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Biomedical subjects

L Villa

Publications and source records attributed to L Villa.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1989

Mutants of pertussis toxin suitable for vaccine development.

Immunization with chemically detoxified pertussis toxin can prevent severe whooping cough with an efficacy similar to that of the cellular pertussis vaccine, which normally gives unwanted side effects. To avoid the reversion to toxicity and the loss of immunogenicity that may follow chemical treatment of pertussis toxin, inactive toxins were constructed by genetic manipulation. A number of genetically engineered alleles of the pertussis toxin genes, constructed by replacing either one or two key amino acids within the enzymatically active S1 subunit, were introduced into the chromosome of strains of Bordetella pertussis, B. parapertussis, and B. bronchiseptica. These strains produce mutant pertussis toxin molecules that are nontoxic and immunogenic and that protect mice from the intracerebral challenge with virulent Bordetella pertussis. Such molecules are ideal for the development of new and safer vaccines against whooping cough.

Animals↗
PubMed1989

A monoclonal antibody to the IL-1 beta peptide 163-171 blocks adjuvanticity but not pyrogenicity of IL-1 beta in vivo.

The synthetic fragment VQGEESNDK, corresponding to the amino acid sequence in position 163-171 of human IL-1 beta, possesses the immunostimulatory but not the pyrogenic activity of the mature IL-1 beta polypeptide in vivo. To assess the relevance of this domain of IL-1 beta for its biologic activities, a mAb was raised against the synthetic peptide 163-171. The mAb Vhp20 could effectively recognize human rIL-1 beta in RIA and immunoblotting. In vivo, the mAb Vhp20 was able to selectively inhibit the immunostimulatory activity of IL-1 beta, but it could not affect the fever-inducing capacity of IL-1 beta. It is proposed that functional domains could be identified in the human IL-1 beta protein and that the fragment in position 163-171 is of major importance for the adjuvant capacity of the entire molecule, but irrelevant to its pyrogenic activity.

Adjuvants, Immunologic↗
PubMed1989

Natural antibacterial activity against Salmonella typhi in human cord blood.

Cord blood mononuclear cells from normal human newborns possess natural antibacterial (NA) activity against Salmonella typhi, as assessed by an in vitro test. NA activity was significantly higher than that observed in PBMC from normal adult donors. Using fractionation on nylon wool and Percoll gradient or C-dependent killing with mAb, it was found that cells of the monocyte-macrophage series and CD4+ T lymphocytes were capable of exerting NA activity in newborns, in contrast with results obtained in adults, where the effector cell was a CD4+ T lymphocyte. The capability of expressing NA activity by CD4+ T lymphocytes from cord blood was also confirmed by flow cytometry sorting. Pretreatment of cord blood mononuclear cells with F(ab')2 fragments against human IgG, but not against human IgA, abrogate the NA activity. Furthermore, human IgA anti-S. typhi cannot arm CD4+ lymphocytes in cord blood. Thus it can be suggested that in newborns, the immune system still being immature, NA activity might be the expression of a mechanism of defence against infections, acting as antibody-dependent cellular cytotoxicity expressed by monocytes and CD4+ T lymphocytes armed with preexisting maternal IgG antibodies. This differs from NA activity of adults which is only mediated by CD4+ T lymphocytes armed by IgA.

Adult↗
PubMed1989

Interleukin 1 and its synthetic peptides as adjuvants for poorly immunogenic vaccines.

The adjuvant activity of the peptide corresponding to the fragment 163-171 of human interleukin 1 beta (VQGEESNDK) has been evaluated on the immune response to both T-dependent and T-independent antigens. The hydrochloride derivative of the peptide showed an effect quantitatively comparable in molar terms to that of the entire protein. At variance with the entire IL 1 protein the peptide appeared devoid of inflammatory effects and therefore it may find clinical applications as adjuvant for poorly immunogenic vaccines or as immunorestorative agent. The activity of other fragments in proximity of the sequence 163-171 was also evaluated. The shorter fragment 165-171 appeared as active as the 163-171 peptide.

Adjuvants, Immunologic↗
PubMed1989

A radiologic method for determining the thickness of the hard crown tissues.

This study describes a radiologic method that provides a reliable evaluation of the thickness of the hard crown tissues of the tooth scheduled for prosthetic and conservative preparation. The first stage consisted of calculating the discrepancy between the actual dimensions of the specimen under examination and the dimensions of the same specimen as measured and radiographed. Some coefficients of distortion were calculated for the distance(s) more usually involved clinically. Radiographs were made by using the "paralleling" technique. In the second stage, radiographs were made of 83 extracted teeth (22 incisors, 12 canines, and 51 premolars). On the resulting radiographs some prefixed distances were measured. Finally, to gain an anatomic comparison of the values obtained radiologically, 24 of the previously radiographed teeth were sectioned along the sagittal plane at the diameter, and measurements were made and compared with the radiologic data to which the correction coefficients had been applied.

Data Interpretation, Statistical↗
PubMed1989

[Karyotype study of blood lymphocytes in sarcoidosis].

Among 31 patients presenting with pulmonary sarcoidosis, two had abnormalities of their blood lymphocyte karyotypes. The karyotype of the first patient showed an initially high percentage of non-specifically broken chromosomes. The second patient, who had been treated with azathioprine (AZ) one year previously, had an apparently balanced translocation 46 XX, t (11; 11) (p 12, p 14) in blood T lymphocytes but not in skin fibroblast culture. Various hypotheses can be discussed to explain this translocation: a direct toxic effect of AZ or a genomic abnormality depending upon sarcoidosis and possibly revealed by AZ. It is important to note that this translocation concerned a region of the short arm of chromosome 11, where Harvey ras I and parathormone genes have been located.

