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Biomedical subjects

R Boni

Publications and source records attributed to R Boni.

At least 19 recordsLinked to original sources
PubMed2005

D-aspartate and reproductive activity in sheep.

D-aspartic acid (D-Asp) has been isolated from neuroendocrine tissues of many invertebrates and vertebrates. Recently, it has been demonstrated that this D-amino acid may be converted to N-methyl-D-aspartic acid (NMDA), a neuromodulator associated with sexual activity. In this study, we determined D-Asp and NMDA concentrations in endocrine glands and other tissues in ewes after D-Asp administration and in controls. We also evaluated the effects of d-Asp administration on the reproductive activity of ewes by determining either progesterone concentrations or LH pulses in the presence or absence of estradiol benzoate. The pineal gland showed the highest natural content of D-Asp (1.47+/-0.22 micromol/g tissue), whereas the pituitary gland had the highest capability to store d-Asp, with a peak value (9.7+/-0.81 micromol/g tissue) 6 h after its administration. NMDA increased sharply 12 h following D-Asp administration, reaching values three times higher than the baseline in both the pituitary and brain. D-Asp was quickly adsorbed after subcutaneous administration, with a peak in plasma levels 2 h after administration and a return to baseline values after 6 h. D-Asp administration achieved a significant (P < 0.001) increase in LH values with respect to estradiol or estradiol + D-Asp treatments. d-Asp treatment once or twice a week did not successfully drive acyclic ewes into reproductive activity. In conclusion, the results obtained in this study demonstrated that D-Asp is endogenously present in sheep tissues and electively stored in endocrine glands and brain after its administration. NMDA and LH increase following D-Asp administration suggesting a role of this D-amino acid in the reproductive activity of sheep.

Animals↗
PubMed2002

Fertilization and activation currents in bovine oocytes.

One of the first events that occurs at fertilization is a transient modification of the electrical properties of the oocyte plasma membrane. The whole-cell voltage clamp technique was used to demonstrate an outward ion current and a hyperpolarization of the plasma membrane after fertilization in bovine oocytes. These electrical events, together with measurement of internal calcium concentrations, were also recorded after injection with sperm factor and exposure to parthenogenetic activators, such as Ca(2+) ionophore, ethanol and thapsigargin. Experiments were carried out simultaneously in immature and in vitro matured oocytes. Significant differences were recorded in the activation current and hyperpolarization among oocyte activators and between immature and matured oocytes. However, outward ion current and Ca(2+) release showed similar dynamics. The injection of the calcium chelator EGTA completely abolished both ion current and hyperpolarization, indicating that these electrical events are calcium dependent. Addition of specific calcium releasers, such as 1,4,5-inositol trisphosphate (IP(3)) and caffeine, triggered ion activation current and hyperpolarization indicating that IP(3) and ryanodine receptors are active in both immature and matured oocytes. Different ion channel inhibitors were used to characterize the channels underlying outward currents. Only addition of rIberiotoxin caused a complete inhibition of the current, indicating the involvement of high conductance Ca(2+)-activated K(+) channels in generating activation current. In conclusion, these findings provide evidence that bovine oocyte activation is associated with Ca(2+)-dependent electrical events. Oocytes have the potential to react to different activators even when immature; however, oocyte maturation seems to increase sensitivity to physiological activators, such as spermatozoa and sperm factor, and chemicals, such as ethanol.

Animals↗
PubMed2000

Ca(2+) current activity decreases during meiotic progression in bovine oocytes.

By using the whole cell voltage-clamp technique, we studied changes in plasma membrane permeability at different meiotic stages of bovine oocytes. Follicular oocytes were matured in vitro and activated by Ca(2+) ionophore. Oocytes at germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), metaphase II (MII), and meiosis exit were used for electrophysiological recording. By clamping the oocytes at -30 mV, we found that the L-type voltage-dependent Ca(2+) channels were active at the GV stage and that their activity decreased after the GVBD stage. Furthermore, the resting potential decreased from the GV to the MI stage and increased again at MII. A significant decrease of the steady-state conductance occurred from the GV to the MI stage, followed by a sharp increase at the MII stage. With the addition of organic L-type Ca(2+) channel blockers (nifedipine and verapamil), we inhibited the Ca(2+) currents. However, only in the case of verapamil was there a decrease of in vitro maturation efficiency. Our results suggest that, in addition to the cumulus-oocyte junctions, the plasma membrane channels provide another mode of Ca(2+) entry into bovine oocytes during meiosis.

