Search PubMed⌕ Search

Biomedical subjects

C Peris

Publications and source records attributed to C Peris.

At least 19 recordsLinked to original sources
PubMed2004

Effect of milking pipeline height on machine milking efficiency and milk quality in sheep.

This experiment studied the effect of milking pipeline height (mid- vs. low-level milking system) on milking efficiency and milk composition. The experiment was of 8 wk duration: 2 wk preexperimental period and 6 wk experimental, in crossover design (2 x 2). Ewes were milked in a 2 x 12 milking parlor with 2 milking pipelines set at a milking vacuum of 36 kPa with a pulsation rate of 180 cycle/min and ratio of 50%. Height of the milkline had no effect on yield of milk at the time of milking, yield after stripping, milk composition, SCC, and number of teatcup fall-offs. Nor did milkline height have any effect on milk lipolysis or on the distribution of fatty acids. The level of free fatty acids was higher in evening than in morning milk (60.5 vs. 25.6 mg/L). Likewise, the increase in the degree of lipolysis between the receiver (40.4 mg/L) and the refrigeration tank (45.8 mg/L) underlines the importance of the milk delivery line design. The parameters (time and flow rate) that define the first peak in the milk emission kinetics were statistically different between lines, so care must be taken when comparing milk emission curves from both types of pipeline.

Animals↗
PubMed2003

Influence of pulsation rate on udder health and teat thickness changes in dairy ewes.

In this work on machine milking of ewes, pulsation rates of 120 and 180 cycles per min were compared, both with a pulsation ratio of 50:50 and a vacuum level of 36 kPa, comparing intramammary infection (IMI), somatic cell count (SCC) and teat end thickness changes. To this end, two groups of 20 Manchega ewes were used in a crossover experimental design with two experimental periods of 24 d for each. Bacterial exposure of all teats was increased by dipping them in a suspension of Staphylococcus simulans at four consecutive milkings of each period. Pulsation rate of 180 cycles per min, compared with 120 cycles per min, had no negative effect upon new IMI (11 and 16% of ewes infected, respectively) and SCC. No teat end lesions were observed in those animals milked with the two pulsations assayed. Also, teat thickness changes (-0.38 and -0.36 mm at 120 and 180 cycles per min, respectively) were not affected significantly. Finally, in absence of IMI, the two pulsation rates assayed did not affect the SCC.

Animals↗
PubMed2003

Influence of vacuum level and overmilking on udder health and teat thickness changes in dairy ewes.

The effects of vacuum level and overmilking on udder health were studied in ewes. Vacuum levels of 36 and 42 kPa were assigned to two groups of 23 Manchega ewes in a crossover study design with two experimental periods of 5 wk for each. Moreover, for each ewe, one teat was overmilked 1.5 to 2 min at all milkings during these 10 wk. The milking machine used had a midlevel milkline and pulsation was fixed at 180 cycles per min and a pulsation ratio of 50:50. Bacterial exposure of all teats was increased by dipping them in a suspension of Staphylococcus simulans at eight milkings of each period. New intramammary infections (IMI) were not significantly affected by the vacuum level used (18 and 23% of ewes infected, at 36 and 42 kPa, respectively) or application of overmilking (9 and 11% of half udders infected without and with overmilking, respectively). Likewise, neither factor significantly affected the somatic cell count (SCC) of the milk. Teat thickness changes after milking varied significantly due to the presence of overmilking (-13.6 and -7.4%, in teats not overmilked and overmilked, respectively) but were not affected by vacuum level. At no time were any lesions or variations visibly noted in the teat walls or orifice. So, in this work we were unable to demonstrate that the vacuum and overmilking levels assayed, both used with a pulsation rate of 180 cycles/min, have an important effect on the state of udder health in the short term. Furthermore, it was also observed that, in absence of IMI, the two factors studied did not cause irritation of any kind in the gland that might influence the SCC of the milk.

Animals↗
PubMed2002

Helicobacter pylori infection and infertility.

