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Biomedical subjects

R B Moss

Publications and source records attributed to R B Moss.

At least 73 records · Page 4Linked to original sources
PubMed1995

Activation of CFTR chloride current by nitric oxide in human T lymphocytes.

Nitric oxide, which is produced by cytokine-activated mononuclear cells, is thought to play an important role in inflammation and immunity. While the function of nitric oxide as a direct cytotoxic effector molecule is well established, its function as a transducer molecule in immune cells is not. By use of whole-cell patch clamp recordings, we show that nitric oxide activates cystic fibrosis transmembrane conductance regulator CI- currents in normal human cloned T cells by a cGMP-dependent mechanism. This pathway is defective in cystic fibrosis-derived human cloned T cells. These findings not only delineate a novel transduction mechanism for nitric oxide but also support the hypothesis that an intrinsic immune defect may exist in cystic fibrosis.

Aminoquinolines↗
PubMed1995

Management of sinusitis in cystic fibrosis by endoscopic surgery and serial antimicrobial lavage. Reduction in recurrence requiring surgery.

OBJECTIVE: An effective treatment program for refractory chronic sinusitis in patients with cystic fibrosis has not been achieved. We developed a long-term management approach by combining endoscopic surgery with serial antimicrobial lavage (ESSAL). DESIGN: In a before and after trial, results of ESSAL in 32 patients were compared with those of conventional sinus surgery without serial antimicrobial lavage in 19 patients. At least 1 year follow-up was available in all but one patient. SETTING AND PATIENTS: Patients attending the Stanford (Calif) Cystic Fibrosis Center were consecutively referred for otolaryngologic evaluation for symptoms and signs of refractory sinusitis. Those subjects who were evaluated before 1990 were treated conventionally and afterward by ESSAL. INTERVENTION: Conventionally treated patients underwent one or more of the following procedures: polypectomy, ethmoidectomy, antrostomy, or Caldwell-Luc operation. The ESSAL approach incorporated preoperative rhinosinuscopy and computed tomography, endoscopic surgery, a postoperative course of antral antimicrobial lavage, and monthly maintenance antimicrobial lavage via brief antral catheterization. MAIN OUTCOME MEASURE: Intensity and frequency of sinus surgery after initial presentation. RESULTS: The two groups were similar demographically and in clinical presentation, including the presence of nasal polyposis in 34% and 42%, respectively. The ESSAL group had fewer operations per patient, Caldwell-Luc procedures, and a decrease in repeated surgery at 1-year (10% vs 47%) and 2-year (22% vs 72%) follow-ups. CONCLUSION: The ESSAL is a successful approach to treatment of sinusitis in cystic fibrosis that reduces recurrence requiring further surgery for at least 2 years.

Adolescent↗
PubMed1995

Viral load in peripheral blood mononuclear cells as surrogate for clinical progression.

During the symposium on surrogate markers of HIV, the Scientific Advisory Committee posed the following question: "Which surrogate markers currently deserve the greatest commitment of investigative resources to validate them in a clinical setting?" The Committee concluded that for antiretroviral drugs measurements of HIV RNA in plasma deserve the greatest priority, and for immune-based therapies assessing viral load still had the highest priority. But it was recognized that assessing viral load should not be restricted to plasma RNA because the primary mechanisms of action are different from antiretroviral drugs. Thus, the Committee voted that based on current knowledge, investigating the clinical relevance of changes in HIV-1 DNA and RNA copy number in peripheral blood mononuclear cells (PBMCs) with validated assays should be given equal focus for immune-based therapies. This article reviews the rationale for using HIV-1 DNA and RNA load in PBMCs for the monitoring of clinical trials and presents recent data that indicate that the postseroconversion level and the dissemination of proviral DNA in the blood cells have prognostic value, i.e., high levels correlate with disease progression. In addition, longitudinal studies show that an increase in proviral DNA and/or HIV mRNA load correlates with disease progression. We present evidence that these markers are relevant activity markers for anti-HIV therapies. Changes in both DNA and RNA load can be achieved using either antiretroviral drugs or immune-based therapies. These results suggest that these markers should be evaluated in clinical studies to firmly establish their value as surrogates of clinical progression.

