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Biomedical subjects

L Villa

Publications and source records attributed to L Villa.

At least 19 recordsLinked to original sources
PubMed1992

Conformational behaviour and molecular similarity of some beta 1-adrenergic ligands.

The conformational behaviour of a series of aryloxypropanolamines was investigated by means of a new procedure which allows the sampling of the molecular torsional surface in a very efficient way. The combination of such a procedure with the standard molecular mechanics algorithms for the geometry optimization gives, as a result, the definition of a powerful computational scheme for the detailed analysis of the potential energy surface of complex molecules. The compounds studied show a remarkable tendency to form intra-molecular hydrogen bonds, which seem to play a key role in determining the lowest energy structures. The indices of molecular similarity proposed by Carbó, computed for the most stable conformers, do not account for differences between diastereoisomers, and, as a consequence, can hardly be used to attempt a structure-activity correlation.

Hydrogen Bonding↗
PubMed1992

Binding and internalization of the 163-171 fragment of human IL-1 beta.

The mechanisms of cell association of the human interleukin (IL-1 beta) immunostimulatory fragment 163-171 have been studied. The fragment was able to associate abundantly to both IL-1R- and IL-1R+ cells. Binding was strictly temperature dependent, was not saturable and could be inhibited by excess amounts of unlabelled 163-171 peptide but not by IL-1 beta, suggesting that the 163-171 fragment is not an IL-1R-binding domain of IL-1 beta. The fragment is readily internalized by cells by a cytochalasin-insensitive mechanism and it localizes mainly in the cytoplasm. It is concluded that the active domain 163-171 of IL-1 beta can be taken up by cells through a receptor-independent, temperature-dependent mechanisms and that its ability to activate cellular functions is based on IL-1R-independent intracellular pathways.

Amino Acid Sequence↗
PubMed1992

Superovulation with human menopausal gonadotropins in the treatment of infertility associated with minimal or mild endometriosis: a controlled randomized study.

OBJECTIVE: To determine the efficacy of superovulation with buserelin acetate, human menopausal gonadotropins (hMG), and human chorionic gonadotropin (hCG) in the treatment of infertility associated with minimal or mild endometriosis. DESIGN: Prospective, randomized, controlled study. SUBJECTS: Forty-nine infertile women with a laparoscopic diagnosis of endometriosis stage I (n = 29) or II (n = 20) according to the revised American Fertility Society classification, randomly assigned to three superovulation cycles (n = 24) or 6 months' expectant management (n = 25). MAIN OUTCOME MEASURES: Cycle fecundity rates and cumulative pregnancy rates (CPR) in the two groups. RESULTS: Nine pregnancies were obtained in the superovulation-treated patients and six in the nontreated ones. The cycle fecundity rates and CPR were 0.15% and 37.4% after three superovulation cycles and 0.045% and 24% after 6 months of expectant management (P less than 0.05 and P = not significant, respectively). The women who did not achieve a pregnancy after three cycles of superovulation were followed for a total of 50 months during which no therapy was given. One pregnancy started in this period (cycle fecundity rate = 0.020). One spontaneous abortion occurred in each group. Three treated patients had multiple pregnancies, and four had ovarian hyperstimulation syndrome. CONCLUSION: Superovulation seems to be associated with a better cycle fecundity rate but not a better CPR than expectant management in infertile women with endometriosis stages I and II. The efficacy and side effects of this therapeutic approach should be evaluated in larger series.

Adult↗
PubMed1992

Molecular variants of human papillomavirus type 16 from four continents suggest ancient pandemic spread of the virus and its coevolution with humankind.

