Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 39
Filter
Add more filters










Publication year range
1.
BJOG ; 127(2): 264-274, 2020 01.
Article in English | MEDLINE | ID: mdl-31573753

ABSTRACT

OBJECTIVE: To characterise vaginal bacterial composition in early pregnancy and investigate its relationship with first and second trimester miscarriages. DESIGN: Nested case-control study. SETTING: Queen Charlotte's and Chelsea Hospital, Imperial College Healthcare NHS Trust, London. POPULATION: 161 pregnancies: 64 resulting in first trimester miscarriage, 14 in second trimester miscarriage and 83 term pregnancies. METHODS: Prospective profiling and comparison of vaginal bacteria composition using 16S rRNA gene-based metataxonomics from 5 weeks' gestation in pregnancies ending in miscarriage or uncomplicated term deliveries matched for age, gestation and body mass index. MAIN OUTCOME MEASURES: Relative vaginal bacteria abundance, diversity and richness. Pregnancy outcomes defined as first or second trimester miscarriage, or uncomplicated term delivery. RESULTS: First trimester miscarriage associated with reduced prevalence of Lactobacillus spp.-dominated vaginal microbiota classified using hierarchical clustering analysis (65.6 versus 87.7%; P = 0.005), higher alpha diversity (mean Inverse Simpson Index 2.5 [95% confidence interval 1.8-3.0] versus 1.5 [1.3-1.7], P = 0.003) and higher richness 25.1 (18.5-31.7) versus 16.7 (13.4-20), P = 0.017), compared with viable pregnancies. This was independent of vaginal bleeding and observable before first trimester miscarriage diagnosis (P = 0.015). Incomplete/complete miscarriage associated with higher proportions of Lactobacillus spp.-depleted communities compared with missed miscarriage. Early pregnancy vaginal bacterial stability was similar between miscarriage and term pregnancies. CONCLUSIONS: These findings associate the bacterial component of vaginal microbiota with first trimester miscarriage and indicate suboptimal community composition is established in early pregnancy. While further studies are required to elucidate the mechanism, vaginal bacterial composition may represent a modifiable risk factor for first trimester miscarriage. TWEETABLE ABSTRACT: Vaginal bacterial composition in first trimester miscarriage is associated with reduced Lactobacillus spp. abundance and is independent of vaginal bleeding.


Subject(s)
Abortion, Spontaneous/microbiology , Microbiota/physiology , Vagina/microbiology , Adult , Case-Control Studies , Female , Humans , London , Pregnancy , Pregnancy Trimester, First , Pregnancy Trimester, Second , Prospective Studies , RNA, Ribosomal, 16S
2.
mBio ; 10(3)2019 05 28.
Article in English | MEDLINE | ID: mdl-31138748

ABSTRACT

Cryptococcus neoformans is an encapsulated yeast responsible for approximately a quarter of a million deaths worldwide annually despite therapy, and upwards of 11% of HIV/AIDS-related deaths, rivaling the impact of tuberculosis and malaria. However, the most effective antifungal agent, amphotericin B, requires intravenous delivery and has significant renal and hematopoietic toxicity, making it difficult to utilize, especially in resource-limited settings. The present studies describe a new nanoparticle crystal encapsulated formulation of amphotericin B known as encochleated amphotericin B (CAmB) that seeks to provide an oral formulation that is low in toxicity and cost. Using a 3-day delayed model of murine cryptococcal meningoencephalitis and a large inoculum of a highly virulent strain of serotype A C. neoformans, CAmB, in combination with flucytosine, was found to have efficacy equivalent to parental amphotericin B deoxycholate with flucytosine and superior to oral fluconazole without untoward toxicity. Transport of fluorescent CAmB particles to brain as well as significant brain levels of amphotericin drug was demonstrated in treated mice, and immunological profiles were similar to those of mice treated with conventional amphotericin B. Additional toxicity studies using a standardized rat model showed negligible toxicity after a 28-day treatment schedule. These studies thus offer the potential for an efficacious oral formulation of a known fungicidal drug against intrathecal cryptococcal disease.IMPORTANCECryptococcus neoformans is a significant global fungal pathogen that kills an estimated quarter of a million HIV-infected individuals yearly and has poor outcomes despite therapy. The most effective therapy, amphotericin B, is highly effective in killing the fungus but is available only in highly toxic, intravenous formulations that are unavailable in most of the developing world, where cryptococcal disease in most prevalent. For example, in Ethiopia, reliance on the orally available antifungal fluconazole results in high mortality, even when initiated as preemptive therapy at the time of HIV diagnosis. Thus, alternative agents could result in significant saving of lives. Toward this end, the present work describes the development of a new formulation of amphotericin B (CAmB) that encapsulates the drug as a crystal lipid nanoparticle that facilitates oral absorption and prevents toxicity. Successful oral absorption of the drug was demonstrated in a mouse model that, in combination with the antifungal flucytosine, provided efficacy equal to a parental preparation of amphotericin B plus flucytosine. These studies demonstrate the potential for CAmB in combination with flucytosine to provide an effective oral formulation of a well-known, potent fungicidal drug combination.