Biomarkers↗
PubMed1995

Safety and immunogenicity of a gp120-depleted, inactivated HIV-1 immunogen: results of a double-blind, adjuvant controlled trial.

We report the safety and immunogenicity results of a double-blind adjuvant controlled trial of the human immunodeficiency virus type 1 (HIV-1) immunogen. Healthy, asymptomatic HIV-1-seropositive individuals received either three 100 microgram doses of the inactivated HIV-1 antigen in incomplete Freund's adjuvant (IFA) or three doses of IFA alone. The results of this study show that this HIV-1 immunogen is safe, with mild and transient adverse events. No difference in the number or type of adverse events was noted between the treatment groups. Rises in HIV-1-specific humoral and cell-mediated immune (CMI) responses were also noted, favoring the HIV-1 immunogen-treated group. The results of this study confirm and extend the safety and immunogenicity profile of this HIV-1 immunotherapeutic agent. The observation that this treatment can augment HIV-1-specific CMI is encouraging because this immunological marker may represent a key surrogate end point in HIV-1 infection and disease.

AIDS Vaccines↗
PubMed1994

Primed in situ DNA amplification (PIDA).

A novel PCR in situ protocol is described which can be implemented in one day. An initial amplification step with a single primer pair is followed by an amplification with an internal oligonucleotide probe with labeled nucleotides (dig-dUTP). Detection is then accomplished with an antidigoxigenin antibody and substrate solution. This rapid and sensitive method may be useful in diagnosing low copy DNA in tissue specimens and cells.

DNA, Viral↗
PubMed1994

Osteopenia in adults with cystic fibrosis.

PURPOSE: To examine the frequency and severity of osteopenia in adults with cystic fibrosis and the clinical variables associated with reduced bone mineral. PATIENTS AND METHODS: The bone mineral status of 22 white adults (14 women) with cystic fibrosis was compared with normative data from healthy white control subjects in a university medical center. Lumbar spine, femoral neck, and whole-body bone mineral was determined by dual energy x-ray absorptiometry and expressed as bone mineral content (g), bone mineral density (g/cm2), and bone mineral apparent density (g/cm3). Bone mass was related to age, body mass, gonadal function, pulmonary status, and glucocorticoid exposure to identify variables associated with reduced bone mineral in cystic fibrosis. RESULTS: Bone mineral in adults with cystic fibrosis was significantly below expected values for age and sex at all sites using all expressions of bone mass. The mean Z-score was -2.8 for the lumbar spine bone density, -2.5 for the femoral neck, and -2.0 for the whole body. Bone mineral apparent density (a term that minimizes the influence of bone dimensions) was also significantly reduced in patients at the lumbar spine (p < 0.0001) and femoral neck (p < 0.001 to p < 0.0001), indicating that the bone mineral deficit seen in adults with cystic fibrosis could not be attributed to differences in bone size. Age, weight, height, and body mass index were significantly correlated with bone mineral. Pulmonary status, glucocorticoid use, and gonadal function failed to predict bone mineral status. CONCLUSIONS: Osteopenia and osteoporosis occur commonly in young adults with cystic fibrosis. Age and body mass are predictive of bone mineral, although the pathogenesis of this bone mineral deficit is likely multifactorial.

Absorptiometry, Photon↗
PubMed1994

Effect of immunization with inactivated gp120-depleted human immunodeficiency virus type 1 (HIV-1) immunogen on HIV-1 immunity, viral DNA, and percentage of CD4 cells.

A 1-year study measured the effect of administration of an inactivated human immunodeficiency virus type 1 (HIV-1) immunogen in incomplete Freund's adjuvant (IFA) on HIV-1-specific immunity and viral burden in asymptomatic HIV-1-infected patients. A total of 103 patients were enrolled in this double-blind, randomized study comparing immunogen in adjuvant with adjuvant alone. This study was conducted at nine medical centers throughout the United States. Significant differences in cell-mediated immune responses to HIV-1 and p24 core antigen were observed between the treated and control groups (P < .01). Compared with controls, treated patients as a group had a significantly lower rate of increase in viral DNA as determined by quantitative HIV-1 DNA-polymerase chain reaction (P = .016). Significant differences in the rate of percent CD4 cell decline were also observed between the 2 groups (P = .024). These data suggest that augmentation of HIV-1-specific immunity via immunotherapy may alter the rate of increase of HIV-1 DNA in peripheral blood mononuclear cells and stabilize the percent of CD4 cell decline in relatively healthy HIV-1-infected persons.

