PubMed Health⌕ Search

Biomedical subjects

B Ronchi

Publications and source records attributed to B Ronchi.

18 recordsLinked to original sources
PubMed2006

Photoperiod affects gene expression of leptin and leptin receptors in adipose tissue from lactating dairy cows.

Leptin is mainly secreted by adipocytes and is implicated in the regulation of metabolic status, feed intake, and body condition. Day length (DL) can affect leptin gene expression and secretion. The aim of the study was to evaluate the effect of DL on gene expression of leptin and leptin receptors in adipose tissue (AT). Four lactating and pregnant Holstein cows were housed in a climate-controlled chamber for 51 d. The first 30 d were used to adapt animals to the new housing conditions. During that period the DL adopted was 12 h light:12 h dark (12:12). The experimental period included 3 different and consecutive phases: 7 d of neutral DL (12:12); 7 d of long DL (18 h light:6 h dark); and 7 d of short DL (6 h light:18 h dark). Subcutaneous AT biopsies were performed at the end of each phase. Prolactin, growth hormone, cortisol, leptin, glucose, nonesterified fatty acids, beta-OH-butyrate, and cholesterol were determined in plasma samples. Abundance of leptin mRNA, and Ob-Ra and Ob-Rb leptin receptor mRNA were determined in AT samples by ribonuclease protection assay. Day length did not affect feed intake or body condition score. Exposure to short DL significantly reduced milk yield (13.1 +/- 2.2 vs. 15.8 +/- 1.7 and 16.0 +/- 2.0 kg/d for short vs. neutral and long DL, respectively). Plasma leptin, growth hormone, cortisol, nonesterified fatty acids, beta-OH-butyrate, and glucose were not affected by DL; cholesterol was lowest under short DL (3.93 +/- 0.38 vs. 4.36 +/- 0.39 and 4.07 +/- 0.38 mmol/L for short vs. neutral and long DL, respectively). Prolactin increased under long DL (134.82 +/- 16.94 vs. 81.98 +/- 20.25 and 96.16 +/- 0.38 ng/mL for long vs. neutral and short DL, respectively). Gene expression of leptin and its receptors was affected by DL. Leptin mRNA increased under long DL (11.91 +/- 0.84 vs. 7.82 +/- 0.84 and 7.56 +/- 0.84 pg of mRNA/microg of total RNA for long vs. neutral and short DL, respectively). Leptin receptors Ob-Ra and Ob-Rb mRNA were higher under long DL, whereas Ob-Ra and Ob-Rb mRNA were lower under short DL (Ob-Ra: 1.91 +/- 0.41, 2.49 +/- 0.41, and 0.65 +/- 0.41 pg of mRNA/microg of total RNA for neutral, long, and short DL, respectively; Ob-Rb: 5.29 +/- 0.79, 5.98 +/- 0.68, and 2.02 +/- 0.70 pg of mRNA/microg of total RNA for neutral, long, and short DL, respectively). Results of the present study appear to exclude an effect of feed intake and metabolic status on leptin gene expression. A prolactin-mediated effect of photoperiod on AT leptin modulation may be proposed in lactating dairy cows.

Adipose Tissue↗
PubMed2005

Lymphocyte functions in overconditioned cows around parturition.

The objective of the study was to evaluate the relationships between body condition and lymphocyte functions in periparturient dairy cows. Thirty days before expected calving, 21 Holstein cows were categorized as thin (n = 6), medium (n = 8), or overconditioned (n = 7) based on body condition score (BCS). Blood samples were collected on 21, 14, 7, and 3 d before calving and on d 3, 7, 14, 21, 28, and 35 after parturition. An aliquot of blood was used to determine plasma nonesterified fatty acids (NEFA) and glucose. At 14 and 7 d before, and 14 and 35 d after calving, a second aliquot of blood was used to assess peripheral blood mononuclear cell (PBMC) functions: DNA synthesis, immunoglobulin (Ig) M, and interferon-gamma (IFN-gamma) secretion after mitogen stimulation. During the experiment, all 21 cows showed a decline in BCS. Overconditioned cows lost significantly more BCS than thin cows. After calving, overconditioned cows had higher plasma NEFA compared with thin and medium cows. Conversely, plasma glucose never differed between the 3 categories of cows. Regardless of BCS, DNA synthesis and IgM secretions were significantly lower in PBMC isolated on 7 d before calving compared with those recorded 14 and 35 d after parturition. Conversely, PBMC from the 21 cows did not show any change of IFN-gamma secretion during the experimental period. Taking into consideration the BCS categories, PBMC isolated from overconditioned cows presented lower IgM secretion compared with thin cows on d 14 and 35 after calving. Furthermore, PBMC isolated from overconditioned cows secreted less IFN-gamma compared with thin and medium cows on d 7 before calving. The DNA synthesis of PBMC stimulated with the 3 mitogens did not differ between the 3 categories of cows. In conclusion, immunodepression occurring in cows around calving would be particularly evident in overconditioned cows.