We have amplified by the polymerase chain reaction, cloned, and sequenced genomic segments of 118 human papillomavirus type 16 (HPV-16) isolates from 76 cervical biopsy, 14 cervical smear, 3 vulval biopsy, 2 penile biopsy, 2 anal biopsy, and 1 vaginal biopsy sample and two cell lines. The specimens were taken from patients in four countries--Singapore, Brazil, Tanzania, and Germany. The sequence of a 364-bp fragment of the long control region of the virus revealed 38 variants, most of which differed by one or several point mutations. Phylogenetic trees were constructed by distance matrix methods and a transformation series approach. The trees based on the long control region were supported by another set based on the complete E5 protein-coding region. Both sets had two main branches. Nearly all of the variants from Tanzania were assigned to one (African) branch, and all of the German and most of the Singaporean variants were assigned to the other (Eurasian) branch. While some German and Singaporean variants were identical, each group also contained variants that formed unique branches. In contrast to the group-internal homogeneity of the Singaporean, German, and Tanzanian variants, the Brazilian variants were clearly divided between the two branches. Exceptions to this were the seven Singaporean isolates with mutational patterns typical of the Tanzanian isolates. The data suggest that HPV-16 evolved separately for a long period in Africa and Eurasia. Representatives of both branches may have been transferred to Brazil via past colonial immigration. The comparable efficiencies of transfer of the African and the Eurasian variants to the New World suggest pandemic spread of HPV-16 in past centuries. Representatives of the African branch were possibly transferred to the Far East along old Arab and Indonesian sailing routes. Our data also support the view that HPV-16 is a well-defined virus type, since the variants show only a maximal genomic divergence of about 5%. The small amount of divergence in any one geographic location and the lack of marked divergence between the Tanzanian and Brazilian African genome variants two centuries after their likely introduction into the New World suggest a very slow rate of viral evolution. The phylogenetic tree therefore probably represents a minimum of several centuries of evolution, if not an age equal to that of the respective human races.

Base Sequence↗
PubMed1991

The proteolytic system of the fission yeast Schizosaccharomyces pombe.

Proteinase and peptidase activities of the fission yeast Schizosaccharomyces pombe were investigated. Several intracellular proteolytic enzymes were found: two endoproteinases, one carboxypeptidase, one aminopeptidase and one dipeptidyl-aminopeptidase. In addition, proteinase inhibitors were detected. In fresh crude extracts an activation procedure is needed to measure maximal activities of endoproteinases and carboxypeptidase, whose level is markedly dependent on growth medium composition and on growth phase, while aminopeptidase and dipeptidyl-aminopeptidase activities are very little, if at all, regulated by the carbon source.

Aminopeptidases↗
PubMed1991

Re-examination of the anatomic indications for hysteroscopic metroplasty.

Until now the indication for hysteroscopic metroplasty has been based on laparoscopic findings and thus depended on the operator's experience. Using ultrasound and magnetic resonance images of double uteri it should be possible to find more objective indications for this operation. When three points are identified on longitudinal scans of the uterine fundus, the two tubal ostia and the mid-point of the fundal perimetrium, hysteroscopic metroplasty is indicated only in uteri in which the third point is at least 5 mm above a straight line drawn between the tubal ostia. This classification criterion includes more cases than laparoscopic criteria in this study; we performed hysteroscopic metroplasty in 23 double uteri and had we followed the laparoscopic criteria the operation would have been performed only in 19.

Diagnosis, Differential↗
PubMed1991

Argon laser versus microscissors for hysteroscopic incision of uterine septa.

We performed hysteroscopic metroplasty in 21 women with repeated abortion and subseptate uterus. The patients were randomly allocated to septal incision with the argon laser (group I, 10 subjects) or microscissors (group II, 11 subjects) to compare these instruments in terms of surgical feasibility and anatomic results. The mean operating time was 57% longer in group I than in group II (p = 0.001), the intra- and postoperative morbidity of the whole series was negligible, and the anatomic results at abdominal ultrasonography and hysteroscopy performed 2 months postoperatively were similar in the two groups. This study confirms that microscissors are the simplest, fastest, most effective, and least expensive instrument to correct a septate uterus. The complete agreement of the findings at follow-up hysteroscopy and ultrasonography suggest the use of the latter as the method of choice to check the surgical results.

Adult↗
PubMed1991

Clinical applicability of the radiographic method for determining the thickness of calcified crown tissues.

