Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antibodies directed to capsular polysaccharides form an essential component in the defence against infections with encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenzae type b. Immune responses to polysaccharide antigens can occur in the absence of a functional thymus and the antigens are therefore designated as thymus independent. However, regulatory T cells may influence the magnitude of the antibody response to capsular polysaccharide antigens. So-called thymus independent type 2 antigens share several features of their immune response such as late development of antibody synthesis in ontogeny, no memory formation and a restricted isotype (IgM, IgG2) and idiotype usage. In infants and young children up to the age of 2 years the antibody response to capsular polysaccharides is inadequate resulting in an increased incidence of diseases such as pneumonia, meningitis, otitis and other forms of bacteremic disease. Anti-capsular polysaccharide antibody deficiency does occur in a number of well defined immunodeficiency syndromes including hypo- or agammaglobulinaemia, selective IgA and/or IgG subclass deficiency, Wiskott-Aldrich syndrome, DiGeorge anomaly and also in acquired immune deficiencies such as AIDS, and some forms of lymphoid malignancies. In elderly and in conditions such as splenectomy an increased incidence of infections with encapsulated bacteria does occur, sometimes but not always on basis of a defect in antibody formation. Clinicians are often confronted with young patients older than 2 years of age suffering from recurrent severe bacterial infections of the respiratory tract. In these patients no overt immunodeficiency is demonstrable but recent results indicated that a small percentage may show a selective defect in the antibody response since upon vaccination with polysaccharide vaccines no increase in antibody titer does occur. Though antibodies to polysaccharide antigens in young children are mainly of the IgM and IgG1 (IgG3) isotype, in older children and adults the polysaccharide antibodies are predominantly localized in the IgG2 subclass. The bridge between IgG2 type antibodies and phagocytosis of encapsulated bacteria is constituted by Fc gamma receptors for IgG2 on effector cells. The recent finding that allotypes of Fc gamma RIIa do exist that either bind or do not bind IgG2 type antibodies strongly suggests that the defence of a given individual to encapsulated bacteria apart from an intact antibody formation and the complement system also is determined by the allotype of the appropriate Fc gamma receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Anti-capsular polysaccharide antibody deficiency states. 816 45

Patients with HIV infection are at increased risk for community-acquired bacterial pneumonias, due in part to their defects in B-cell function. Streptococcus pneumoniae is the commonest cause of community-acquired pneumonia, with the second most common bacterial agent being Haemophilus influenzae. These two organisms account for about two-thirds of community-acquired bacterial pneumonias. Frequently bacterial pneumonias appear difficult to distinguish from Pneumocystis carinii pneumonia or other opportunistic lung infections, because of their atypical clinical and radiologic presentations. Community-acquired pneumonias may be recurrent but have low fatality rates. In comparison, nosocomial pneumonias occur primarily in patients with AIDS and are usually due to Staphylococcus aureus, Pseudomonas aeruginosa and other aerobic gram-negative bacilli. Nosocomial pneumonias have high fatality rates. S.aureus is an important cause of morbidity and mortality in patients with AIDS and has emerged as a secondary opportunist in lungs of patients with opportunistic diseases. While appropriate laboratory study is being done, empiric antibiotic therapy should be directed against the microorganisms above described.
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PMID:Bacterial pneumonia in adult patients with HIV infection. 856 41

Pulmonary infections are a very common complication in acquired immune deficiency syndrome (AIDS) patients. These infections may be severe enough to initiate the admission of these patients to intensive care units (ICU). Pneumocystis carinii pneumonia (PCP) is the most frequent cause of ICU admission because of acute respiratory failure. Mortality of ICU-admitted patients with this infection has changed with time. Initial reports confirmed a high mortality (80% to 90%). After 1985, the mortality rate decreased (50%). Factors such as the use of corticosteroids, better patient care, and a better knowledge of the disease probably explain this change. In recent years (1990 to 1995), mortality has worsened again, perhaps, because ICU facilities were offered more liberally to patients failing aggressive conventional treatment, including adjuvant therapy with corticosteroids. However, for those patients able to be discharged, the prognosis is not worse than expected according to the stage of their human immunodeficiency virus-1 (HIV-1) infection and immunologic status. Consequently, at least a limited period of ICU care and some respiratory support (either continuous positive airway pressure or mechanical ventilation) should be considered and offered to all HIV-1-infected patients with PCP and respiratory failure. Cytomegalovirus may be another cause of severe pulmonary infection in AIDS patients. This infection is difficult to diagnose; hence, it should be suspected when patients with PCP do not progress appropriately, or when no responsible pulmonary pathogen is found. When associated with PCP, mortality is very high. Disseminated tuberculosis is another potential cause of severe respiratory failure and respiratory secretions should be routinely examined for acid-fast bacilli in AIDS patients with pulmonary infiltrates. Finally, bacterial pneumonia (Streptococcus pneumoniae, Neisseria catarrhalis, Haemophilus influenzae, Staphylococcus aureus, and Pseudomonas aeruginosa) may also be the etiological agents of severe acute respiratory failure. Empiric antibacterial treatment to cover these microorganisms should be given when a bacterial agent is suspected.
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PMID:Severe pulmonary infections in AIDS patients. 877 81

