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Biomedical subjects

C L Daley

Publications and source records attributed to C L Daley.

36 records · Page 2Linked to original sources
PubMed1998

Differences in contributing factors to tuberculosis incidence in U.S. -born and foreign-born persons.

To determine the factors contributing to tuberculosis incidence in the U.S.-born and foreign-born populations in San Francisco, California, and to assess the effectiveness of tuberculosis control efforts in these populations, we performed a population-based molecular epidemiologic study using 367 patients with strains of Mycobacterium tuberculosis recently introduced into the city. IS6110-based and PGRS-based restriction fragment length polymorphism (RFLP) analyses were performed on M. tuberculosis isolates. Patients whose isolates had identical RFLP patterns were considered a cluster. Review of public health and medical records, plus patient interviews, were used to determine the likelihood of transmission between clustered patients. None of the 252 foreign-born cases was recently infected (within 2 yr) in the city. Nineteen (17%) of 115 U. S.-born cases occurred after recent infection in the city; only two were infected by a foreign-born patient. Disease from recent infection in the city involved either a source or a secondary case with human immunodeficiency virus (HIV) infection, homelessness, or drug abuse. Failure to identify contacts accounted for the majority of secondary cases. In San Francisco, disease from recent transmission of M. tuberculosis has been virtually eliminated from the foreign-born but not from the U.S.-born population. An intensification of contact tracing and screening activities among HIV-infected, homeless, and drug-abusing persons is needed to further control tuberculosis in the U.S.-born population. Elimination of tuberculosis in both the foreign-born and the U.S. -born populations will require widespread use of preventive therapy.

AIDS-Related Opportunistic Infections↗
PubMed1997

Methods for diagnosing tuberculosis among in-patients in eastern Africa whose sputum smears are negative.

SETTING: Two University hospitals in Eastern African capital cities where large prospective studies had been carried out on hospitalized patients to determine the cause of their respiratory diseases. OBJECTIVE: To identify features that differentiated between tuberculosis (TB) and non-tuberculous respiratory disease (non-TB) in hospitalized patients from Bujumbura, Burundi (n = 111) and Dar es Salaam, Tanzania (n = 71) whose sputum smears were negative on microscopic examination for acid-fast bacilli (AFB). DESIGN: Review of clinical findings, radiologic abnormalities, and laboratory test results from 182 patients, first by univariate and then by multivariate (stepwise logistic regression) analysis to assess the contribution of each factor to the final diagnosis. RESULTS: Of the 182 patients with two or more negative AFB smears, 41 had TB and 141 had non-TB. Stepwise regression analysis revealed four easily ascertained symptoms were associated with TB: 1) cough > 21 days; 2) chest pain > 15 days; 3) absence of expectoration; and 4) absence of shortness of breath. Any two of the four diagnosed TB with 85% sensitivity and 67% specificity; any three of the four with 49% sensitivity and 86% specificity. Multivariate analysis showed that adding lymphadenopathy and hematocrit < 30% improved discrimination. CONCLUSION: This methodological approach provides a means for diagnosing TB among all AFB smear-negative hospitalized patients. In this setting, simple clinical symptoms alone are helpful. Similar studies are needed to develop a system for out-patient TB suspects.

Adolescent↗
PubMed1996

Generalized immune activation in pulmonary tuberculosis: co-activation with HIV infection.

Parameters of immune activation/differentiation were studied in a group of newly diagnosed HIV- and HIV+ pulmonary tuberculosis (TB) patients. Compared with controls, HLA-DR expression on both CD4 and CD8 T cells from the HIV- TB patients was approximately doubled; HLA-DR on T cells from the HIV+ group was tripled. The monocytes from both groups of patients expressed abnormally high levels of the Fc gamma receptors I and III. Serum levels of tumour necrosis factor-alpha (TNF-alpha), neopterin and beta 2-microglobulin were increased in HIV- and even more so in HIV+ TB patients. The expression of HLA-DR on T cell subsets and of Fc gamma R on monocytes correlated with each other, but not with serum activation markers. This pattern of non-specific activation during TB infection may be associated with enhanced susceptibility to HIV infection.

Adult↗
PubMed1996

Pulmonary complications of HIV infection in Dar es Salaam, Tanzania. Role of bronchoscopy and bronchoalveolar lavage.

