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Biomedical subjects

V L Yu

Publications and source records attributed to V L Yu.

At least 73 records · Page 4Linked to original sources
PubMed1997

Cirrhotic fever in the 1990s: a prospective study with clinical implications.

Fifty consecutive patients with fever and cirrhosis were prospectively studied to assess if cirrhotic fever was a true clinical entity and to determine its characteristics and outcome. In 20% (10) of the 50 patients, an identifiable source of fever or infection, was not documented (these patients were defined as having cirrhotic fever). The patients with cirrhotic fever were significantly less toxic, as indicated by lower temperature (P = .0001), tachycardia (P = .0005), and tachypnea (P = .05), but had fever for a longer duration (P = .009) than did patients with infectious fever. Patients with cirrhotic fever were significantly less likely to have focal signs or symptoms (P < .0001) or a portal of infection confirmed by culture (P = .0001), as compared with patients with infectious fever. Outcome (at 30-days or long-term) was not different for patients with cirrhotic fever vs.-patients with infectious fever or matched controls who did not have fever. Eight (80%) of the 10 patients with cirrhotic fever underwent transplantation; fever did not recur after transplantation in any of these patients. Thus, fever in up to 20% of the febrile patients with cirrhosis may be attributable to cirrhosis itself; such patients may be spared the ongoing diagnostic maneuvers and unnecessary trials of antibiotics.

Adult↗
PubMed1997

Psychological stress and depression in older patients with intravenous drug use and human immunodeficiency virus infection: implications for intervention.

We aim to assess the age-related differences in psychological stress and depression in patients with human immunodeficiency virus (HIV) infection. Prospective, longitudinal, observational study of patients with HIV followed at a university affiliated VA Medical Center. Fifty-six consecutive patients with HIV infection aged 19-68 were studied. Data on demographics, living arrangements, education, employment, income, social, religious, and community support, medical status, psychological stress, depression, and coping was assessed at baseline and every 6 months. Instruments for psychological testing included Beck Depression Inventory, Profile Mood Status (POMS) scale and ways of coping scale (inventory of coping with illness scale). Sixty-nine per cent (38/56) of the patients were older than 35 years of age. Older patients exhibited significantly greater emotional and psychological stress; the mean POMS score for older patients was 56.8 as compared to 21.5 for younger patients (P = 0.004). Older patients had significantly greater depression (P = 0.001), higher tension and anxiety (P = 0.005), greater anger and hostility (P = 0.03), greater confusion and bewilderment (P = 0.01), and more fatigue (P = 0.003) as compared with younger patients. Older patients were significantly more likely to have intravenous drug use as an HIV risk factor (P = 0.02), less likely to be employed (P = 0.005), and more likely to use non-traditional therapies (P = 0). Intravenous drug use was an independent predictor of psychological stress in older patients. Patients with HIV, older than 35 years of age, are significantly more likely to suffer from depression and psychological stress; intravenous drug use was an independent predictor of stress. Interventions for the treatment of depression should be especially sought in this subgroup of patients with HIV.

Adult↗
PubMed1997

Macrolides are ideal for empiric therapy of community-acquired pneumonia in the immunocompetent host.

We propose that macrolides, especially the newer macrolides (azithromycin, clarithromycin, roxithromycin), are ideal agents for community-acquired pneumonia in the immunocompetent host who is not a resident of a nursing home or long-term care facility. Macrolides have proven effective in clinical trials against typical and atypical pathogens; thus, unlike beta-lactam agents, they can be given as monotherapy. Streptococcus pneumoniae isolates exhibiting high-level resistance to penicillin and cephalosporins pose a problem not only for the macrolides, but also for quinolones, tetracyclines, and most other beta-lactam agents. The tetracycines, quinolones, and beta-lactam agents have broader spectrum activity against aerobic gram-negative bacilli, which are uncommon pathogens of community-acquired pneumonia in the immunocompetent host. This broader spectrum is not only superfluous, but the potential of emergence of resistant bacteria is enhanced unnecessarily. Serious adverse reactions to the macrolides are rare. The newer macrolides have improved bioavailability and improved pharmacokinetics such that once- or twice-daily dosing regimens can be used. Finally, a comparison of the costs of macrolides to quinolones and beta-lactam agents (especially cephalosporins) show that the oral macrolides are among the least expensive antibiotics that can be prescribed for pneumonia. Thus, macrolides seem to be the ideal empiric antibiotic for community-acquired pneumonia based on spectrum of activity, safety, and cost.

