Biomedical subjects

C Enger

Publications and source records attributed to C Enger.

At least 19 recordsLinked to original sources

PubMed2001

Acute bleeding and thrombocytopenia after bone marrow transplantation.

The relationship between hemorrhage and low platelet count was first established in patients with acute leukemia, and has been widely applied to thrombocytopenic patients, including BMT patients. Yet, the role of thrombocytopenia in bleeding post BMT has not been systematically studied. We evaluated the risk of bleeding and outcome associated with thrombocytopenia in BMT patients who had prophylactic platelet transfusions at a trigger of 20 x 10(9)/l. Thrombocytopenia was investigated in 321 patients with moderate or severe bleeding (BLD), and in a matched comparison group of 287 patients who did not bleed (NBLD). Profound thrombocytopenia (< or = 10 x 10(9)/l) was found in 8.6% of the BLD patients during the week before the bleeding onset, significantly more frequent than in NBLD patients (2.1% to 4%, P < 0.02), during weeks 2 to 6 post BMT (the period when 75% of the bleeding initiated). On the first day of bleeding, platelet counts < or = 10 x 10(9)/l were found in 13.5%, 11-20 x 10(9)/l in 20.4%, and > 20 x 10(9)/l in 66.1% of all episodes. Overall survival in BLD patients was not associated with the severity of thrombocytopenia before bleeding onset. Severity of thrombocytopenia was significantly associated with reduced survival in NBLD patients. We concluded that bleeding post BMT was significantly associated with thrombocytopenia, but the attributable risk of bleeding from profound thrombocytopenia was not large. Thrombocytopenia may be an important clinical sign in NBLD patients, and should be further explored in relation to acute toxicities other than bleeding.

Acute Disease↗

PubMed1999

Ex vivo culture of cord blood CD34+ cells expands progenitor cell numbers, preserves engraftment capacity in nonobese diabetic/severe combined immunodeficient mice, and enhances retroviral transduction efficiency.

Ex vivo culture of hematopoietic stem/progenitor cells could potentially improve the efficacy of human placental/umbilical cord blood (CB) in clinical hematopoietic stem cell (HSC) transplantation and allow gene transduction using conventional retroviral vectors. Therefore, we first examined the effects of a 7-day period of ex vivo culture on the hematopoietic capacity of CB CD34+ cells. Medium for the ex vivo cultures contained either serum and six recombinant human hematopoietic growth factors (GFs), including Flt-3 ligand (FL), Kit ligand (KL = stem cell factor), thrombopoietin (Tpo), interleukin 3 (IL-3), granulocyte colony-stimulating factor (G-CSF), and interleukin 6 (IL-6), or a serum-free medium containing only FL, KL, and Tpo. After culture under both ex vivo conditions, the total numbers of viable cells, CD34+ cells, colony-forming cells (CFCs), and long-term culture initiating cells (LTC-ICs) were increased. In contrast, the severe combined immunodeficiency (SCID) mouse engrafting potential (SEP) of cultured cells was slightly decreased, as compared with fresh cells. Nevertheless, cultured human CB CD34+ cells were able to generate engraftment, shown to persist for up to 20 weeks after transplantation. We next tested the efficacy of retroviral transduction of cultured cells. Transduced cultured human cells were able to engraft in NOD/SCID mice, as tested 4 weeks after transplantation, and EGFP+CD34+ cells and EGFP+ CFCs were isolated from the chimeras. Thus, although additional improvements in ex vivo culture are still needed to expand the numbers and function of human HSCs, the current conditions appear to allow gene transduction into hematopoietic SCID engrafting cells, while at least qualitatively preserving their in vivo engraftment potential.

Animals↗

PubMed1999

Diagnosis of renal cancer by molecular urinalysis.