OBJECTIVE: To determine (1) the prevalence of Helicobacter pylori infection in male and female patients with reproductive disorders and controls; (2) the presence of anti-H. pylori antibodies in samples of follicular fluid, vaginal secretions and sperm; and (3) the existence of a structural homology between a major spermatozoa protein, tubulin, and H. pylori proteins. PATIENTS AND METHODS: Serum samples from 167 patients with infertility and 837 age- and gender-matched controls (blood donors) were examined by enzyme-linked immunosorbent assay (ELISA) and Western blotting to determine the seropositivity for H. pylori infection. The presence of anti-H. pylori antibodies in samples of follicular fluid, vaginal secretions and sperm was determined using the same techniques. The possible cross-reactivity with spermatozoa of anti-H. pylori hyperimmune sera and human antibodies was studied by immunofluorescence. The N-acid homology of human tubulin with the principal H. pylori proteins was assayed by the WU-blastp program available on the Internet. RESULTS: The prevalence of infection was significantly higher in patients than controls (49.1% v. 33.5%, P < 0.001). Follicular fluids from infected patients contained specific antibodies in all cases, sperm samples in about 50% of cases, and vaginal secretions in a minority of cases. Sera to H. pylori whole antigens and VacA reacted with the tails and the pericentriolar area of human spermatozoa (which are rich in tubulin); sera to urease and heat-shock protein (Hsp) did not. Follicular fluids with anti-H. pylori antibodies immune reacted with spermatozoa. A linear homology was found between beta-tubulin and three H. pylori proteins, flagellin, VacA and CagA. CONCLUSIONS: H. pylori infection may increase the risk of developing reproductive disorders or worsen the clinical expression of this syndrome.

Adolescent↗
PubMed2001

Increase in hepatic expression of SREBP-2 by gemfibrozil administration to rats.

It is well known that gemfibrozil increases the biliary output of cholesterol and phospholipids, but we have little knowledge about the impact these changes have on liver cholesterol and phospholipid biosynthetic pathways. In the present study, no changes were detected in liver lipids and CTP:phosphocholine cytidylyltransferase after gemfibrozil administration to rats. On the contrary, 3-hydroxy-3-methylglutaryl-CoA reductase mRNA (9.9-fold) and Rd activity (16.7-fold) and phosphatidate phosphohydrolase activity (1.7-fold) increased, while plasma apo B-cholesterol (40%) and triglyceride (43%) levels decreased. As a part of a compensatory homeostatic response, we report for the first time that gemfibrozil administration to rats increased the hepatic sterol regulatory element binding protein-2 (SREBP-2) mRNA (2.9-fold) and mature protein (2.2-fold) levels. An early increase in the transcriptional activity of SREBP-2 elicited by gemfibrozil administration might be responsible for the observed changes in HMG-CoA reductase, phosphatidate phosphohydrolase, and SREBP-2 expression.

Animals↗
PubMed1999

Different effect of simvastatin and atorvastatin on key enzymes involved in VLDL synthesis and catabolism in high fat/cholesterol fed rabbits.

The effects of atorvastatin (3 mg kg(-1)) and simvastatin (3 mg kg(-1)) on hepatic enzyme activities involved in very low density lipoprotein metabolism were studied in coconut oil/cholesterol fed rabbits. Plasma cholesterol and triglyceride levels increased 19 and 4 fold, respectively, after 7 weeks of feeding. Treatment with statins during the last 4 weeks of feeding abolished the progression of hypercholesterolaemia and reduced plasma triglyceride levels. 3-Hydroxy-3-methyl-glutaryl Coenzyme A reductase, acylcoenzyme A:cholesterol acyltransferase, phosphatidate phosphohydrolase and diacylglycerol acyltransferase activities were not affected by drug treatment. Accordingly, hepatic free cholesterol, cholesteryl ester and triglyceride content were not modified. Simvastatin treatment caused an increase (72%) in lipoprotein lipase activity without affecting hepatic lipase activity. Atorvastatin caused a reduction in hepatic phospholipid content and a compensatory increase in CTP:phosphocholine cytidylyl transferase activity. The results presented in this study suggest that, besides the inhibitory effect on 3-hydroxy-3-methyl-glutaryl Coenzyme A reductase, simvastatin and atorvastatin may have additional effects that contribute to their triglyceride-lowering ability.