Animals↗
PubMed1999

Intercellular communication in in vivo- and in vitro-produced bovine embryos.

In vivo bovine embryos were obtained by nonsurgical flushing of uterine horns of cows submitted to superovulatory treatment, while in vitro embryos were generated from oocytes collected from slaughtered donors. Lucifer Yellow injected into single blastomeres did not diffuse into neighboring cells until the morula stage in in vivo embryos and the blastocyst stage in in vitro embryos. In both cases diffusion was limited to a few cells. In contrast, diffusion was extensive in microsurgically isolated inner cell mass (ICM) but absent in the trophectoderm (TE). At the blastocyst stage, diffusion was always more extensive in in vivo than in in vitro embryos. Ultrastructural analyses confirmed these functional observations, and gap junction-like structures were observed at the blastocyst stage. These structures were diffuse in the ICM of in vivo embryos, scarce in the ICM of in vitro embryos and in the TE of in vivo embryos, and not observed in the TE of in vitro embryos. Blastomeres at all stages of development from the 2-cell stage to the blastocyst stage in in vitro embryos and at the morula and blastocyst stage in in vivo embryos were electrically coupled, and the junctional conductance (Gj) decreased in in vitro embryos from 4.18 +/- 1.70 nS (2-cell stage) to 0.37 +/- 0.12 nS (blastocyst stage). At each developmental stage, in vivo embryos showed a significantly (P < 0. 05) higher Gj than in vitro-produced embryos. Moreover, a significantly (P < 0.01) higher Gj was found in isolated ICM than in the respective blastocyst in both in vivo- and in vitro-produced embryos (3.5 +/- 1.4 vs. 0.7 +/- 0.3 and 2.6 +/- 1.6 vs. 0.37 +/- 0. 12 nS, respectively). The electrical coupling in absence of dye coupling in the early bovine embryo agrees with observations for embryos from other phyla. The late and reduced expression of intercellular communicative devices in in vitro-produced embryos may be one of the factors explaining their developmental low efficiency.

Animals↗
PubMed1998

11q13 allelic loss in pituitary tumors in patients with multiple endocrine neoplasia syndrome type 1.

Pituitary adenomas may develop sporadically or as part of the multiple endocrine neoplasia type 1 (MEN 1) syndrome. The gene responsible for MEN 1 syndrome was recently identified and cloned. Low rates of MEN 1 gene mutations and deletions have been reported in sporadic pituitary adenomas. To elucidate the role of the MEN 1 gene in the pathogenesis of MEN 1-associated pituitary tumors, we examined pituitary adenomas from 11 MEN 1 patients for the presence of 11q13 allelic loss. Ten of the 11 pituitary tumors were informative by PCR-based loss of heterozygosity analysis. Using a combination of family pedigree analysis and restriction analysis directed at the mutated allele in 8 of the 10 informative cases, it was demonstrated in all 8 cases that it is the wild-type allele that undergoes deletion. All 11 tumors, 4 of which were growth hormone secreting, were additionally analyzed for mutation in the Gs alpha subunit (gsp) gene. None of the tumors (0 of 11 tumors) revealed a gsp gene mutation. Therefore, genetic alterations of the MEN 1 gene seem to play a dominant role in MEN 1-associated pituitary tumorigenesis, whereas gsp gene mutations do not seem to be a frequent event in either growth hormone-secreting or other types of MEN 1-associated pituitary tumors. These results suggest that MEN 1-associated pituitary tumors develop via genetic pathways that differ from those of most sporadic pituitary tumors.

Adenoma↗
PubMed1997

Follicular dynamics, repeatability and predictability of follicular recruitment in cows undergoing repeated follicular puncture.