BACKGROUND: Organ-confined renal malignancies can be cured in the majority of patients, whereas more extensive lesions have a poor prognosis. We sought to develop a noninvasive test for renal cancer detection based on a novel molecular approach. METHODS: Matched urine and serum DNA samples were obtained before surgery from 30 patients with clinically organ-confined solid renal masses (25 with malignant tumors and five with tumors of low malignant potential) and were subjected to microsatellite analysis. Serum samples and urine samples obtained from 16 individuals without clinical evidence of genitourinary malignancy served as controls. RESULTS: Nineteen (76%) of the 25 patients with malignant tumors were found to have one or more microsatellite DNA alterations in their urine specimen, and 15 (60%) were found to have alterations in their serum DNA by microsatellite analysis. In every case, the microsatellite changes in urine or serum were identical to those found in the primary tumor. Three of five patients with tumors of low malignant potential were found to have DNA alterations in their urine, but none displayed alterations in their serum. Moreover, microsatellite alterations were not identified in either the urine or the serum samples from normal control subjects and patients with hematuria due to nephrolithiasis (renal stones). CONCLUSION: These data suggest that microsatellite DNA analysis of urine specimens provides a potentially valuable tool for the early detection of resectable kidney cancer. Furthermore, microsatellite analysis of serum samples reveals evidence of circulating tumor-specific DNA in approximately half of these patients and may reflect the propensity of these tumors to spread to distant sites at an early stage.

Aged↗

PubMed1999

Acute bleeding after allogeneic bone marrow transplantation: association with graft versus host disease and effect on survival.

BACKGROUND: Hemorrhagic complications are frequently implicated clinically for the high morbidity and mortality of acute graft versus host disease (GVHD), however, only few reports characterize the incidence and timing of bleeding in relation to GVHD, and essentially no study has quantified the effect of bleeding on survival of allogeneic patients with GVHD. This study examines the association of bleeding with acute GVHD and the effect of both complications on survival. METHODS: A total of 463 allogeneic patients transplanted at the Johns Hopkins Hospital, were included in the study. Bleeding evaluation was based on daily scores of intensity and blood transfusions. All bleeding sites were recorded. GVHD staging was defined by the extent of rash, serum bilirubin, diarrhea, and confirmatory histology. RESULTS: The incidence of GVHD was 27.4%, bleeding occurred in 40.2%. The incidence of bleeding was higher in patients with GVHD as compared with non-GVHD, and correlated with GVHD severity. The higher bleeding incidence in GVHD was due to gastrointestinal hemorrhage, hemorrhagic cystitis, and pulmonary hemorrhage. While the majority of bleeding (51/75) in non-GVHD patients initiated within 30 days after bone marrow transplantation (BMT), only 32.3% (21/65) of the bleeding in the GVHD group initiated within 30 days, and the risk for bleeding continued until day 100. Bleeding was a late event compared to GVHD, however, most bleeding episodes were associated with active GVHD. Both GVHD and bleeding were individually associated with reduced survival, with profound additive adverse effect: median survival in 221 nonbleeding non-GVHD was >83.2 months, GVHD nonbleeding (39 patients) had median of 10.6 months, bleeding non-GVHD (99 patients) had median of 4.3 months, and median survival of the GVHD bleeding group (85 patients) was 3.2 months. CONCLUSIONS: Our results support an association of bleeding with acute GVHD, suggesting that GVHD is a risk factor for bleeding after BMT. The occurrence of bleeding clearly identified poor outcome subgroup within GVHD, suggesting further evaluation for clinical application of bleeding in the assessment of GVHD severity.

Acute Disease↗

PubMed1999

Comparison of viral load and human leukocyte antigen statistical and neural network predictive models for the rate of HIV-1 disease progression across two cohorts of homosexual men.

We compared the performance of HIV-1 RNA and models based on human leukocyte antigen (HLA) in predicting the rate of HIV-1 disease progression using both linear regression and neural network models across two different cohorts of homosexual men. In all, 139 seroconverters from the Multicenter AIDS Cohort Study were used as the training set and 97 seroconverters from the District of Columbia Gay (DCG) cohort were used for validation to assess the generalizability of trained predictive models. Both viral load and HLA markers were strongly predictive of disease progression (p < .0001 and p = .001, respectively), with viral load superior to HLA (change in -2 log likelihood [-2LL] 26.7 and 10.2, respectively, in proportional hazards models). Consideration of both HLA markers and viral load offered no significant predictive advantage over viral load alone in most cases; however, HLA-based predictions obtained from neural networks modeling improved the discrimination among patients with high viral load (p = .02). Viral load, HLA scores, and rapid disease progression were moderately correlated (p < .01 for all three pairs of these variables). The median viral load was 10(3.70) copies/ml among DCG patients who had more favorable than unfavorable HLA markers and 10(4.66) copies/ml among patients with more unfavorable than favorable HLA markers. Viral load is a simpler, stronger predictor of disease progression than early developed HLA models, but neural network methods and further refined HLA models may offer additional prognostic information, especially for rapid progressors. The correlation between viral load and HLA markers suggests a possible HLA effect on setting viral load levels.