We identified 31 patients with human immunodeficiency virus (HIV) infection and lung abscess. All patients had advanced HIV disease, and the mean CD4 cell count was 17/mm3 (range, 2-50/mm3). Twenty-two patients (71%) had previous opportunistic infections, and 24 (77%) had previous pulmonary infections. Symptoms at the time of presentation included fever (90% of patients), cough (87%), dyspnea (35%), pleuritic chest pain (26%), and hemoptysis (10%). The microbiological etiology was established for 28 patients, and the pathogens recovered were bacteria (65%), Pneumocystis carinii (6%), fungi (3%), and mixed microorganisms (16%). The pathogens included Pseudomonas aeruginosa (11), Streptococcus pneumoniae (6), P. carinii (5), Klebsiella pneumoniae (5), Staphylococcus aureus (4), Aspergillus species (3), viridans streptococcus (2), Haemophilus influenzae (1), Streptococcus milleri (1), Proteus mirabilis (1), and Cryptococcus neoformans (1). Mycobacterium tuberculosis was not isolated; two patients for whom a microbiological etiology was not established responded to antituberculous therapy. Patients were treated for 2-12 weeks; 25% of the patients received > 4 weeks of therapy. The outcome was poor: 36% of the patients had recurrences, and 19% died. In patients with AIDS, lung abscess is associated with advanced HIV infection, is due to a broad spectrum of pathogens, responds poorly to antibiotics, and has a poor prognosis.
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PMID:Lung abscess in patients with AIDS. 882 70

Antimicrobials are frequently used to prevent infections. Principles of prophylaxis, and antimicrobial prophylaxis in surgery, tuberculosis, acquired immunodeficiency syndrome, influenza A, traveller's diarrhoea, malaria, recurrent otitis media, Haemophilus influenzae type b infection, pertussis, rheumatic fever, and urinary tract infection are described. Various strategies to improve the prophylactic use of antibiotics are discussed. Collaborative efforts among health care disciplines are needed to assure optimal antimicrobial prophylaxis. This should maximize efficacy and minimize adverse effects, the development of bacterial resistance and associated costs.
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PMID:Guidelines for antimicrobial prophylaxis. 893

Macrolide antibiotics have proven to be valuable alternatives to penicillins and cephalosporins for the treatment of a number of infections. Currently, a number of macrolides are available. When choosing a particular macrolide, the types of organisms causing the infection, the tolerability of the drug, convenience of dosing and possible drug interactions all must be taken into account. Erythromycin, azithromycin and clarithromycin are equally effective against most gram-positive organisms. However, clarithromycin and azithromycin have much better activity against Haemophilus influenza and Moraxella catarrhalis. Thus, these 2 drugs are better choices for the treatment of community-acquired pneumonia. However, the low serum concentrations of azithromycin may be a problem in patients with bacteraemia associated with with community-acquired pneumonia. Clarithromycin appears to be effective for the treatment and prophylaxis of Mycobacterium avium complex (MAC) in patients with AIDS, while azithromycin appears to be effective for prophylaxis. Treatment of MAC with azithromycin is currently undergoing study. Although clarithromycin is the macrolide of choice for the treatment of Helicobacter pylori, azithromycin is the preferred macrolide for the treatment of Chlamydia trachomatis infections. The major factor limiting the use of azithromycin and clarithromycin has been their cost. However, these drugs may be cost effective if compliance is improved due to better tolerability and more convenient dosing regimens.
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PMID:Choosing the right macrolide antibiotic. A guide to selection. 907 39

