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Biomedical subjects

L Ortona

Publications and source records attributed to L Ortona.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

[Detection of HBsAg and the related antibody (HBsAb) with the radioimmunological method. Behavior of the HBeAg-HBcAb system in HBsAg-positive patients].

A radioimmunological assay was made of HBsAg and HBsAb in 183 patients during the course of acute viral hepatitis, 23 with prior HBsAg-positive hepatitis, 72 with chronic liver disease, 822 blood donors, 44 patients and 28 staff members from two dialysis centres, and the medical and paramedical staff of several high-risk departments. Microimmunodiffusion on agar was also used to determine HBeAg and HBeAb in the same 183 acute hepatitis patients, 37 HBsAg+ blood donors, 20 asymptomatic HBsAg carriers, the patients of two haemodialysis centres and the staff of departments at high risk for hepatitis B. Attention is drawn to the marked incidence (5.5%) of chronic HBsAg carriers in the blood donors, and the considerable circulation of virus B in the population examined, HBsAb-positivity (27.6%) being also an expression of this. Stress is also laid on the diagnostic and prognostic significance of the study of the HBsAg-HBsAb system during acute and chronic hepatitis. The importance of serum hepatitis B markers in the transmission of this disease in dialysis centres and other high-risk departments and in its prevention is underscored. Lastly, emphasis is laid on the appreciable progress that analysis of the e-anti-e system offers in the prognostic assessment of type B hepatitis, attention being also drawn to the fact that the dynamics of this system is even more complex and interesting than had first been thought. An assessment of this kind is useful in the differentiation of "contagious" and "non-contagious" HBsAg carriers.

Antibodies, Viral↗
PubMedDate not supplied

Elevated serum levels of a 90,000 daltons tumor-associated antigen in cancer and in infection by human immunodeficiency virus (HIV).

Levels of a 90,000 daltons monoclonal antibody-defined tumor-associated antigen, termed 90K, were measured in the serum from 649 patients with various types of cancer and 1215 patients infected by the human immunodeficiency virus (HIV). Significantly increased 90K serum levels (12.1 +/- 0.5 U/ml) were found in cancer patients with respect to healthy controls (5.7 +/- 0.3 U/ml), with the highest levels in neoplasms of the breast, lung and gastrointestinal tract. In 355 patients with breast cancer, the elevation of serum 90K levels was more pronounced at advanced stages of disease. Mean levels of 90K for 1215 HIV-infected subjects (21.2 +/- 0.8 U/ml) were significantly higher than controls and cancer patients, and the levels progressively increased with disease worsening from asymptomatic infection to full blown AIDS. These data suggest that 90K is not merely a tumor-associated antigen and lead us to postulate it to be a signalling molecule whose production might be related to the immune deficit caused by pathogenetic events such as neoplastic progression and virus infection.

Antigens, Neoplasm↗
PubMedDate not supplied

[The diagnosis of lung inflammation in AIDS patients. The use of 99mTc-labelled human polyclonal immunoglobulins and a comparison with 67Ga citrate and high-resolution computed tomography].

Technetium-99m (99mTc) labelled polyclonal human immunoglobulin (HIG) is a new agent for the localization of active inflammatory diseases. The results obtained with HIG in 29 AIDS patients referred for suspected lung infections are reported (Table I). The patients also underwent Gallium-67 citrate scanning (GS), chest radiography (Rx), high-resolution thin-layer computed tomography (HRCT) and broncho-alveolar lavage (BAL). The study population was classified as follows: 12 patients (Table II) were studied before treatment for suspected Pneumocystis carinii pneumonia (PCP), 7 patients (Table III) had known PCP and were studied during medical therapy, and 10 patients (Table IV) had lung infections other than PCP. In all PCP patients studied before treatment, positive agreement was observed between HIG, Rx and HRCT findings. In 4 patients with final clinical diagnosis of no lung conditions, both nuclear and radiologic imaging were negative. 99mTc-HIG results in the PCP patients studied during therapy were consistent with clinical and radiologic improvement; there was disagreement with 67Ga findings in one case (no. 9). In lung infections other than PCP, HIG studies were often negative (always negative in mycobacteriosis), while they were positive in 3 pyogenic abscesses. In conclusion, as for PCP and abscesses, the results obtained with 99mTc-HIG are usually in agreement with GS findings, while HIG scans seem to be negative in mycobacterial infections. Moreover, HIG scintigraphy seems to be suitable for the evaluation of treatment results in PCP (this subject deserves further research). To assess respiratory impairment a semiquantitative index (ISQ) of 99mTc-HIG lung uptake is suggested, which showed a significant linear correlation with arterial pO2.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

General epidemiology of tuberculosis.

An outline of the history of tuberculosis is offered for consideration including the present estimated incidence world-wide. The epidemiology of the disease with respect to its etiology is described focusing on the risk of infection, the development of clinical manifestations subsequent to the exposure to the bacillus, and the risk of reactivation. The situation of the epidemiology of tuberculosis in Italy is analyzed based on available information after the closure of TB dispensaries following the introduction of National Health Service in 1978. In last years over 5000 cases of tuberculosis per year have been notified; however what percentage of the real incidence of TB this data represents, is unknown.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Epidemiology of multidrug-resistant tuberculosis.