A previously developed radiologic method for determining the thickness of the mineralized crown tissues was applied clinically to 10 teeth diagnosed for extraction. The thickness of the mineralized crown tissues as measured radiographically was compared with that measured directly on the extracted tooth. A statistical analysis indicated accuracy of 4.46%, equivalent to an error of 0.12 mm.

Dental Cementum↗
PubMed1991

Risk of recurrence after myomectomy.

The risk of recurrence of uterine myomas was analyzed in 622 patients who underwent myomectomy between 1970 and 1984 at the First Department of Obstetrics and Gynecology of the University of Milan. The cumulative 10-year recurrence rate was 27%, and this increased steadily up to the end of the observation period. Differences were not observed in frequency of recurrence by age at diagnoses or by the site of the myomas at surgery. Patients with a single myoma tended to experience a lower rate, but this finding was not statistically significant. Women who gave birth to a child after myomectomy had a 10-year recurrence rate of 15%, against 30% for those who did not; this difference was statistically significant.

Adult↗
PubMed1991

Differential inhibition of IL-1 beta activities and receptor binding by monoclonal antibodies mapping within a discrete region of the protein.

The importance of the region in position 148-192 for the biological activities and receptor-binding capacity of the human IL-1 beta protein has been assessed by the use of mAbs. Four mAbs have been used, which recognize different epitopes within the 148-192 region. None of the mAbs could inhibit binding of IL-1 beta to IL-1RI (expressed on T cells and fibroblasts), suggesting that the 148-192 region does not contain IL-1RI binding sites. Conversely, mAbs Vhp20 (recognizing the fragment 166-169) and BRhD2 (directed to an epitope in the sequence 177-186) recognize sites partially involved in binding to IL-1RII (expressed on B cells, macrophages, and PMN). Only mAbs BRhD2 and FIB 1 (which recognizes an epitope in the sequence 174-186) can inhibit IL-1 beta-induced thymocyte proliferation, whereas all four can inhibit the adjuvant capacity of IL-1 beta in vivo. It is concluded that the region 148-192 encompasses domains important for T cell activation but not for binding to the IL-1RI on T cells, others involved in immunostimulation in vivo, and others important for binding to IL-1RII, although not directly involved in it.

Amino Acid Sequence↗
PubMed1991

Early detection of ectopic pregnancy. Use of a sensitive urine pregnancy test and transvaginal ultrasonography.

We performed a prospective study to evaluate the reliability of a rapid monoclonal antibody urine pregnancy test with a sensitivity limit of 20 mIU/mL combined with transvaginal ultrasonography in the early diagnosis of ectopic pregnancy in 116 women with subacute pelvic pain and a stable general condition. The diagnosis of tubal pregnancy was confirmed with laparoscopy in 100 of the 103 women with positive sensitive urine pregnancy tests and no intrauterine gestational sac at transvaginal ultrasonography. Laparoscopy revealed a hemorrhagic corpus luteum in four of the eight subjects with negative monoclonal antibody pregnancy tests and no intrauterine gestational sac, an ovarian cyst in three and a normal pelvis in one. Of the five women with a positive pregnancy test and an intrauterine gestational sac, two had a hemorrhagic corpus luteum, two a normal pelvis and one a tubal pregnancy at laparoscopy. The sensitivity of a monoclonal antibody urine pregnancy test and transvaginal ultrasonography combined for the diagnosis of ectopic pregnancy was 99%, and the specificity was 80%, with positive and negative predictive values of 97% and 92%, respectively.

Adolescent↗
PubMed1990

Differential activity of interleukin 1 alpha and interleukin 1 beta in the stimulation of the immune response in vivo.