With changes in the demographics of human immunodeficiency virus (HIV) infection, women and children are becoming the fastest growing group of newly infected patients. With longer survival after HIV infection, more women infected with HIV are becoming pregnant. Pulmonary disease is one of the most common presenting conditions in an AIDS-defining illness. Pneumocystis carini pneumonia and tuberculosis are the most common disorders that herald the onset of AIDS. They are also the most frequently encountered HIV-related pulmonary complications during pregnancy. Others have been rarely reported during pregnancy and include fungal infections (Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitus), bacterial infections (Haemophilus influenzae and Streptococcus pneumoniae along with Pseudomona aeruginosa), viral infections (CMV), opportunistic neoplasms (Kaposi's sarcoma, lymphoma) and miscellaneous conditions peculiar to HIV-infected individuals (nonspecific interstitial pneumonitis, lymphoid interstitial pneumonitis, isolated pulmonary hypertension, and pulmonary edema secondary to cardiac disease or drug abuse). Most of the data regarding the pulmonary complications of HIV infection come from studies in nonpregnant patients. The extent to which pregnancy affects the course of respiratory disease in HIV infection and vice versa is not well documented. Clinical presentation is usually not altered by pregnancy. Except for minor modifications mainly related to potential fetal effects, the diagnostic work-up and management are similar to those in the nonpregnant patient. The most important effect of pregnancy on these conditions remains the delay in diagnosis and treatment. A high index of suspicion should, therefore, be maintained. In addition, most prophylactic measures recommended in nonpregnant HIV-infected individuals also apply to pregnant women.
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PMID:Human immunodeficiency virus (HIV)-related pulmonary complications in pregnancy. 929 23

We have reviewed the incidence, type and site of microbiologically proven bacterial infection occurring in 52 patients with the acquired immunodeficiency syndrome (AIDS) who presented to Southmead Hospital, Bristol between 1990 and 1994. A total of 30 (58%) patients had significant bacterial isolates. The majority of infections were community acquired. Overall, more infections were caused by Gram-negative organisms but Gram-positive organisms predominated in bacteraemia. Mycobacterium avium intracellulare (MAI) caused infection in the largest number of patients, followed by Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas sp, and Campylobacter sp. When individual episodes of infection were considered, after MAI, Haemophilus influenzae, Streptococcus pneumoniae and Pseudomonas sp were the organisms most frequently isolated; often these same organisms caused recurrent chest infection. Bacterial infections in AIDS patients are common and although they generally respond well to antimicrobial chemotherapy there is a high recurrence rate, particularly in the respiratory tract, which is the commonest site of infection.
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PMID:Microbiologically proven bacterial infections in AIDS. 937 97

Systemic corticosteroids have been used in the treatment of numerous medical conditions for approximately 50 years. Short-acting products such as hydrocortisone are the least potent. Prednisone and methylprednisolone, which are intermediate-acting products, are four to five times more potent than hydrocortisone. Dexamethasone is a long-acting, systemic corticosteroid; its potency is about 25 times greater than the short-acting products. Corticosteroids reduce the need for hospitalization in patients with croup and decrease morbidity and the incidence of respiratory failure in the treatment of patients with AIDS who have Pneumocystis carinii pneumonia. Other often overlooked indications for corticosteroids are the treatment of hyperthyroid states, including thyroid storm, subacute thyroiditis and ophthalmopathy of Graves' disease. Systemic steroids can be used as adjuvant analgesics in the treatment of neuropathic and cancer-related pain. They may also decrease mortality in patients with severe alcoholic hepatitis and concomitant encephalopathy. Corticosteroids can reduce complications in patients with meningitis caused by Haemophilus influenzae or Mycobacterium tuberculosis.
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PMID:A different look at corticosteroids. 971 98

People infected with human immunodeficiency virus (HIV) are at increased risk for bacterial infections due to HIV-associated immunologic defects. Bacterial infections were found to be, both a predictor of progression to AIDS and a substantial cause of mortality in pre-AIDS stages. Most bacterial infections are caused by Streptococcus pneumoniae, Haemophilus influenzae, Salmonella spp. and Pseudomonas aeruginosa. Rhodococcus equi, Nocardia spp., Campylobacter spp. and Bartonella spp. are less common. Data derived from two AIDS Clinical Trials Group studies showed that the most common bacterial infections were sinusitis (8.5 per 100 episodes per person years [py]), bacterial pneumonia (5.0 per 100 py), bronchitis (4.1 per 100 py) and soft tissue infections (3.5 per 100 py). In this review clinical characteristics and treatment recommendations according to data available in the literature for these infections are summarized.
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PMID:[Other infections (Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Salmonella spp., Campylobacter spp., Nocardia asteroides, Rhodococcus equi and Bartonella spp.)]. 985 21


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