Incidence of major clinical outcomes in a cohort of Ugandan and Zimbabwean women with HIV-1 infection followed from seroconversion

We conducted a prospective cohort study of 306 HIV-1-infected women, followed from seroconversion for median 6.4 years in Uganda (UG) and Zimbabwe (ZM) to describe the incidence of major clinical outcomes (MCOs), defined as World Health Organization stage 4 conditions and any tuberculosis (TB). In Uganda, 19 MCOs occurred in 13 participants at median 4.6 years and a median CD4 count of 213 cells/mm(3). In Zimbabwe, 29 MCOs occurred in 27 participants at median 4.0 years (P < 0.001 versus UG) and median CD4 count of 219 cells/mm(3) (P = 0.83 versus UG). MCO incidence was not statistically different (UG: 2.82 cases/100 person-years versus ZM: 2.45; P = 0.64) except for TB (UG: 0.59 versus ZM: 2.02 cases/100 person-years; P = 0.02). This significant difference in TB incidence is primarily due to a TB screening and isoniazid prevention therapy programme that was implemented in Uganda, but not in Zimbabwe, highlighting the importance of integrated TB screening and treatment within HIV programmes.

Identification of gentian violet concentration that does not stain oral mucosa, possesses anti-candidal activity and is well tolerated

Gentian violet (GV) is recommended for initial treatment of oral candidiasis in HIV-infected patients in resource-limited settings. Currently GV is not used because of its staining effects. In this study, we investigated the staining capacity of three different concentrations of GV to determine a concentration that does not cause staining. The selected concentration that did not cause staining was evaluated for its physical stability and antifungal activity. Fifteen healthy participants were randomized to rinse twice daily for 14 days with one of three GV concentrations: 0.1%, 0.0085%, or 0.00165%. Oral examination and intra-oral photographs were performed at baseline and at the end of therapy. Participants responded to a questionnaire to assess adverse events. Antifungal activity was evaluated using the Clinical and Laboratory Standard Institute methodology. GV at a concentration of 0.00165% did not stain the oral mucosa and was well tolerated. GV at a concentration of 0.00165% was stable and possessed antifungal activity when stored at certain temperatures for different time periods. Gentian violet solution at the concentration of 0.00165% does not stain the oral mucosa, is stable and possesses potent antifungal activity.

Acceptability of treatment of latent tuberculosis infection in newly HIV-infected young women in Uganda

We studied the acceptability of isoniazid preventive therapy (IPT) in newly human immunodeficiency virus (HIV) infected Ugandan women. Women were followed in an out-patient clinic where they received HIV care including IPT. Of 52 women who were purified protein derivative-positive, 48 were eligible for IPT and 39 (81%) completed therapy. This completion rate was higher than reported in similar observational studies.

Variations in CD4 cell counts among HIV-uninfected and infected women in Uganda and Zimbabwe

We conducted a cross-sectional study with 208 HIV-uninfected and 188 HIV-infected women in Uganda and Zimbabwe to investigate differences in median CD4 counts. Absolute CD4 counts were determined by flow cytometry. Multivariate analyses were used to examine the association of country and HIV-infection status on CD4 counts. Median CD4 counts were significantly lower in Zimbabwe than in Uganda overall (649 and 783 cells/mm(3), P = 0.009) and among HIV-infected women (470 and 614 cells/mm(3), P = 0.003). In separate multivariable models, CD4 counts were significantly lower in Zimbabwe in HIV-uninfected (P = 0.014) and infected (P < 0.001) women, controlling for age, contraceptive method, education and living with partner status. In a model combining HIV-uninfected and infected women, there was no significant interaction between country and HIV infection status (P = 0.344), suggesting that the relationship between country and CD4 count was not significantly modified by HIV infection status. This study reinforces the importance of establishing country-specific reference CD4 levels as CD4 count continues to be used as a key biomarker in clinical decision-making for HIV-infected individuals in sub-Saharan Africa.

Stevens - Johnson syndrome due to nevirapine

A 25-year-old HIV-infected woman participating in a study of the effects of hormonal contraception on HIV disease progression was started on antiretroviral therapy-Combivir & Nevirapine (NVP) on May 27, 2004. NVP was 200mg daily initially for two weeks to be increased to 200mg bid thereafter. On day twelve, she presented with a mild skin rash on the trunk, purulent conjunctivitis, pharyngitis and fever. She was treated symptomatically and sent home. The following day she returned with a generalized erythematous eruption. She was admitted to JCRC (Joint Clinical and Research Centre) on June 14 and was diagnosed with Stevens - Johnson syndrome (SJS). Antiretroviral therapy was stopped. By July 05, 2004, she had improved and was discharged. After recovery she was restarted on Combivir and Efavirenz and is subsequently doing well on this regimen.

Human papillomavirus genotypes associated with cervical cytologic abnormalities and HIV infection in Ugandan women

Human papillomavirus (HPV) infection is associated with almost all cases of cervical cancer, and cervical cancer is a common malignancy in women living in developing countries. A cross-sectional study was conducted to determine the prevalence of HPV infection, human immunodeficiency virus (HIV) infection, and cervical cytologic abnormalities in women presenting to a sexually transmitted infections clinic in Kampala, Uganda. In June and July, 2002, 135 women underwent complete physical exams including Papanicolaou (Pap) smears. HIV status was evaluated by serology. Cervical and vaginal swabs were obtained by clinicians and tested for HPV genotypes by PCR/reverse blot strip assay. Of the 106 women with cervical swabs adequate for HPV testing, the HPV prevalence was 46.2% (49/106). HIV prevalence was 34.9% (37/106). High risk genotypes 52, 58, and 16 were the genotypes detected most commonly. Eighteen percent (9/49) of women infected with HPV were found to have genotypes 16 and/or 18. Seventy-three percent (27/37) of HIV-positive women versus 16% (10/63) of HIV-negative women had abnormal Pap smears (P < 0.0001). Among HIV-positive women, abnormal Pap smears were associated with the presence of high risk HPV genotypes (P < 0.001). The majority of women infected with HPV attending this sexually transmitted infections clinic in Uganda were infected with high risk HPV genotypes other than 16 and 18. Future studies should focus on whether current HPV vaccine formulations, that are limited to high risk genotypes 16 and 18, would be effective at decreasing the burden of cervical cancer in this population.