The aim of our study was to characterize follicular recruitment and growth in response to the repeated removal of follicles. All tertiary follicles (> 2 mm of diameter) in the ovaries of 10 non-lactating Holstein Friesian cows were punctured at midcycle (Day 0) by means of an ultrasound-guided needle. Puncture sessions were scheduled twice weekly at 3- or 4-d intervals over 3 mo. In the middle of the experiment, i.e., Week 7, the effects of 2- and 5-d intervals between follicular punctures were tested and compared with the previous 3- and 4-d intervals. After this period, 6 animals were slaughtered to study the effect of puncturing on gross ovarian morphology. The protocol of puncturing follicles with 3- to 4-d intervals was continued for an additional 3 mo in the remaining 4 animals. Twice-weekly puncturing of all tertiary follicles abolished estrous cycles and lead to an increase in follicular wave frequency without apparent negative effects on either the reproductive tract or ovaries. After puncture the new follicular wave attained full numerical development within 3 d. Two-day intervals resulted in a lower number of follicles than the 3-d interval (11.0 -/+ 3.8 vs 15.4 -/+ 6.1; P < 0.05). In contrast 4- and 5-d intervals between puncture resulted in an increase in follicle size when compared with that of the 3-d interval. The mean+SD number of recruited follicles varied between animals ranging between 78 +/- 2.5 to 19.2 -/+ 6.0. The mean number of follicles recruited increased from the first month (March) to the third month (May) of sampling (11.8 +/- 4.7 vs 16.4 +/- 6.5; P < 0.01), and then decreased between the third (May) and the sixth (August) month of sampling (21.5 +/- 4.7 vs 16.8 +/- 5.0; P < 0.01). During the experiment, the number of recruited follicles varied cyclically, with waves having a length of 6 puncture session (PS) or 3 wk (i.e., the mean length the bovine estrous cycle). Follicular recruitment after repeated ovum pick-up showed a high repeatability (r = 0.576) A model was also developed showing good predictability of the potential of animals to recruit follicles on the basis of the first 4 to 6 PS. Our results showed that despite large variation in follicular recruitment between animals, the high repeatability and good predictability of follicle recruitment demonstrates the possibility of characterizing animals on their potential for follicle growth.

Journal Article↗
PubMed1997

Structure-activity relationship studies of the amide functionality in (p-O-sulfamoyl)-N-alkanoyl tyramines as estrone sulfatase inhibitors.

Recently, we reported the synthesis and biomedical studies of a series of (p-O-sulfamoyl)-N-alkanoyl tyramines as nonsteroidal estrone sulfatase inhibitors. One of the most potent inhibitors in this series is (p-O-sulfamoyl)-N-tridecanoyl tyramine 1 with an 1C50 value of 61.3 nM. In this study, we synthesized four analogs of 1 (compounds 2-5) to investigate the structure-activity relationships of the amide functionality in (p-O-sulfamoyl)-N-tridecanoyl tyramine. Replacement of the amide functionality in 1 with an ethylene moiety to form the alkyl analog 5 resulted in complete loss of sulfatase inhibitory activity (IC50 of 61.3 nM vs. > 20 microM). The keto, hydroxy, and ester analogs (inhibitors 2-4) are 8-15 times less in affinity to the sulfatase than inhibitor 1. However, their inhibitory activities are significantly higher than the alkyl analog 5. The results suggest that the amide functionality is favorable for sulfatase inhibitory activity and that there may be a hydrogen bonding component to the enzyme interaction in this region.

Amides↗
PubMed1997

No evidence of HTLV-I proviral integration in lymphoproliferative disorders associated with cutaneous T-cell lymphoma.

Several recent studies have reported detection of HTLV-I genetic sequences in patients with cutaneous T-cell lymphoma (CTCL) including mycosis fungoides and Sezary syndrome. The purpose of this study was to determine whether HTLV-I was detectable in lesional tissues of patients suffering from diseases known to be associated with CTCL. Thirty-five cases were obtained from diverse geographical locations including Ohio, California, Switzerland, and Japan. Six of them had concurrent CTCL. Cases were analyzed using a combination of genomic polymerase chain reaction (PCR)/ Southern blot, dot blot, and Southern blot analyses. All assays were specific for HTLV-I provirus. Sensitivity ranged from approximately 10(-6) for PCR-based studies to 10(-2) for unamplified genomic blotting. Lesional DNA from patients with lymphomatoid papulosis (fourteen cases), Hodgkin's disease (twelve cases), and CD30+ large-cell lymphoma (nine cases) was tested for the HTLV-I proviral pX region using a genomic PCR assay followed by confirmatory Southern blot analysis with a nested oligonucleotide pX probe. All cases were uniformly negative. All of the Hodgkin's disease cases, eight of the large-cell lymphoma cases, and six of the lymphomatoid papulosis cases were then subjected to dot blot analysis of genomic DNA using a full-length HTLV-I proviral DNA probe that spans all regions of the HTLV-I genome. Again, all cases were negative. Finally, eleven of the Hodgkin's disease cases were also subjected to Southern blot analysis of EcoRI-digested genomic DNA using the same full-length HTLV-I probe. Once again, all cases were negative. These findings indicated that, despite utilization of a variety of sensitive and specific molecular biological methods, HTLV-I genetic sequences were not detectable in patients with CTCL-associated lymphoproliferative disorders. These results strongly suggest that the HTLV-I retrovirus is not involved in the pathogenesis of these diseases.

