucleus of the stria terminalis, septum, frontal/parietal cortex, cerebellum, cingulate cortex, locus ceruleus and the nucleus of the solitary tract. Animals that received 7 days of continuous corticosterone supplementation via osmotic minipump either did not exhibit an afternoon rise in CRF concentrations (median eminence, cingulate cortex and locus ceruleus) or exhibited significantly attenuated afternoon increases in CRF concentrations (hypothalamus minus median eminence). In rats killed at 09.00 h, corticosterone reduced CRF concentrations in the median eminence. Chronic corticosterone exposure did not affect CRF concentrations in any of the extrahypothalamic brain regions studied in rats killed at 09.00 h. These results suggest that a number of CRF-containing neurons in both hypothalamic and extrahypothalamic brain regions presumably undergo diurnal changes in their activity as evidenced by changes in CRF concentrations. Furthermore, chronic corticosterone supplementation can alter these changes, particularly those in the endocrine hypothalamus.

Dose-dependent effect of prenatal dexamethasone treatment on beta-adrenergic receptor coupling to ornithine decarboxylase and cyclic AMP

Glucocorticoids regulate the coupling of beta-adrenergic receptors to cell function. In the current study, the potential role of these agents in the development of adrenergic responses was evaluated in the offspring of pregnant rats given 0.8 mg/kg of dexamethasone on gestational days 17, 18 and 19. We examined the postnatal development of beta-receptors coupling to ornithine decarboxylase in heart and kidney throughout neonatal life into young adulthood; this enzyme is involved in transduction of neural signals controlling cellular replication and differentiation. Dexamethasone exposure perturbed the basal pattern of cardiac ornithine decarboxylase activity and attenuated the response of the enzyme in both heart and kidney to acute challenge with the beta-agonist, isoproterenol. Subsensitivity persisted into the postweaning period. This dosage regimen of dexamethasone also suppressed renal cyclic AMP responses to isoproterenol, but exposure to a lower dose (0.2 mg/kg) enhanced the response. Thus, although low doses of glucocorticoids foster development of the coupling of beta-receptors to cellular transduction mechanisms, higher doses such as those used to stimulate lung function may lastingly obtund adrenergic sensitivity.

Differential sensitivity to dexamethasone suppression in an animal model of the DST

The present study reports the feedback suppression of basal and stimulated corticosterone secretion in rats by low doses of dexamethasone (DEX). DEX suppression of basal secretion 6 hr after administration was observed with doses as low as 0.005 mg/kg. The lowest dose capable of suppressing basal corticosterone levels for 24 hr with a return to normal values by 36 hr was established to be 0.025 mg/kg. The ability of DEX to decrease corticosterone responses to physostigmine, morphine, immobilization, and ether stress was determined. Although the magnitude of the rise in corticosterone did not differ significantly among these evocative stimuli, the degree to which DEX attenuated these responses varied. The response to morphine was completely prevented by 0.025 mg/kg and the rises following ether or immobilization were decreased significantly. In contrast, the response to physostigmine was not affected by DEX. With a higher dose of DEX (0.25 mg/kg), responses to morphine, ether, and immobilization were completely eliminated, but the response to physostigmine was only attenuated partway. The time course of the suppression in basal levels, the attenuation of several stimuli for corticosterone secretion, and the "escape" of physostigmine-induced corticosterone secretion resemble the clinical Dexamethasone Suppression Test of endogenous depression and suggest that this test might be useful in the study of animal models of depression.

Role of sympathetic neurons in development of beta-adrenergic control of ornithine decarboxylase activity in peripheral tissues: effects of neonatal 6-hydroxydopamine treatment

Sympathetic neurons are thought to regulate the development of their postsynaptic targets. In the current study, we examined the effects of sympathectomy with 6-hydroxydopamine in neonatal rats on the ontogeny of beta-receptor binding sites and their linkage to both cyclic AMP production and ornithine decarboxylase activity. Cardiac norepinephrine levels and turnover were used to confirm the completeness and permanence of the lesion. The ability of isoproterenol, a beta-adrenergic agonist, to stimulate ornithine decarboxylase (a growth-related enzyme) in heart, lung and kidney, was reduced by neonatal sympathectomy; the effect persisted into young adulthood. The effect represented a selective uncoupling of enzyme activity from receptor activation, as receptor binding capabilities were unaffected and the linkage of beta-receptors to cyclic AMP was enhanced. Comparison of the effects of peripheral sympathectomy with those of central lesions (intracisternal 6-hydroxydopamine) confirmed the importance of sympathetic nerve terminals in determining the coupling of the receptors to ornithine decarboxylase. These data suggest that sympathetic neurons program their target organs to specific trophic responses during development.

