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Biomedical subjects

A Casanova

Publications and source records attributed to A Casanova.

At least 19 recordsLinked to original sources
PubMed2006

Secondary serological response of patients with chronic hepatosplenic suppurative brucellosis.

Chronic hepatosplenic suppurative brucellosis (CHSB) is a local reactivation of a previous brucellosis, coursing with an immunoglobulin G (IgG) and IgA secondary immunological response. The observation of two cases of CHSB with an apparent IgM response gave rise to a detailed serological study of three of our patients. We studied the first sample from all three patients and successive samples from two of them. In cases 1 and 2, we found samples with positive IgM lateral flow and IgM enzyme-linked immunosorbent assay results concomitantly with rheumatoid factor (RF); after absorption with anti-RF serum, these results were rendered negative. In patients 2 and 3 the diagnosis of brucellosis was delayed, because none of the test results were initially very significant. However, a clear seroconversion of IgG antibodies was observed in subsequent months; titers of the Brucellacapt and Coombs tests increased in similar ways, although Brucellacapt decreased more rapidly than Coombs, which persisted at high titers for years. In patient 3 a relapse was observed in the fourth year of follow-up, detected by Coombs and also by IgG lateral flow and counterimmunoelectrophoresis (CIEP), although not by the rose bengal, agglutination, or Brucellacapt tests. Serological changes in CHSB may sometimes be mild and are detected mainly by the Coombs test. Brucellacapt does not offer additional information, although IgG lateral flow and CIEP may be of some use. Careful surveillance of titer changes in the Coombs test is the best marker of infection activity. As the disease progresses, an intense IgG response may develop and RF sometimes appears, simulating an IgM response.

Adult↗
PubMed2004

[Polyradiculitis and Wegener's granulomatosis].

Wegener's granulomatosis is a systemic vasculitis of unknown etiology, primarily affecting the upper and lower respiratory tract and the kidneys, although there is a form restricted to the lungs. Wegener's granulomatosis occurs infrequently, with an estimated annual incidence of 8.5 cases per million. The principal symptoms at onset usually involve the upper and lower airway. The central nervous system is involved in approximately 22% of cases, but neurological signs occur infrequently among the initial clinical manifestations. Proteinase 3-specific antineutrophil cytoplasmic antibodies are useful serological markers for establishing a diagnosis, which should, however, be confirmed by a tissue biopsy of the affected organ.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2001

Etiology, reasons for hospitalization, risk classes, and outcomes of community-acquired pneumonia in patients hospitalized on the basis of conventional admission criteria.

We performed an observational analysis of prospectively collected data on 533 nonseverely immunosuppressed adult patients who were hospitalized for community-acquired pneumonia on the basis of conventional admission criteria. For this population, we correlated etiology, reasons for admission, and outcomes using the Pneumonia Severity Index (PSI), to identify major discrepancies between the PSI risk class and the conventional criteria for deciding the site of care. PSI classes and corresponding mortality rates were as follows: class I, 51 patients (0%); class II, 62 (2%); class III, 117 (3%); class IV, 198 (10%); and class V, 105 (29%). We identified significant discrepancies between both methods. Overall, 230 patients (40%) who were hospitalized according to conventional criteria were assigned to low-risk classes. Of these 230 patients, 137 (60%) needed supplementary oxygen or had pleural complications; for the remaining patients, there were no irrefutable reasons for admission. This latter group deserves prospective evaluation in randomized studies that compare ambulatory and in-hospital management.

Adolescent↗
PubMed2001

tRNA genes were found in Piscirickettsia salmonis 16S-23S rDNA spacer region (ITS).

Piscirickettsia salmonis is the etiological agent of Salmonid Rickettsial Septicemia, a disease affecting salmon aquaculture industry. We analyzed the 16S-23S rDNA spacer region (internal transcribed spacer, ITS) of Chilean P. salmonis isolates LF-89 and EM-90. Two main ITS amplification products were obtained by PCR using L1 and G1 primers, differing from that described where only one ITS region was found. By Southern blot, it was established that these two amplification products contained sequences related to P. salmonis ITS. Sequence analysis confirmed that P. salmonis had two ITS regions: ITS A and ITS B. In both isolates, the smaller (ITS B) corresponded to ITS sequences previously described for each one, and the larger (ITS A) were almost the same as their respective ITS B sequences interrupted by an insert which contained two tRNAs genes: tRNA-Ile and tRNA-Ala.