To determine the pulmonary complications in HIV-1-infected patients in Dar es Salaam, Tanzania, and to evaluate the diagnostic utility of bronchoscopy and bronchoalveolar lavage, we carried out a prospective study of 237 patients with acute respiratory disease who were hospitalized at Muhimbili Medical Center (MMC). Diagnoses were made using well-defined criteria. Of the total, 127 (54%) were HIV-1-seropositive and 110 (46%) were seronegative. Tuberculosis was the most common diagnosis occurring in 95 (75%) HIV-1-seropositive and 87 (79%) seronegative patients. Bacterial pneumonia was the next most common diagnosis occurring in 18 (14%) HIV-1-seropositive and 17 (15%) seronegative patients. Pneumocystis carinii pneumonia was diagnosed in one and Kaposi's sarcoma was seen in only two HIV-1-seropositive patients. Bronchoscopy with bronchoalveolar lavage was the sole source of a diagnosis in nine (8%) seropositive and six (5%) seronegative patients. We conclude that the HIV seroprevalence rate among patients hospitalized for acute respiratory disease at MMC is extremely high. Tuberculosis was the most common cause of pulmonary disease, regardless of HIV serostatus, and other HIV-associated opportunistic pulmonary infections were unusual. Bronchoscopy with bronchoalveolar lavage added little to the diagnosis and thus should not be high-priority procedures for the routine workup in resource-poor areas where tuberculosis is endemic.

AIDS-Related Opportunistic Infections↗
PubMed1996

The transcontinental transmission of tuberculosis: A molecular epidemiological assessment.

Many tuberculosis control activities are based on principles learned from studies of tuberculosis transmission. To date, these have largely been limited to outbreak investigations in confined geographical regions. In this report conventional and computerized DNA fingerprint- based approaches were integrated to demonstrate that the most widely prevalent strain of Mycobacterium tuberculosis from New York City was cultured from only 1 of 755 patients in San Francisco, Calif, who was a traveling salesman. Large-scale molecular epidemiologic studies may provide a better understanding of the dynamics of tuberculosis transmission between geographic regions and suggest rational measures to interrupt such transmission.

Adult↗
PubMed1995

Impact of Streptococcus pneumoniae bacteremia and human immunodeficiency virus type 1 on oral mucosal immunity.

To determine whether defects in mucosal immunity were associated with invasive disease caused by a mucosal pathogen, Streptococcus pneumoniae, levels of salivary immunoglobulins and nonspecific immune factors were compared in subjects with human immunodeficiency virus type 1 (HIV-1) infection and in HIV-1-seronegative subjects with and without pneumococcal bacteremia. The IgA2 subclass may be of particular importance because S. pneumoniae produces IgA1 protease, which cleaves IgA1 but not IgA2. Levels (37-56 micrograms/mL) and proportions (11%-17%) of IgA2 were similar among groups. Serotype-specific capsular salivary IgA was present in a minority of patients with acute bacteremia. Levels of lactoferrin were increased with bacteremia. Neither selective mucosal IgA2 deficiency nor impaired nonspecific upper respiratory mucosal responses were associated with invasive pneumococcal disease during HIV-1 infection; thus, other defects in mucosal cellular responses and systemic immunity may predispose HIV-1-infected patients to invasive pneumococcal disease.

AIDS-Related Opportunistic Infections↗
PubMed1995

Impaired natural immunity to pneumolysin during human immunodeficiency virus infection in the United States and Africa.

Human immunodeficiency virus (HIV) infection is associated with a significantly increased incidence of pneumococcal pneumonia and concomitant bacteremia. We hypothesized that the predisposition of HIV-infected patients to invasive pneumococcal infection may be related, in part, to an impaired immune response to the pneumococcal antigen pneumolysin (PLY) because PLY facilitates bacterial invasion. We measured serum anti-PLY antibodies in two separate populations of HIV-infected and HIV-seronegative controls, using both an enzyme-linked immunosorbent assay method and a functional assay of antibody inhibition of PLY-induced hemolysis and cytotoxicity. HIV-infected patients in the United States had significantly lower titers of anti-PLY antibodies by both methods than did seronegative control subjects. Moreover, HIV-infected patients in Kenya who later developed pneumococcal bacteremia also had significantly lower anti-PLY antibody levels at baseline compared with seronegative control subjects. We conclude that lower baseline levels of antibodies to PLY are associated with the higher incidence of bacteremic pneumococcal infections among HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

The epidemiology of tuberculosis in San Francisco. A population-based study using conventional and molecular methods.