Cohort Studies↗

PubMed1999

Bilateral prophylactic mastectomy decision making: A vignette study.

BACKGROUND: Little is known about the perception of bilateral prophylactic mastectomy (BPM), and whether perceptions are influenced by a family history of breast cancer. It is also unclear what factors may play a role in selecting BPM for follow-up care. METHODS: Samples of predominantly Caucasian, well-educated women with (n = 129) and without (n = 104) family histories of breast cancer were provided a vignette of a woman at increased risk. They selected one of two follow-up options: (1) clinical breast examination, breast self exam, and annual mammography or (2) BPM. RESULTS: The samples did not differ on the decision to select BPM (29.5% vs 22.1%). The family history sample reported worry about breast cancer as a problem (34.4%) more often than women with no history (15.7%). Multivariate analysis found worry and estimated 10-year risk of the woman in the vignette as significant predictors of selecting BPM. CONCLUSIONS: Approximately 25% of our sample selected BPM as the preferred option. The majority supported the need to discuss BPM among women at increased risk. Finally, both factors associated with the selection of BPM (worry, risk assessment) are potentially amenable to psychosocial or educational approaches. There is a clear need for assessment of worry and risk perception prior to surgical decision making.

Adult↗

PubMed1999

Determinants of cognitive change after coronary artery bypass surgery: a multifactorial problem.

BACKGROUND: Several studies have investigated predictors of cognitive decline after coronary artery bypass grafting (CABG), but there is little consensus as to which specific factors are predictive of poor cognitive outcomes. METHODS: We evaluated 127 patients undergoing CABG with standardized neuropsychological tests preoperatively, at 1 month and at 1 year. The outcome measure was a continuous variable reflecting change in z-scores for eight cognitive domains over time for individual patients. Univariate analyses were performed to evaluate the association between the demographic, operative, and postoperative factors and the cognitive outcome variables. Factors that were significant were included in a multiple linear regression analysis. RESULTS: Among the medical history variables, diabetes was associated with change in executive functions and psychomotor speed. Some of the operative variables were associated with short-term changes, but none with the 1-year outcomes. For example, the surgeon's rating of degree of difficulty in selecting a cross-clamp site was associated with change in attention. Higher mean pump rate during the procedure was associated with improved performance on tests of language. The cognitive domains associated with medical variables were different from those associated with surgical variables, and the associations observed at 1-year were different from those seen at 1-month. CONCLUSIONS: Change in cognition after CABG is associated with both medical and surgical variables. The specifics of these associations depend on the choice of time points after surgery. This suggests that there are multiple etiologies for these changes, with nonspecific effects of anesthesia and prolonged surgery interacting with the more specific effects of the surgical procedure itself.

Aged↗

PubMed1999

Consistent associations of HLA class I and II and transporter gene products with progression of human immunodeficiency virus type 1 infection in homosexual men.

Polymorphic products of genes in the HLA region contributing to variability in the course of human immunodeficiency virus type 1 (HIV-1) infection were identified by screening 375 Caucasian seroconverters who were aggregated from 3 cohorts. AIDS-free time was related to numerous (15) class I alleles, alone or in conjunction with transporter protein variants, to homozygosity at the A or B locus, and to alleles of two class II haplotypes. A prognostic scoring algorithm derived from the 3 cohorts captured multiple HLA contributions to protection or to risk (relative hazard=0.57-60 per unit increase in score, all P<<.001). The impact of HLA was strong and appeared independent of the effects of chemokine receptor/ligand polymorphisms and antiretroviral treatment. The algorithm also predicted divergent rates of CD4+ cell decline in 2 other groups, totaling 227 seropositive persons (P=.06 - <.001). Confirmation of these relationships should encourage investigation of HIV-1 antigen processing and presentation mediated by polymorphisms in the HLA region.

Adult↗

PubMed1999

Comparison of cytomegalovirus loads in plasma and leukocytes of patients with cytomegalovirus retinitis. The Cytomegalovirus Retinitis and Viral Resistance Study Group.