Animals↗
PubMed2005

Influence of body condition score on relationships between metabolic status and oxidative stress in periparturient dairy cows.

Twenty-four dairy cows were monitored during the transition period. We observed changes of oxidative status and relationships between oxidative and metabolic status. Body condition score (BCS) of the 24 animals at the beginning of the trial (30.4 +/- 2 d before expected calving) was between 2.0 and 3.6. The BCS was recorded and blood samples were collected weekly during the last 30 d of pregnancy and the first 30 DIM. Plasma samples were analyzed to determine indices of oxidative status: reactive oxygen metabolites (ROM); thiobarbituric acid-reactive substances (TBARS); thiol groups (SH); glutathione peroxidase (GSH-Px), and indices of energy metabolism: glucose, beta-hydroxybutyrate, and nonesterified fatty acids. In erythrocytes we determined indices of oxidative status: GSH-Px, superoxide dismutase (SOD), and intracellular SH. Before calving, cows showed an increase of plasma SH, SOD, and GSH-Px, a decrease of erythrocyte GSH-Px and plasma ROM, and no changes in erythrocyte SH. After calving, cows showed a decrease of plasma and erythrocyte SH and SOD, and an increase of ROM, TBARS, and plasma GSH-Px. Cows with higher BCS at the beginning of the trial and greater loss of BCS after calving, had higher plasma ROM, TBARS, and SH, and lower SOD and erythrocyte SH in the postpartum period. Oxidative status of dairy cows was related to energy status. Cows with higher BHBA and NEFA showed higher ROM and TBARS and lower levels of antioxidants. Results of the present study demonstrated that cows can experience oxidative stress during the peripartum period, and cows with higher BCS and greater BCS losses are more sensitive to oxidative stress.

3-Hydroxybutyric Acid↗
PubMed2004

Short communication: effects of nonesterified fatty acids on lymphocyte function in dairy heifers.

This in vitro study was performed to assess the effects of various concentrations of nonesterified fatty acids (NEFA) on lymphocyte function of heifers. Nine Holstein heifers were studied. Peripheral blood mononuclear cells were incubated with various concentrations of NEFA (0, 0.0625, 0.125, 0.25, 0.5, 1, and 2 mmol/L). The mixture of NEFA was represented by C16:0 (30%), C16:1 (5%), C18:0 (15%), C18:1 (45%), and C18:2 (5%). The DNA synthesis was diminished at concentrations of NEFA of 2, 1, and 0.5 mmol/L. The IgM secretion was inhibited at concentrations of NEFA of 2, 1, 0.5, and 0.25 mmol/L. Secretion of IFN-gamma was depressed at concentrations of NEFA of 2, 1, 0.5, 0.25, and 0.125 mmol/L. Increases of plasma NEFA might contribute to explain the higher incidence of infections observed in cows suffering from energy deficit.

Animals↗
PubMed2004

Abundance of mRNA of apolipoprotein b100, apolipoprotein e, and microsomal triglyceride transfer protein in liver from periparturient dairy cows.