Characterization of Penicillin Intermediate Serotypes ofStreptococcus pneumoniaeCarried by Human Immunodeficiency Virus-Infected Adults and Healthy Children in Uganda

There are little data on the genetic relatedness between antibiotic-resistant pneumococcal isolates colonizing the Ugandan population. Penicillin-intermediate pneumococci of serogroups or serotypes rarely or not previously reported as being penicillin nonsusceptible were selected out of 166 isolates representing 26 capsular serogroups or serotypes isolated from Ugandan children in 1995 and human immunodeficiency virus (HIV) infected Ugandan adults in 2004-2005. Pairs of penicillin-intermediate pneumococci of the same serogroup or serotype present in both patient populations were characterized further by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Seven such pairs of isolates were found and included serogroups 7, 11, 15B/C, and 16 as well as serotypes 13, 21, and 35B. PFGE of these seven pairs showed no clonality between serogroups or serotypes, and clonality only within serogroup 11 and serotype 13. MLST of the 14 individual isolates revealed 13 different sequence types (STs), 11 of which had not previously been recorded. Comparisons with all known STs revealed that most of these strains were related only to strains of the same serotype in other countries, with these related strains frequently also being penicillin intermediate. These findings suggest that penicillin nonsusceptibility in Uganda is likely due to the introduction of antibiotic-resistant pneumococcal clones into Uganda rather than development of resistance within the country.

Gender differences in human immunodeficiency virus (HIV) RNA and CD4 cell counts among new entrants to HIV care

Clinic database extraction identified 806 new entrants to human immunodeficiency virus (HIV) care in Cleveland, OH, USA. At entry, women had higher CD4 counts and lower HIV RNA levels than men (mean, 388 vs. 310 cells/microL, and 8.94 x 10(4) vs. 1.27 x 10(5) copies/mL, respectively), but the proportion of entrants with category C illnesses, category B conditions, sexually transmitted diseases and CD4 counts < 200 microL did not differ between genders. Hepatitis B seroprevalence was higher in men (8.7% vs. 0.6%), but there was no difference in hepatitis C prevalence. Whether women in Cleveland seek HIV care earlier, or whether early markers of HIV disease differ between the genders, remains to be determined.

Gene dosage and linezolid resistance in Enterococcus faecium and Enterococcus faecalis

Resistance to linezolid has been associated with a G2576U mutation in domain V of the 23S rRNA. We analyzed nine clinical isolates of linezolid-resistant enterococci and showed a clear association between the number of 23S rRNA genes containing this mutation and the level of linezolid resistance expressed.

Deactivation of the innate cellular immune response following endotoxic and surgical injury

The innate cellular immune (iCMI) system provides for the rapid production of interferon-gamma (IFN gamma) by NK cells in response to microbial threats. In this review, we examine the cellular and cytokine mechanisms of innate cellular immunity as determined in murine endotoxemia. This will be contrasted to the subsequent suppression of these same responses present in the mouse model of endotoxin tolerance, which is characterized by profound deficiency in both IL-12 and IFN gamma synthesis. Transient IFN gamma deficiency due to altered iCMI function has also been described in trauma or burn patients and is termed "clinical immune paralysis." If the common pathogenesis of these entities can be better understood, immune-based interventions might be identified for restoring iCMI function. In addition to the gain in basic immunologic insight, research on this subject may deliver future forms of prophylaxis against infection that do not rely on antibiotics and that will not promote antimicrobial resistance.

Changing spectrum of mortality due to human immunodeficiency virus: analysis of 260 deaths during 1995--1999

We analyzed the deaths in an outpatient human immunodeficiency virus (HIV) care clinic at University Hospitals in Cleveland from January 1995 through December 1999. The number of annual deaths decreased progressively, from 112 in 1995 to 32 in 1999. The median final CD4(+) cell count before death increased progressively from 10 cells/microL in 1995 to 90 cells/microL in 1999 (P<.01); 20%--25% of patients who died from 1997 through 1999 had plasma HIV RNA levels below detection limits. From 1995 through 1998, deaths due to infection, to end-stage acquired immune deficiency syndrome, and to malignancies decreased, whereas the proportion of deaths due to end-organ failures and of uncertain relationship to HIV infection increased. The spectrum of mortality in HIV disease has changed recently; although opportunistic infections cause death less frequently, deaths are occurring in people who have control of HIV replication and with some preservation of immune function. These observations underscore the need to monitor the etiologies of HIV-associated mortality and to better our understanding of the relationships among immune defenses, treatment-related toxicities, and end-organ failure in patients with HIV disease.

Use of linezolid, an oxazolidinone, in the treatment of multidrug-resistant gram-positive bacterial infections

We report our experience with linezolid in an investigation of its use against resistant gram-positive bacterial infections. Fifteen patients who had renal failure (n=6), recent liver transplantation (n=5) or surgery (n=6), cancer (n=3), endocarditis (n=2), or human immunodeficiency virus infection (n=1), along with infections due to vancomycin-resistant enterococcus (VRE), and 2 patients with infections due to methicillin-resistant Staphylococcus species who had adverse reactions to vancomycin were treated with linezolid (600 mg every 12 h for 5-42 days (mean+/-SD, 20.5+/-3.5 days). Abscess drainage or prosthetic device removal was undertaken. Microbiological cure occurred in all 10 patients who completed therapy, and all 7 patients alive at follow-up were free of infection. No deaths were attributable to the index infection. Adverse events associated with linezolid use were mild leukopenia in 1 patient and nausea in another. It appears that administration of linezolid, in conjunction with surgical intervention or device removal, is an effective treatment option for serious resistant gram-positive bacterial infections.

Bat-associated histoplasmosis in returning travelers: case presentation and description of a cluster

Histoplasma capsulatum is a dimorphic fungus with the mycelial form producing spores that are readily airborne and able to reach small bronchi and alveoli. Isolation of the mycelial form of H. capsulatum in nature shows a striking correlation with moist, acidic soils, frequently contaminated with bird or bat excreta. Bats, but not birds, may be infected by H. capsulatum and may excrete the fungus in their feces. Skin test surveys show that the infectious agent is present worldwide in the areas between 45 degrees north and 30 degrees south of the equator. Clusters of cases may occur because of the disturbance of soil contaminated with H. capsulatum, or by visiting bat caves. Cave-associated histoplasmosis has been reported from the Americas, Africa, Oceania, and Africa. Recently, cave-associated histoplasmosis has been reported in travelers returning from Costa Rica and Peru. We report a cluster of cave-associated acute histoplasmosis that occurred in college students returning from Ecuador. Advice regarding histoplasmosis prevention should be given to travelers planning to visit bat-infested caves, and histoplasmosis should be considered in the differential diagnosis of febrile illness in returning travelers with a history of epidemiologic or geographic exposure.