Nutritional influences on adrenal chromaffin cell development: comparison with central neurons

Neurotransmitter systems in the developing brain are generally protected from growth retardation associated with nutritional deprivation. To investigate if such protective mechanisms extend to similar tissues in the peripheral sympathetic system, maturation of the chromaffin cells of the adrenal medulla and development of their centrally derived splanchnic innervation were evaluated in rats whose nutritional status had been altered during the neonatal period by increasing (16-17 pups/litter) or decreasing (five to six pups/litter) the litter size from the standard (11-12 pups/litter). Ontogeny of adrenal catecholamine stores and activities of catecholamine-biosynthetic enzymes tyrosine hydroxylase and phenylethanolamine N-methyltransferase were monitored, along with activity of choline acetyltransferase, a marker enzyme for the preganglionic neurons innervating the chromaffin cells. Neonatal nutritional deprivation slowed body weight gain and retarded development of the chromaffin cells, as evidenced by subnormal catecholamine stores, tyrosine hydroxylase and phenylethanolamine N-methyltransferase activities. The effects persisted despite the complete recovery of body weights postweaning. The developmental alterations were not caused by overcrowding stress, as plasma corticosterone levels were not elevated in the large litter group. Neonatal nutritional enrichment promoted body weight gain but failed to enhance development of adrenal catecholamines; tyrosine hydroxylase and phenylethanolamine N-methyltransferase activities were elevated only in the preweaning period. In contrast to effects on the chromaffin cells, altered neonatal nutritional status had only minor, transient effects on the development of the centrally derived cholinergic innervation of the adrenal and produced only small changes (less than 10%) in brain tyrosine hydroxylase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of brain beta-adrenergic receptors after neonatal 6-hydroxydopamine treatment

We used [125I]-cyanopindolol in vitro autoradiography and neonatal 6-hydroxydopamine treatment to study the development of beta-adrenergic receptor subtypes in rat brain. Brain regions receiving locus coeruleus innervation, such as cerebral cortex and cerebellum, displayed low receptor densities at birth and increased in density rapidly during the second and fourth weeks postnatally. By contrast, regions which receive little innervation from the locus coeruleus, such as substantia nigra, striatum, and globus pallidus, displayed relatively high beta-receptor densities even at birth. The striatum appeared to be an exception to these generalizations. 6-Hydroxydopamine administration was associated with an increase in the densities of beta-receptor subtypes and, unexpectedly, with a change in the proportions of the two subtypes. These data support the view that innervation determines the ontogenetic patterns of some receptors in brain.

Effects of prenatal dexamethasone on development of ornithine decarboxylase activity in brain and peripheral tissues of rats

The use of glucocorticoids in the management of neonatal respiratory distress syndrome may be associated with abnormalities of growth and neurologic development. In our study, pregnant rats received either 2 or 0.2 mg/kg of dexamethasone on gestational days 17, 18, and 19 and tissues of the offspring were examined for ornithine decarboxylase activity, a marker enzyme for perturbations of cellular maturation. Acutely, the higher dose of dexamethasone suppressed ornithine decarboxylase activity in all tissues except lung, where a short-term stimulation was obtained. Repeated administration of 2 mg/kg resulted in an ornithine decarboxylase pattern consistent with delayed cellular development in all tissues (suppressed activity followed by prolonged postnatal elevations), accompanied by impaired viability and general growth. Lowering the dose of dexamethasone to 0.2 mg/kg eliminated all the adverse effects on viability but still produced perturbations of tissue ornithine decarboxylase, most notably a prolonged suppression of activity across all brain regions. These data suggest that administration of glucocorticoids even at the threshold for effects on respiratory function, may compromise neural development.