Subject(s)
Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Cryptococcosis/drug therapy , Meningoencephalitis/drug therapy , Administration, Oral , Amphotericin B/chemistry , Animals , Antifungal Agents/chemistry , Cryptococcus neoformans/drug effects , Deoxycholic Acid/therapeutic use , Disease Models, Animal , Drug Combinations , Drug Compounding , Drug Therapy, Combination , Female , Flucytosine/therapeutic use , Lipids/chemistry , Male , Meningoencephalitis/microbiology , Mice , Nanoparticles/chemistry , Rats , Rats, Sprague-Dawley
3.
Infection ; 40(3): 331-4, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22005933

ABSTRACT

INTRODUCTION: Catheter-related bloodstream infections very often involve the premature removal of long-term intravascular devices (LTID). The antibiotic lock therapy (ALT) represents a conservative approach to the treatment of uncomplicated infections of tunneled LTID when catheter removal is not a feasible option. CASE REPORT: We present here the first reported case of tunneled LTID bloodstream infection due to a multidrug resistant Lactobacillus rhamnosus. The patient, who had large granular lymphocytic leukemia, was successfully treated with systemic tigecycline therapy and lock therapy. CONCLUSION: Our results confirm ALT as a valid catheter-salvage strategy for the treatment of CRBSIs in clinically stable patients when catheter removal is not a feasible option, tigecycline appear to be a good option.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Catheter-Related Infections/drug therapy , Gram-Positive Bacterial Infections/drug therapy , Lacticaseibacillus rhamnosus/isolation & purification , Minocycline/analogs & derivatives , Adult , Catheter-Related Infections/microbiology , Catheterization, Central Venous/adverse effects , Catheters, Indwelling/microbiology , Drug Resistance, Multiple, Bacterial , Female , Gram-Positive Bacterial Infections/microbiology , Humans , Lacticaseibacillus rhamnosus/drug effects , Microbial Sensitivity Tests , Minocycline/therapeutic use , Tigecycline , Treatment Outcome
4.
J Neurosurg Sci ; 53(3): 125-9, 2009 Sep.
Article in English | MEDLINE | ID: mdl-20075825

ABSTRACT

We report the first case in the literature of a solitary metastatic melanoma of the septum pellucidum, mimicking a colloidal cyst of the third ventricle. In a 22-year-old man clinical and radiological examination revealed regional left inguinal, bilateral suprarenal and left broncho-pulmonary parailar nodular masses. Immunohistochemical staining on bronchoscopic, lymph nodes and neuroendoscopic biopsy confirmed the diagnosis of metastatic melanoma, in spite of extensive workup failed to detect a primary cutaneous or systemic tumor site. The clinical course was progressive and lethal. The neuroendoscopic approach to the septal lesion, performed before stereotactic radiosurgery, was extremely useful to obtain biopsy of the tumor and, by means of septum pellucidotomy, to treat biventricular hydrocephalus by monoventriculo-peritoneal drainage, in the same seat. Even if metastases can occur anywhere within the central nervous system, the novelty in this report is their intracranial localization, as they have been detected in the septum pellucidum, a case never reported previously.