Adolescent↗
PubMed1988

Impairment of in vitro natural antibacterial activity in HIV-infected patients.

Circulating PBMC of healthy subjects possess an in vitro natural antibacterial (NA) against enteropathogenic bacteria, including Salmonella species. The effector cell of NA activity is a CD: 4+, 8-, Leu-8/TQ-1+ T lymphocyte acting against bacteria via cytophylic IgA in a mechanism similar to antibody-dependent cellular activity. Because AIDS is a profound immunodeficiency caused by HIV involving primarily CD4 lymphocytes and in particular the Leu-8/TQ-1 subset, it was of interest to assess NA activity of HIV+ subjects at various stages of the disease. Results indicate that NA activity against Salmonella typhi and Salmonella paratyphi C is significantly decreased in AIDS as well as in lymphadenopathy syndrome patients. Furthermore, sera containing IgA against salmonellae were not able to arm PBMC from HIV+ patients. The humoral response against S. typhi-LPS was also greatly decreased after HIV infection, in contrast to the known hypergammaglobulinemia seen in these subjects. Defective NA activity might contribute to the increased incidence of salmonellosis observed in AIDS.

AIDS-Related Complex↗
PubMed1988

In vivo stimulation and restoration of the immune response by the noninflammatory fragment 163-171 of human interleukin 1 beta.

The synthetic nonapeptide VQGEESNDK, corresponding to the fragment 163-171 of human IL-1 beta, showed in vivo immunomodulatory capacities qualitatively and quantitatively comparable to those of the mature human IL-1 beta protein. In fact, both IL-1 beta and the 163-171 fragment stimulated the immune response of normal mice and restored immune reactivities of immunocompromised animals. In addition, the synthetic IL-1 peptide was as efficient as the entire protein in inducing tumor rejection and radioprotection. On the other hand, the 163-171 fragment did not cause any of several inflammation-associated metabolic changes inducible by the whole IL-1 beta molecule in vivo: hypoferremia, hypoglycemia, hyperinsulinemia, increase in circulating corticosterone, SAA and fibrinogen, decrease in hepatic drug-metabolizing enzymes. Furthermore, at variance with IL-1 beta, the 163-171 peptide did not show the toxic effects causing shock and death in adrenalectomized mice. Thus, these results confirm our previous in vitro observations that functional domains are identifiable within the multipotent cytokine IL-1 beta, and demonstrate the biological relevance of this finding in a variety of in vivo systems. The identification of a selectively active fragment of a cytokine may thus represent a significant step towards a better directed and more rational immunotherapeutic approach.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1988

The PAF-acether receptor antagonist BN-52021 inhibits mediator release during guinea-pig active lung anaphylaxis.

An anaphylactic reaction was induced with the specific antigen (1 mg Ovalbumin) in perfused lungs from actively sensitized guinea-pigs in order to evaluate the ability of the ginkgolide BN-52021 (0.4, 4, 40 micrograms/ml) to modulate the mediator release. The ginkgolide reduces in a dose dependent manner the release of histamine (22%, 45% and 75% of inhibition), TXB2 (77% of inhibition at the maximal dose used) and of SRS-A to a lower extent (only 33% at the higher dose). BN-52021 was still powerful in reducing histamine release induced by immunological reaction in indomethacin treated animals. In conclusion, the present "in-vitro" results confirm the beneficial activity of this ginkgolide, already demonstrated by the same Authors in "in-vivo" experiment, in anaphylactic reactions, and further substantiate the wider spectrum of action of the ginkgolide beside its specific PAF receptor antagonistic activity.

Anaphylaxis↗
PubMed1988

Comparative analysis of immunological responses to oral (Ty21a) and parenteral (TAB) typhoid vaccines.

The clinical and immunological responses to typhoid vaccination with parenteral (TAB) and oral (Ty21a) vaccines in two groups of 30 adult male subjects were studied. Parameters monitored included specific anti-Salmonella typhi cell-mediated immunity and total and specific antilipopolysaccharide fecal immunoglobulin A (IgA) titers in Ty21a-vaccinated subjects. Peripheral blood lymphocytes antibacterial activity was significantly increased only in Ty21a-vaccinated subjects. Serum arming activity and results of human F(ab')2 anti-IgG and -IgA inhibition tests suggest antibody-dependent cellular cytotoxicity mediated by IgA in those vaccinated with Ty21a. Interestingly enough, the cells of TAB-vaccinated subjects were able to mediate IgG-dependent cellular cytotoxicity, as was observable from the results of blocking experiments. Moreover, total and specific antilipopolysaccharide fecal IgA levels were observed to be significantly increased with Ty21a, up to 8 months post-vaccination schedule. An early-onset, transitory increase in serum IgM rheumatoid factor was also found, exclusively in subjects treated with TAB, and was no longer detectable on day 240. Ty21a was well tolerated and free of side effects, whereas 65% of subjects administered TAB reported fever, headache, malaise, and local tenderness at the injection site. Our data show that the two typhoid vaccines induce different cell-mediated specific immune responses. The role of these responses in protection against Salmonella infection, however, requires further investigation.

Administration, Oral↗