Limited secretion of very low density lipoproteins (VLDL) in dairy cows is strongly related to fatty liver and other metabolic disorders in the early postpartum. Currently, there is limited information on which roles apolipoprotein B(100) (ApoB(100)), apolipoprotein E (ApoE), and microsomal triglyceride transfer protein (MTP) play in that VLDL limitation. To our knowledge, no studies have simultaneously measured ApoB(100), ApoE, and MTP mRNA in periparturient dairy cows. Therefore, a trial was conducted to assess liver gene expression of these proteins in transition dairy cows and to evaluate the relationships between their expression and metabolic status. Eight multiparous Holstein cows were monitored during the transition period. To evaluate metabolic and nutritional status, body condition score was registered, and plasma indexes of energy metabolism and VLDL were determined from 35 d before to 35 d after calving. Liver biopsies were performed on d -35, 3, and 35 relative to day of calving, and gene expression of ApoB(100), ApoE, and MTP were determined on liver tissue. Body condition, plasma glucose and VLDL decreased, and plasma NEFA and BHBA increased after calving. Compared with values of d -35, on d 3 after calving the ApoB(100) mRNA synthesis was lower, whereas MTP and ApoE mRNA abundance were higher. Negative correlation (r = -0.57) between plasma NEFA concentration and ApoB(100) mRNA abundance, and positive correlation between ApoB(100) mRNA abundance and plasma cholesterol (r = 0.65) and plasma albumins (r = 0.52) were detected at 3 d postpartum. Data on changes of gene expression of the 3 main proteins involved in the regulation of synthesis and secretion of VLDL in the liver suggest that decreased mRNA for ApoB(100) may be consistent with decreased synthesis and/or secretion of VLDL from liver during the periparturient period.

3-Hydroxybutyric Acid↗
PubMed2002

Markers of oxidative status in plasma and erythrocytes of transition dairy cows during hot season.

The study was carried out to assess whether hot seasons affect the oxidative status of transition dairy cows. Twenty Holstein cows were utilized. Eleven of those cows gave birth in spring; the remaining nine cows gave birth in summer. Oxidative status was evaluated from 21 d before to 35 d after calving, determining oxidative markers in plasma [glutathione peroxidase activity, thiol groups, reactive oxygen metabolites, and thiobarbituric acid reactive substances (TBARS)] and in erythrocytes [glutathione peroxidase activity (GSH-Px-E), intracellular thiols (SH), superoxide dismutase activity (SOD) and TBARS]. The season did not modify plasma oxidative markers. In contrast, cows exposed to moderate heat stress (39.5 +/- 0.2 degrees C rectal temperatures) due to summer temperature-humidity index (73.2 +/- 2.5 mean daily THI), showed higher erythrocyte SOD, GSH-PxE, SH, and TBARS compared with spring cows, indicating a condition of oxidative stress in summer transition dairy cows. Some changes (the increase of SOD, for example), represent compensatory changes the cow is undergoing in response to increased oxidative stress. Under the conditions compared, the effect of heat stress on oxidative status in transition dairy cows by use of plasma markers does not give enough information to reach definitive conclusions. Erythrocytes are an appropriate and sensitive model to study the oxidative status of transition dairy cows exposed to hot environments.

Animals↗
PubMed2001

Usefulness of Helicobacter pylori stool antigen test to monitor response to eradication treatment in children.

BACKGROUND: The monitoring of the results of eradication treatment is a crucial step for patients with Helicobacter pylori gastritis. A non-invasive test for H. pylori antigens in stools (HpSA) was recently validated for children. AIM: To evaluate the accuracy of HpSA in monitoring eradication treatment in children. METHODS: In 60 children, H. pylori gastritis was diagnosed by endoscopy and the 13C-urea breath test. The children were treated and returned for a follow-up (13)C-urea breath test 6 weeks after the end of treatment. Children were considered cured when the (13)C-urea breath test was negative. Stool were collected at baseline, and at 2 and 6 weeks. Stool antigens were measured by HpSA. RESULTS: According to (13)C-urea breath test, 6 weeks after the end of treatment 49 children were cured and 11 were still H. pylori-positive. The sensitivity and specificity of HpSA on stools collected 2 weeks after therapy were 100%. At 6 weeks specificity was 93.9 and sensitivity 100%. Results by visual reading were concordant with the plate-reader in all but two cases at baseline. CONCLUSIONS: HpSA is accurate for monitoring treatment in children as early as 2 weeks after therapy, when information is most useful and unachievable with other tests. Results by visual reading are accurate, and this can make the test cheaper and more practical.

Adolescent↗
PubMed2001

Effects of subclinical pregnancy toxemia on immune responses in sheep.