Subject(s)
Brain Neoplasms/secondary , Central Nervous System Cysts/pathology , Melanoma/secondary , Septum Pellucidum/pathology , Third Ventricle/pathology , Adult , Brain Neoplasms/surgery , Diagnosis, Differential , Humans , Immunohistochemistry , Lung Neoplasms/secondary , Lymphatic Metastasis/pathology , Magnetic Resonance Imaging , Male , Melanoma/surgery , Nevus, Pigmented/pathology , Nevus, Pigmented/surgery , Radiosurgery , Septum Pellucidum/surgery , Skin Neoplasms/pathology , Skin Neoplasms/surgery , Third Ventricle/surgery
5.
Bone Marrow Transplant ; 43(4): 335-8, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18850015

ABSTRACT

From May to October 2006, six severe Pseudomonas aeruginosa infections were diagnosed in patients undergoing SCT in the SCT unit of the Careggi hospital (Florence, Italy). Four of the infected patients were treated consecutively in the same room (room N). On the hypothesis of a possible environmental source of infection, samples were collected from different sites that had potential for cross-contamination throughout the SCT unit, including the electrolytic chloroxidant disinfectant used for hand washing (Irgasan) and the disinfectant used for facilities cleaning. Four of the environmental samples were positive for P. aeruginosa: three Irgansan soap samples and a tap swab sample from the staff cleaning and dressing room. The AFLP (amplified fragment length polymorphism) typing method employed to evaluate strain clonality showed that the isolates from the patients who had shared the same room and an isolate from Irgasan soap had a significant molecular similarity (dice index higher than 0.93). After adequate control measures, no subsequent environmental sample proved positive for P. aeruginosa. These data strongly support the hypothesis of the clonal origin of the infective strains and suggest an environmental source of infection. The AFLP method was fast enough to allow a 'real-time' monitoring of the outbreak, permitting additional preventive measures.


Subject(s)
Disease Outbreaks , Pseudomonas Infections/epidemiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/genetics , Stem Cell Transplantation , Adult , Amplified Fragment Length Polymorphism Analysis/methods , Female , Humans , Italy/epidemiology , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Epidemiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Serotyping
6.
J Neurosurg Sci ; 45(2): 75-82, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11533531

ABSTRACT

BACKGROUND: We performed cerebral 201Tl SPECT study on 38 presurgical patients with equivocal neuroradiological supratentorial lesions to detect differences in 201Tl uptake index between tumor/non-tumor and high-grade/low-grade samples. METHODS: Authors identified 38 cases with presurgical equivocal neuroradiological supratentorial mass lesions. All cases were submitted to histological confirmation of the lesion by biopsy, sub-total or gross-total removal of the tumor. Between 23 patients suffering from gliomas, 13 were histologically classified as being of low-grade malignant tumors and 10 were classified as being of high-grade malignancy. Fifteen non-tumor histopathological specimens were also detected. The 201Tl index was defined as the ratio of average counts per pixel in the lesion to these in the opposite region. Analysis of variance (ANOVA) and unpaired Student's OtO-test statistical methods were applied. Actuarial survival time from the date of diagnosis was calculated using the Kaplan-Meier method. Follow-up evaluation and survival time were obtained through referring physicians. Cerebral CT or MR images were obtained every three months after discharged, or more often if indicated. RESULTS: Results showed that the 201Tl uptake index ranged from 1.10 to 3.00 in the tumors lesions (mean+/-SD: 1.68+/-0.51) and from 0.80 to 1.40 in the non-tumors lesions (mean+/-SD: 1.07+/-0.17), (alpha < 0.0006 percent;). The 201Tl uptake index ranged from 1.10 to 2.30 in 13 patients with low-grade tumors (mean+/-SD: 1.45+/-0.34) and from 1.30 to 3.00 in 10 patients with high-grade tumors (mean+/-SD: 1.98+/-0.55), (alpha < 0.5 percent;). CONCLUSIONS: Our results demonstrate the clinical utility of 201Tl brain SPECT to differentiate equivocal neuroradiological supratentorial lesions and to correlate relationship between preoperative diagnosis, histological tumor grade and prognosis.