Acyl Coenzyme A↗
PubMed1998

Dissipation of some citrus selective residual herbicides in an irrigation well.

The aim of this work was to study the behaviour of some of the main citrus selective residual herbicides in the water of an irrigation well. The chemicals used were: atrazine, simazine, terbuthylazine, terbutryn, terbumeton, bromacil and diuron. The simetric triazines and bromacil were analyzed by gas chromatography and diuron by HPLC. The mentioned pesticides were introduced in the well in order to simulate a point-source contamination. Levels of contamination of the well due to herbicide application were about 1 mg/l, however, dissipation of the herbicides was almost complete 8 days after application, except for bromacil and diuron which persisted longer than the s-triazines.

Chromatography, Gas↗
PubMed1997

Bovine somatotropin dose titration in lactating dairy ewes. 2. Dose determination and factors affecting the response.

Seventy-four lactating dairy ewes were injected with recombinant bovine somatotropin (bst; sometribove) in a sustained-release formulation. Ewes received 0, 80, 160, or 240 mg of bST/14 d from wk 3 to 8 of lactation (part 1) and 0, 80, or 160 mg of bST/14 d from wk 11 to 18 of lactation (part 2). The optimal dose of bST was studied as well as the factors (lactation stage, lactation number, initial milk production, body weight, and body condition) possibly affecting the increase in milk production following bST injection. Using a quadratic regression model, the maximum theoretical dose was determined to be 181 mg of bST/14 d during the first part of lactation. During the second part of lactation, 143 mg of bST/14 d was the maximum theoretical dose. The increment of milk production did not vary with lactation number, but first lactation ewes, in general, responded better than did multiparous ewes. Relative to initial milk production, improvement was greatest for ewes with average milk production (1500 ml/d) that received a dose of 192.3 mg of bST/14 d during the first part of lactation; improvement was also measured from the highest producers (2000 ml/d) during the second part of lactation. The best response was obtained from ewes with average body condition (score 3 on a five-point scale where 1 = thin to 5 = fat) and a dose of 200 mg of bST/14 d during the first part of lactation; during the second part of lactation, body condition score had no effect. Body weight had no effect on the increment of production at any time.

Animal Nutritional Physiological Phenomena↗
PubMed1996

UV detection of triazine herbicides and their hydroxylated and dealkylated degradation products in well water.

The aim of this work was to develop a simple method to confirm the presence of hydroxytriazine products (hydroxyatrazine, hydroxysimazine, hydroxyethylterbutyltriazine and hydroxydiaminotriazine) in water and to apply it to well water samples. The hydroxytriazines were concentrated on a Sep-Pak C18 cartridge. Analysis was performed by HPLC using an RP8-DB column with phosphate buffer (pH 4.7)-acetonitrile (72:28, v/v) as the mobile phase and photodiode-array detection at 233 nm. Hydroxyatrazine, hydroxysimazine and hydroxyethylterbutyltriazine were detected at ppb levels in samples from two shallow wells under a very sandy soil citrus orchard taken at three different times in a 1-year period.

Chromatography, High Pressure Liquid↗
PubMed1996

[Spermatic phlebography and sclerotherapy of the male varicocele].

Phlebographic sclerotherapy and embolization are better methods, from the biological and cost-effectiveness viewpoints, to treat male varicocele than conventional surgery. On the other hand, positive technical results are not always obtained and the rates of relapses and recurrences are high. A retrospective study was carried out on 70 (of 81) sclerotherapies performed in the Radiology Department of S. Anna Hospital, Turin, from 1993 to September, 1995. The results confirmed the feasibility of this treatment in a nonangiographic department, with technical success rates increasing with growing operators' experience (70% success rate in 1993, vs. more than 95% in 1994-95). Recurrence rate was 4.9% and the rate of limited persistence was 7.3% at clinical and Doppler follow-up ranging 6-24 months (mean: 10.2 months). Both rates appeared to be related to varicocele initial size, increasing progressively from grade I to grade III. Therefore, such new and expensive techniques as balloon or spiral embolization are justified only in the most severe cases. The follow-up showed improved or normalized sperm exams in 70.4% of treated and followed-up patients, with 5 full-term pregnancies. To conclude, sclerotherapy and embolization of the spermatic vein are very good tools to treat male varicocele with subfertility.