Antiviral effect of recombinant gamma interferon in chronic hepatitis B virus infection: a pilot study

A pilot study has been designed in order to determine the tolerance and effectiveness of recombinant interferon gamma (rIFN-gamma) in chronic hepatitis B virus (HBV) infection. Eight HBsAg, HBeAg, HBV-DNAp and HBV-DNA-positive patients were randomly assigned to one of two groups. In group 1, 0.25 mg of rIFN-gamma/m2 body surface was administered daily for 28 days to 4 patients. In group 2, 0.10 mg of rIFN-gamma was administered to 4 patients under the same conditions. All the patients concluded the treatment and were observed over 11 more months. During treatment, 6 out of 8 patients showed decreased levels of HBV-DNA and HBV-DNAp. In addition, by the 8th month of follow-up, six patients became negative for HBV-DNAp and 2 for HBcAg; all patients remained positive for HBV-DNA. At the end of the study, only 2 patients remained negative for HBV-DNAp, 4 for HBcAg and one became negative for HBV-DNA. No differences in antiviral effect were observed between the two groups. Furthermore, the T4/T8 lymphocytes ratio increased during therapy. In conclusion, rIFN-gamma may play a role in the treatment of chronic HBV infection.

Prenatal exposure to methylmercury alters development of adrenergic receptor binding sites in peripheral sympathetic target tissues

In order to assess the impact of prenatal exposure to methylmercury on sympathetic neurotransmission, effects on development of adrenergic receptor binding sites in peripheral tissues were evaluated. In the liver, methylmercury produced a dose-dependent increase in alpha 1-, alpha 2- and beta-receptor binding of radioligands throughout the first 5 weeks of postnatal life. Similarly, renal alpha-receptor subtypes showed increased binding capabilities, but binding to beta-receptor sites was reduced. At least some of the changes in receptors appear to be of functional significance, as physiological reactivity to adrenergic stimulation is altered in the same directions in these two tissues. The actions of methylmercury displayed tissue specificity in that the same receptor populations were largely unaffected in other tissues (lung, heart). These results suggest that methylmercury exposure in utero alters adrenergic responses through targeted effects on postsynaptic receptor populations in specific tissues.

Functional consequences of prenatal methylmercury exposure: effects on renal and hepatic responses to trophic stimuli and on renal excretory mechanisms

The effects of prenatal exposure to methylmercury on the functional development of renal and hepatic response systems was examined in the developing rat. Methylmercury produced an elevation of basal activity of renal ornithine decarboxylase (ODC, an enzyme involved in regulation of cellular maturation) and an eventual relative hypertrophy; liver ODC was reduced and hypertrophy was not evident. In contrast, the reactivity of liver ODC to trophic stimulants (vasopressin, isoproterenol) was markedly enhanced by prenatal methylmercury exposure, whereas renal ODC responses were much less affected (vasopressin) or actually reduced (isoproterenol). Targeted actions of methylmercury on renal excretory function were also prominent, with increased fractional excretions of urea and electrolytes and an eventual reduction in glomerular filtration as assessed by creatinine clearance. In addition, the reactivity of the kidney to challenge with desmopressin was altered coincidentally with the appearance of the effects on basal clearance mechanisms. These studies show that doses of methylmercury ordinarily associated with selective actions on development of neurobehavioral patterns also influence the functional ontogeny of other organ systems; furthermore, the fact that the target tissues are different for prenatal vs. postnatal methylmercury exposure, indicates that the functional teratology of methylmercury exhibits critical periods of sensitivity.

Effects of neonatal methylmercury exposure on adrenergic receptor binding sites in peripheral tissues of the developing rat

Neonatal exposure to methylmercury produces changes in patterns of tissue growth and function, in part, due to alterations in adrenergic neuronal input. To explore the mechanisms by which these changes come about, newborn rats were exposed to methylmercury (1 or 2.5 mg/kg per day) throughout the preweaning stage and the ontogeny of adrenergic receptor binding sites evaluated in liver, kidney, heart and lung, using [3H]prazosin (alpha 1-receptors), [3H]rauwolscine (alpha 2-receptors) and [125I]pindolol (beta-receptors). In the kidney, methylmercury caused decreases in beta- and alpha 1-receptor binding and increases in alpha 2-binding; previous work has shown that beta-receptor-mediated responses are generally enhanced in methylmercury-exposed pups, and the down-regulation of beta-receptor binding thus probably represents a compensatory action secondary to alterations in post-receptor coupling mechanisms. The effects of methylmercury on hepatic adrenergic receptors were different from those seen in the kidney, with substantial elevations in beta- and alpha 1-receptor binding apparent in the preweaning stage; this agrees also with the differences in effects of the mercurial on trophic reactivity and growth in the 2 tissues. Despite the fact that methylmercury causes activation of neonatal cardiac sympathetic nerves, beta-receptor binding sites in the heart were unaffected by methylmercury exposure; the failure to down-regulate cardiac postsynaptic receptors in the face of increased nerve activity again represents an anomaly of synaptic regulatory function. These results indicate that methylmercury alters adrenergic responsiveness, in part, through actions on the development of receptor binding sites, and further, that the organ-specificity and receptor subtype-selectivity are consistent with subsequent effects of the organomercurial on adrenergic participation in target organ growth; however, changes in receptor binding alone do not account for all of the effects of methylmercury on synaptic activity or trophic responses.