Alphaproteobacteria↗
PubMed2001

Current understanding and management of chronic hepatosplenic suppurative brucellosis.

To outline the characteristics and define appropriate management of chronic hepatosplenic suppurative brucellosis (CHSB), 905 patients with brucellosis were analyzed. Sixteen episodes of CHSB (14 in the liver and 2 in the spleen) were found in 15 patients. Six patients had had previous remote brucellosis. Twelve patients presented with systemic symptoms, and 12 with local symptoms. Cultures of blood samples yielded negative results in all cases except 1, and the results of cultures of pus specimens were positive for Brucella melitensis in only 2 cases. All patients showed calcium deposits surrounded by a hypodense area on computed tomography. Patients often had low titers of agglutinating antibody. In patients who were receiving conservative management, early response was successful in 50% and late response was successful in 33.3%. In the patients who underwent surgery and concomitant antibiotic therapy, early and late response was successful in 100%. Thus, CHSB mainly represents a local reactivation of previous brucellosis. Its diagnosis may be difficult to establish and surgery may be required to cure many patients.

Adult↗
PubMed2001

A combination of interleukin-2 and 60 nm cationic supramolecular biovectors for the treatment of established tumours by subcutaneous or intranasal administration.

The Supramolecular Biovector (SMBV) KY is a drug delivery nanocarrier which consists of a discretely sized, ionically charged, cross-linked polysaccharide core surrounded by a lipid membrane. We used the non-immunogenic spontaneous mammary adenocarcinoma TS/A tumour to test the efficacy on tumour growth of low (10(4) IU) or ultra-low (10(3) IU) doses of interleukin-2 (IL-2) adsorbed to these 60 nm cationic synthetic particles. In comparison with the progressive growth of TS/A cells in syngeneic mice, KY/IL-2 particles coinjected with TS/A cells or administered at a distance from the tumour, inhibited tumour growth while free IL-2, even at 10-100 times the dose used in the KY/IL-2 formulations, had no effect. Studies performed on implanted tumours (treatment at day 6 (D6)) showed that KY/IL-2 administered subcutaneously (s.c.) at five sites distant from the tumour (10(3) IL-2 IU per site) induced rejection of the implanted tumours. Six out of 10 mice were cured while the other four had residual tumours only. In the same experiment, free IL-2 induced only tumoral growth reduction. Protection induced by KY/IL-2 administered s.c. at five sites involved recruitment of a CD8(+) T cell response since nu/nu mice and CD8-depleted mice did not reject the tumours. Mice cured were protected significantly to completely against a rechallenge with TS/A tumour cells, and a systemic tumour-specific CTL activity was induced. Finally, we showed that repeated intranasal (i.n.) administration of KY/IL-2 (low-dose) also led to complete regression of pre-established tumours and partial protection from tumour rechallenge. We therefore suggest that, in contrast to free IL-2, a KY/IL-2 formulation could be used as a systemic immunostimulant leading to the eradication of non-immunogenic, established tumours.

Adenocarcinoma↗
PubMed2001

Efficacy of interferon for chronic hepatitis C virus-related hepatitis in kidney transplant candidates on hemodialysis: results after transplantation.

