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Biomedical subjects

G Crotti

Publications and source records attributed to G Crotti.

17 recordsLinked to original sources
PubMed2003

Bovine embryo technologies.

Embryo technologies are a combination of assisted reproduction, cellular and molecular biology and genomic techniques. Their classical use in animal breeding has been to increase the number of superior genotypes but with advancement in biotechnology and genomics they have become a tool for transgenesis and genotyping. Multiple ovulation and embryo transfer (MOET) has been well established for many years and still accounts for the majority of the embryos produced worldwide. However, no progress has been made in the last 20 years to increase the number of transferable embryos and to reduce the side effects on the reproductive performance of the donors. In vitro embryo production (IVP) is a newer and more flexible approach, although it is technically more demanding and requires specific laboratory expertise and equipment that are most important for the quality of the embryos produced. Somatic cell cloning is a rapidly developing area and a very valuable technique to copy superior genotypes and to produce or copy transgenic animals. More knowledge in oocyte and embryo biology is expected to shed new light on the early developmental events, including epigenetic changes and their long lasting effect on the newborn.Embryo technologies are here to stay and their use will increase as advances in the understanding of the mechanisms governing basic biological processes are made.

Animals↗
PubMed2001

Embryo production by ovum pick up from live donors.

Embryo production by in vitro techniques has increased steadily over the years. For cattle where this technology is more advanced and is applied more, the number of in vitro produced embryos transferred to final recipients was over 30,000 in 1998. An increasing proportion of in vitro produced embryos are coming from oocytes collected from live donors by ultrasound-guided follicular aspiration (ovum pick up, OPU). This procedure allows the repeated production of embryos from live donors of particular value and is a serious alternative to superovulation. Ovum pick up is a very flexible technique. It can be performed twice a week for many weeks without side effects on the donor's reproductive career. The donor can be in almost any physiological status and still be suitable for oocyte recovery. A scanner with a sectorial or convex probe and a vacuum pump are required. Collection is performed with minimal stress to the donor. An average of 8 to 10 oocytes are collected per OPU with an average production of 2 transferable embryos. The laboratory production of embryos from such oocytes does not differ from that of oocytes harvested at slaughter as the results after transfer to final recipients. For other species such as buffalo and horses OPU has been attempted similarly to cattle and data will be presented and reviewed. For small ruminants, laparotomy or laparoscopy seems the only reliable route so far to collect oocytes from live donors.

Animals↗
PubMed2001

Bovine oocytes treated prior to in vitro maturation with a combination of butyrolactone I and roscovitine at low doses maintain a normal developmental capacity.

Butyrolactone I (BL-I) and Roscovitine (ROS), two specific and potent inhibitors of M-phase promoting factor (MPF) kinase activity, were used to block germinal vesicle breakdown (GVBD) of cattle oocytes. A concentration 6.25 microM BL-I and 12.5 microM ROS blocked over 93.3 +/- 2.5% of oocytes in germinal vesicle (GV) stage during a 24-hr culture period. Following a second 24-hr culture step in maturation medium (IVM) almost all (91.5 +/- 3.0%) inhibited oocytes resumed meiosis and reached the metaphase II (MII) stage. The MII kinetics was different for inhibited and control oocytes. Fifty percent MII was reached at 13-14 hr in BL-I + ROS treated oocytes, compared to 18 hr in control oocytes. Therefore, control oocytes were fertilised (IVF) after 22 hr IVM and inhibited oocytes after 16 or 22 hr IVM. After IVF, percentage of grade 1 freezable embryos on day 7 (D + 7) as well as percentage of blastocyst formation on D + 8 in the group of BL-I + ROS treated oocytes fertilised after 16 hr IVM were higher (P < 0.05) compared with the other experimental group fertilised after 22 hr IVM but not different in comparison with the control. Survival to freezing and thawing of grade 1 embryos frozen on D + 7 was employed as viability criteria and was similar in all groups. Thus, the presence of BL-I + ROS in the prematuration medium of bovine oocytes determines a reversible meiotic block, without compromising their subsequent developmental competence.

