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Biomedical subjects

A Verna

Publications and source records attributed to A Verna.

At least 19 recordsLinked to original sources
PubMed2003

Application of different methods for the diagnosis of paratuberculosis in a dairy cattle herd in Argentina.

Paratuberculosis (Ptbc) has a high prevalence in Argentina, that affects dairy and beef cattle. The culture is the gold standard to the diagnosis of the disease. Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis), the aetiological agent, is difficult to isolate and grow in culture. In this study, 24 randomly selected cows of the Fresian breed from a dairy herd with a history of Ptbc were used to evaluate the performance of different diagnostic techniques. These animals did not show clinical signs of the disease. However, another animal from this herd presented evidence of clinical disease at the moment of the present study. This animal was necropsied and one strain of M. paratuberculosis was isolated from faeces, lymph nodes and intestine. Serum for indirect absorbed enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) tests and whole blood samples to perform gamma interferon (gammaIFN) release assays were obtained from each animal. Faeces and milk samples to carry out bacteriological cultures, PCR identification of M. paratuberculosis, and direct examinations of smears with Ziehl-Neelsen's (ZN) stain were also collected. Tuberculin test with bovine purified protein derivative (PPD) in the caudal fold was performed. The results showed that 10 out of 24 animals (41.6%) were positive to ELISA. Eight strains of M. paratuberculosis were isolated, six from faeces, two from milk. Five of the animals that excreted the bacteria through faeces were ELISA-positive, whereas the excreters through milk were negative to ELISA. No positive samples by AGID were obtained in clinical asymptomatic animals. Seven samples gave positive gammaIFN results with avian PPD, but only two of these animals were confirmed with culture. Direct PCR, to detect IS900 (M. paratuberculosis) in faeces and milk samples, was negative, but PCR using material taken from faecal and milk cultures gave positive results before visualizing the colonies. No sample was positive by PCR directed to IS6110 (M. tuberculosis complex). There was not always agreement between isolations and ZN in the studied samples. In conclusion, the absorbed ELISA was useful to detect positive animals and excreters through faeces but not through milk. PCR applied to cultures with incipient development before the visualization of colonies was effective to specifically determine the presence of M. paratuberculosis. The gammaIFN test was not able to detect the most positive animals confirmed by culture. The importance of using ELISA and cultures is emphasized by this study but it is necessary to continue with the gammaIFN test development for early detection of the disease.

Animals↗
PubMed2000

Differential budding efficiencies of human T-cell leukemia virus type I (HTLV-I) Gag and Gag-Pro polyproteins from insect and mammalian cells.

In this study, we examined the ability of human T-cell leukemia virus type I (HTLV-I) Gag and Gag-Pro to assemble immature virus-like particles (VLPs) and bud from insect and mammalian cells. Transmission electron microscopy of insect cells infected with a recombinant baculovirus carrying the entire gag gene revealed that Pr53(Gag) is targeted to the plasma membrane, where it extensively accumulates and forms electron-dense evaginations. However, no particles could be detected either inside the cells or in the culture supernatants. With the Gag-Pro-expressing construct, we observed HTLV-I-specific cytoplasmic proteolysis of the Gag precursor, but again no particle released in the culture supernatants. Transmission electron microscopic analysis of insect cells expressing Gag-Pro polyprotein revealed large vacuoles in the cytoplasm and no budding particles at the plasma membrane. In contrast, human immunodeficiency virus type 1 Gag polyprotein expressed in insect cells is able to release VLPs. These data showed that unlike other retroviruses, Pr53(Gag) is unable to be released as immature VLPs from insect cells. To determine whether the block in particle budding and release is due to an intrinsic property of Pr53(Gag) or the absence of essential cellular factors in insect cells, we expressed Gag and Gag-Pro polyproteins in human 293 cells. The results indicate that Pr53(Gag) and p24 capsid are released within particles into the culture supernatants of human 293 cells. We found that the myristylation of the N-terminal glycine residue is essential for Gag release. Altogether, these results strongly suggest that the proper assembly of HTLV-I particles is dependent on mammalian host cell factors.