A polyclonal outbreak of predominantly VanB vancomycin-resistant enterococci in northeast Ohio. Northeast Ohio Vancomycin-Resistant Enterococcus Surveillance Program

We studied the molecular epidemiology of vancomycin-resistant enterococci (VRE) isolated in northeast Ohio during 1996 and examined the association between isolation of VRE from samples other than stool and antimicrobial purchases for five Cleveland hospitals. Susceptibility testing and pulsed-field gel electrophoresis were used to analyze 363 isolates from individual patients from 13 hospitals. Susceptibility testing indicated that 287 strains (79%) expressed the VanB phenotype and 76 (21%) expressed the VanA phenotype. The outbreak was polyclonal, with 30 total genotypes. Both VanA and VanB VRE demonstrated multiple genotypes. One genotype was present in all hospitals, suggesting spread between hospitals. For five teaching hospitals, rates of isolation from non-stool sources and from blood correlated positively with purchases of ticarcillin/clavulanic acid (P = .005). In summary, this outbreak demonstrates transmission of VRE between several hospitals in a geographic region and suggests that use of certain beta-lactam antibiotics may be associated with an increased prevalence of VRE.

Determination and validation of a predictive model for Clostridium difficile diarrhea in hospitalized oncology patients

BACKGROUND

Clostridium difficile colitis in the cancer patient receiving chemotherapy is a frequent cause of morbidity which may prolong hospitalization. Techniques for identifying infection often delay the initiation of therapy.

PATIENTS AND METHODS

In this retrospective case-control analysis, we identified predictors for C. difficile-associated diarrhea in 29 patients hospitalized from 1988 to 1993 on a hematologic malignancy/bone marrow transplant unit (hospital A). We then validated our model with 58 C. difficile cases and 74 controls admitted to an oncology unit from a different institution (hospital B).

RESULTS

We found that low intensity of chemotherapy (P < 0.001), lack of parenteral vancomycin use (P = 0.03) and hospitalization within the past two months (P = 0.05) were independently predictive of C. difficile colitis by multivariate analysis. These variables were weighted for predictive capability using a receiver operator characteristic score; low intensity chemotherapy was assigned two points, lack of parenteral vancomycin received one point and prior hospitalization one point (P < 0.001 by chi 2 for trend). The receiver operating characteristic (ROC) curve areas were 0.78 for patients at hospital A and 0.70 at hospital B indicating moderate drop off in discrimination. Compared to hospital A patients, hospital B patients hospitalized between 1989 and 1994 were more often women (P = 0.04), received less systemic vancomycin (P = 0.01), were less frequently neutropenic (P < 0.05), and received less intense chemotherapy regimens (P < 0.05). Despite these differences in demographics in patients between these institutions, our predictive model was validated in hospital B patients (P = 0.02 by chi 2 for trend).

CONCLUSIONS

The results of this study may help clinicians predict the risk of C. difficile disease in the hospitalized immunocompromised oncology patient and may help guide empiric therapy while awaiting results of stool toxin assays.

Oral antibiotics in the nineties: new drugs and new challenges in primary care

The primary care physician is faced with a bewildering array of new oral antimicrobials to treat common infections. These agents promise to be extremely effective as replacements for time-honored drugs, as prophylaxis, and for the treatment of infections previously requiring prolonged intravenous therapy. The overuse of the newer macrolides, quinolones, and beta-lactam beta-lactamase inhibitors may prove to be ecologically and economically costly. It is feared that the selective pressure from these broad spectrum agents may burden society with an even greater problem of multiply resistant community-acquired pathogens. The specific therapeutic and economic advantages and disadvantages of each class should be considered and the decision to employ these agents should be highly individualized.

Histoplasmosis and kidney disease in patients with AIDS

Renal disease in patients infected with human immunodeficiency virus (HIV) often presents with significant proteinuria and progressive renal failure; focal glomerulosclerosis is the most common renal pathology identified. To our knowledge, we report the first case of nephrotic-range proteinuria and preserved renal function in an HIV-infected patient in association with disseminated histoplasmosis. The initial level of proteinuria was 12.5 g/24 h. The patient developed a concomitant lesion on his neck, which was biopsied and identified as Histoplasma capsulatum by fungal stains and culture. The serum CF titer of antibody against yeast antigens of H. capsulatum was 1:8. The level of serum albumin decreased to 2.0 g/dL, and the level of serum cholesterol increased to 284 mg/dL. Immunohistochemical staining of renal biopsy tissue demonstrated immune complexes within the mesangium; H. capsulatum antigen was also demonstrated in the mesangium. Therapy with oral itraconazole resulted in marked clinical improvement. The findings in this case emphasize the need to rule out treatable causes of the nephrotic syndrome in AIDS, especially in cases of immune-complex glomerulonephritis.

Pityriasis rubra pilaris: an unusual cutaneous complication of AIDS

Pityriasis rubra pilaris is an uncommon hyperkeratotic, papulosquamous disorder that has been reported in patients infected by HIV. We recount a case of pityriasis rubra pilaris in an HIV-seropositive man. A 36-year-old man with a history of ulcerative colitis and recurrent otitis externa had diffuse psoriaform erythroderma. He was treated initially with methotrexate and isoretinoin without clinical improvement. Skin examination showed large, erythematous, orange, scaly patches on the upper extremities and thickening of the nail beds. The palms and soles were hyperkeratotic. Skin biopsy revealed changes that were consistent with pityriasis rubra pilaris. Six months before the onset of symptoms, results of an enzyme-linked immunosorbent assay (ELISA) and Western Blot assay for HIV were negative. Six months after symptoms, results of repeat enzyme-linked immunosorbent assay and Western blots for HIV were positive (CD4+ T-cell count = 200 cells/ mm3). Clinical course had been complicated by episodes of Staphylococcus aureus bacteremia, mucocutaneous candidiasis, and development of localized squamous cell carcinoma of the skin. The increased severity of pityriasis rubra pilaris should prompt clinicians to consider coinfection with HIV in patients who have disease that is refractory to treatment. Clinicians also should remain vigilant for the development of squamous cell carcinoma.