OBJECTIVE: To determine the effects of moderate feed restriction, single or twin pregnancy, and subclinical pregnancy toxemia (PT) on immune responses of ewes. ANIMALS: 16 Sardinian ewes. PROCEDURE: Six weeks before lambing, ewes were assigned to 1 of 2 groups (n = 8/group) matched for number of fetuses, body condition score, and plasma glucose, non-esterified fatty acids (NEFA), and beta hydroxybutyrate (BHBA) concentrations, and feed intake was restricted for 1 of the groups. Cell-mediated immunity was evaluated in vivo and in vitro. Humoral immunity was evaluated in vivo by determining production of IgG antibodies against keyhole limpet hemocyanin (KLH). RESULTS: Four ewes developed subclinical PT (plasma BHBA concentration > 0.86 mmol/L without any clinical signs of disease). Whether feed was restricted and type of pregnancy (single vs twin) did not have any significant effects on cell-mediated and humoral immune responses. Ewes with subclinical PT had significantly lower in vitro proliferation of phytohemagglutinin-stimulated peripheral blood mononuclear cells and significantly lower values for KLH-specific IgG than did healthy ewes. Plasma BHBA and NEFA concentrations were negatively correlated with in vitro proliferation of peripheral blood mononuclear cells; plasma NEFA concentration was negatively correlated with values for KLH-specific IgG. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that subclinical PT may be associated with impairments in cell-mediated and humoral immune responses in sheep.

3-Hydroxybutyric Acid↗
PubMed1999

Influence of short- and long-term exposure to a hot environment on rumen passage rate and diet digestibility by Friesian heifers.

Effects of short- and long-term exposure to a hot environment on diet digestibility and rumen passage rate were studied in four, 10-mo-old Friesian heifers housed in a climatic chamber. The trial lasted 65 d. Twenty-five days were spent under thermal comfort (temperature-humidity index = 64), and 40 d were spent under hot conditions (temperature-humidity index = 84). Three digestibility and rumen passage rate trials were performed during the 65 d. Chromium oxide was used as an external marker. The first digestibility and rumen passage rate trial (trial 1) was performed under thermal comfort; trials 2 and 3 were performed under hot conditions. Exposure to the hot environment reduced dry matter intake and increased water intake and rectal temperature compared with those during the thermal comfort period. Digestibility coefficients for dry matter, organic matter, neutral detergent fiber, and acid detergent fiber were higher in trial 2 than in trials 1 and 3. No statistical differences were found between trials 1 and 3 for these variables. Rumen passage rate was more rapid in trial 1 than in trials 2 and 3. No difference was observed between trials 2 and 3. These results indicated that exposure to a hot environment can affect digestibility in a time-dependent fashion, suggesting an adaptation of the digestive tract to hot environments.

Animals↗
PubMed1997

Composition of colostrum from dairy heifers exposed to high air temperatures during late pregnancy and the early postpartum period.

This study examined the effects of heat stress on composition of colostrum from primiparous cows during late pregnancy and the early postpartum period. Two groups of 6 Holstein heifers were utilized. During the last 3 wk of pregnancy and during the first 36 h after calving, one group was exposed to thermal comfort (temperature-humidity index = 65); the other group was exposed to high air temperatures (temperature-humidity index = 82 from 0900 to 2000 h and temperature-humidity index = 76 from 2100 to 0800 h). Heifers under heat stress had higher rectal temperatures and respiratory rates; lower plasma triiodothyronine and glucose; higher plasma nonesterified fatty acids and beta-hydroxybutyrate; lower intakes of dry matter, net energy for lactation, and crude protein; higher water intakes; and lower body condition scores. The decline of plasma immunoglobulins (Ig) over the final 2 wk of pregnancy was less pronounced for heifers under heat stress. For the first four milkings, colostrum of cows exposed to high air temperatures had lower mean concentrations of IgG and IgA; lower mean percentages of total protein, casein, lactalbumin, fat, and lactose; lower contents (grams per liter) of short- and medium-chain fatty acids; lower energy; lower titratable acidity; and higher pH. Thus, high air temperatures during late pregnancy and the early postpartum period markedly affected the composition of colostrum from primiparous dairy cows.

3-Hydroxybutyric Acid↗
PubMed1996

Effects of selenium and vitamin E administration during a late stage of pregnancy on colostrum and milk production in dairy cows, and on passive immunity and growth of their offspring.