Animals↗
PubMed2000

Elastin-derived protein coating onto poly(ethylene terephthalate). Technical, microstructural and biological studies.

Recently, it has been shown in our laboratory that certain proteins solubilized from elastin (ESP) formed a tight association with certain polymers such as elastin or polyethylene glycol terephthalate (PET) ... . The present paper deals with the description of the optimal chemical conditions of this unexpected association, its microstructure and its biological properties. A microstructural study of the composite ESP-PET material was performed using scanning and transmission electron microscopy. The thickness of the yield composite was evaluated (0.4-2 microm) but its imperviousness was unsatisfactory using ESP alone. So, we tentatively coated PET with the elastin-ESP complex. The microscopic views confirmed that the polymer was better filled by the organic matrix, the thickness of the layer being markedly improved (3 microm). Simultaneously, we attempted to verify whether the yielded composite retains the biological properties previously demonstrated with the 'Biopatches' and probably due to ESP. Thus, the culture of endothelial cells on an ESP-coating (with elastin or not) showed that a 100 microg/cm2 ESP concentration was able to promote endothelial cell growth in perfect conditions, maintaining their phenotypic character. While several physico-chemical determinations are in progress in our laboratory to identify and characterize the protein involved, a prototype of small-calibre vascular prosthesis was elaborated with elastin-ESP-PET composite and will be placed in a dog at the abdominal femoral junction to evaluate the in vivo performance of such an attractive material in artery restoration.

Adsorption↗
PubMed1997

Combined cisplatin, doxorubicin, and mitomycin for the treatment of advanced pleural mesothelioma: a phase II FONICAP trial. Italian Lung Cancer Task Force.

BACKGROUND: In a previous FONICAP trial, the combination of doxorubicin (D) and cisplatin (P) yielded an objective response rate of 25% and a subjective response rate of 50% in patients with mesothelioma. In human mesothelioma cell lines, mitomycin (M) showed a synergic activity with P and in a recent randomized study, the combination of M and P showed slightly superior activity when compared with the PD regimen. METHODS: The authors tested the activity and toxicity of a combination chemotherapy regimen including P, 60 mg/m2, D, 60 mg/m2, and M, 10 mg/m2, all by intravenous infusion on Day 1 every 28 days in a Phase II study. RESULTS: Twenty-four chemotherapy-naive mesothelioma patients were enrolled in the study. Patient characteristics were the following: the median age was 58 years; the median performance status was 1; there were 6 Stage I patients, 15 Stage II patients, 2 Stage III patients, and 1 Stage IV patient; and 10 patients had previous asbestos exposure. All patients had pretreatment symptoms: 13 had chest pain, 9 had pleural effusion, and 7 had dyspnea. A total of 78 cycles of chemotherapy were administered. The only significant side effect was myelosuppression, with only 9.5% of patients having Grade 4 toxicity. Among 23 patients evaluable for response, 5 achieved a partial response (20.8%; 95% confidence interval, 7.1-42.1%), 9 had stable disease, and 9 had progressive disease (including 1 early death). One patient was not evaluable because of treatment refusal. A clinical improvement was observed in 7 of 24 patients (29%). CONCLUSIONS: The combination of PDM in patients with pleural mesothelioma is feasible and moderately active. However, the observed level of activity is similar to that obtained with other two-drug regimens.

Adult↗
PubMed1997

Severe endobronchial obstruction in a girl with relapsing polychondritis: treatment with Nd YAG laser and endobronchial silicon stent.

Relapsing polychondritis (RP) is an uncommon disorder of unknown aetiology characterized by inflammation and destruction of the cartilaginous structures of many organs, including the tracheobronchial tree. When untreated, there is a high mortality rate, usually from respiratory obstructive complications. An 8 year old white girl, with a previous diagnosis of RP, was referred to our department for evaluation of worsening dyspnoea. Bronchoscopy showed localized inflammatory and fibrotic alterations of the mucosa, leading to severe obstruction of the left mainstem bronchus at its origin. The condition was successfully treated by endoscopic neodymium yttrium aluminium garnet (Nd YAG) laser. Re-evaluation of the patient, 7 months later, demonstrated bronchial stenosis and malacia requiring mechanical dilatation and positioning of an endobronchial silicon stent, which was well-tolerated by the patient.