Role of ornithine decarboxylase and the polyamines in nervous system development: a review

Development of nervous tissue is controlled, in part, by the ornithine decarboxylase (ODC)/polyamine system. Each brain region possesses a unique ontogenetic pattern for ODC, with highest levels of the enzyme associated with periods of most rapid growth. For this reason, perturbation of the ODC profile has proven useful in examinations of teratologic mechanisms and detection of adverse environmental effects during development. More recently, the replication of neuronal cells in developing brain has been shown to require the maintenance of polyamine levels and consequently, depletion of polyamines by alpha-difluoromethylornithine (DFMO, an ODC inhibitor) arrests brain cell maturation. DFMO also interferes with neuronal migration, axonogenesis and synaptogenesis, leading to disruption of the cytoarchitectural organization of brain structures: these results imply a similarly important role for polyamines in post-replicative events. Indeed, [3H]DFMO-autoradiographic localization of ODC in developing cerebellar lamina indicates high levels of activity associated with neuropil, areas of axonal outgrowth, and post-mitotic granule cells. Axonal outgrowth during regeneration after nerve damage in the mature nervous system may display some of the same characteristics as in developing neurons, suggesting that the two processes share common polyamine-dependent mechanisms.

Early biochemical detection of adverse effects of a neurobehavioral teratogen: influence of prenatal methylmercury exposure on ornithine decarboxylase in brain and other tissues of fetal and neonatal rat

Ornithine decarboxylase (ODC), an enzymatic regulator of macromolecule synthesis, has proven useful as a biochemical marker for teratologic events. Daily administration of methylmercury (0.5 or 1 mg/kg s.c.) to pregnant rats during the second and third trimesters had a profound effect on ODC in whole fetus that was detectable as early as 13 days of gestation. Levels of enzyme activity in fetal brain also showed a marked increase centered about gestational day 17 as well as a significant elevation during early postnatal life; in the latter case, the cerebellum appeared to be a major target for methylmercury-induced aberrations. These effects were accompanied by little or no alteration in general growth rate, brain weights, or weights of other tissues (liver, heart, lung). Furthermore, no other tissue displayed such dramatic effects on ODC activity. Lowering the dose of methylmercury by an order of magnitude (0.05 to 0.1 mg/kg), levels which are associated with almost purely neurobehavioral effects of the teratogen, still resulted in clear-cut elevations of both whole fetus ODC and fetal and neonatal brain ODC. These results indicate that a sensitive biochemical detection procedure used in the fetus/neonate can successfully predict the subsequent tissue-specific damage to neurotransmitter systems and behavior resulting from methylmercury.

Biochemical and functional alterations in renal and cardiac development resulting from neonatal methylmercury treatment

Administration of methylmercury (1 or 2.5 mg/kg daily) to neonatal rats caused alterations in both cardiac and renal growth patterns. Heart weights were elevated in the preweaning period in association with hyperplasia (supranormal DNA content); after weaning, the cardiac overgrowth regressed and there was an eventual hypoplasia as evidenced by low DNA content in young adulthood. Renal overgrowth was more pronounced and persistent, but reflected a pure hypertrophy, with no changes in DNA. Renal function was affected by neonatal methylmercury exposure, as assessed through basal clearance techniques. In the immediate period after beginning treatment, there was an impairment of renal function (elevated serum urea, creatinine and osmolality; increased fractional excretions of water, sodium and osmotic particles), with a return to normal by 10 days postnatally. Thereafter, there was a secondary phase of tubular impairment which peaked at the time of maximum hypertrophy. Thus, biochemical and functional indices of organ development can be adversely affected at doses of methylmercury which are usually associated primarily with nervous system-specific damage; effects of methylmercury on neuronal and/or hormonal factors may contribute to the perturbations.