OBJECTIVES: Interferon-alpha (IFN) may have undesirable effects on a functioning graft. The aim of this study was to evaluate IFN treatment in kidney transplant candidates during the hemodialysis period as well as the results after transplantation. METHODS: A total of 29 noncirrhotic hemodialysis patients with chronic hepatitis C virus (HCV) infection (based on long-term rise in ALT, HCV serology, HCV RNA by polymerase chain reaction methods, and histological evidence) were included. Tolerability to IFN treatment, pre- and posttransplantation therapeutic results, and long-term outcome were recorded. IFN regimen consisted of 3 million units (MU) times per week after hemodialysis sessions for 6 months, followed by 1.5 MU after each hemodialysis session for an additional 6 months. All patients gave informed consent for participation. RESULTS: IFN therapy was fairly well tolerated. Adverse effects due to IFN toxicity, renal disease, or causes related to the immunological properties of IFN were observed in 24% of patients. At the end of treatment, ALT had normalized in 23/28 patients (82.1%), and HCV RNA had cleared in 23/28 patients (82.1%). During follow-up, HCV RNA was persistently negative in 18 patients (64%, including transplant recipients). A total of 14 patients (nine HCV RNA-negative) received a kidney transplant. Mean follow-up after the procedure was 41 +/- 28 months. In all, 12 patients had a functioning graft, one had acute vascular rejection, and one died of carcinoma. All transplanted patients maintained normal ALT levels, and eight remained HCV RNA-negative. CONCLUSIONS: Treatment results in our study population were better than those observed in the general population. The long-term response achieved, which was maintained after transplantation, supports the use of IFN for HCV hepatitis in kidney transplant candidates under hemodialysis.

Adult↗
PubMed2000

[Respiratory syncytial virus infection in adult patients hospitalized with community-acquired pneumonia].

OBJECTIVE: To determine the incidence and distribution of infection caused by respiratory syncytial virus (RSV) in hospitalized adults with community-acquired pneumonia. PATIENTS AND METHODS: Patients were immunocompetent adults hospitalized with community-acquired pneumonia, who were prospectively studied in our hospital. As a part of the diagnostic protocol, we performed RSV serology with paired acute and convalescent phase sera of patients admitted between February 1995 and May 1997. Clinical and epidemiological characteristics of patients with and without acute infection were compared. RESULTS: Paired RSV serology was performed in 250 patients hospitalized with community-acquired pneumonia. 97% of them had presence of IgG antibodies but only 17 patients (6.8%) had serologic evidence of acute infection; of these, seroconversion was observed in eight and positive IgM in nine. Fourteen cases with acute infection (82%) occurred between November and May. Three patients had pneumococcal pneumonia, 2 Legionella pneumophila and 12 pneumonia of unknown etiology. There were no clinical differences between patients with and without RSV acute infection but those with acute infection had more frequently bilateral involvement in chest radiography and a greater proportion of pneumonias of unknown etiology. CONCLUSIONS: RSV is a cause of acute infection among adults hospitalized with community-acquired pneumonia, mainly between November and May. Further studies to assess the role of RSV as a causative agent of pneumonia in this population are needed.

Adult↗
PubMed1999

Usefulness of PCR and antigen latex agglutination test with samples obtained by transthoracic needle aspiration for diagnosis of pneumococcal pneumonia.

In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the "gold standard." When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20. 1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33. 3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy.

Antibodies, Bacterial↗
PubMed1999

Evaluation of effect of charge and lipid coating on ability of 60-nm nanoparticles to cross an in vitro model of the blood-brain barrier.

A cell culture model of the blood-brain barrier (BBB) consisting of a coculture of bovine brain capillary endothelial cells and rat astrocytes has been used to examine the ability of 60-nm nanoparticles with different physicochemical characteristics to cross the BBB. Neutral, anionic, and cationic nanoparticles were made from crosslinked malto-dextrins derivatized or not (neutral) with phosphates (anionic), quaternary ammoniums (cationic) ligands. Then, these particles were coated or not with a lipid bilayer made of dipalmitoyl phosphatidyl choline and cholesterol. Lipid coating of ionically charged nanoparticles was able to increase BBB crossing 3- or 4-fold compared with uncoated particles, whereas coating of neutral particles did not significantly alter their permeation characteristics across the endothelial cell monolayer. Lipid-coated nanoparticles were nontoxic toward BBB integrity, and crossed the BBB by transcytosis without any degradation. Furthermore, a 27-fold increase in albumin transport was observed when albumin had previously been loaded in the cationic lipid-coated nanoparticles. The influence of red blood cells was studied; a marked inhibition of the transport was observed, probably due to strong interaction between nanoparticles and red blood cells.

Animals↗
PubMed1997

Localization of putative receptors for tetanus toxin and botulinum neurotoxin type A in rat central nervous system.