Airway Obstruction↗
PubMed1995

Localization of dopamine D2 receptor mRNA in glomus cells of the rabbit carotid body by in situ hybridization.

The localization of mRNA coding for the dopamine D2 receptor was studied in the rabbit carotid body using in situ hybridization with synthetic 35S-labelled oligodeoxynucleotides. Using autoradiography on cryostat or semi-thin sections, labelling was observed over the cytoplasm of glomus cells, but not over sustentacular cells. A quantitative study showed that labelling intensity (silver grain density) was increased by haloperidol treatment. These results suggest that glomus cells express the dopamine D2 receptor gene and that this expression is regulated.

Animals↗
PubMed1995

Immunotherapy with the use of tumor-infiltrating lymphocytes and interleukin-2 as adjuvant treatment in stage III non-small-cell lung cancer. A pilot study.

This study assesses the feasibility and toxicity of adoptive immunotherapy with tumor infiltrating lymphocytes and recombinant interleukin-2 in 29 patients who underwent resection for stage III non-small-cell lung cancer. In five patients cultures yielded no growth of tumor infiltrating lymphocytes. In the remaining 24 patients (stage IIIa, 14 cases; stage IIIb, 10 cases) tumor infiltrating lymphocytes were in vitro expanded from surgically obtained tissue samples, including samples from both the tumor and surrounding lung. A number of tumor infiltrating lymphocytes, ranging from 4 to 70 billion cells, were reinfused intravenously 4 to 6 weeks after operation. Interleukin-2 was administered subcutaneously at escalating does for 2 weeks and then at reduced doses for 2 to 3 months. Median survival was 14 months, and the 2-year survival was 40%. Three patients remain alive and disease-free at more than 2 years after operation. Two of these patients did not have complete resection at thoracotomy. Multivariate analysis showed no correlation between the factor of incomplete resection and survival. Intrathoracic recurrence without concomitant distant failure was documented in two patients only and none of the patients with incomplete resection (12 cases) had relapse within the thorax. The present experience demonstrates that adoptive immunotherapy may be applied with safety in patients operated on for stage III non-small-cell lung cancer and suggests that it can be useful, notably in patients with locally advanced disease.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Biologic and clinical effects of continuous infusion interleukin-2 in patients with non-small cell lung cancer.

BACKGROUND: Interleukin-2 (IL-2) has shown antitumor activity in some neoplasms, such as melanoma and renal carcinoma, but toxicity derived from bolus administration is significant, particularly at the cardiorespiratory level. METHODS: To test feasibility, antitumor activity, pulmonary and systemic immunologic effects, and pulmonary function changes of continuous-infusion recombinant IL-2 given to patients with non-small cell lung cancer, eleven subjects with Stage III-IV disease were treated in a standard pulmonary medicine unit with a dose of 18 million IU/m2/day from day 1 to day 13 with 1-day rest on day 7. A second induction course was given after a 3-week rest. In patients with nonprogressive disease, four maintenance courses of 6 days' duration at the same dose were planned. Immunologic tests, including lymphocyte phenotype analysis and assays for the detection of tumor necrosis factor (TNF) and of anti-IL-2 antibodies, were performed before and after treatment in serum and bronchoalveolar lavage fluid (BAL). Cardiopulmonary function tests, including spirometry, arterial blood gas analysis, diffusion capacity, and echocardiography, were obtained before, during, and after treatment. RESULTS: Twenty-one cycles (15 induction courses plus 6 maintenance courses) were administered. No patient was able to complete the six planned courses, and only 3 patients entered the maintenance phase. Reasons for discontinuation included progressive disease in five cases, toxicity in three cases, and patient request in three cases. The most common side effects were fever, hypotension, oliguria, and elevated serum creatinine and liver enzyme levels. No patient required intubation or intensive care. No objective response was seen, and the median survival time was 10 months. Lymphocytosis and eosinophilia were observed in all patients. Surface marker analysis revealed a statistically significant increase in the percentage of CD3+, CD4+, CD25+ and DR+ cells in peripheral blood. Lymphoid cells derived from BAL disclosed an increased natural killer activity after IL-2 treatment, and TNF was increased in BAL fluid. Pulmonary function tests evidenced an increased alveolar-arterial difference for oxygen allied with a decrease of forced expiratory volume in 1 second, forced vital capacity, and carbon monoxide transfer coefficient consistent with a significant, albeit not clinically relevant, interstitial lung defect. CONCLUSION: Continuous-infusion IL-2 is feasible in patients with advanced lung cancer even outside an intensive care unit, but overall compliance is poor. Although clinical pulmonary toxicity is negligible, small but statistically significant alterations of the pulmonary function are evident. In addition, this regimen produces a significant activation of the immune system at the pulmonary level.