Prednisone improves renal function and proteinuria in human immunodeficiency virus-associated nephropathy

PURPOSE

To determine if prednisone ameliorates the course of human immunodeficiency virus-associated nephropathy (HIV-AN).

PATIENTS AND METHODS

Twenty consecutive HIV-infected adults with biopsy-proven HIV-AN (n = 17) or clinical characteristics of HIV-AN (n = 3) with serum creatinine concentrations > 177 mumol/L (2 mg/dL) or proteinuria > 2.0 g/d or both were prospectively evaluated and treated with prednisone at a dose of 60 mg/d for 2 to 11 weeks, followed by a tapering course of prednisone over a 2- to 26-week period. Serum creatinine concentration, 24-hour protein excretion, serum albumin, and steroid-related adverse effects were assessed before and after treatment.

RESULTS

Nineteen patients had serum creatinine concentrations > 117 mumol/L (2 mg/dL). Two of them progressed to end stage renal disease (ESRD) in 4 to 5 weeks. In 17 patients serum creatinine levels decreased from 717 +/- 103 mumol/L (8.1 +/- mg/dL) (mean +/- SE) to 262 +/- 31 mumol/L (3.0 +/- 0.4 mg/dL) (P < 0.001). Five patients relapsed after prednisone was discontinued and were retreated. In these 5 the serum creatinine declined from 728 +/- 107 mumol/L (8.2 +/- 1.2 mg/dL) to 344 +/- 47 mumol/L (3.9 +/- 0.5 mg/dL) (P < 0.01) in response to the second course of prednisone. Twelve of 13 tested patients showed a reduction in 24-hour urinary protein excretion with an average decrement from 9.1 +/- 1.8 g/d to 3.2 +/- 0.6 g/d (P < 0.005). Serum albumin increased from 24.4 +/- 3.6 g/L to 29.3 +/- 2.6 g/L (P = NS) in the 11 patients with paired 24-hour urine collections for whom pre- and post-treatment determinations were available. In one non-azotemic patient with nephrotic syndrome, protein excretion declined from 15.2 to 2.2 g/day and the serum albumin increased from 4.0 g/L to 31.0 g/L. The 20 patients have been followed for a median of 44 weeks (range 8 to 107). Eight ultimately required maintenance dialysis. Eleven died from complications of HIV disease 14 to 107 weeks after institution of prednisone; none was receiving prednisone at the time of death. Seven are alive and free from ESRD a median of 25 weeks (range 8 to 81) from the initiation of prednisone therapy. Six patients developed a total of seven serious infections while receiving prednisone, including Mycobacterium avium-complex infection in 2 and CMV retinitis in 3.

CONCLUSION

Prednisone improves serum creatinine and proteinuria in a substantial proportion of adults with HIV-AN. Corticosteroid-related side effects are not prohibitive. A prospective, randomized controlled trial is required to confirm these preliminary results.

A predictive model to identify Clostridium difficile toxin in hospitalized patients with diarrhea

OBJECTIVES

Although Clostridium difficile is a common pathogen in hospitalized patients with diarrhea, no study has attempted to develop a predictive model to estimate the likelihood of C. difficile positivity.

METHODS

We conducted a cross-sectional study at a single hospital of 271 patients with diarrhea for whom stool was tested for C. difficile toxin. The sample was randomly divided into a subset to derive the model (n = 180) and another to validate it (n =91), and independent predictors of toxin positivity were identified using logistical regression analysis.

RESULTS

C. difficile toxin was present in 81 patients and absent in 190. In the derivation set, a positive toxin was independently predicted (p < 0.0005) by readmission within 2 wk of prior hospitalization, by a white blood cell count > or = 10,000/mm3, and by presence of fecal leukocytes. In the validation set, C. difficile toxin was present in 24, 29, and 77% of patients with 0, 1, and > or = 2 risk factors, respectively.

CONCLUSION

If validated prospectively and/or other centers, the model could identify patients who should be considered for empirical management while awaiting results of toxin assays.

Development of amebicidal cell-mediated immunity in gerbils (Meriones unguiculatus) immunized with the galactose-inhibitable adherence lectin of Entamoeba histolytica

The galactose-inhibitable adherence lectin of Entamoeba histolytica is a protective antigen in the gerbil model of amebic liver abscess. To further understand the mechanisms of vaccine efficacy, we studied the cell-mediated immune response to the lectin in gerbils. Splenocytes harvested from immunized gerbils demonstrated in vitro proliferation and production of interleukin-2 and gamma-interferon in response to purified adherence lectin (P < 0.05 for each compared to control splenocytes). Splenocytes from immunized gerbils developed direct amebicidal activity (P = 0.014) following in vitro stimulation with the adherence lectin. Splenocytes harvested from immunized gerbils following intrahepatic challenge with viable E. histolytica adherence lectin. Splenocytes harvested from immunized gerbils following intrahepatic challenge with viable E. histolytica trophozoites demonstrated proliferative and amebicidal responses (P < 0.05). In conclusion, immunization with the E. histolytica galactose-inhibitable adherence lectin elicits an amebicidal cell-mediated response that is enhanced by parasite challenge.

Cultures of skin biopsy tissue from immunocompromised patients with cancer and rashes

BACKGROUND AND DESIGN

Microbiological cultures of skin biopsy tissue are often recommended in immunocompromised patients with cancer and rashes, but in a previous study, they were usually sterile or grew clinically insignificant organisms. To examine the use and bacteriological results of these cultures more comprehensively, we reviewed records from all immunocompromised adults with cancer and acute rash on which skin biopsy was performed during 39 months on a bone marrow transplantation/acute leukemia unit of a university hospital (108 episodes of rash in 80 patients).

RESULTS

Of the 158 cultures that were performed, one (1%; 95% confidence interval [CI], 0% to 4%) was a true positive; 11 (7%; 95% CI, 3% to 13%) were false positive; 143 (91%; 95% CI, 87% to 95%) were true negative; and three (2%; 95% CI, 1% to 6%) were false negative. Thus, the sensitivity of culture was 0.25, and the specificity was 0.93. Coagulase-negative Staphylococcus was the single pathogenic organism that grew, yet was judged to be a contaminant in three episodes. Among the 95 rashes in which fewer than four types of culture were performed, viral culture may have been helpful in one case (1%; 95% CI, 0% to 6%).