Anti-Bacterial Agents↗
PubMed1996

Pulmonary infections in liver transplant recipients receiving tacrolimus. Changing pattern of microbial etiologies.

Pulmonary infections are a significant cause of morbidity after liver transplantation; Gram-negative bacilli, cytomegalovirus, and Pneumocystis carinii were the usual pulmonary pathogens in the earlier studies in liver transplant recipients receiving cyclosporine. We prospectively assessed the impact of pulmonary infection in 101 consecutive liver transplant recipients receiving the new immunosuppressive agent tacrolimus (FK506). Fifteen percent (15/101) of the patients had 19 episodes of pneumonia; 58% (11/19) of the pneumonias were bacterial, 37% (7/19) were fungal, and 5% (1/19) were protozoal (Toxoplasma gondii). Twenty-seven percent of the bacterial pneumonias were due to Legionella. None of the patients had cytomegalovirus or P carinii pneumonia. Seven percent (7/10) of the study patients had fungal pneumonitis; 4% had invasive aspergillosis and 3% had cryptococcosis. Mortality was significantly higher (53%, 8/15) for patients with pneumonia than for patients without pneumonia (10%, 9/86, P = 0.0004). Only fungal pneumonias were the direct cause of death; 63% (5/8) of the deaths were in patients with fungal pneumonitis. Our data suggest a changing pattern of microbial etiologies of pneumonitis in the era of modern immunosuppressive agents. We show that P carinii pneumonia and cytomegalovirus can be effectively curtailed with appropriate prophylaxis. Fungal infections, on the contrary, not only constituted a major proportion of the pneumonia, but also carried the highest pneumonia-associated mortality. Legionella infections can be overlooked unless specialized laboratory methodology (cultured on selective media, urinary antigen) are applied routinely on all cases of pneumonia. We recommend routine culture on the water supply for Legionella in all transplant centers.

Adult↗
PubMed1996

A high incidence of native portal vein thrombosis in veterans undergoing liver transplantation.

The incidence of native portal vein thrombosis (PVT) in liver transplant recipients has been reported to range from 2.1 to 13.8%. We have identified an inordinately high incidence of PVT in a consecutive series of U.S. veterans receiving liver transplants. Between October 1989 and February 1994, 88 consecutive U.S. veterans received 99 orthotopic liver transplants under primary Tacrolimus (Prograf, formerly FK506) based immunosuppression. A number of clinical features were examined in an effort to identify risk factors for PVT and outcome was compared to patients without PVT. Native PVT was present in 23/88 (26%) patients. All of these patients were male U.S. veterans with a mean age of 47 years. When compared to the 65 patients without PVT, we found no significant difference with respect to underlying liver disease, age, Childs-Pugh score (mean = 12), UNOS status as defined prior to April 1995 (95% UNOS 3 or 4), previous abdominal surgery, or liver volume. Median blood loss for patients with PVT (21 units of packed red blood cells) was greater than for those without PVT (14 units, P = 0.04). Portal thrombectomy was performed in 11 patients, 11 patients required mesoportal jump grafts, and 1 patient had an interposition graft. Standard veno-venous bypass was used in 10 patients with single bypass utilized for the remainder. Actuarial patient survival for all patients at 1, 2, and 4 years was 88, 85, and 79%, respectively. There was no significant difference in patients with or without PVT. Patients with PVT had poorer graft survival than patients without PVT (86% vs 65%, 1 year; 81% vs 65%, 2 years; 81% vs 61%, 4 years; P = 0.03); however, this was not related to technical problems with the portal venous inflow. PVT occurred in 26% of U.S. veterans undergoing liver transplantation. These patients had significantly higher operative blood loss and poorer graft survival. The high incidence of postnecrotic cirrhosis in a predominantly male group of patients with advanced disease, as is evident by the high mean Childs-Pugh score and UNOS status, perhaps accounts for our observations.