Antibodies↗
PubMed1994

Recombinant interferon alpha-2b in the treatment of diffuse malignant pleural mesothelioma.

Fourteen patients with diffuse malignant pleural mesothelioma (DMPM) were enrolled in a Phase II study to assess activity and toxicity of the systemic administration of recombinant (r)-alpha-interferon (IFN)-2b. The IFN schedule was: 3 x 10(6) IU i.m. days 1-4, 6 x 10(6) IU days 5-8, 10 x 10(6) IU days 9-12; then IFN was administered at 10 x 10(6) IU 3 days/week. If grades II-III toxicity occurred, IFN dose was reduced and drug continued at the previous dose level. All patients were evaluated by CT scan. Only one patient was not evaluable for response and toxicity because of inadequate follow-up. Of 13 evaluable patients, we observed 1 objective response, 6 stable disease, and 6 failures (3 progressive disease and 3 early interruptions due to subjective toxicity). The median time to progression was 19 weeks, and the median overall survival was 62 weeks. Toxicity was mild: of 13 patients evaluable for toxicity we observed fever (9 patients), flu-like syndrome (3 patients), fatigue (4 patients), anorexia (2 patients), myelosuppression (3 patients), and muscle pain (1 patient). The results of this study indicate only marginal activity of r-alpha-IFN in the treatment of DMPM.

Aged↗
PubMed1993

[The surgical treatment of a rare pulmonary infection: mucormycosis].

Pulmonary mucormycosis (phycomycosis) is an uncommon infection occurring in immunodepressed or debilitated patients. Mortality is very high. Recovery depends upon underlying disease and upon early diagnosis, although difficult to obtain. Aggressive medical therapy is requested and surgical treatment in some instances is indicated. The following is a report of pulmonary mucormycosis occurring in a man with lymphocytic leukemia under chemotherapy treatment. Surgical treatment was considered as medical treatment had been unsuccessful. No success has been achieved, as also diffuse bone metastases showed up.

Candida albicans↗
PubMed1992

Norepinephrine-containing glomus cells in the rabbit carotid body. I. Autoradiographic and morphometric study after tritiated norepinephrine uptake.

Rabbit carotid bodies were investigated by autoradiography at both the light and electron microscope levels following tritiated norepinephrine administration either in vivo or in vitro. Two kinds of labelled structures were found: nerve fibres (absent in sympathectomized carotid bodies) and some type I glomus cells. Desipramine (a specific norepinephrine uptake inhibitor) prevented labelling. Most of the labelled cells differed from unlabelled ones by the presence of (i) large dense-cored vesicles characterized by a large halo between the membrane and an eccentric dense core; (ii) a nucleus showing a more electron dense chromatin and a more irregular shape; and (iii) relatively abundant glycogen particles. A new weakly-labelled cells were characterized by a pyknotic nucleus and very swollen dense-cored vesicles, and were presumed to be degenerating. Dense core diameters of dense-cored vesicles were distributed according to a unimodal distribution in labelled cells as in unlabelled ones but with an extension towards both large and very small diameters in labelled cells. The mean diameter was higher in labelled cells than in unlabelled ones (127 nm versus 113 nm, P less than 0.01). The labelling intensity (as estimated by the number of silver grains per unit of cytoplasmic area) was maximum in cells having dense-cored vesicles whose mean diameter was between 130 and 170 nm, but decreased for cells with mean diameter of dense cores smaller than 130 nm, or larger than 170 nm. Thus, in the rabbit carotid body, some glomus cells differ from others by their ability to take up tritiated norepinephrine and by the presence of larger dense-cored vesicles. However, this distinction is not clearcut and there are many intermediates. The observations suggest a phenomenon of evolution deriving from a unique cell type and typified by both metabolic norepinephrine uptake ability, glycogen accumulation) and morphologic changes (increase in diameter of dense-cored vesicles). It seems, therefore, more appropriate to consider these results in terms of different functional states rather than different types of glomus cells.