Cytomegalovirus (CMV) DNA loads in paired leukocyte and plasma samples from 199 patient visits by 66 patients with CMV retinitis were determined. Leukocyte CMV load determinations had a greater range of values (mean, 24,587 copies/10(6) leukocytes; maximum, 539, 000) than did plasma CMV load determinations (mean, 10,302 copies/ml; maximum, 386,000), and leukocyte viral loads were detectable in a greater proportion of patients at the time of diagnosis of CMV retinitis prior to initiation of anti-CMV therapy (82%) than were plasma viral loads (64%) (P = 0.0078). Agreement with CMV blood cultures was slightly better for plasma (kappa = 0. 68) than for leukocytes (kappa = 0.53), due to a greater proportion of patients with detectable viral loads in leukocytes having negative blood cultures.

Cytomegalovirus↗

PubMed1998

Association of HLA profiles with early plasma viral load, CD4+ cell count and rate of progression to AIDS following acute HIV-1 infection. Multicenter AIDS Cohort Study.

BACKGROUND: Host genetic factors, such as HLA alleles, play an important role in mediating the course of HIV-1 disease progression through largely undefined mechanisms. OBJECTIVES: To examine the association of HLA markers with HIV-1 RNA plasma viral load and other factors associated with course of disease progression in HIV-1 infection. DESIGN AND METHODS: A group of 139 HIV-1 seroconverters from the Multicenter AIDS Cohort Study had been typed for a variety of HLA markers. HIV-1 RNA plasma viral load was measured from frozen plasma specimens obtained approximately 9 months following seroconversion. CD4+ cell counts were available from the same study visit. Statistical analysis was performed using survival techniques and linear regression models to quantify the relative associations of an HLA score profile, HIV-1 RNA plasma viral load, CD4+ cell count and age with each other and with rate of progression to AIDS and death. RESULTS: Cox proportional hazards models showed statistically significant differences in time to AIDS by HLA score profile category per unit increase [relative hazard (RH), 0.64; P < 0.0001], HIV-1 RNA plasma viral load per 10-fold increase (RH, 2.04; P = 0.0003), and CD4+ cell count per 100 cell (x 10(6)/l) increase (RH, 0.90; P = 0.02). Multivariate linear regression showed that viral load was 39% lower (P = 0.0001) for each unit increase in HLA score profile and 13% lower (P = 0.002) for each 100 cell (x 10(6)/l) increase in CD4+ cell count. CONCLUSION: The means by which the HLA score profile influences the time to AIDS is probably through immunologic responses that affect the rate of HIV-1 replication, as manifested by the HIV-1 RNA plasma viral load during the first 6-12 months following acute infection.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Acute bleeding after bone marrow transplantation (BMT)- incidence and effect on survival. A quantitative analysis in 1,402 patients.

Acute bleeding after bone marrow transplantation (BMT) was investigated in 1,402 patients receiving transplants at Johns Hopkins Hospital between January 1, 1986 and June 30, 1995. Bleeding categorization was based on daily scores of intensity used by the blood transfusion service. Moderate and severe episodes were analyzed for bleeding sites. Analysis of the cause of death and the interval of the bleeding episode to outcome endpoints was recorded. Survival estimates were computed for 1,353 BMT patients. The overall incidence was 34%. Minor bleeding was seen in 10.6%, moderate bleeding was seen in 11.3%, and severe bleeding was seen in 12% of all patients. Fourteen percent of patients had moderate or severe gastrointestinal hemorrhage, 6.4% had moderate or severe hemorrhagic cystitis, 2.8% had pulmonary hemorrhage, and 2% had intracranial hemorrhage. Sixty-one percent had 1 bleeding site and 34.4% had more than 1 site. Moderate and severe bleeding was more prevalent in allogeneic (31%) and unrelated patients (62.5%) compared with autologous patients (18.5%). Significant distribution of incidence was found among the different diagnoses, but not by disease status in acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, Hodgkin's disease, and non-Hodgkin's lymphoma. Bleeding was associated with significantly reduced survival in allogeneic, autologous, and unrelated BMT and in each disease category except multiple myeloma. Survival was correlated with the bleeding intensity, bleeding site, and the number of sites. Although close temporal association was evident to mortality, bleeding was recorded as the cause of death in only the minority of cases compared with other toxicities after BMT (graft-versus-host disease, infections, and preparative regimen toxicity). Acute bleeding is a common complication after BMT that is profoundly associated with morbidity and mortality. Although bleeding was not a direct cause of death in the majority of cases, it has a potential prognostic implication as a predictor of poor outcome in clinical assessment of patients after BMT.