Female↗
PubMed1996

Determinants of nontraditional therapy use in patients with HIV infection. A prospective study.

BACKGROUND: The popularity and use of nontraditional therapies among patients with human immunodeficiency virus (HIV) infection has grown enormously. DESIGN: A prospective, longitudinal cohort study of 56 patients aged 23 through 68 years with HIV infection followed up at the HIV clinic at a university-affiliated Veterans Affairs Medical Center. OBJECTIVE: To assess the demographic and psychologic characteristics of patients who seek nontraditional remedies, and their impact on disease progression and mortality from HIV. METHODS: A standardized, self-administered questionnaire to assess the incidence and type of nontraditional therapies used by patients with HIV. Data on demographics, medical status, physical functioning (Karnofsky performance score), CD4 lymphocyte counts, depression (Beck Depression Inventory), coping (inventory of coping with illness scale), psychological and/or emotional stress (Profile of Mood States scores), and compliance with prescribed therapy were prospectively assessed on all patients at baseline and every 6 months. RESULTS: Thirty percent of patients reported using nontraditional therapies. Nontraditional therapy users were significantly older than patients who did not use such therapies (44 vs 38 years, P = .03); with 94% of patients who used nontraditional therapy being older than 35 years compared with 56% of conventional therapy users (P = .005). Alternative therapy use did not correlate with race, education, HIV-risk group affiliation, duration of HIV seropositivity, stage of HIV disease, CD4 cell count, or Karnofsky performance scores. Nontraditional therapy users reported greater community-based acquired immunodeficiency syndrome group support (P = .06), greater perceived social support (P = .08), and significantly higher recreational or "street drugs" use (P = .02). Depression, adaptive coping, and emotional stress were not different between nontraditional and conventional therapy users; however, nontraditional therapy users were significantly more assertive (P = .04). On follow-up, CD4 cell count, HIV disease progression, physical functioning, or mortality were similar between the two groups. CONCLUSIONS: Recourse to nontraditional therapy is common among patients with HIV. Because of the possibility of untoward effects and potential adverse drug interactions associated with nontraditional therapy, HIV care givers should be aware of its use in their patients and take a history of nontraditional therapy first. Patients who choose nontraditional remedies do so not because they are depressed or emotionally disturbed, but rather because they seek greater control of the outcome of their disease. However, no beneficial effect on disease progression, CD4 cell count, or mortality was observed in these patients when compared with patients receiving only conventional medical therapy.

Adaptation, Psychological↗
PubMed1996

The changing face of candidemia: emergence of non-Candida albicans species and antifungal resistance.

OBJECTIVES: To assess the changing epidemiology of candidemia in the 1990s, to evaluate the clinical implications for the presence of non-Candida albicans in blood, and to evaluate the presence of antifungal resistance in relation to prior antifungal administration. DESIGN: Multicenter prospective observational study of patients with positive blood cultures for Candida species or Torulopsis glabrata. SETTING: Four tertiary care medical centers. RESULTS: Four hundred twenty-seven consecutive patients were enrolled. The frequency of candidemia due to non-C. albicans species significantly increased in each hospital throughout the 3.5-year study period (P = 0.01). Thirteen percent of candidemias occurred in patients who were already receiving systemic antifungal agents. Candidemias developing while receiving antifungal therapy were more likely caused by non-C. albicans species than by C. albicans species (P = 0.0005). C. parapsilosis and C. krusei were more commonly seen with prior fluconazole therapy, whereas T. glabrata was more commonly seen with prior amphotericin B therapy. Candida species isolated during episodes of breakthrough candidemia exhibited a significantly higher MIC to the antifungal agent being administered (P < 0.001). CONCLUSION: In this large scale study, the non-C. albicans species, especially T. glabrata, emerged as important and frequent pathogens causing fungemia. This finding has major clinical implications given the higher complication and mortality rate associated with the non-C. albicans species. The change in the pattern of candidemia might be partly attributed to the increase in number of immunocompromised hosts and the widespread use of prophylactic or empiric antifungal therapy. This is an ominous sign given the in vitro resistance of the non-C. albicans species to currently available antifungal agents.