Subject(s)
Brain Neoplasms/diagnostic imaging , Thallium Radioisotopes , Adult , Aged , Brain Neoplasms/pathology , Brain Neoplasms/physiopathology , Cranial Sinuses/diagnostic imaging , Cranial Sinuses/pathology , Diagnosis, Differential , Disease Progression , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prognosis , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed , Venous Thrombosis/diagnostic imaging , Venous Thrombosis/pathology
7.
J Neurosurg Sci ; 44(3): 140-4, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11126449

ABSTRACT

The authors report the case of a 31-year-old man, who presented an hemorrhagic onset of a cerebral-isolated sarcoidosis, to date never described in the literature. Unusual clinical manifestation, neuroradiological study and direct histological confirmation are presented. Moreover, Gallium-67 Single Photon Emission Computed Tomography (Ga-67 SPECT) contribution is indicated to complete the evaluation of patients with cerebral inflammatory lesions, such as neurosarcoidosis, and in cases of equivocal neuroradiological imaging, to evaluate uptake activity of the inflammatory tissue. The patient did well and reported no further progression of his disease during 7 months of follow-up.


Subject(s)
Brain Diseases/complications , Cerebral Hemorrhage/etiology , Sarcoidosis/complications , Adult , Brain Diseases/diagnosis , Brain Diseases/pathology , Cerebral Hemorrhage/diagnosis , Humans , Magnetic Resonance Imaging , Male , Sarcoidosis/diagnosis , Sarcoidosis/pathology , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed
8.
Antimicrob Agents Chemother ; 44(9): 2356-60, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10952579

ABSTRACT

Amphotericin B (AMB) remains the principal therapeutic choice for deep mycoses. However, its application is limited by toxicity and a route of administration requiring slow intravenous injection. An oral formulation of this drug is desirable to treat acute infections and provide prophylactic therapy for high-risk patients. Cochleates are a novel lipid-based delivery system that have the potential for oral administration of hydrophobic drugs. They are stable phospholipid-cation crystalline structures consisting of a spiral lipid bilayer sheet with no internal aqueous space. Cochleates containing AMB (CAMB) inhibit the growth of Candida albicans, and the in vivo therapeutic efficacy of CAMB administered orally was evaluated in a mouse model of systemic candidiasis. The results indicate that 100% of the mice treated at all CAMB doses, including a low dosage of 0.5 mg/kg of body weight/day, survived the experimental period (16 days). In contrast, 100% mortality was observed with untreated mice by day 12. The fungal tissue burden in kidneys and lungs was assessed in parallel, and a dose-dependent reduction in C. albicans from the kidneys was observed, with a maximum 3.5-log reduction in total cell counts at 2.5 mg/kg/day. However, complete clearance of the organism from the lungs, resulting in more than a 4-log reduction, was observed at the same dose. These results were comparable to a deoxycholate AMB formulation administered intraperitoneally at 2 mg/kg/day (P < 0.05). Overall, these data demonstrate that cochleates are an effective oral delivery system for AMB in a model of systemic candidiasis.


Subject(s)
Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Candidiasis/drug therapy , Drug Delivery Systems , Administration, Oral , Amphotericin B/administration & dosage , Animals , Antifungal Agents/administration & dosage , Candidiasis/transmission , Chemistry, Pharmaceutical , Delayed-Action Preparations , Disease Models, Animal , Drug Carriers , Female , Kidney/microbiology , Lung/microbiology , Mice , Mice, Inbred BALB C , Treatment Outcome
9.
Antimicrob Agents Chemother ; 44(6): 1463-9, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10817694

ABSTRACT

Cochleates are lipid-based supramolecular assemblies composed of natural products, negatively charged phospholipid, and a divalent cation. Cochleates can encapsulate amphotericin B (AmB), an important antifungal drug. AmB cochleates (CAMB) have a unique shape and the ability to target AmB to fungi. The minimal inhibitory concentration and the minimum lethal concentration against Candida albicans are similar to that for desoxycholate AmB (DAMB; Fungizone). In vitro, CAMB induced no hemolysis of human red blood cells at concentrations of as high as 500 microg of AmB/ml, and DAMB was highly hemolytic at 10 microg of AmB/ml. CAMB protect ICR mice infected with C. albicans when the agent is administered intraperitoneally at doses of as low as 0.1 mg/kg/day. In a tissue burden study, CAMB, DAMB, and AmBisome (liposomal AmB; LAMB) were effective in the kidneys, but in the spleen CAMB was more potent than DAMB at 1 mg/kg/day and was equivalent to LAMB at 10 mg/kg/day. In summary, CAMB are highly effective in treating murine candidiasis and compare well with AmBisome and AmB.