AIDS Vaccines↗
PubMed1994

Inactivated HIV-1 Immunogen: impact on markers of disease progression.

The pursuit of valid markers of disease progression in human immunodeficiency virus type 1 (HIV-1) infection is especially relevant considering the potential treatment alternatives that presently are under evaluation. Because HIV-1 infection results in a virally induced immune suppression characterized by the loss of cell-mediated immunity (CMI), depletion of CD4+ cells, loss of core antibody, and an increase in viral burden, these markers seemed to be appropriate to monitor in a controlled study. We monitored a number of virologic, immunologic, and cytologic markers of disease progression in 103 subjects who were enrolled in a 12-month, double-blind, randomized, adjuvant-controlled study of the HIV-1 inactivated Immunogen. The markers included HIV-1 DNA, HIV-1 RNA, CD4 percent, p24 antibody, and lymphocyte proliferation. Analysis of HIV-1 DNA with a quantitatively polymerase chain reaction (PCR) assay indicated a treatment effect on viral burden in the HIV-1 Immunogen-treated group. Analysis of HIV-1 RNA revealed a similar trend favoring the Immunogen-treated group. In addition, a significant effect was shown on CD4 percent and CMI in the Immunogen-treated group. An analysis of CMI that used stimulation indices underrepresented the immunogenicity of the Immunogen. Further examination revealed that the lymphocytes of the HIV-1 Immunogen-treated patients were proliferating in vitro without exogenous antigen. Although the clinical significance of this phenomenon currently is unknown, it may be a relevant prognostic marker for assessment of HIV-1 therapy. The data presented here support the concept that immunotherapy with the HIV-1 Immunogen may slow disease progression.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Vaccines↗
PubMed1993

Chronic Pseudomonas aeruginosa endobronchitis in rhesus monkeys: II. A histopathologic analysis.

We have recently established a rhesus monkey model of chronic Pseudomonas aeruginosa (PA) endobronchitis by bronchoscopic instillation of PA-embedded agar beads. All experimental animals developed chronic neutrophilic endobronchitis similar to chronic PA endobronchitis in cystic fibrosis (CF). Histopathologic studies further confirmed similarities to chronic PA endobronchitis in CF, including marked peribronchial inflammation, epithelial damage, presence of degraded cilia and ciliary abnormalities, appearance of PA bacterial clusters, mucosal hyperplasia, goblet cell hypertrophy/hypersecretion, airway obstruction, alveolar abnormalities, bronchiectasis, and fibrosis.

Animals↗
PubMed1993

[Passive immunotherapy for treatment of endobronchitis in cystic fibrosis].

Chronic endobronchial infection with Pseudomonas aeruginosa is a major clinical problem in cystic fibrosis, a genetic disorder of epithelial ion transport and mucus secretion. Functional defects in the opsonic antibody response to critical surface antigens of P. aeruginosa, including lipopolysaccharide and mucoid exopolysaccharide (alginate), have been implicated in the initial colonization and/or persistence of infection of the respiratory tract of cystic fibrosis patients with this bacterium. These defects are correctable in vitro with functional opsonic antibodies against P. aeruginosa present in intravenously administered immunoglobulins (ivIg). Moreover, functional opsonic polyclonal and monoclonal antibodies against P. aeruginosa are protective in animal models of chronic pseudomonal endobronchitis. Two pilot studies on passive immunotherapy with ivIg--one with standard ivIg and one with hyperimmune globulin enriched with anti-Pseudomonas lipopolysaccharide antibodies (Psomaglobin N)--have demonstrated safety and short-term efficacy in terms of improved pulmonary function. Multicenter placebo-controlled trials of passive immunotherapy with conventional ivIg and hyperimmune globulin enriched with antibodies against P. aeruginosa alginate are planned in the United States.

Antibodies, Bacterial↗
PubMed1992

Deficiency of IgG4 in children: association of isolated IgG4 deficiency with recurrent respiratory tract infection.