Postnatal methyl mercury exposure: effects on ontogeny of renal and hepatic ornithine decarboxylase responses to trophic stimuli

The effects of postnatal methyl mercury exposure on the ontogeny of renal and hepatic responsiveness to trophic stimuli were examined. Increased ornithine decarboxylase (ODC) activity was used as an index of tissue stimulation. In the rat, renal ODC responsiveness to growth hormone, angiotensin, vasopressin, isoproterenol, and serotonin was absent at birth and matured 3 to 4 weeks later. However, pups exposed to methyl mercury showed marked, ODC responses to these same agents as early as 10 to 19 days of postnatal age, accompanied by a significant renal hypertrophy. In contrast to the kidney, the liver of normally developing rats was responsive to trophic factors even in the neonate. In this tissue, there was no consistent effect of neonatal methyl mercury treatment on ODC responses at any developmental stage tested; although absolute liver weights were reduced, liver/body weight ratio was not affected. These results demonstrate that postnatal methyl mercury exposure causes a precocious onset of ODC responses to trophic agents specifically in the kidney. Altered responsiveness may mediate some of the effects of this organomercurial on overall renal development and function.

Effects of neonatal methylmercury exposure on development of nucleic acids and proteins in rat brain: regional specificity

Exposure of neonatal rats to methylmercury (1 or 2.5 mg/kg SC daily) during the preweaning period caused regionally-specific alterations in DNA, RNA and protein content in brain. In midbrain + brainstem, where neuronal replication and differentiation conclude early, reduced DNA content was prominent at either dose and was apparent well before evidence of general body growth impairment; small deficits in protein content and brain region weight were seen. In contrast, cerebral cortex showed an elevation of DNA in the high dose group and a tendency toward supranormal RNA values at either dose. In cerebellum, where maturation occurs last, both DNA and RNA were markedly stimulated in pups receiving either 1 or 2.5 mg/kg and little effect was seen on proteins or region weight. These results indicate that the response of the developing central nervous system to cell loss caused by methylmercury is dependent upon the stage of development at which exposure occurs: whereas clear-cut reductions in cell number (DNA content) occur in fairly mature, post-replicative regions, those areas undergoing rapid replication and differentiation are likely to exhibit compensatory stimulation or replacement of cells.

Control of nucleic acid and protein synthesis in developing brain, kidney, and heart of the neonatal rat: effects of alpha-difluoromethylornithine, a specific, irreversible inhibitor of ornithine decarboxylase

Ornithine decarboxylase (ODC) and the polyamines are thought to play a role in maturation of mammalian tissues. Daily postnatal administration of alpha-difluoromethylornithine (DFMO, a specific inhibitor of ODC) to newborn rats caused organ-specific deficits in tissue weight gain, with brain and kidney as the major targets. Subnormal organ weights were associated with deficits in the levels of nucleic acids and proteins in the affected tissues, and examination of the synthetic rates of DNA ([3H]thymidine incorporation), RNA ([3H]uridine incorporation) and protein ([14C]leucine incorporation) confirmed that macromolecule synthesis was inhibited in DFMO-treated pups. The time of onset of effect of DFMO on the synthesis of nucleic acids and proteins was the same as that reported for depletion of polyamines by this treatment. Potential adverse effects of DFMO on cell survival were also assessed by labeling DNA with [3H]thymidine on day 3 and examining retention of label 12 days later; DFMO did not cause an increase in cell death. In contrast to the sensitivity of brain and kidney to postnatally administered DFMO, development of cardiac tissue was relatively resistant to growth inhibition despite polyamine depletion. The organ specificity of effect of DFMO results, in part, from the different timetables for cellular events in tissue development displayed by each organ type; administration of DFMO earlier in development (during days 15 to 17 of gestation) did produce deficiencies in cardiac growth and nucleic acid levels similar to those which had been seen for brain and kidney. These data support the view that polyamines play a key role in cell replication, differentiation and growth during critical periods of mammalian organ development through their regulation of DNA, RNA, and protein synthesis.