BACKGROUND: The epidemiology of tuberculosis in urban populations is changing. Combining conventional epidemiologic techniques with DNA fingerprinting of Mycobacterium tuberculosis can improve the understanding of how tuberculosis is transmitted. METHODS: We used restriction-fragment-length polymorphism (RFLP) analysis to study M. tuberculosis isolates from all patients reported to the tuberculosis registry in San Francisco during 1991 and 1992. These results were interpreted along with clinical, demographic, and epidemiologic data. Patients infected with the same strains were identified according to their RFLP patterns, and patients with identical patterns were grouped in clusters. Risk factors for being in a cluster were analyzed. RESULTS: Of 473 patients studied, 191 appeared to have active tuberculosis as a result of recent infection. Tracing of patients' contacts with the use of conventional methods identified links among only 10 percent of these patients. DNA fingerprinting, however, identified 44 clusters, 20 of which consisted of only 2 persons and the largest of which consisted of 30 persons. In patients under 60 years of age, Hispanic ethnicity (odds ratio, 3.3; P = 0.02), black race (odds ratio, 2.3; P = 0.02), birth in the United States (odds ratio, 5.8; P < 0.001), and a diagnosis of the acquired immunodeficiency syndrome (odds ratio, 1.8; P = 0.04) were independently associated with being in a cluster. Further study of patients in clusters confirmed that poorly compliant patients with infectious tuberculosis have a substantial adverse effect on the control of this disease. CONCLUSIONS: Despite an efficient tuberculosis-control program, nearly a third of new cases of tuberculosis in San Francisco are the result of recent infection. Few of these instances of transmission are identified by conventional contact tracing.

AIDS-Related Opportunistic Infections↗
PubMed1993

Bacterial pneumonia in HIV-infected patients.

Individuals infected with the human immunodeficiency virus (HIV) are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. Streptococcus pneumoniae and Haemophilus influenzae are the most common causes of bacterial pneumonia in HIV-infected patients. However, more unusual bacteria can also cause pneumonia. Response to therapy is generally good for infections caused by pyogenic organisms, and complications are relatively few. Unfortunately, infections caused by Rhodococcus equi and Nocardia species are associated with significant morbidity and mortality. Moreover, the duration of therapy is long, and relapes are common. Prevention of bacterial pneumonia is an important part of the care of HIV-infected patients; the 23 valent pneumococcal vaccine is currently recommended for all HIV-infected patients. The role of other preventative measures remains unknown.

Adult↗
PubMed1992

Pneumococcal disease during HIV infection. Epidemiologic, clinical, and immunologic perspectives.

OBJECTIVE: To characterize the epidemiology, clinical manifestations, and immunologic risk factors for infections with Streptococcus pneumoniae among persons infected with human immunodeficiency virus (HIV); and to delineate a practical approach for diagnosis, treatment, and prevention of these infections. DATA SOURCES: English-language articles from Index Medicus and their references as well as abstracts from conference proceedings that compared rates as well as clinical and microbiologic features of S. pneumoniae infections in HIV-infected patients. STUDY SELECTION: All human studies that included denominators, appropriate control groups, or sufficient clinical descriptions and animal studies with key immunologic observations were cited. DATA EXTRACTION: We compared epidemiologic and clinical responses to pneumococcal disease in HIV-infected patients and control subjects and correlated clinical and experimental data on immunologic defects associated with HIV infection with those on regulation of pneumococcal infections. DATA SYNTHESIS: Among patients with HIV infection, the incidence of invasive pneumococcal disease is high, bacteremia is a common complication of pneumonia, and relapses occur frequently. However, the clinical presentation, response to therapy, and serotypes isolated are similar to those in persons without HIV infection, and mortality is similar or lower. Specific local and systemic defects in host defense, particularly humoral immunity, may contribute to the high incidence of invasive pneumococcal disease. CONCLUSIONS: Streptococcus pneumoniae is the leading cause of invasive bacterial respiratory disease in adults and children with HIV infection. Prompt diagnosis and antimicrobial therapy are associated with a favorable clinical outcome. Characterizing the specific immunologic defects associated with invasive pneumococcal disease in HIV-infected patients may facilitate development of successful, cost-effective strategies for prophylaxis.