Subject(s)
Amphotericin B/pharmacology , Amphotericin B/therapeutic use , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Candida albicans/drug effects , Candidiasis/drug therapy , Animals , Humans , Mice
11.
Mol Cell Biochem ; 145(2): 169-75, 1995 Apr 26.
Article in English | MEDLINE | ID: mdl-7675036

ABSTRACT

Cellular physiology has a significant influence on the efficiency of various gene transfer procedures, as shown by the fact that transfection efficiency varies dramatically among different cell lines. However, the aspects of cellular physiology which influence the transfection process remain substantially uncharacterized. In this study, NIH3T3 cells were treated with inhibitors of protein synthesis, DNA synthesis, and RNA synthesis to determine the importance of these processes in the calcium-phosphate transfection process. The results suggest that protein synthesis during the first 4 h after DNA addition enhances transfection. In contrast, inhibition of RNA synthesis has no effect on transfection during the first 24 h post-DNA addition. The DNA synthesis inhibitor results remain inconclusive due to a secondary inhibition of an unknown cellular factor. Secondly, agents that destabilize microtubules, microfilaments, and the golgi apparatus were used to determine whether these elements play a role in the transfection process. The results suggest that microtubules are not involved in the transfection process, microfilaments are important but not necessary for the transfection process, and a functional golgi apparatus is essential early in the transfection process. These studies provide a foundation from which further investigations into the cellular processes involved in the uptake and expression of exogenous DNA can proceed.


Subject(s)
3T3 Cells/physiology , DNA/biosynthesis , Gene Transfer Techniques , RNA, Messenger/biosynthesis , Animals , Brefeldin A , Colchicine/pharmacology , Cycloheximide/pharmacology , Cyclopentanes/pharmacology , Cytochalasin B/pharmacology , Dichlororibofuranosylbenzimidazole/pharmacology , Mice , Transformation, Genetic/drug effects
12.
Pharm Biotechnol ; 6: 363-87, 1995.
Article in English | MEDLINE | ID: mdl-7551226

ABSTRACT

For more than a decade our laboratories have been combining concepts in biochemistry, virology, and immunology in order to develop a conceptual basis for vaccine design. Our long-term goals have been to construct simple and well-defined immunogens that would stimulate specific immune responses in vivo. Using this approach, we hypothesized that it should be possible to define the structural and biochemical parameters of an immunogen that are necessary and sufficient to stimulate designated effector arms of the immune system. Through the use of covalently coupled peptide complexes, we have been able to define minimal requirements for the induction of humoral immune responses (Mannino et al., 1992). This represents a significant advance in eliciting an immune response to peptides, because it requires only peptides and phospholipids in the absence of additional adjuvants. It is different from the previous use of peptides and liposomes since here the peptides are covalently linked to a hydrophobic anchor and integrated into the phospholipid complex, rather than passively adsorbed or encapsulated. The presentation of peptide as part of a peptide-phospholipid complex (in contrast to encapsulation or nonspecific absorption) may be more similar to the natural presentation of an epitope in the context of an in vivo antigenic challenge. This technology also allows us to incorporate B and Th epitopes in a number of forms--as a single peptide, as two peptides in the same liposome, or as a peptide with viral glycoproteins in the same liposome. These data also demonstrate that Th epitopes do not have to be covalently linked to the B-cell epitope in order to provide help for that epitope. The implications of the data reported here are significant for both basic science and applied technologies. In basic science, the peptide-phospholipid complexes are potentially useful for analyzing the cooperative effects of B- and T-cell epitopes in the in vivo immune response. Since the peptide-phospholipid complexes are totally synthetic and highly immunogenic, they may be constructed in any formulation required to answer questions on the roles of B and T cells in promoting an immune response. Furthermore, since the number of antigenic sites is limited only by the number of peptides included in the peptide-phospholipid complexes, these constructs may be useful in producing antisera or monoclonal antibodies to weakly antigenic regions of a large protein, since the lack of antigenic competition should enhance the immunogenicity of these regions. Clinically, this technology will expand the potential for subunit vaccines.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Immunization , Lipids/chemistry , Vaccines/administration & dosage , Vaccines/immunology , Adjuvants, Immunologic , Administration, Oral , Animals , Humans , Liposomes
13.
Anticancer Res ; 14(2B): 739-45, 1994.
Article in English | MEDLINE | ID: mdl-7516642

ABSTRACT

Authors present a review of the intracavitary treatment of malignant effusions in cancer patients, experience with tetracycline, mechloretamine, quinacrine, radio-isotopes, interferon beta and interferon alpha are reviewed. Personal experience with interferon alpha is reported.