CONCLUSIONS

Cultures of skin tissue from immunocompromised cancer patients with rashes were often unable to diagnose infection or the absence of infection. Clinical judgement was crucial to the interpretation of culture results.

Effect of corticosteroid therapy on human immunodeficiency virus-associated nephropathy

PURPOSE

Human immunodeficiency virus-associated nephropathy (HIV-AN) occurs predominantly in blacks and is characterized histologically by focal segmental glomerulosclerosis or mesangial proliferation and a lymphohistiocytic tubulointerstitial infiltrate. Patients manifest heavy proteinuria and, once azotemia occurs, progress rapidly to end-stage renal disease within 2 to 6 months. No treatment has been shown to be useful for HIV-AN. The purpose of this study was to determine the effect of corticosteroid agents on the progression of HIV-AN.

PATIENTS AND METHODS

Four consecutive HIV-infected adults with fewer than 200 CD4 cells/microL, moderate to severe renal insufficiency, proteinuria greater than 2 g per 24 hours, and HIV-AN demonstrated by renal biopsy were treated with 60 mg of prednisone daily for 2 to 6 weeks. Patients were followed with respect to serum creatinine level, 24-hour protein excretion, adverse drug reactions, and the occurrence of opportunistic infections.

RESULTS

CD4 counts ranged from 30 to 80 cells/microL before therapy with steroids. The mean (+/- SD) pretreatment serum creatine concentration was 9.1 +/- 5.7 mg/dL and decreased to 3.3 +/- 1.8 mg/dL (P < 0.05) after 2 to 6 weeks of corticosteroid therapy. Twenty-four hour protein excretion did not change (5.2 +/- 2.4 g pretreatment versus 4.6 +/- 4.1 g posttreatment). One patient was able to discontinue dialysis after 10 days. Two patients developed Mycobacterium avium-complex infections and steroid-associated psychosis. One of these patients developed a recurrence of genital herpes, and the other developed dermatomal zoster. None of the four required dialysis during a 1.5- to 5.5-month period of follow-up after cessation of steroid treatment.

CONCLUSION

In selected patients with HIV-AN, short-term treatment with corticosteroid agents improves renal function and prevents the development of end-stage renal disease during a 1.5- to 5.5-month period of observation, but may be associated with an increased risk of opportunistic infection.

Intraabdominal infection: differences in presentation and outcome between younger patients and the elderly

Although the elderly account for a disproportionate number of patients with intraabdominal infections, few studies have compared these patients with younger patients in terms of presentation and outcome. Therefore, we conducted a retrospective cohort study of 131 patients at an urban university hospital that included 88 patients (67%) < or = 65 years of age and 43 (33%) > 65 years of age, all of whom had culture-proven intraabdominal infections. Geriatric patients presented more frequently without the typical symptoms and signs of abdominal pain, nausea and vomiting, diarrhea, and fever and had symptoms for a longer period before presentation. Diagnosis on admission was more often unknown or considered to be of an extraabdominal nature for the elderly patients, and sources of infection were more commonly biliary or pancreatic. Mortality was not significantly different between the groups, but length of stay and duration until normalization of body temperature were longer for the older patients. We concluded that elderly patients with intraabdominal infections frequently present atypically and have a more-protracted course of illness than their younger counterparts.

Central nervous system Whipple's disease: relapse during therapy with trimethoprim-sulfamethoxazole and remission with cefixime

The central nervous system (CNS) is frequently involved in patients with Whipple's disease and is the most common site of disease relapse. Antibiotics such as trimethoprim-sulfamethoxazole (TMP-SMX) that have reliable CNS penetration, are therefore recommended as first-line therapy. We report a patient with Whipple's disease who was treated with TMP-SMX and presented 14 months after initiation of therapy with visual decline and severe headaches. The patient was also treated concurrently with low-dose weekly methotrexate for severe psoriasis. Evaluation by magnetic resonance imaging revealed bilateral posterior white matter abnormalities that pathologically were consistent with Whipple's disease. He was ultimately treated with cefixime, an orally administered third-generation cephalosporin. Visual function improved on this regimen and follow-up magnetic resonance imaging showed regression of the lesions. This case represents the first report of both CNS relapse during therapy with TMP-SMX and successful treatment with cefixime. We also speculate that methotrexate, which impairs cell-mediated immunity, may have contributed to the relapse.

Application of an immune-tolerizing procedure to generate monoclonal antibodies specific to an alternate protein isoform of bovine growth hormone

An immune-tolerizing protocol was employed to generate monoclonal antibodies to a variant protein isoform of bovine growth hormone arising from alternative pre-mRNA processing. Variant bovine growth hormone used for immunization was obtained by expression in bacteria and electroelution of the protein from preparative sodium dodecyl sulfate-polyacrylamide gels. Balb/c mice were first immunized with wild-type bovine growth hormone in the presence of the cytotoxic drug cyclophosphamide, thereby tolerizing the mouse to common epitopes shared among the two proteins. Subsequently, the mice were immunized with variant bovine growth hormone to produce antibodies specific to variant epitopes. Comparisons of fusions resulting from standard and tolerizing immunization protocols resulted in a significantly enhanced production of variant bovine growth hormone-specific antibodies as a result of the immunotolerizing protocol. The specificity of the antibodies to the variant growth hormone was substantiated by differential enzyme-linked immunosorbent assay and Western blot. Nearly all hybridomas positive for variant growth hormone were negative for wild-type growth hormone. Finally, the antibodies were used to demonstrate intracytoplasmic staining of COS I cells transiently transfected with a variant growth hormone-producing plasmid. Given the power of the polymerase chain reaction to conveniently clone alternatively processed mRNA species, followed by expression in bacteria to provide antigen, the immunotolerizing protocol provides a convenient general method for producing antibodies specific to desired protein isoforms.