Adolescent↗
PubMed1995

Potential impact on breast cancer risk of circulating insulin-like growth factor I modifications induced by oral HRT in menopause.

Unlike parenteral estrogens, oral estrogen administration in menopause causes, through its hepatocellular action, a significant decrease of circulating insulin-like growth factor I (IGF-I) levels; this effect is opposed by the addition of an androgenic progestogen. In vitro studies show that IGF-I is a potent mitogen for 'estrogen responsive' breast cancer cells. Moreover, some findings in breast cancer patients and in women treated with tamoxifen suggest that reduction of circulating IGF-I could be protective to the breast. However, by also considering (1) the potential action on breast cancer cells of IGF-II, (2) the possible consequences of the growth hormone (GH) increase caused by the IGF-I reduction and (3) the fact that in vitro results are not simply transferable to the in vivo condition, other 'scenarios' can be envisaged, besides the favorable one. In support of the latter, there are epidemiologic data which suggest that oral estrogen use could have some favorable peculiarities with regards to breast cancer risk. The associated decrease in circulating IGF-I level could well be one of these peculiarities.

Breast Neoplasms↗
PubMed1995

Bovine somatotropin dose titration in lactating dairy ewes. 1. Milk yield and milk composition.

Seventy-four lactating dairy ewes were injected with recombinant bST (sometribove) in a sustained-release formulation. Ewes received 0, 80, 160, or 240 mg of bST every 14 d from wk 3 to 8 of lactation (part 1) and 0, 80, or 160 mg of bST every 14 d from wk 11 to 23 of lactation (part 2). Sometribove increased milk yield over that of the controls for all treatment groups. The increase was largest for the group that was administered 160 mg of bST: milk yield was 34.1 and 53.2% and 6% FCM was 36.9 and 51.8% for parts 1 and 2 of the study, respectively. Sometribove increased milk fat during part 1 of the study, but decreased milk fat during part 2. Protein contents of milk were decreased throughout the study. For all group, bST increased the yield of milk constituents over that of the controls. When milking frequency was reduced from twice to once daily, the difference in milk yield between control ewes and those treated with bST was maintained. Neither mastitis incidence nor milk SCC were affected by bST treatment. Recombinant bST is efficacious in increasing both actual milk yield and 6% FCM over the dose range of 80 to 240 mg/14 d without adverse effects for lactating ewes.

Animals↗
PubMed1994

Androgenic progestogens oppose the decrease of insulin-like growth factor I serum level induced by conjugated oestrogens in postmenopausal women. Preliminary report.

Oral oestrogen treatment in postmenopausal women causes a decrease of insulin-like growth factor I (IGF-I) serum level, probably through a hepatocellular effect. To explore the possibility that the androgenic progestogens oppose this effect, serum IGF-I and sex hormone binding globulin (SHBG) were evaluated in two groups of patients treated respectively with oral conjugated oestrogens (oCE) or transdermal oestradiol (tdE2), in a first phase with the addition of dydrogesterone (DYDR), a non-androgenic progestogen, and subsequently with the addition of norethisterone acetate (NETA). With respect to basal values, treatment with oCE+DYDR caused an increase of SHBG (P < 0.002) and a decrease of IGF-I serum levels (P < 0.05); the shift to NETA addition opposed both effects: SHBG levels decreased partially but significantly (P < 0.01 vs. oCE + DYDR) and IGF-I returned to basal values with a significant increase with respect to the oCE + DYDR phase (P < 0.02). No changes were observed in the tdE2 + DYDR treated women; in this group the shift to NETA addition caused a significant decrease of SHBG values (P < 0.001 vs. before treatment and vs. tdE2 + DYDR phase) and a slight increase of IGF-I values. These differential effects on IGF-I and SHBG serum levels might be relevant as far as breast cancer risk is concerned.