Amphotericin B↗
PubMed1996

Recurrent hepatitis C virus hepatitis in liver transplant recipients receiving tacrolimus: association with rejection and increased immunosuppression after transplantation.

BACKGROUND: Recurrent hepatitis C virus is associated with significant morbidity and mortality after liver transplantation. However, the risk factors for clinical recurrence including the role of rejection and immunosuppression have not been defined in patients receiving tacrolimus (FK506) as primary immunosuppression. METHODS: Sixty-six consecutive adult liver transplant recipients receiving tacrolimus as primary immunosuppression were monitored; 31 of 66 underwent transplantation for end-stage liver disease caused by hepatitis C virus. Median follow-up for the patients in the study was 3 1/2 years. Recurrent hepatitis C virus hepatitis determined on histopathologic evaluation developed in 58% (18 of 31). A number of clinical variables including rejection and intensity of immunosuppression were assessed for patients with and without recurrence. RESULTS: Rejection episodes preceding recurrence were documented in 72% (13 of 18) of patients with recurrence compared with 23% (3 of 13) in those without recurrence (p=0.007). A total of 33% (5 of 15) of patients with no rejection experienced recurrence versus 83% (5 of 6) with one episode of rejection (p=0.06) and 80% (8 of 10) with more than one episode of rejection (p=0.04). The mean number of steroid boluses for the treatment of rejection was higher for patients with recurrence (2.3 versus 0.77, p=0.01). Overall immunosuppression (as measured by steroids boluses, recycles, OKT3, and azathioprine) was significantly more intense for patients with recurrence (p=0.013). CONCLUSIONS: Greater rejection concurrent with increased immunosuppression was associated with a higher recurrence of hepatitis C in liver transplant recipients.

Adult↗
PubMed1996

Candida infection of the arteriovenous fistula used for hemodialysis.

Arteriovenous fistula infection is an exceedingly rare manifestation of Candida infection, with only one case previously reported in the English literature. This report describes three cases of Candida arteriovenous fistula infection seen in a prospective study and reviews the previously reported case. All cases involved the polytetrafluoroethylene graft. The presentations can be either acute or subacute in onset, with drainage at the fistula site as the most common sign. The diagnosis of Candida arteriovenous fistula infection relies on the isolation of the organism from an intraoperative culture of the fistula. Candida was isolated from blood in three of four cases, and wound drainage in two of three cases. Antifungal therapy should be given, but complete removal of the arteriovenous fistula may be necessary for long-term cure.

Aged↗
PubMed1996

Determinants of compliance with antiretroviral therapy in patients with human immunodeficiency virus: prospective assessment with implications for enhancing compliance.

Non-compliance with therapy is a significant problem, particularly when the disease process is chronic and therapeutic regimens are employed for prolonged periods. We assessed the prevalence and variables associated with compliance with antiretroviral therapy in patients with human immunodeficiency virus infection, by means of a longitudinal observational study of 46 patients aged 23 to 68 years, with human immunodeficiency virus infection, followed at the Pittsburgh VA Medical Center. Data on demographics, medical status, physical functioning (Karnofsky performance scores), CD4 lymphocyte count, depression (Beck depression inventory), coping (inventory of coping with illness scale scores), and psychological and emotional stress (profile of mood states scale scores), were prospectively assessed on all patients at baseline and every 6 months. Compliance was assessed at 6 and 12 months: patients taking > or = 80% of antiretroviral therapy were considered compliant. Overall, 63% of patients were compliant with antiretroviral therapy. Age, education, employment, religious support, and perceived quality of life did not correlate with compliance. By univariate analysis, lack of prior intravenous drug use was significantly associated with compliance (p = 0.01). Compliant patients had significantly better adaptive coping (p = 0.03), and less depression (p = 0.04). By multivariate analysis, black race was significantly associated with non-compliance independent of intravenous drug use and educational status. History of prior opportunistic infection (which presumably heightens the perceived severity of illness) (p = 0.02), and lesser psychological disturbance scores (p = 0.02) were associated with compliance. Compliance was observed despite the greater number of prescription medications taken by compliant patients (p = 0.04). At 12 months, Karnofsky scores were better in compliant patients (p = 0.02), although mortality was not different. Besides identifying predictors of compliance, our data suggest that symptoms of depression and psychological stress be sought in patients with non-adherence.