The biological activities of human recombinant interleukin (IL) 1 alpha and IL 1 beta were compared in different biological systems. The two IL 1 forms were equally active in vitro in inducing proliferation of murine thymocytes and of the murine T helper clone D10.G4.1, and in triggering release of prostaglandin E2 from human skin fibroblasts. In vivo, IL 1 alpha and IL 1 beta were similarly pyrogenic both in rabbits and mice, and could equally increase the circulating levels of the acute phase protein serum amyloid A in mice. However, only IL 1 beta showed immunostimulatory activity in vivo, as it could enhance the number of specific antibody-producing cells in the spleen of mice immunized with either a T-dependent or a T-independent antigen. Although devoid of immunostimulatory activity, IL 1 alpha could efficiently compete immunostimulation induced by IL 1 beta, suggesting an effective interaction with the IL 1 receptor. Thus, IL 1 beta appears to have an important role in the positive regulation of immune responses, while IL 1 alpha may act as down-regulator of the IL 1 beta effect.

Animals↗
PubMed1990

Radiolabeling of the biologically active peptide 163-171 of human interleukin-1 beta.

N-succinimidyl[2,3-3H]propionate was used for the radiolabeling of the biologically active peptide fragment 163-171 of human interleukin-1 beta (VQGEESNDK). Suitable reaction conditions were studied to obtain useful labeling of the molecule. A mixture of mono- (70%) and bi- (30%) propionyl derivatives was obtained with a total 3H specific activity of 87 Ci/mmol of peptide. The conditions for an efficient chromatographic separation of labeled peptide from unreacted reagents and by-products were established. The labeled peptide maintained the same biological activity as that of the corresponding unlabeled molecule, indicating that the labeling procedure did not alter the biological characteristics of the peptide. This thus allows the use of the radiolabeled peptide for receptor binding studies.

Amino Acid Sequence↗
PubMed1990

Magnetic resonance imaging of unicornuate uterus.

Five patients with a hysterosalpingographic diagnosis of unicornuate uterus underwent magnetic resonance imaging (MRI) and subsequently laparoscopy/laparotomy to evaluate the ability of MRI to identify the various subclasses of this malformation. The method was demonstrated to be valid, since in all 5 cases (one subclass A1b, two subclass A2, two subclass B) were correctly diagnosed. Compared with laparoscopy, MRI is less expensive, less invasive, and can be performed in women in whom laparoscopic examination is risky. However, unlike laparoscopy, MRI can not detect the presence of minimal and mild endometriosis and does not allow assessment of the tubal conditions.

Adult↗
PubMed1990

[Total bone mineral content in premenopausal women].

Because of the controversy about the loss of bone mass in premenopausal women, we decided to study the total mineral bone content (TMBC), measured by dual-photon absorptiometry (DPA), a technique with low variation coefficient and high level of discrimination, in a group of 96 premenopausal women with a age range between 20-49 years, who were selected by homogeneous criteria of habits and life stile and body mass lower than 25. In all women, the TMBC were quantify in supine with the densitometer type Norland XR-26 and its value correlated with age following the "Pearson's test"; there were not statistical significance. We concluded that women in a fertile period of life do not lose bone mass as a TMBC, which mean the importance of obtaining the bone mass peak during the childhood and adolescency.

Absorptiometry, Photon↗
PubMed1990

Metabolic behavior and distribution of the synthetic nonapeptide fragment 163-171 of human IL-1 beta.

The pharmacokinetic parameters and distribution of the adjuvant synthetic nonapeptide VQGEESNDK, corresponding to the fragment in position 163-171 in human IL-1, were analyzed after administration to rabbit through different routes. The radiolabeled peptide did not bind to plasma proteins and, when inoculated i.v., it disappeared very rapidly from the circulation, with a t1/2 alpha of 1 min and a t 1/2 beta of 166 min. Upon administration through i.m., s.c. and oral route, the Cmax was reached between 30 and 90 min after inoculum and ranged between 7 and 4% of the administered dose. Organ distribution showed that most of the radioactivity was concentrated in kidneys and excreted in urine. From Sephadex G-10 chromatography, about 60% of the peptide recovered in the urine 4h after i.v. inoculum was intact, whereas it was more than 85% degraded when administered by other routes. The amount of intact peptide recovered in the urine correlated with the biological effectiveness through different routes, suggesting that the adjuvant effect in vivo is exerted by the intact peptide, rather than by its metabolites.

Amino Acid Sequence↗