4-Butyrolactone↗
PubMed2001

Calibration and evaluation of uncertainty in the measurement of environmental electromagnetic fields.

After a brief description of the reference systems for the calibration of the electromagnetic field meters set up at IEN and the Ivrea Department of ARPA, the procedures for the evaluation of the measurement uncertainty are discussed, with reference to the problem of identifying and quantifying the different uncertainty components. which are due both to the field meter characteristics and to the measurement procedure and conditions. The problem of how to compare a measurement result, which consists of the measurement value and its associated uncertainty, with a limit fixed by the standards is also faced.

Calibration↗
PubMed1985

[Hemorheological changes induced by uremia. Effects of hemodialysis].

Fifteen patients affected by chronic uremia and treated with hemodialysis were studied. The main hemorheological parameters were evaluated in basal conditions and after hemodialytic therapy and were correlated with some hematochemical indices. Although some limitations to the purpose of this study derive from the heparinization of the blood during hemodialysis, the results of this study demonstrate that erythrocyte filtration does not significantly change during the hemodialytic therapy. The only hemorheological parameter altered in the uremic patient is represented by plasma viscosity; this is probably due to the increase of fibrinogenemia in these patients.

Adult↗
PubMed1984

[Lung survival or healing? Description of a case of acute non-lymphoblastic leukosis].

Only few patients (3,8%) affected by ANLL survive for more than 3 years from the time of diagnosis. In the present study the Authors try to determine which clinical and haematological factors can determine long-terme survival. The Authors describe the case of a male patient (25 years old) affected by ANLL (M2), who became and is still now a long-survivor (80 months from 1th complete remission). He has been treated with DNB, ARA-C and TG (TRA schedule) for two cycles. After CR he refused consolidation and reinduction therapy and was treated only with 6-MP and MTX for 3 years, as maintenance chemotherapy. The Authors suggest that important factors for a favourable prognosis are early diagnosis and young age. A relatively high number of platelets can be correlated with a good prognosis.

Acute Disease↗
PubMed1984

Sweet's syndrome in chronic lymphocytic leukemia.

We describe the case of a man, previously affected by B-CLL, who developed Sweet's syndrome four months later the previous diagnosis. Sweet's syndrome was diagnosed by cutaneous biopsy. Neither infections nor drugs administration were demonstrated, in order to explain beginning of Sweet's syndrome. Altered immune responsiveness, as seen in B-CLL, could cause Sweet's syndrome.

Adrenal Cortex Hormones↗
PubMed1983

Absolute bioavailability of ceftriaxone after intramuscular administration to healthy volunteers.

The disposition and bioavailability of ceftriaxone, a novel cephalosporin, was studied in 7 healthy volunteers after a single 1.5-gram intramuscular administration in comparison with the same dose given by the intravenous route. The plasma levels were measured by means of a high-performance liquid chromatography method up to 48 h after administration. Comparable areas under plasma concentration-time curve (AUC) and biological half-life were obtained proving that ceftriaxone, if assessed by conventional methods, is completely bioavailable when given by the intramuscular route. However, taking into account its nonlinear pharmacokinetics it becomes obvious that direct comparison of AUC values generally leads to a certain overestimation of bioavailability after extravascular administration. This aspect is briefly discussed.

Adult↗
PubMed1983

[Evaluation of the redox status of neoplastic patients].

Free radicals and peroxides of our organism, that are very unstable, are now recognized as a product of biological oxido-reductive processes. The evaluation of free radicals and peroxides in blood was done by counting Heinz-bodies (H.B.) (Beutler method). The Authors examined 40 healthy subjects, at rest, and 37 neoplastic patients (19 carcinomas, 10 leukemias, 8 lymphomas) at the admission to hospital. The results show that the rate per cent of H.B. in neoplastic patients is significantly higher than in healthy subjects. According to us, neoplastic patients have free radicals hematic levels higher than healthy volunteers.

Adult↗