Administration, Cutaneous↗
PubMed1993

Long-term hormone replacement treatment in menopause: new choices, old apprehensions, recent findings.

In recent years there has been an increase in the use of parenteral oestradiol as an alternative to the conventional oral preparations used in hormone replacement treatment (HRT) in menopause, such as conjugated equine oestrogens (CEE). The latter have been subject in the past to apprehensions, partly due to misunderstanding and oversimplification but also in relation to problems that have arisen during the history of HRT, for example the increase in endometrial cancer risk deriving from the use of non-progestogen-opposed treatment. However, confidence in long-term HRT comes from the epidemiological findings, which refer mainly to the use of oral CEE unopposed by progestogen: a reduced risk of osteoporotic fractures and of cardiovascular disease, and a very limited risk of breast cancer. Oral oestrogens produce marked hepatocellular effects. These effects are, on the whole, favourable from the point of view of cardiovascular risk. In addition, it cannot be excluded that some hepatocellular effects of oral oestrogen, for example increased sex hormone binding globulin levels and reduced circulating insulin-like growth factor I activity, offer protection to the breast. As progestogen supplementation is needed in non-hysterectomized women, priority should be given to preparations, such as progesterone or dydrogesterone, that feature good endometrial activity without opposing oestrogen hepatocellular effects.

Estradiol↗
PubMed1993

Differential effects of oral conjugated estrogens and transdermal estradiol on insulin-like growth factor 1, growth hormone and sex hormone binding globulin serum levels.

In postmenopausal women oral ethinylestradiol causes a reduction in circulating insulin-like growth factor 1 (IGF-1) and an increase in serum growth hormone levels. There are no data on the effect of conjugated estrogens, the preparation most often used in estrogen replacement treatment (ERT), on these parameters. We evaluated serum IGF-1 and growth hormone levels, together with the levels of sex hormone binding globulin (SHBG), an indicator of estrogen hepatocellular action, before and after 6 months of ERT in two comparable groups of postmenopausal women. Sixteen women were treated with oral conjugated estrogens, 0.625 mg/day, and 14 with transdermal estradiol, 0.05 mg/day. In the women treated with oral conjugated estrogens, an increase in SHBG (p < 0.001), a decrease in IGF-1 (p < 0.001) and an increase in growth hormone (p < 0.05) serum levels were observed. No such effects were seen with the use of transdermal estradiol, devoid of hepatocellular effects. Undoubtedly, oral conjugated estrogens, 0.625 mg/day, through a hepatocellular effect, cause marked modifications in the IGF-1/growth hormone axis, which may have clinical relevance. For instance, the decreased IGF-1 level, together with the increased level of SHBG, might provide some explanation of the favorable epidemiological data on breast cancer risk in women receiving oral conjugated estrogens.

Administration, Cutaneous↗
PubMed1993

[Indications for tubal recanalisation in diagnostic and interventional hysterosalpingography].

Three hundred and seventy-seven hysterosalpingographies performed in 1992 in the Radiology Department of the S. Anna Hospital, Turin, Italy, were reviewed to assess the role and the real incidence of indications to catheterization and to selective salpingography. Proximal tube obstruction treatable by means of extemporary mono-bilateral catheterization was found in 18.3% of cases, but only in 7.4% was catheterization really indicated. In 67.2% of patients repeated contrast medium injections, at high pressure, with the catheter end in front of the internal ostium of the Fallopian tube, allowed recanalization--which made catheterization unnecessary. Catheterization was performed in 18 cases where double injection had failed and was successful in 15 patients (83.3%). Even though selective interventional salpingography is valuable, its use in rarely necessary, especially if conventional hysterosalpingography is performed at the correct injection pressure. Therefore, we conclude that the interventional kit for proximal tube recanalization must always be available, but its use in routine exams is unnecessary.

Adult↗