Blotting, Southern↗
PubMed1997

[Half-life of blood PSA after radical prostatectomy. Correlations with pathological stage and clinical course of the disease].

PSA half-life was calculated in 37 patients after radical prostatectomy to identify earlier patients with residual disease. The half-life calculated in patients potentially "cured" with absolute PSA values inferior to 0.5 ng/ml after 28 days, was significantly different (P = 0.0008) from the group of patients "uncured" (PSA > 1.0 ng/ml) and from those ones that, despite of detectable PSA level, had evidence of recurrence in the following follow-up. In comparison with the absolute value, the PSA half-life is able to define in the group of patients potentially "cured" those who could have a recurrence in the future.

Adenocarcinoma↗
PubMed1996

Repeated ovum pick-up in Italian Mediterranean buffalo cows.

The potential of the ovum pick-up technique, used over a long period, was evaluated in 6 Italian Mediterranean buffalo cows that had more than 500 d open. The cows were submitted to ovum pick-up twice weekly for 2 mo. An additional 2-mo cycle of ovum pick-up was performed in 3 of the buffalo. The ovum pick-up sampling did not affect the resumption of reproductive activity of these animals. In fact, all the buffalo conceived, on average, 47.5 +/- 27.5 d after the last ovum pick-up. An average of 5.48 follicles was punctured, and 2.71 oocytes were collected per session. However, only 53.5% of these oocytes were suitable for in vitro embryo production. The number of punctured follicles differed between individual cows. There were no differences in the number of collected oocytes or in the recovery rates. The number of punctured follicles, the number of collected oocytes and the recovery rate were similar in the first and second months; the quality of the oocytes was, however, better in the second than in the first month (P < 0.05). The increasing interval between 2 consecutive ovum pick-up sampling (intersession interval) caused an increase of the percentage of large follicles. Moreover, the increase of the intersession interval from 4 to 5 d decreased the quality of the collected oocytes (P < 0.05). The efficiency of in vitro production of embryos to expanded blastocysts was 16.7%.

Journal Article↗
PubMed1996

Lack of the t(2;5) or other mutations resulting in expression of anaplastic lymphoma kinase catalytic domain in CD30+ primary cutaneous lymphoproliferative disorders and Hodgkin's disease.

The t(2;5) (p23;q35) chromosomal translocation has been found in a high proportion of lymph node-based CD30+ large cell lymphomas of T-cell lineage. This translocation is believed to result in the expression of a fusion protein containing the catalytic domain of anaplastic lymphoma kinase (ALK) under the control of the promoter for nucleophosmin, a nucleolar phosphoprotein. Expression of ALK activity, which does not normally occur in lymphocytes, is postulated to be involved in the pathogenesis of lymphomas bearing the t(2;5) translocation. Several primary cutaneous lymphoproliferative disorders and Hodgkin's disease are also known to contain CD30+ large lymphoid cells. To determine the role of the t(2;5) translocation in these diseases, we developed a DNA-based polymerase chain reaction (PCR)/Southern blot assay to detect this translocation at the genomic level in lymphomatoid papulosis (14 cases), primary cutaneous CD30+ large cell lymphoma of T-lineage (10 cases) and Hodgkin's disease (13 cases). Two cases of pityriasis lichenoides were also studied. The t(2;5) translocation was not present in any of these specimens. To determine if some other somatic mutation might have resulted in inappropriate expression of ALK catalytic domain, we devised an RNA-based reverse transcriptase-PCR assay to detect transcripts encoded by this ALK region. None were found in the six additional cases of lymphomatoid papulosis that were studied. In aggregate, these results strongly suggest that inappropriate expression of ALK is not involved in the pathogenesis of these CD30+ lymphoproliferative disorders, and that lymph node-based CD30+ large cell lymphoma is a disease that is biologically distinct from skin-based CD30+ lymphoproliferative disorders and Hodgkin's disease. Using methods developed for this report, we also cloned and sequenced the t(2;5) genomic junctional sequences present in the SUP-M2 and SU-DHL-1 cell lines. These intron sequences will be useful for mapping t(2;5) breakpoint clusters.

Adult↗
PubMed1995

[Whipple disease. Report of a case with unusual therapeutic aspects].