Human T-lymphocyte proliferation, lymphokine production, and amebicidal activity elicited by the galactose-inhibitable adherence protein of Entamoeba histolytica

We studied human T-lymphocyte responses to the purified Entamoeba histolytica galactose-inhibitable adherence protein. Individuals having serum anti-adherence protein antibodies possess peripheral blood lymphocytes which demonstrate antigen-specific responses to the purified adherence protein (10 micrograms/ml) and whole soluble amebic antigen (100 micrograms/ml). This was determined by incorporation of [3H]thymidine (53,080 and 73,114 dpm, respectively) and by increased production of interleukin-2 and gamma interferon (42.0 and 67.5 U/ml, respectively) (P less than 0.05 for each in comparison with values for control lymphocyte responses). Lymphocytes from antiamebic antibody-positive subjects develop in vitro amebicidal activity only when incubated for 5 days with the purified adherence protein (P = 0.02). In conclusion, the E. histolytica galactose-inhibitable adherence protein elicits an in vitro amebicidal cell-mediated immune response, further supporting the potential for the use of this protein in a subunit amebiasis vaccine.

Purification and characterization of the 30,000 dalton native antigen of Mycobacterium tuberculosis and characterization of six monoclonal antibodies reactive with a major epitope of this antigen

The 30,000 dalton native antigen of Mycobacterium tuberculosis is a major constituent of this organism and is secreted into culture medium. We purified this antigen by ammonium sulfate precipitation, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography to yield a single 29 to 30 kd component. The first 20 N-terminal amino acid sequence was determined and found to be identical to that reported for M. bovis alpha-antigen. Immunoelectrophoresis studies demonstrated the purified 30,000 dalton antigen to be immunologically identical with antigen 6 and antigen 85B. The 30,000 dalton native antigen was a potent skin test antigen in sensitized guinea pigs. Six immunoglobulin G1 murine monoclonal antibodies against the 30,000 dalton antigen were generated. By enzyme-linked immunosorbent assay and western immunoblotting, all six monoclonal antibodies reacted with the 30,000 dalton antigen, perhaps with the same epitope. When used with culture filtrates of other mycobacteria, the monoclonal antibodies demonstrated reactivity with M. gordonae and M. kansasii and to a lesser extent with M. avium and M. scrofulaceum.

Characterization of calcium channel forming activity of Entamoeba histolytica in model biological membranes

Entamoeba histolytica is an invasive enteric protozoan parasite whose cytolytic activity is associated with irreversible increases in target cell intracellular calcium. We studied the effect of homogenates of virulent E. histolytica on calcium permeability of bovine chromaffin granules and rat liver mitochondria, model membrane systems whose mechanisms of ion transport and permeability are well characterized. Treatment of chromaffin granules, with an extract of E. histolytica resulted in a dose-dependent increase in calcium uptake. These effects were similar to that seen with the calcium ionophore A23187 and indicate that the homogenate acts as a divalent cation ionophore. However, unlike what is observed with A23187, the Ca2+ uptake was greater in the presence of the permeable anion Cl- than in its absence. Also, in contrast to the calcium ionophore A23187, a homogenate of E. histolytica caused no calcium release from rat liver mitochondria but resulted in a dramatic increase in the rate of calcium accumulation. The amebic homogenate did not bind calcium in the absence of mitochondria. The increase in mitochondria calcium uptake occurred only in the presence of respiration and with normal state 3 and 4 oxygen consumption. Calcium accumulation occurred both in the presence and absence of 5 mM Pi. Substitution of NaCl or KCl for sucrose in the medium did not alter the enhanced mitochondria calcium uptake. Most data are consistent with the hypothesis that the E. histolytica homogenate is acting as a calcium ionophore transporting charged calcium electrophoretically across the chromaffin granules and the mitochondria inner membrane. This activity may contribute to the cytopathogenicity by E. histolytica.

Suppression of T-lymphocyte responses to Entamoeba histolytica antigen by immune sera

Lymphocytes from patients cured of amebic liver abscesses proliferate and produce gamma interferon upon incubation with soluble Entamoeba histolytica antigen: however, amebic liver abscesses exhibit a relentless progression without treatment. To determine whether suppressive factors are present in sera, we studied T-lymphocyte responses to total soluble E. histolytica antigen by using cells from five patients treated for amebic liver abscesses in the presence of 15 different immune sera and 10 control sera. In the presence of immune sera, E. histolytica antigen-induced lymphocyte proliferation decreased by 63% and production of gamma interferon was reduced by 93.2% (P less than 0.01). Immune sera had no effect on the mitogenic responses of patient lymphocytes to phytohemagglutinin or on the proliferative responses of control lymphocytes to phytohemagglutinin or tetanus toxoid. The suppressive activity of immune sera diminished as the time between therapy for amebic liver abscesses and serum collection increased (P less than 0.05). Suppressive activity did not correlate with the titers of serum anti-amebic antibody and was not affected when serum was absorbed with viable amebic trophozoites. In conclusion, soluble factors present in the sera of amebic liver abscess patients suppressed in vitro lymphocyte responses to E. histolytica antigen and may have contributed to the lack of development of effective in vivo cell-mediated immune responses following the onset of amebic liver abscesses.

Definition of the complete Schistosoma mansoni hemoglobinase mRNA sequence and gene expression in developing parasites

Schistosoma mansoni uses a variety of proteases termed hemoglobinases to obtain nutrition from host globin. Previous reports have characterized cDNAs encoding 1 of these enzymes. However, these sequences did not define the primary structures of the mRNA and protein. The complete sequence of the 1390 base mRNA has now been determined. It encodes a 50 kDa primary translation product. In vitro translations coupled with immunoprecipitations and Western blots of parasite lysates allowed visualization of the 50 kDa form. Production of the 31 kDa mature hemoglobinase from the 50 kDa species involves removal of both NH2 and COOH terminal residues from the primary translation product. Expression of hemoglobinase mRNA and protein was examined during larval parasite development. Low levels were observed in young schistosomula. After 6-9 days in culture, high hemoglobinase levels were seen which correlated with the onset of red blood cell feeding. Immunoelectron microscopy was employed to examine hemoglobinase location and function. In adult worms the enzyme was associated with the gut lumen and gut epithelium. In cercariae, the protease was observed in the head gland, suggesting new roles for the protease.

Invasive infection with Saccharomyces cerevisiae: report of three cases and review

Saccharomyces cerevisiae (brewer's or baker's yeast) is a common colonizer of human mucosal surfaces, but its role as a clinically important pathogen has been unclear. We report three cases of life-threatening invasive infection with S. cerevisiae resulting in pneumonia, liver abscess and sepsis, and disseminated infection with cardiac tamponade, respectively. A review of the English-language literature reveals 14 other cases of saccharomyces infection in humans. Severe immunosuppression, prolonged hospitalization, prior antibiotic therapy, and/or prosthetic cardiac valves are the settings where saccharomyces infection has been observed. Because Saccharomyces can be a common saprophytic contaminant, biopsy and pathologic confirmation of infection are often necessary for a definitive diagnosis. Amphotericin B is the treatment of choice for serious infections with this organism.