Since the nineties, the increasing incidence of tuberculosis was accompanied by numerous epidemic foci of multidrug-resistant strains of Mycobacterium tuberculosis, especially of nosocomial transmission. In the United States and other countries there was an increase in both primary and acquired drug-resistant tuberculosis. HIV infection and the poor social and health care facilities of different population groups, the lack of compliance with therapy and the reduction of programs of nosocomial and extranosocomial surveillance and control of tuberculosis are all concomitant causes of the increase in multi-drug resistant cases. The improvement in surveillance and treatment closely monitored therapies and nosocomial control by specific regulations, when applied, have contributed to the decrease in the rate of drug-resistant forms.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Genetics of Mycobacterium tuberculosis and genotyping of drug resistance.

During the last decade, molecular genetics has been applied to the study of mycobacteria, of Mycobacterium tuberculosis in particular. The identification of plasmids and phages able to transfer DNA cloned from Escherichia coli to M. tuberculosis has allowed to draw important information on immunogenic proteins, drug resistance, virulence and mechanisms of mycolic acid biosynthesis. Insertion sequences have been isolated and used in diagnosis, strain typing and mutagenesis studies. The definition of functional promoters has enabled their use in the production of recombinant mycobacteria which can express foreign antigens. Furthermore, the identification of the molecular basis of drug resistance for major antituberculosis drugs has potentially allowed the applicability of methods of rapid determination of drug resistance in clinical laboratories.

Antitubercular Agents↗
PubMedDate not supplied

Immunity and pathogenesis of tuberculosis.

The activity of cell-mediated immune response involved in immunopathogenetic and protection mechanisms of tuberculosis is analyzed. The role of tuberculosis during HIV infection is outlined.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Pulmonary and extrapulmonary tuberculosis.

Pulmonary tuberculosis: primary tuberculosis, usually asymptomatic, represents the first infection and is shown by a parenchymal mostly mid-pulmonary focus and satellite lymphadenopathy. Postprimary pulmonary tuberculosis, mostly located in the upper fields may be caused by endogenous reinfection for reactivation of a hematogenous focus formed during primary infection or from exogenous reinfection. Extrapulmonary tuberculosis: it includes numerous forms mostly from hematogenous spread. Miliary tuberculosis may involve a number of organs and apparatus besides the lung. Tuberculous meningitis predominantly involves the base of the skull, the fluid is clear with hypoglycorrhachia and lymphocyte pleocytosis. Lymph node tuberculosis is generally unilateral and cervical. Tuberculous pleuritis is exudative or dry. Other forms of tuberculous serositis are pericarditis and peritonitis. Renal tuberculosis involves the medullaris and intestinal tuberculosis the ileocecum; tuberculous spondilitis (Pott's disease) involves the last dorsal vertebrae. Other forms are osteoarthritis, genital tract tuberculosis, pancreatitis, laryngitis, otitis.

Adult↗
PubMedDate not supplied

Tuberculosis in patients with HIV infection.

The close connection between tuberculosis and HIV infection was evident since the onset of the epidemic. The spread of HIV has contributed to the increased incidence of tuberculosis world-wide. With the progressively impaired cell-mediated immunity, HIV alters the pathogenesis of tuberculosis and markedly increases the risk of tuberculosis in simultaneously infected subjects. An altered pathogenesis of tuberculosis leads to a more frequent extrapulmonary involvement and atypical radiologic findings. Furthermore, HIV infection is one of the major factors of increased risk of M. tuberculosis multidrug resistance. Even if tuberculosis in HIV-positive patients to some extent can be treated and prevented, it spread in this population is increasing and at present tuberculosis represents the most common opportunistic HIV-related infection several areas world-wide and globally, the first cause of death of HIV-infected patients.

AIDS-Related Opportunistic Infections↗
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Principles of therapy for tuberculosis.

The therapeutic strategy for tuberculosis is based on some fundamental principles. First, the multi-drug approach to decrease resistant mutants. Second, the concept of two-phase therapy, with initial three-four drugs to rapidly decrease the microbial concentration and with two drugs in the remaining period. Short six-month regimens based on two-phase protocols at present represent the standard therapy for most patients. An application of reference, especially in cases of adequate compliance is the directly observed therapy (DOT) which allows intermittent two-three-week administrations. The initial therapeutic approach includes rifampicin, isoniazid and pyrazinamide in the first two months, with the addition of ethambutol or streptomycin in case of primary over 4% isoniazid resistance in the population. Subsequently, rifampicin and isoniazid are administered daily or intermittently as DOT. In HIV-positive patients, initially 4 drugs are administered for at least nine months as DOT wherever possible. Multidrug resistance (MDR) is clinically associated to some peculiar features as the higher frequency of cavitations, the persistent elimination of mycobacteria in the sputum, a more aggressive course with a higher mortality. In MDR-TB some factors should be considered: previous antituberculosis therapy, results of previous in vitro susceptibility tests, patients' compliance, modes of administration, patterns of susceptibility of the population of origin of the patient with suspected MDR-TB. While waiting for the results of susceptibility tests, the therapeutic regimen should include 5 to 6 or 7 drugs selected based on the patient's characteristics. Close monitoring should be performed combining close surveillance of clinical course with bacteriology.

AIDS-Related Opportunistic Infections↗