HIV Infections↗
PubMed1992

An outbreak of tuberculosis with accelerated progression among persons infected with the human immunodeficiency virus. An analysis using restriction-fragment-length polymorphisms.

BACKGROUND: Tuberculosis typically develops from a reactivation of latent infection. Clinical tuberculosis may also arise from a primary infection, and this is thought to be more likely in persons infected with the human immunodeficiency virus (HIV). However, the relative importance of these two pathogenetic mechanisms in this population is unclear. METHODS: Between December 1990 and April 1991, tuberculosis was diagnosed in 12 residents of a housing facility for HIV-infected persons. In the preceding six months, two patients being treated for tuberculosis had been admitted to the facility. We investigated this outbreak using standard procedures plus analysis of the cultured organisms with restriction-fragment-length polymorphisms (RFLPs). RESULTS: Organisms isolated from all 11 of the culture-positive residents had similar RFLP patterns, whereas the isolates from the 2 patients treated for tuberculosis in the previous six months were different strains. This implicated the first of the 12 patients with tuberculosis as the source of this outbreak. Among the 30 residents exposed to possible infection, active tuberculosis developed in 11 (37 percent), and 4 others (13 percent) had newly positive tuberculin skin tests. Of 28 staff members with possible exposure, at least 6 had positive tuberculin-test reactions, but none had tuberculosis. CONCLUSIONS: Newly acquired tuberculous infection in HIV-infected patients can spread readily and progress rapidly to active disease. There should be heightened surveillance for tuberculosis in facilities where HIV-infected persons live, and investigation of contacts must be undertaken promptly and be focused more broadly than is usual.

Adult↗
PubMed1991

Pyogenic bacterial pneumonia in the acquired immunodeficiency syndrome.

Individuals with human immunodeficiency virus (HIV) infection are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. The most common causes of community-acquired pyogenic bacterial pneumonia in HIV-infected patients are Streptococcus pneumoniae and Haemophilus influenzae. The clinical presentation of HIV-infected patients with pyogenic pneumonia does not seem to differ significantly from that of patients without HIV infection. Response to therapy is generally good, and complications relatively few. Prevention of bacterial pneumonia is very important in the care of HIV-infected persons. The pneumococcal vaccine is currently recommended for all HIV-seropositive individuals, although its efficacy is unknown is this setting. Other forms of prevention require further investigation but may prove to be helpful.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The runny nose. Infection of the paranasal sinuses.

Infection of the paranasal sinuses is an important although infrequent complication of the common cold. This article discusses the pathophysiology, etiology, clinical presentation, complications, differential diagnosis, treatment, and prevention of these infections. Proper treatment with the appropriate antibiotic may help in avoiding irreversible mucosal damage, thus decreasing the incidence of chronic sinusitis.

Acute Disease↗
PubMed1976

Apparent opposing effects of cyclic AMP and dibutyryl cyclic GMP on the neuronal firing of the blowfly chemo-receptors.

Cyclic AMP and its dibutyryl derivative inhibit neuronal firing of the labellar sugar sensitive receptor of the blowfly when applied in conjunction with the stimulant sucrose. Furthermore, simultaneous application of aminophylline (phosphodieterase inhibitor) and sucrose or in combination with cyclic AMP caused a similar depression of the sugar receptors response. In contrast, dibutyryl cyclic GMP elicited an increase in sugar receptor firing when applied with sucrose to sugar receptor. Either 5'-AMP or 5'-GMP in combination with sucrose had no discernable effect on the sugar receptors response. Different ratio combinations of cyclic AMP and dibutyryl cyyclic GMP showed the striking inhibitory effect of cyclic AMP upon the dibutyryl cyclic GMP elicited increases in receptor firing frequency. Therefore, it is suggested that these two nucleotides may be mediating different but complimentary aspects of sugar receptor function in a push-pull manner.

Aminophylline↗