Whipple's disease is a chronic systemic syndrome which typically involves small intestinal mucosa. There is no doubt today about its bacterial etiology and its good response to antibiotic therapy. A peculiar case is reported, in which the failure of a protracted corticosteroidal treatment is demonstrated and a particularly prompt endoscopic healing after therapy with cotrimoxazole is obtained. The value of duodenal biopsy in course of upper gastrointestinal endoscopy in comparison with classic intraluminal jejunal biopsy is confirmed for the diagnosis of Whipple's disease.

Anti-Bacterial Agents↗
PubMed1994

[Possibilities of ovum pickup in cattle].

Cattle breeding has a new reproduction technique in addition to artificial insemination and embryo transfer. It is the collection of ova from living animal by means of ultrasound guided follicle aspiration (ovum pick-up), followed by embryo-production in vitro. Follicles larger than 2 mm were punctured and the ova were collected twice weekly during 3 months. In total 1677 ova were collected from ten cows; 1342 (80%) were used for in vitro maturation, fertilization, and embryoculture. All ova were fertilized with semen from one bull, and 218 transferable embryos were produced. Calculated on a year basis, this would amount to 87 embryos per animal, with an intra-animal variation between 28 and 132. This new technique may replace MOET (Multiple Ovulation and Embryo Transfer; yearly average of 25 transferable embryos per animal), if the embryo-production via OPU can be performed with semen from any selected bull.

Animals↗
PubMed1994

Potential use of ovum pick-up for embryo production and breeding in cattle.

The efficacy of transvaginal ultrasound-guided puncturing of ovarian follicles for collecting immature oocytes in cattle was studied. Three experiments were conducted to examine the effects of puncturing on follicle recruitment and on the number of oocytes collected. Puncture sessions were executed twice weekly at regular intervals of 3 and 4 d respectively. The oocytes were matured, fertilized and allowed to develop in vitro and the number of transferable embryos was recorded. The health of the cows was checked daily. In Experiment 1, dairy cows (n=10) were punctured over a period of 5 mo, and the collected oocytes were fertilized with the semen of 1 bull. In Experiment 2, oocytes were collected from one 12 year old high pedigree dairy cow and an one month pregnant cow were punctured. The oocytes of the old cow were fertilized with semen of 8 different bulls. In Experiment 3, beef cows (n=6) were punctured over a 2 mo period and the semen of 2 different bulls of the same breed was used to fertilize the oocytes from 3 of these cows. In Experiment 1, 14.5 +/- 0.4 (mean +/- SEM) follicles were punctured per session, and 8.0 +/- 0.3 (mean +/- SEM) oocytes were recovered. A mean of 16% of the oocytes developed into transferable embryos with a pregnancy rate of 40%. The results did not differ between the months of the experiments, indicating that the transvaginal puncturing method can be used successfully over a 5 mo period. No detrimental effects were observed after clinical and post mortem examinations, nor did breed, age or reproductive status appear to affect the results. However, large differences were observed between individual cows and between cow/bull combinations.

Journal Article↗
PubMed1994

[Color Doppler ultrasonography in the identification and characterization of secondary focal lesions of the liver].

This study was aimed at assessing the potentials of color Doppler US in the detection of hepatic metastases by measuring changes in hepatic perfusion. Color-Doppler US was performed on 40 patients with multiple metastatic lesions (mean theta: 3 cm). In each patient both smaller and bigger lesions were studied--80 lesions on the whole. Differences in flow distribution (peritumoral or intratumoral) and the highest systolic peak flow velocity were investigated on color Doppler US scans. Hepatic arterial and portal venous blood flow measured in 40 patients with hepatic metastases were compared with those in 40 healthy controls. The two groups were homogeneous relative to age, sex, height and weight. The ratio of hepatic arterial to total liver blood flow (Doppler perfusion index, DPI) and the ratio of hepatic arterial to portal venous blood flow (Doppler flow ratio, DFR) were calculated. Color flow US scans were obtained in 56 of 80 metastatic lesions. We observed peritumoral flow in 76% of the lesions, intratumoral flow in 6% and mixed peritumoral and intratumoral flow in 18% of cases. The DPI and DFR values were significantly higher in the patients with liver metastases than in the control group. The changes in DPI and DFR resulted from an increase in hepatic arterial flow; no changes in portal venous blood flow were observed. These results suggest that Doppler measurements of hemodynamic hepatic changes may be of great value for the earlier detection of hepatic metastases.

Aged↗