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Biomedical subjects

G Lazzari

Publications and source records attributed to G Lazzari.

At least 19 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↗
PubMed2000

The insulin-dependent glucose transporter isoform 4 is expressed in bovine blastocysts.

We have investigated the expression of two glucose transporter isoforms, Glut1 and 4, in 14- and 16-day-old bovine blastocysts (d14, d16) using RT-PCR, competitive RT-PCR and in situ hybridization. The blastocysts were grown in vivo or had been produced in vitro. Glut1 mRNA was detected in all blastocysts studied, Glut4 in all d14 blastocysts, but only in a few d16 blastocysts. Glut4 mRNA was localized in trophoblast and endoderm cells. Glut1 mRNA increased from d14 to d16 while Glut4 transcription was down-regulated in d16 blastocysts. The mRNA amounts varied between 0.8 to 23 pg and 3.9 to 65 fg per 100 ng embryonic RNA for Glut1 and Glut4, respectively, displaying a 100- to 1500-fold lower expression of Glut4 compared with Glut1 during blastocyst elongation. This is the first report on the expression of the insulin-sensitive Glut4 isoform in mammalian preimplantation embryos.

Animals↗
PubMed1998

Oral iron chelating therapy. A single center interim report on deferiprone (L1) in thalassemia.

BACKGROUND AND OBJECTIVE: Deferiprone (L1) is a largely studied oral chelator in clinical setting, however, no definite conclusions concerning efficacy and toxicity still could be drawn. In an ongoing prospective trial with L1, we evaluated the efficacy and tolerance-toxicity in patients with thalassemia major previously treated by desferrioxamine (DFO); the specific aim of the study is to demonstrate that L1 could be an alternative to DFO in some patients with an acceptable toxicity. DESIGN AND METHODS: Sixty-nine patients over 13 years of age with poor compliance to DFO were considered for the study. The design included a liver biopsy before starting L1 in all patients in order to define liver siderosis either by histologic grading or by hepatic iron concentration (HIC); only patients with a minimum HIC of 4 mg/g dry weight entered the study. A repetition of the liver biopsy after one year of L1 was planned; further evaluations included serum ferritin, plasma iron, transferrin TIBC and iron urine excretion. L1 was given at 70 mg/kg/day in three divided doses. Toxicity was monitored either clinically or by controlling liver, kidney and marrow function by specific tests. Concerning clinical characteristics 52 patients showed hypogonadism (78%), 39 growth retardation (58%), 6 diabetes (9%), 4 cardiomyopathy (6%), 9 hypothyroidism (12%); 45 patients had chronic liver damage (65%). RESULTS: We focus this report on data collected in a group of 29 patients with a minimum follow-up of one year (14-33 months). The mean ferritin value was 3748 ng/mL (range: 200-10,000) and 2550 ng/mL (range: 80-14,500), before and while on L1 therapy, respectively (p = 0.001); the mean sideruria changed from 17.25 mg/dL (range: 5.4-50) to 20.98 mg/dL (range: 10-40), on DFO and L1, respectively (p = 0.078); the ratio between plasma iron (sideremia) and transferrin TIBC changed from 0.96 with DFO to 0.86 with L1 (0.014). A correlation with grade of liver siderosis and serum ferritin (p = 0.069) and iron urine excretion (p = 0.008) was recorded. The judgement of efficacy showed that L1 was effective (EF) in 9 patients, no assessable (UN) in 11 patients, not effective (NE) in 2 patients and with no advantages with respect to DFO in 7 patients. Liver biopsy was repeated in 20 patients showing a reduction of grade of liver siderosis and iron content in 7 patients. Clinical toxic effects of L1 were gastric intolerance (one patient), joint pain (three patients) and mild and temporary neutropenia (one patient). INTERPRETATION AND CONCLUSIONS: This preliminary experience shows that L1 is effective in several patients with thalassemia with poor compliance to DFO and to improve iron burden and iron excretion with generally minor side effects. L1 could be an alternative to DFO in some patients, however the recognition of neutropenia warrants a careful evaluation of patients and efforts finalized to early recognition of those to be addressed with this new and still experimental therapy.

Adolescent↗
PubMed1994

[Ultrasonographic findings and integration with computerized tomography in pathology of the abdominal wall].

Ultrasonography (US) plays a major role in the study of the anterior and lateral abdominal wall. Our experience refers to 150 patients examined over a 5-year period, who were divided into two groups according to disease etiology: 72 patients suffered from iatrogenic and 78 from non-iatrogenic conditions. The first group was mainly composed of alterations caused by anticoagulation therapy, e.g., hematomas, and recent or previous surgery, i.e., 19 incisional hernias and 19 inflammatory-abscess processes. The second group included above all 32 cases of abdominal wall hernia, 18 neoplasms, 13 traumas with abdominal wall involvement only and 12 inflammatory processes. US yielded valuable pieces of information to diagnose iatrogenic conditions, even for small or non-relevant conditions. Moreover, US allowed non-iatrogenic conditions to be located and identified, accurately demonstrating abdominal wall layers involvement. US was also very useful in the patients whose physical examination is of no use or difficult, e.g., in the patients with much pain and trauma or obese patients. CT was used in selected cases only, as a complement to US, when a more detailed spatial assessment of wide or deep lesions was necessary.

Abdominal Muscles↗
PubMed1993

[Ultrasonographic evaluation of the sciatic nerve and thigh trauma].

This study was aimed at studying the normal morphology of the main extrapelvic trunk of the sciatic nerve, its average size and its anatomo-topographic relationships by means of high resolution US. The involvement of the sciatic nerve in traumas was also investigated. The lower gluteal region and the posterior aspect of both thighs were examined in 30 healthy subjects and in 11 patients with recent or previous traumas. The sciatic nerve is clearly demonstrated, on US images, between the biceps femoris muscle and the semimembranosus and semitendinosus muscles. The average dorsoventral diameter of the nerve is 6.4 mm at the upper third and 4.8 mm at the middle third of the thigh, while its average transverse diameter is 11.8 mm at the middle third of the thigh. In traumas, US demonstrated compression and displacement of the sciatic nerve in 6 recent hematomas and in 2 hypertrophic ossei calli of the femoral diaphysis. In 2 osteomyelitis cases with a posterior thigh fistula, US showed sciatic nerve involvement by the phlogistic process. Moreover, US allowed an old thick thrombosis of a satellite vein of the sciatic nerve to be depicted. In conclusion, the present study has demonstrated that US not only clearly depicts the sciatic nerve but also provides accurate information on its involvement in recent or previous traumas.

Adolescent↗
PubMed1992

Centrifugal elutriation of porcine oocytes isolated from the ovaries of newborn piglets.

A two step enzymatic procedure for the isolation of ovarian follicles and oocytes at early stages of development from the ovaries of newborn piglets was devised. The isolated oocytes were then separated from the overwhelming majority of the ovarian somatic cells using a centrifugal elutriation system. Twenty to thirty thousand oocytes were routinely collected after elutriation of the cell suspension derived from a pair of ovaries. In the enriched fraction the ratio of oocyte:somatic cells was between 1:1 and 1:3. The validation of the method as an efficient procedure for the isolation of a large, viable, and highly enriched population of oocytes at early stages of development was provided by uptake studies carried out after each step of the isolation and separation technique and by a comparative analysis of the pattern of structural proteins of the enriched fraction and of fully grown porcine oocytes. The results confirmed that the isolated cells were actually oocytes at early stages of development and that they were viable throughout the entire procedure.

Animals↗