Clostridial neurotoxins (tetanus and botulinum toxins) are potent blockers of neurotransmitter release. These toxins act specifically on the nervous system by interacting with still non-identified protein receptors together with gangliosides. Whereas many biochemical data are available on their binding properties to neuronal membranes in vitro, there is poor morphological evidence of their binding to mammalian central nervous system. In the present study, the binding of tetanus and botulinum neurotoxin type A to rat brain sections is reported. Both toxins bound to nerve terminals with a broad distribution in brain. Tetanus toxin additionally bound to nerve fibres. The staining patterns were clearly shown to be due to the interaction of the heavy chains, which contain the binding moiety, with the tissue. In an attempt to investigate the nature of the acceptors present in the tissue, some sections were pre-incubated with periodic acid. This treatment resulted in the additional binding of botulinum neurotoxin type A to nerve fibres. Since the extended staining of nerve terminals was not modified by this pretreatment, it is suggested that protein receptors of clostridial neurotoxins are located at the nerve terminals, which may be common constituents of the synapses.

Animals↗
PubMed1997

Helicobacter pylori, efficacy of the new triple therapy in six and twelve-day schedules.

OBJECTIVE: Assessment of four eradicating patterns of 6 and 12 days duration with new triple therapies adapted to our environment. PATIENTS: After an endoscopic diagnosis of Duodenal or Gastric Ulcer, and the confirmation of the presence of Helicobacter pylori using a rapid urease test in antral biopsies, 274 patients were treated with one of four eradicating therapies, verifying its efficacy with the C-13 urea breath test, at least one month after the end of the treatment and 10 days after withdrawal of proton pump inhibitors. RESULTS: Maximum eradicating efficacy was achieved with Omeprazole (20 mg/12 hours), Clarithromycin (500 mg/12 hours) and Amoxycillin (1 g/12 hours), given for 12 days (96.6%), and Omeprazole (20 mg/12 hours), Tinidazole (500 mg/12 hours) and Clarithromycin (500 mg/12 hours), also given for 12 days (95.2%). The same drugs and doses, when given during six days, achieved percentages of 78.3% and 82.2% respectively. Results with Tinidazole suggest lack of resistance to this drug in the Community of Madrid.

Amoxicillin↗
PubMed1996

Chloracne in the 1990s.

BACKGROUND: Chloracne is a disease associated with toxicity of halogenated compounds used in some industrial processes. A patient affected by chloracne led us to study a total of nine cases from a single factory. METHODS: We studied the clinical features of nine patients exposed chronically to chlorobenzenes. On all of them blood samples were drawn and biopsies of affected skin and liver were taken. Their work environment was visited and studied. RESULTS: All nine patients were men and had polymorphic skin lesions, characterized mainly by comedones and cysts. They had chronic conjunctivitis and seven had cysts in the Meibomian glands. All of them had polyneuropathy and liver damage and seven had hypertriglyceridemia. Compounds known to cause chloracne were found in exceedingly high concentrations in the water used in the workplace. CONCLUSIONS: Every patient exposed to halogenated compounds with the cutaneous manifestations of chloracne should be carefully investigated for systemic complications (such as ophthalmic, neuropathic, hepatic, and lipoprotein abnormalities).

Acne Vulgaris↗
PubMed1996

Expression of synaptosomal-associated protein SNAP-25 in endocrine anterior pituitary cells.

A growing body of evidence indicates that the fundamental molecular mechanism of exocytosis in the secretory pathway may be structurally similar in all eukaryotic cells. The synaptosomal-associated protein of 25 kDa (SNAP-25) is a plasma membrane protein involved in regulated exocytosis in neurons. In order to compare exocytotic components in neurons and endocrine cells, we have analyzed the expression of SNAP-25 in the rat anterior pituitary. Western blotting analysis documented the presence of SNAP-25 in anterior pituitary homogenates and cultured anterior pituitary cells. In addition to SNAP-25, other neuronal proteins involved in exocytosis (syntaxin, VAMP/synaptobrevin and Rab3A) were also detected in the anterior pituitary. The specific expression of SNAP-25 mRNA in anterior pituitary cells was also corroborated by Northern analysis. SNAP-25 immunoreactivity was located at the plasma membrane of endocrine anterior pituitary cells. Characteristically, patches of fine punctate deposits exhibited intense SNAP-25 immunoreactivity. Double-labeling immunocytochemistry revealed that SNAP-25 was mainly associated with gonadotroph cell populations. Furthermore, we demonstrate that in the anterior pituitary, SNAP-25 is selectively cleaved by clostridial neurotoxins. In conclusion, our results establish the presence of SNAP-25 in secretory anterior pituitary cells and suggest a potential role of this protein in the secretion of adenohypophysial hormone.