OBJECTIVE: To determine effects of selenium (Se) and vitamin E (VE) administration in late pregnancy on Se status, plasma immunoglobulin concentrations, and colostrum and milk production of dairy cows, and on Se status, passive immunity, and growth of their offspring. ANIMALS: 25 Holstein cows and their offspring. PROCEDURE: 3 and 1.5 weeks before calving, sodium selenite (5 mg/100 kg of body weight) and d,l-alpha-tocopheryl acetate (25 IU/100 kg) were administered to 13 cows. The other 12 cows were not treated. Se status was assessed by measurement of glutathione peroxidase activity of erythrocytes (GSH-Px-E). RESULTS: The 13 treated cows had higher (P < 0.01) GSH-Px-E values at calving and during the first 12 weeks of lactation. Changes in plasma immunoglobulin concentrations before or after calving did not differ between the 2 groups of cows. During the first 36 hours after calving (4 milkings), treated cows produced 22% more colostrum than did their nontreated counterparts (P < 0.005). Percentages of colostral immunoglobulins did not differ between the 2 groups. During the first 12 weeks of lactation, treated cows produced 10% more milk than did nontreated cows (P < 0.005). GSH-Px-E values at birth and 28 days of life were significantly higher in calves from treated cows. Plasma immunoglobulin concentrations and body weight during the first 56 days after birth did not differ between calves born to treated or nontreated cows. CONCLUSIONS AND CLINICAL RELEVANCE: Cows given Se and VE in late pregnancy produce large quantities of colostrum and milk. Colostrum produced from cows given Se and VE is suitable to feed newborn calves and to be stored for later use. Improvement of Se status in calves born to cows given Se and VE in late pregnancy is not beneficial to passive immunity and growth.

Animals↗
PubMed1975

[Indications and limits in the use of digitalis in chronic cor pulmonale (author's transl)].

The analysis of the haemodymanic responses and the behaviour of many "contractility indices" of the right ventricle -- after acute intravenous injection of large doses of acetil-digoxin, in twelve patients with CPC caused by COLD with predominant clinical signs of emphysema (group A) or bronchitis (group B) -- showed an alarming, although transient, increase of the average pulmonary pressure (PAP), accompanied by rise of pulmonary arteriolar resistanced (RAP), especially in patients of the first group. In these cases a slow and cautious digitalization is required. It furthermore suggested that such treatment should start only after an efficient restoration of ventilation, in order to allow a good response of the heart to cardiocynetic treatment.

Chronic Disease↗
PubMedDate not supplied

The effects of injectable sodium selenite on immune function and milk production in Sardinian sheep receiving adequate dietary selenium.

The aim of this preliminary study was to determine the effects of selenium (Se) injection on Se status, cell-mediated immunity (CMI), milk yield and milk somatic cell count (MSCC) of ewes fed adequate amounts of Se, and on Se status, passive immunization and CMI of their offspring. Thirty days before lambing, 36 Sardinian ewes were assigned to one of three groups. One group (NT) was not treated; a second group (BL) was given 5 mg of Se on day 30 before lambing; a third group (BLL) was given 2.5 mg of Se on day 30 before lambing and at lambing. Selenium was given intramuscularly as sodium selenite. Selenium status was assessed by measuring glutathione peroxidase activity of erythrocytes (GSHpx-E). The CMI was measured by determining the increases in double skinfold thickness after intradermal injection of phytohaemagglutinin (PHA). Compared to their NT counterparts, ewes belonging to BL and BLL groups and their offspring had significantly higher GSHpx-E (P < 0.01). The GSHpx-E values of lambs were positively related to those of their mothers (P < 0.0005). Ewes of group BL had a greater (P < 0.01) response to PHA 6 h after injection than ewes of the NT group. Lambs born to BL and BLL ewes had a greater (P < 0.0001) response to PHA 24 h after injection. Responses of ewes and lambs to PHA 24 h after injection were positively related (P < 0.05). Serum immunoglobulin at 10 days of age did not differ significantly among the three groups of lambs. Compared to the NT group, milk yield on day 70 of lactation was significantly higher in BL ewes (P < 0.05). The MSCC was not affected significantly by Se injection. Immunoresponsiveness and milk yield might represent additional and appropriate criteria to consider when re-evaluating Se requirements of dairy sheep.

Animals↗