Subject(s)
Ascitic Fluid/therapy , Neoplasms/physiopathology , Pleural Effusion/therapy , Bleomycin/therapeutic use , Humans , Interferon alpha-2 , Interferon-alpha/therapeutic use , Interferon-beta/therapeutic use , Mechlorethamine/therapeutic use , Neoplasms/therapy , Quinacrine/therapeutic use , Recombinant Proteins , Tetracycline/therapeutic use
14.
AIDS Res Hum Retroviruses ; 10 Suppl 2: S99-103, 1994.
Article in English | MEDLINE | ID: mdl-7865342

ABSTRACT

Immunization is today the most effective defense mechanism against microbial infections. Although highly effective vaccines are currently available for a number of infectious diseases, vaccine formulations can still be improved in a number of important areas. The ability to induce antigen-specific humoral and cell-mediated immunity is crucial to the development of effective prophylactic and therapeutic vaccines for HIV and other pathogens. The approach of our laboratory has been to design and test simple, highly defined antigen-lipid complexes that would stimulate antibody and cell-mediated immune responses in the absence of any nonspecific immunological activators such as Freund's adjuvant, lipopolysaccharide (LPS), or alum. These studies have provided insight into the relationships between the properties of an immunogen and the induction of the desired immune responses. We have previously utilized this approach to define the minimal structures required for the induction of antibody responses. Our more recent studies have focused on defining the parameters involved in the induction of cell-mediated and mucosal immune responses. Toward this end we have developed a new type of subunit vaccine that is effective when given orally or intramuscularly, and elucidated structure-function relationships in peptide vaccines that affect induction of CD8+ cell responses.


Subject(s)
Proteolipids/administration & dosage , Vaccines, Synthetic/administration & dosage , AIDS Vaccines/administration & dosage , AIDS Vaccines/isolation & purification , Administration, Oral , Animals , Drug Carriers , Humans , Immunochemistry , Injections , Liposomes/chemistry , Proteolipids/chemistry , Proteolipids/isolation & purification , Structure-Activity Relationship , T-Lymphocytes, Cytotoxic/immunology , Vaccines, Synthetic/isolation & purification
15.
Biochim Biophys Acta ; 1177(1): 49-53, 1993 May 08.
Article in English | MEDLINE | ID: mdl-8485168

ABSTRACT

The efficiency of stable gene transfer and expression in NIH3T3 cells has been shown to be significantly enhanced by a brief treatment with the phorbol ester tetradecanoylphorbol 12,13-acetate (TPA) immediately following calcium-phosphate transfection. Several lines of evidence indicated that this effect was mediated through protein kinase C activation. These studies were expanded to determine whether this was a consistent and widespread phenomenon among other cell lines. The efficiency of transfection in two other established fibroblast lines, LMtk- and 2A3 3T3, was unaffected by TPA treatment, and primary human foreskin fibroblasts were similarly unaffected. Transfection was inhibited by TPA treatment in the transformed cell lines EJ and HeLa. Protein kinase C enzyme assays indicated that TPA causes a translocation of the enzyme from cytosol to membrane in both NIH3T3 and EJ cells, suggesting that the PKC translocation event does not account for the TPA effect on transfection. The TPA-mediated inhibition of transfection in EJ cells was not blocked by sphingosine, suggesting that this phenomenon is unrelated to PKC activation. The results suggest that TPA treatment may either enhance, inhibit, or have no effect on transfection, depending on the cell line.