Animals↗
PubMed1995

Botulinum toxin type A inhibits Ca(2+)-dependent transport of acetylcholine in reconstituted giant liposomes made from presynaptic membranes from cholinergic nerve terminals.

Giant liposomes were made from a mixture of asolectin phospholipid vesicles and presynaptic plasma membranes isolated from Torpedo cholinergic nerve endings. Acetylcholine filled giant liposomes were able to release neurotransmitter upon stimulation by the Ca2+ ionophore A23187 and Ca2+. Botulinum neurotoxin type A inhibited this Ca(2+)-dependent acetylcholine transport. Additionally, Botulinum toxin type A decreased membrane fluidity of liposomes. These results suggest that Botulinum toxin can interact directly with components of the presynaptic plasma membrane and inhibit acetylcholine translocation. Furthermore, since the reconstituted liposomes do not have synaptic vesicle components, the observed effects may account for the action of Botulinum toxin on the non-quantal release of acetylcholine from motor nerve terminals.

Acetylcholine↗
PubMed1995

Intermittent trimethoprim-sulfamethoxazole compared with dapsone-pyrimethamine for the simultaneous primary prophylaxis of Pneumocystis pneumonia and toxoplasmosis in patients infected with HIV.

OBJECTIVE: To evaluate the efficacy and safety of two oral, intermittent drug regimens for the simultaneous primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmosis in patients with HIV infection. DESIGN: Nonblinded randomized study: Patients received either 1) trimethoprim-sulfamethoxazole (160 mg-800 mg orally twice a day on a thrice weekly regimen) or 2) 100 mg of dapsone plus 50 mg of pyrimethamine orally twice weekly. SETTING: University teaching hospital in Barcelona. PATIENTS: 230 patients infected with HIV who had CD4 cell counts of less than 200 x 10(6)/L and who had not previously had P. carinii pneumonia or toxoplasmosis. MEASUREMENTS: Clinical and biological evaluations; adverse reactions; and end points of P. carinii pneumonia, toxoplasmosis, and death. RESULTS: After a median follow-up of 430 days, 6 (6.3%) of 96 evaluable patients receiving dapsone-pyrimethamine and 0 of 104 evaluable patients receiving trimethoprim-sulfamethoxazole developed P. carinii pneumonia (P < 0.0001). The cumulative rates of P. carinii pneumonia at 12 and 24 months were 0% and 0% for patients receiving trimethoprim-sulfamethoxazole and 4% and 11% for patients receiving dapsone-pyrimethamine (Mantel-Cox, P = 0.014). However, only one episode of P. carinii pneumonia developed while patients were taking these drugs. No differences were observed for toxoplasmosis (one episode in the trimethoprim-sulfamethoxazole arm and two in the dapsone-pyrimethamine arm), with cumulative rates at 12 and 24 months of 0% and 4% for the trimethoprim-sulfamethoxazole arm and 2% and 7% for the dapsone-pyrimethamine arm (P = 0.65). Similar mortality rates were observed during follow-up (P = 0.85). Nineteen patients (9.5%) discontinued therapy with the drugs because of adverse effects: Ten were in the trimethoprim-sulfamethoxazole arm and 9 were in the dapsone-pyrimethamine arm (P = 0.95). CONCLUSIONS: Thrice-weekly trimethoprim-sulfamethoxazole is an effective and well-tolerated regimen for the simultaneous primary prophylaxis of P. carinii pneumonia and toxoplasmosis in patients infected with HIV. Twice-weekly dapsone-pyrimethamine appears to be a safe and effective alternative.

AIDS-Related Opportunistic Infections↗