Polymicrobial bacteremia in the late 1980s: predictors of outcome and review of the literature

Although polymicrobial bacteremia has been described in several previous series, there has been no recent study of patients using rigorous statistical analysis. Our objective was to characterize a present-day patient population with polymicrobial bacteremia and to define factors prognostic of survival. Polymicrobial bacteremia accounted for 6% of all positive blood cultures at a university hospital and a Veterans Administration hospital over a 2 1/2 year period in the late 1980s. The majority of these patients were elderly with significant underlying diseases, notably malignancies, and 56% of all episodes were nosocomially acquired. Enterobacteriaceae have remained the most common organisms, though the frequency of gram-positive cocci isolated has increased compared to older studies. Gastrointestinal, genitourinary, and skin and soft-tissue sources were the most common, although the incidence of infections due to central venous catheters appeared to be increasing. The source of 25% of bacteremia was not identified despite newer diagnostic techniques. By univariate analysis, mortality, which was 36% overall, correlated with thrombocytopenia, respiratory failure, disseminated intravascular coagulation, encephalopathy, severity of underlying disease, hemolysis, adult respiratory distress syndrome, use of steroids, renal insufficiency, institution, presence of central lines, and nosocomial acquisition. Using stepwise logistic regression analysis, mortality was predicted by respiratory failure, severity of underlying disease, and hemolysis. We conclude that polymicrobial bacteremia remains an important entity in the present-day hospitalized population, with an increasing frequency of gram-positive organisms and catheter sources, and a large proportion of undiagnosed etiologies.

Chemoattractant activity of Entamoeba histolytica for human polymorphonuclear neutrophils

The ability of axenic Entamoeba histolytica trophozoites and amoebic protein preparations to stimulate chemotaxis of human polymorphonuclear neutrophils (PMN) was evaluated. Virulent E. histolytica (strain HM1:IMSS) stimulated chemotaxis (delta distance = 0.55 +/- 0.02 mm, P less than 0.01 vs. control medium). Sonicated (100 micrograms protein/ml) or homogenized (500 micrograms protein/ml) virulent amoebae also significantly stimulated PMN chemotaxis, whereas preparations of the nonpathogenic "Entamoeba-like" Laredo strain did not stimulate chemotaxis. Preparations of subcellular fractions of E. histolytica demonstrated maximal stimulation of PMN chemotaxis existed in nonvesiculated membranes and the supernatant from plasma membranes.

Infections due to Lancefield group C streptococci

Our experience with group C streptococcal infection over the past 15 years demonstrates an important and emerging role for this hemolytic organism as an opportunistic and nosocomial pathogen. Significant risk factors in this predominantly male population included chronic cardiopulmonary disease, diabetes, malignancy, and alcoholism. Bacteremia occurred in 74% of cases seen in our series. Nosocomial acquisition of infection was observed in 26%, and infection was frequently polymicrobial in nature with gram-negative enteric bacilli isolated most commonly along with group C streptococci. We observed a broad spectrum of infections including puerperal sepsis, pleuropulmonary infections, skin and soft-tissue infection, central nervous system infection, endocarditis, urinary tract infection, and pharyngeal infections. Several cases of bacteremia of unknown source were observed in neutropenic patients with underlying leukemia. New syndromes of infection due to group C streptococci observed in our series included intra-abdominal abscess, epidural abscess, and dialysis-associated infection. Response to therapy and outcome was related to the underlying disease. While the literature suggests that patients with group C endocarditis respond better to synergistic penicillin-aminoglycoside regimens, patient numbers are too small to draw definite conclusions. The clinical significance of antibiotic tolerant group C streptococci remains uncertain. In patients with serious group C infections including endocarditis, meningitis, septic arthritis, or bacteremia in neutropenic hosts, we advocate the initial use of cell-wall-acting agents in combination with an aminoglycoside.

Serious infectious complications of corticosteroid therapy for COPD

We report seven elderly patients with COPD who developed serious infectious complications during prolonged treatment with high doses of corticosteroids. Infections included invasive pulmonary aspergillosis, Herpes simplex stomatitis and esophagitis, cytomegalovirus pneumonia, bacterial sepsis, fungemia and meningitis due to Cryptococcus neoformans. Each of the three patients who developed invasive aspergillus pneumonia died. The efficacy of prolonged therapy with high doses of corticosteroids in patients with COPD is not proven. These cases illustrate the potential for serious infections in patients with COPD treated with corticosteroids.

Modulation of polymorphonuclear leukocyte microbicidal activity and oxidative metabolism by fibrinogen degradation products D and E

Fibrinogen degradation products (FDP) D and E are typically present in blood of patients with disseminated intravascular coagulation and related conditions in which granulocyte (PMN) defense against bacterial infection may be compromised. This study was intended to determine whether FDP modify PMN functions critical to their bactericidal activity. Incubation of human PMN and Escherichia coli with 50-100 micrograms/ml FDP did not affect phagocytosis, but reduced by greater than 90% the cells' ability to inhibit bacterial colony growth compared with control PMN incubated with albumin or fibrinogen. FDP (10-100 micrograms/ml) inhibited PMN O2- release and chemotaxis stimulated by FMLP by 17-50% (P less than 0.005) and 41% (P less than 0.01), respectively. Fragment E3, and not fragment D1, was primarily responsible for inhibition of FMLP-induced PMN O2- release. Phorbol myristate acetate (10 ng/ml), 1-oleoyl-2-acetylglycerol (10(-6) M), AA (4.2 x 10(-5) M), and zymosan-activated serum-stimulated PMN O2- release were also decreased 37-63% by FDP compared with control protein. There are at least two mechanisms by which FDP may impair PMN responses. With respect to FMLP, FDP (16-100 micrograms/ml) inhibited specific binding to the cell surface over a ligand concentration range of 1.4-85 nM [3H]FMLP. In contrast, FDP did not effect the extent of phorbol ester binding to PMN but blocked activation of protein kinase C. These data suggest that elevated plasma FDP inhibit several PMN functions critical to the bactericidal role of these inflammatory cells.