Subject(s)
Tetradecanoylphorbol Acetate/pharmacology , Transfection/drug effects , 3T3 Cells/drug effects , 3T3 Cells/metabolism , Animals , Cell Membrane/enzymology , Cytosol/enzymology , Enzyme Activation/drug effects , HeLa Cells/drug effects , HeLa Cells/metabolism , Humans , Mice , Protein Kinase C/metabolism , Sphingosine/pharmacology , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/metabolism
16.
J Exp Med ; 176(6): 1739-44, 1992 Dec 01.
Article in English | MEDLINE | ID: mdl-1460429

ABSTRACT

An effective vaccine against the human immunodeficiency virus should be capable of eliciting both an antibody and a cytotoxic T lymphocyte (CTL) response. However, when viral proteins and peptides are formulated with traditional immunological adjuvants and inoculated via a route acceptable for use in humans, they have not been successful at eliciting virus-specific, major histocompatibility complex (MHC) class I-restricted CTL. We have designed a novel viral subunit vaccine by encapsulating a previously defined synthetic peptide CTL epitope of the simian immunodeficiency virus (SIV) gag protein within a proteoliposome capable of attaching to and fusing with plasma membranes. Upon fusing, the encapsulated contents of this proteoliposome can enter the MHC class I processing pathway through the cytoplasm. In this report, we show that after a single intramuscular vaccination, rhesus monkeys develop a CD8+ cell-mediated, MHC class I-restricted CTL response that recognizes the synthetic peptide immunogen. The induced CTL also demonstrate antiviral immunity by recognizing SIV gag protein endogenously processed by target cells infected with SIV/vaccinia recombinant virus. These results demonstrate that virus-specific, MHC class I-restricted, CD8+ CTL can be elicited by a safe, nonreplicating viral subunit vaccine in a primate model for acquired immune deficiency syndrome. Moreover, the proteoliposome vaccine formation described can include multiple synthetic peptide epitopes, and, thus, offers a simple means of generating antiviral cell-mediated immunity in a genetically heterogeneous population.


Subject(s)
CD8 Antigens/immunology , Gene Products, gag/immunology , Proteolipids/immunology , Simian Immunodeficiency Virus/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Cytotoxic/immunology , Vaccines, Synthetic/immunology , Viral Vaccines/immunology , Amino Acid Sequence , Animals , Cell Line , Genes, MHC Class I , Liposomes , Macaca mulatta , Membrane Fusion , Molecular Sequence Data
17.
Minerva Med ; 83(6): 355-8, 1992 Jun.
Article in Italian | MEDLINE | ID: mdl-1630696

ABSTRACT

Hepatobiliary scintigraphy was used to evaluate the action of fenoverine in 16 patients suffering from dyskinesia of the biliary tract; the drug was administered in doses of 300 mg per day per os for 20 days, the patients being subjected to hepatobiliary scintigraphy before and after treatment. The following parameters--accurate indicators of the motor coordination of the biliary tract--were evaluated: tracer appearance time in the gallbladder (Tc) and in the intestine (Ti). After treatment there was a normalization of these two parameters which initially were extended. Statistical analysis showed a highly significant reduction in these times. Stress is laid on the importance of hepatobiliary scintigraphy in the diagnosis of biliary dyskinesia and on the effectiveness of fenoverine in the treatment of this conditions.


Subject(s)
Biliary Dyskinesia/diagnostic imaging , Biliary Dyskinesia/drug therapy , Biliary Tract/diagnostic imaging , Imino Acids , Liver/diagnostic imaging , Organotechnetium Compounds , Phenothiazines/therapeutic use , Tomography, Emission-Computed, Single-Photon , Administration, Oral , Adult , Female , Humans , Male , Middle Aged , Phenothiazines/administration & dosage , Time Factors
18.
J Immunol ; 147(2): 410-5, 1991 Jul 15.
Article in English | MEDLINE | ID: mdl-1712806

ABSTRACT

The design of effective subunit vaccines requires the inclusion of both B and T cell epitopes. The best mechanism for including both types of epitopes within an Ag is dependent upon how the Ag is processed by the APC for presentation to a responsive Th cell. If it is more efficient to process a single molecule for both helper and primary epitopes, than covalent linkage of B cells and T cell epitopes for intramolecular presentation of help would be recommended. If however, separate peptides containing either B or Th cell epitopes could be included within a single complex for the elicitation of intermolecular/intrastructural help, more antigenically diverse structures could be designed. This paper reports that it is possible to generate intermolecular/intrastructural help within an antigenic peptide-phospholipid (PL) complex. These peptide-PL complexes use well defined epitopes from Plasmodium falciparum as Ag. In addition to generating intrastructural help, we have shown that the Ir to these peptide-PL complexes is controlled by Ir genes and is similar to the Ir to the circumsporozoite protein of this pathogen.