Activities of Daily Living↗
PubMed1996

Candida prosthetic valve endocarditis: prospective study of six cases and review of the literature.

Candida prosthetic valve endocarditis (PVE) is a rare entity; however, its incidence is expected to increase given the recent increase in incidence of nosocomial bloodstream candida infection. This report reviews six cases of candida PVE studied prospectively plus 12 cases previously reported in the literature. Transesophageal echocardiography was more sensitive than transthoracic echocardiography in detecting vegetations. Valvular replacement combined with antifungal therapy has been the standard treatment. However, successful therapy with long-term administration of oral fluconazole has been reported for five patients. The mortality due to candida PVE was high, especially when PVE was complicated by congestive heart failure and persistent fungemia. For uncomplicated PVE, the mortality rate for patients receiving antifungal therapy alone (40%) was no worse than for those receiving combined medical and surgical therapy (33%).

Adult↗
PubMed1996

Low-dose fluconazole as primary prophylaxis for cryptococcal infection in AIDS patients with CD4 cell counts of < or = 100/mm3: demonstration of efficacy in a positive, multicenter trial.

The efficacy of low-dose fluconazole (200 mg orally administered thrice weekly) as primary prophylaxis for cryptococcal infection was prospectively assessed in a multicenter trial involving 218 patients who were infected with human immunodeficiency virus (HIV) and who had CD4 cell counts of < or = 100/mm3. The median CD4 cell count at baseline was 39/mm3, 58% of the patients had an AIDS-defining illness or infection prior to enrollment. Cryptococcal meningitis occurred in 0.4% (1) of the 218 patients. The breakthrough isolate was susceptible to fluconazole, and the fluconazole kinetic study demonstrated adequate drug absorption and serum fluconazole levels; noncompliance could not be excluded in this case. Mucocutaneous and/or esophageal candidiasis developed in 18% (40) of the patients. Noncompliance with fluconazole therapy was the only variable independently associated with breakthrough candidiasis in the study patients (P = .00002). Thus, fluconazole (200 mg thrice weekly) given to HIV-infected patients with CD4 cell counts of < or = 100/mm3 was efficacious as primary prophylaxis for cryptococcosis, with notably lower costs and increased convenience for patients in comparison with daily administration of the drug.

AIDS-Related Opportunistic Infections↗
PubMed1996

Analysis of trends in antimicrobial resistance patterns among clinical isolates of Bacteroides fragilis group species from 1990 to 1994.

Antimicrobial resistance, including plasmid-mediated resistance, among Bacteroides fragilis group species is well documented. A 5-year (1990-1994) prospective, eight-center survey of 3,177 clinical isolates of Bacteroides species was undertaken to review trends in resistance, using the breakpoints for full and intermediate susceptibility established by the National Committee for Clinical Laboratory Standards. No documented resistance to either metronidazole or chloramphenicol was found in this survey. Among B. fragilis isolates virtually no resistance was seen to imipenem, meropenem, ampicillin/sulbactam, piperacillin/tazobactam, or ticarcillin/clavulanate. Significant increases in resistance among B. fragilis isolates to cefotetan, ceftizoxime, and clindamycin (p < .01) were noted. Resistance to cefoxitin remained unchanged. Among the non-fragilis species of the B. fragilis group, there was virtually no resistance to imipenem, meropenem, chloramphenicol, or metronidazole. The three beta-lactamase inhibitors had increasing levels of resistance, although 95%-98% of strains were susceptible (p < .05). There was a significant decline in cefoxitin, cefmetazole, and clindamycin activity over time against these strains (p <.01). There was a significant (P < .001) increase in geometric mean minimum inhibitory concentration for most drugs and species tested from 1990 to 1994. Clusters in the eight institutions could not account for this rise in resistance. This survey demonstrates that rates of resistance of B. fragilis and non-fragilis species of B. fragilis group are increasing.