To study the relationship between serum IgG subclass deficiency and clinical host defense impairment, we reviewed the clinical and immunologic features of 123 patients with a history of recurrent infection who had been examined for immunodeficiency in our laboratory (group 1). We then compared immunoglobulin isotype levels with those in sera from 127 age-matched control subjects without recurrent infection from whom blood had been drawn for evaluation of atopy (group 2). There was a significantly higher prevalence of IgG4 deficiencies among patients with recurrent infections (17% vs 7%; p less than 0.02), solely because of a higher prevalence of isolated IgG4 deficiency (n = 9; 7.3%) than in atopic control subjects (n = 1; 0.8%; p less than 0.05); there was a comparable prevalence of multiple isotype deficiencies that included low levels of IgG4 (9.8% and 6.3%, respectively). All nine group 1 patients with isolated IgG4 deficiency had severe recurrent respiratory tract infections requiring multiple hospitalizations; in addition, five were atopic, five had asthma, and one had chronic diahrrea. Antibody responses to bacterial polysaccharide antigens were normal for age in all patients with isolated IgG4 deficiency; two had defective antibody responses to protein antigens. Isolated IgG4 deficiency appears to be associated with impaired respiratory tract defenses and may occur in the absence of an easily definable antibody deficiency state. This association suggests a physiologic defense role for mucosal IgG4.

Adolescent↗
PubMed1992

Selective polysaccharide antibody deficiency in familial DiGeorge syndrome.

A family including three children with DiGeorge syndrome is described. One child died in the neonatal period from cardiac anomalies accompanying complete DiGeorge syndrome. The two surviving siblings shared a common set of pharyngeal pouch anomalies and immunodeficiency consistent with partial DiGeorge syndrome, and other morphologic anomalies characteristic of the velocardiofacial syndrome with which familial DiGeorge syndrome is associated (reviewed in reference 1). Both had normal karyotypes. Both presented with recurrent otitis media and sinopulmonary infections, CD4+ T cell lymphopenia, and defective DCH skin test responses to recall T cell antigens. Both had low serum IgM levels and IgG4 levels at the lower limits of normal. Immunization with bacterial polysaccharides resulted in impaired IgG antibody responses to the same set of antigens (H. influenzae polyribophosphate and S. pneumoniae capsular serotypes 9N and 14), while responses to protein antigens were intact. Both siblings were treated successfully with intravenous gamma globulin. The pattern of selective antibody deficiency in these patients with familial DiGeorge syndrome suggests a heritable lesion in certain regulatory antipolysaccharide CD4+ T cell subpopulations.

Adult↗
PubMed1991

Sensitization to aztreonam and cross-reactivity with other beta-lactam antibiotics in high-risk patients with cystic fibrosis.

The immunogenicity, allergenicity, and cross-reactivity of aztreonam were investigated in 21 patients with cystic fibrosis (CF) (aged 5 to 39 years) with well-documented histories of allergic systemic reactions (SRs) to penicillin and/or cephalosporin antipseudomonal beta-lactam antibiotics (BLAs). Skin tests (STs) with penicilloyl-polylysine (PPL), penicillin minor determinant mixture, and antipseudomonal BLA were positive in 19 patients (90%). The BLA causing the most recent allergic reaction, minor determinant mixture, or PPL, was positive in 89%, 53%, and 32% of ST-positive patients, respectively. Serum PPL-specific IgE antibodies were not detectable, although PPL-specific IgG antibodies were found in 64% of patients tested. STs to aztreonam reagents were performed and were initially negative in 20 patients. One patient was ST positive to the polylysine conjugate of hydrolyzed aztreonam (SQ 27629), despite no prior exposure to aztreonam, and was not treated. Of 20 patients treated with aztreonam, four were demonstrated to be sensitized by exposure (one had an SR during initial treatment course, two had SRs on reexposure, and one patient was asymptomatic after intravenous desensitization) by positive aztreonam reagent skin responses on repeat testing. Aztreonyl-specific IgE and IgG serum antibodies were not detected in any patients, including patients with allergic reactions to aztreonam. Thus, aztreonam is generally well tolerated in high-risk patients with CF allergic to other BLAs and appears to have reduced immunogenicity by serologic testing. However, caution should be exercised with aztreonam in BLA-allergic patients with CF in light of 5% preexisting ST cross-reactivity and 20% sensitization rates found in this study.

Adolescent↗