Subject(s)
Antigens, Protozoan/immunology , B-Lymphocytes/immunology , Peptides/immunology , Phospholipids/immunology , T-Lymphocytes/immunology , Animals , Antibodies, Protozoan/immunology , Antibody Formation , Antigens, Protozoan/chemistry , Epitopes , Genes, MHC Class II , Peptides/chemistry , Phospholipids/chemistry , Plasmodium falciparum/immunology , Protozoan Proteins/chemistry , Protozoan Proteins/immunology , Structure-Activity Relationship , T-Lymphocytes, Helper-Inducer/immunology , Vaccines, Synthetic/immunology
19.
Biochim Biophys Acta ; 1088(2): 270-6, 1991 Feb 16.
Article in English | MEDLINE | ID: mdl-1900439

ABSTRACT

The mechanisms involved in the translocation of exogenously added genetic information through the cellular cytoplasm and into the nucleus are essentially unknown. Several trans-cytoplasmic translocation systems operate within cells to transport information received by the plasma membrane into the nucleus. Protein kinase C may be functionally involved in many of these translocation mechanisms. In order to explore the involvement of protein kinase C activation in the cytoplasmic translocation of DNA, NIH3T3 fibroblasts were transfected using the calcium-phosphate co-precipitation method with a plasmid containing the lacZ gene and treated with tetradecanoylphorbol 12,13-acetate (TPA) or 1,2-dioctanoylglycerol (DiC8). Addition of TPA or DiC8 immediately after glycerol shock resulted in a 5-7-fold increase in the number of cells expressing beta-galactosidase as well as a concomitant increase in the total amount of beta-galactosidase activity in the population during periods of transient and stable expression. TPA added at later times resulted in lesser increases in the efficiency of transfection. In contrast, TPA added at the time of addition of the calcium-phosphate precipitate inhibited transfection. In support of a role for protein kinase C activation in enhancing DNA transfection, the TPA analog 4 alpha-phorbol 12,13-didecanoate, which does not activate protein kinase C, was ineffective at enhancing transfection. Furthermore, treatment of cells with the protein kinase C inhibitor sphingosine blocked the TPA-mediated increase in transient and stable expression. The results suggest that protein kinase C activation enhances transfection of exogenous DNA through an as yet unknown mechanism.


Subject(s)
DNA/genetics , Diglycerides/pharmacology , Phorbol Esters/pharmacology , Protein Kinase C/metabolism , Tetradecanoylphorbol Acetate/pharmacology , Transfection/drug effects , beta-Galactosidase/genetics , Animals , Calcium Phosphates , Cell Line , Enzyme Activation , Gene Expression/drug effects , Mice , beta-Galactosidase/metabolism
20.
Vaccine ; 8(3): 257-62, 1990 Jun.
Article in English | MEDLINE | ID: mdl-1694612

ABSTRACT

The role that individual determinants play in modulating the immune response of an organism to a pathogen is often obscured because of the complexity of the pathogen. In order to gain a better appreciation of the role of individual determinants in the immune response, a pathogen may be dissociated into smaller components, for example peptides representing specific epitopes. These isolated components are often poorly immunogenic and historically have required the use of adjuvants to stimulate antibody production. This report defines the minimal essential requirements for antibody production to a peptide in this system. These are the ability to stimulate both B- and T-helper lymphocytes, anchorage in a phospholipid complex and multivalency within the complex. When these conditions are met, no additional adjuvants are necessary. This procedure has allowed us to identify three distinct T-helper cell epitopes from HIV gp160. In addition, this information has been used to produce a simple, totally synthetic and highly immunogenic preparation for the production of antibodies to peptides.


Subject(s)
Antibody Formation , Antigens , Peptides/immunology , Amino Acid Sequence , Animals , Cross Reactions , Epitopes , Female , HIV Antibodies/biosynthesis , HIV Antigens/immunology , Immunization , Mice , Mice, Inbred CBA , Molecular Sequence Data , T-Lymphocytes, Helper-Inducer/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...