Bacteroides↗
PubMed1996

Nosocomial Legionnaires' disease caused by Legionella pneumophila serogroup 5: laboratory and epidemiologic implications.

Environmental monitoring and clinical surveillance for Legionella species were done for 12 months as recommended by the Allegheny County Health Department (Pittsburgh). The water system of a hospital was found to be colonized with Legionella pneumophila serogroup 5. Three patients with nosocomial L. pneumophila serogroup 5 disease were subsequently diagnosed after laboratory tests for legionellae were made available for all patients with nosocomial pneumonia. All serogroup 5 isolates from the hospital water matched the 3 patient isolates by pulsed-field gel electrophoresis (PFGE). Furthermore, isolates found in the water supply dating back 10 years showed the same PFGE pattern. In contrast, 12 L. pneumophila serogroup 5 isolates from eight other institutions had different PFGE patterns. Routine environmental cultures were important in stimulating the application of Legionella laboratory testing, which subsequently identified unsuspected patients with nosocomial legionnaires' disease.

Aged↗
PubMed1996

Quantitative comparison in vitro of mutational antibiotic resistance of Enterobacter spp. using a spiral plater.

The presence of spontaneous mutational antibiotic resistance among 18 bacteremic isolates of Enterobacter spp. to cefotaxime, ceftazidime, gentamicin, amikacin, ciprofloxacin, and trimethoprim-sulfamethoxazole was determined quantitatively in vitro using a spiral plater. Each drug was delivered using the device and the agar plates were inoculated in radial streaks. The degree of resistance was estimated by dividing the antimicrobial concentration required to inhibit 90% of the colonies growing in the area beyond the MIC by the MIC itself. The degree of resistance to third-generation cephalosporins and aztreonam was statistically significantly greater than that to co-trimoxazole, imipenem, and ciprofloxacin (P < 0.01); the latter three antibiotics showed virtually no mutational resistance. An intermediate level of resistance was induced by aminoglycosides, and mutational resistance to piperacillin varied between this and the higher levels observed for the cephalosporins. By providing a simple and efficient means of detecting spontaneous mutational resistance, the spiral plater may prove useful in identifying those antimicrobial agents which induce few or no mutants and therefore may be more likely to be successful in treating infections due to Enterobacter spp.

Bacteriological Techniques↗
PubMed1996

A mechanism of rifamycin inhibition and resistance in Pseudomonas aeruginosa.

We sought to study the nature of rifampicin resistance in Pseudomonas aeruginosa. We hypothesized that the rifamycin regions of RNA polymerase are conserved in P. aeruginosa and that rifampicin resistance is mediated by a mutation in the rpoB gene encoding the beta subunit of RNA polymerase. Transcription assays showed that 50 nM of rifampicin inhibited transcription > 99% in a clinical isolate (MIC = 32 mg/L) and only < 40% in the rifampicin resistant mutant (MIC = 1000 mg/L). DNA sequencing revealed that the rifampicin regions are conserved in P. aeruginosa and the rifampicin regions of the rifampicin-resistant strain contained a mutation. Sodium hexametaphosphate lowered rifamycin MIC in a rifamycin-resistant mutant four-fold and in the clinical isolate 32-fold, suggesting that P. aeruginosa has a natural membrane barrier to rifamycins.

Amino Acid Sequence↗
PubMed1996

In vitro activities of two novel oxazolidinones (U100592 and U100766), a new fluoroquinolone (trovafloxacin), and dalfopristin-quinupristin against Staphylococcus aureus and Staphylococcus epidermidis.

Two oxazolidinones (U100592 and U100766), trovafloxacin, and a streptogramin combination (dalfopristin-quinupristin) were highly active in vitro against Staphylococcus aureus and Staphylococcus epidermidis, including methicillin-resistant strains. Trovafloxacin was more active than ciprofloxacin. Time-kill synergy studies demonstrated indifference for the oxazolidinones combined with vancomycin and rifampin against methicillin-resistant staphylococci. Spontaneous resistance was observed with all agents.

Acetamides↗