Animals↗
PubMed1992

Norepinephrine-containing glomus cells in the rabbit carotid body. II. Immunocytochemical evidence of dopamine-beta-hydroxylase and norepinephrine.

The presence of noradrenergic glomus cells in the rabbit carotid body was investigated at the light and electron microscope levels, using dopamine-beta-hydroxylase and norepinephrine immunocytochemistry as well as the chromaffin reaction. Frozen and semi-thin plastic sections showed some dopamine-beta-hydroxylase immunoreactive glomus cells either isolated in the connective tissue or, more frequently, mixed with unreactive cells. At the ultrastructural level immunopositive cells differed from immunonegative ones by the larger size of most of their dense-cored vesicles. Similar observations were made after using anti-norepinephrine antibodies. Immunoreactive cells to anti-dopamine-beta-hydroxylase and anti-norepinephrine antibodies were relatively few although their number varied from carotid body to carotid body. The immunolabelling intensity was very variable from cell to cell. Consecutive frozen sections processed for norepinephrine- and dopamine-immunocytochemistry showed many cell clusters containing both norepinephrine and dopamine-immunoreactive glomus cells. Some chromaffin glomus cells were clearly identifiable by the very strong electron opacity of their dense-cored vesicles; most of these vesicles were characterized by their large size, as the dense-cored vesicles observed in dopamine-beta-hydroxylase- and norepinephrine-immunopositive cells. These results demonstrated that dopamine-beta-hydroxylase and norepinephrine-immunopositive, as well as chromaffin cells, were identical to the cells which take up exogenous norepinephrine, described in part I of this study. However, many intermediate levels were found between norepinephrine-immunonegative and strongly norepinephrine-immunopositive glomus cells, suggesting that the distinction between these two kinds of cells is not clearcut.

Animals↗
PubMed1991

[An analysis of 100 consecutive mediastinoscopies for the diagnosis and/or staging of pulmonary carcinoma].

The authors analyze data of 100 consecutive mediastinoscopies, performed for diagnostic and/or staging purposes in suspected or known bronchogenic carcinomas. They confirm once again how mediastinoscopy is, in many cases, the only diagnostic procedure that can give, at the same time, a preoperative histological diagnosis and a quite accurate staging, thus avoiding useless exploratory thoracotomies.

Adult↗
PubMed1991

[Intrahepatic jejunostomy by trans-scission approach in neoplasms of the superior biliary confluent (SBC)].

The Authors consider the trans-scission approach as a quick and safe alternative approach for doing intrahepatic bilio-intestinal anastomoses for the surgical treatment of well confined cancers of hepatic hilus (type I and II of Bismuth e Corlette). This approach should be recommended particularly when the presence of anatomical variations makes the hilar approach hazardous.

Adenocarcinoma↗
PubMed1991

[Soft-tissue sarcomas of the limbs at high risk of malignity. Current role of surgery and conservative treatment].

The authors discuss the role of surgical treatment in patients with highly malignant soft tissue sarcomas in the limbs. A careful analysis is made of different therapies on the basis of the results obtained by the authors and those reported in the literature. The anatomic classification of lesions is based on functional anatomic compartments, defined as intra- or extracompartmental. If a lesion was within an intrafascial compartment, all the muscles with intact fascial sheaths have up till now been removed "en bloc" to obtain radical margins. Many authors now think that all manifest disease be removed with a generous soft tissue margin on all sides to ensure adequate local treatment. Amputation has commonly been performed for extracompartmental lesions, but a multinodal treatment programme, including limb-sparing resection and tumour-bed radiation, should now be considered if possible in the management of these tumours.

Adult↗