Bacterial colonization of the tracheobronchial tree

Bacterial colonization of the tracheobronchial tree is a significant problem in hospitalized and chronically ill individuals. Colonization occurs because of both microbial and host factors, with the foremost mechanism being adherence of pathogenic gram-negative bacteria to mucosal epithelial cells. In the pathogenesis of nosocomial pneumonia, colonization appears to be an essential first step. In the diagnostic approach to hospital-acquired pneumonia, a distinction must be made between colonization and true lower respiratory tract infection. Future approaches to the major problem of colonization with gram-negative bacteria will require a better understanding of pathogenesis and employ strategies that not only focus upon limiting the bacterial pathogens but also attempt to improve upon pulmonary defense mechanisms.

Vasopressin stimulation of adrenocorticotropin hormone (ACTH) in humans. In vivo bioassay of corticotropin-releasing factor (CRF) which provides evidence for CRF mediation of the diurnal rhythm of ACTH

The diurnal response of ACTH release to intravenously administered arginine vasopressin was tested in normal volunteers given consecutively moderate doses of vasopressin every 15 min (0.1, 0.3, 1.0, and 3.0 IU) at 2200 h and again at 0700 h (PM/AM). This protocol was repeated 4 wk later with the times reversed (AM/PM). A dose-related increase in ACTH secretion was observed in all subjects. When the AM response of the AM/PM protocol was compared with the PM response of the PM/AM protocol, the release of ACTH was greater in the morning (P less than 0.05) as evaluated by the following criteria: peak value of ACTH (129.9 +/- 30.4 pg/ml in the AM vs. 57.1 +/- 20.2 in the PM); area under the curve (689 in the AM vs. 259 in the PM); and, sensitivity of the ACTH dose-response curve (first significant increase in ACTH with 1 IU of vasopressin in the AM but not significant even after 3 IU in the PM). In addition, when the AM vasopressin testing followed a previous evening stimulation (PM/AM protocol), there was a blunted ACTH response compared with the AM/PM protocol. Corticotropin-releasing factor (CRF) is probably the major ACTH secretagogue, but since vasopressin acts synergistically with CRF to produce an augmented release of ACTH, we suggest that the ACTH response to administered vasopressin depends upon the ambient endogenous level of CRF. We interpret our data and published data that CRF produces a lesser release of ACTH in the AM as follows: in the morning endogenous CRF is high and administered CRF produces little further release of ACTH, but administered vasopressin acting synergistically with high endogenous CRF causes a greater release of ACTH; conversely, in the evening endogenous CRF is low and administered CRF causes a greater release of ACTH, but vasopressin (a weak secretagogue by itself) gives a low ACTH response. We conclude that vasopressin stimulation of ACTH secretion can be used as an in vivo bioassay of endogenous CRF, and that there is a diurnal rhythm of CRF in hypophyseal portal blood.

Cold water stimulation of oropharyngeal receptors in man inhibits release of vasopressin

The act of drinking ameliorates thirst and inhibits the secretion of vasopressin before changes in extracellular fluid volume or osmolality in both animals and man. We evaluated whether this reflex inhibition of vasopressin secretion might be due to the presence of oropharyngeal receptors in humans. After dehydration, normal subjects (n = 4) were allowed to suck on ice chips for 30 min. Despite the absence of changes in plasma sodium (Na+) or osmolality, the mean plasma vasopressin level decreased promptly within 10 min from 2.8 to 1.8 pg/mL, and it remained low for 30 min after ice ingestion. When the dehydration protocol was repeated with the subjects receiving 100 mL water (25 C) for 30 min rather than ice chips, plasma vasopressin levels did not change. These data demonstrate that activation of cold-sensitive oropharyngeal receptors results in inhibition of vasopressin secretion independently of osmotic or gastric factors. In a second study 0.2 mL/kg X min 3% NaCl was administered for 90 min as a second stimulus to vasopressin secretion, and ice chips were given during the last 30 min of infusion. Plasma vasopressin levels increased steadily to 3.3 +/- 0.5 (+/- SEM) pg/mL by 45 min, and despite ice ingestion increased further to 4.6 +/- 0.8 pg/mL by 90 min. Consequently, hypertonicity appears to be a stronger stimulus to vasopressin release, since the suppressive effect of stimulation of oropharyngeal receptors with ice was not evident during the NaCl infusion. Finally, no changes in vasopressin levels were found in subjects holding concentrated NaCl solutions in their mouths for 30 min, indicating that the oropharyngeal receptors are not responsive to local changes in osmolality. The presence of such cold-sensitive oropharyngeal receptors may explain the desire of severely dehydrated patients, e.g. patients with diabetes insipidus, for cold liquids.

The role of gamma interferon in the generation of human macrophages cytotoxic for Entamoeba histolytica trophozoites

Upon exposure to Entamoeba histolytica antigen, lymphocytes from patients treated for amebic liver abscess produce lymphokines which activate monocyte-derived macrophages to kill E. histolytica trophozoites. We now demonstrate that gamma interferon (IFN-gamma) is produced by these stimulated lymphocytes and is sufficient but not exclusively necessary to activate monocyte-derived macrophage amebicidal activity. Supernatants from mononuclear cells of 7 patients when stimulated with amebic antigen contained more IFN-gamma than comparable supernatants derived from control cells (1,862 U/ml vs. 174 U/ml geometric means, P less than 0.01); IFN-gamma levels were similar in patient and control supernatants following concanavalin A stimulation. Macrophages activated solely by partially purified IFN-gamma or recombinant human IFN-gamma (300 U/ml) killed 47% of virulent amebae by 6 hr at 37 degrees C. Monocyte-derived macrophages stimulated with lymphokines elicited by amebic antigen or concanavalin A killed 48% and 57% of axenic E. histolytica trophozoites, respectively, over 6 hr at 37 degrees C (P less than 0.001 for each compared to control). Macrophages incubated with the identical lymphokines, but in the presence of monoclonal antibody to IFN-gamma, were only able to kill 18% and 27% of amebae, respectively, at 6 hr (P less than 0.05 to control or when antibody to IFN-gamma was not present). If antibody to IFN-gamma was added to the stimulating lymphokine, more macrophages died during interaction with amebae (P less than 0.05). In summary, IFN-gamma has a major but not exclusive role in activating human monocyte-derived macrophages in vitro to kill virulent E. histolytica trophozoites.