Acute Disease↗

PubMed1998

Cytomegalovirus retinitis and viral resistance: 3. Culture results. CMV Retinitis and Viral Resistance Study Group.

PURPOSE: To evaluate the relationship between blood and urine cultures for cytomegalovirus and clinical outcomes in patients with cytomegalovirus retinitis. METHODS: Prospective epidemiologic study of 108 patients with newly diagnosed cytomegalovirus retinitis. Blood and urine were cultured for cytomegalovirus at diagnosis of retinitis, at 1 month and 3 months after diagnosis, and every 3 months thereafter. RESULTS: Of the patients, 80.6% were found to have either a positive blood culture or urine culture for cytomegalovirus at the time of diagnosis of retinitis, and a positive blood culture at diagnosis was associated with an increased mortality (odds ratio = 1.91, P = .012). Follow-up cultures were positive in approximately 20% of patients, and the rate was constant over time. The development of a positive blood or urine culture during follow-up correlated with the occurrence of cytomegalovirus retinitis in the contralateral eye in those patients with unilateral disease at diagnosis (odds ratio = 5.74, P = .001). CONCLUSIONS: Patients with cytomegalovirus retinitis and positive blood cultures for cytomegalovirus have a poorer prognosis.

AIDS-Related Opportunistic Infections↗

PubMed1998

Risk factors for noncompliance with glaucoma follow-up visits in a residents' eye clinic.

OBJECTIVE: This study aimed to identify factors associated with compliance with glaucoma follow-up visits. DESIGN: Computer records of a university residents' eye clinic were reviewed to identify a random sample of all persons who had an examination with International Classification of Disease (ICD) 9 coding (ICD9) for glaucoma suspect or glaucoma during a 2-year period (1991-1993) to undergo telephone interview. PARTICIPANTS: Those who were seen at least every 6 months regardless of earlier return instructions were defined as compliant with follow-up (controls, n = 362). Those who had any lapse between visits of longer than 6 months were defined as noncompliant (cases, n = 362). RESULTS: Interviews were completed for 196 cases and 242 controls. Noncompliant persons were significantly more likely to be suspects for glaucoma rather than to have definite glaucoma and to be dissatisfied with waiting time in the clinic (29.1% vs. 17.8%, P < 0.005) and to state that they did not take their glaucoma medications as prescribed (25.4% vs. 13.4%, P < 0.004). They also were less likely to have been prescribed eyedrop medication. A high percentage of both patients and controls knew that glaucoma can lead to blindness (85.2% and 88.4%, respectively). The most common reasons patients gave for not keeping follow-up visits were the perception that their eye problem was "not serious enough," the cost of examinations, and that the doctor did not tell them to come back. CONCLUSION: Compliance with follow-up visits for glaucoma is associated with markers for early disease. Attempts to improve compliance might focus on improved communication of the seriousness of the disease and improvements in clinic waiting time.

Aged↗

PubMed1998

Stereotactic radiosurgery for brain metastases: comparison of lung carcinoma vs. non-lung tumors.

In the medical literature, stereotactic radiosurgery (SRS) for brain metastases results in rates of local control of 65 to 85 %. To define patient selection criteria, we measured the survival in a population with a high proportion of non-small cell lung carcinoma (NCS lung) metastases that occurred soon after primary diagnosis. Between 9/89 and 10/93 30 adults (21 M, 9 F) had SRS for metastatic NSC lung carcinoma (14 patients) vs. non-lung carcinomas (16 patients having breast (3), renal (3), melanoma (3), GI (2, thyroid (1) or carcinoma of unknown origin (4)). The metastases were solitary for 22 patients and multiple for 8 patients. Average ages (y) (+/-SD) were 58.6+/-10.4 for NSC lung patients and 53.4+/-12.5 (p = 0.32) for non-lung patients. The average interval (months) from diagnosis of the primary to metastasis was 23.8+/-41.4 for all patients. This interval was shorter for NSC lung patients: 3.1+/-6.0 vs. 48.0+/-51.7 (p < 0.001) for non-lung patients. Twenty seven patients had conventional radiotherapy (XRT) before (24 patients) or after (3 patients) SRS. Doses (cGy) were 3303+/-841 for 13 NSC lung patients and 4256+/-992 for 14 non-lung patients (p = 0.034). The median time from primary diagnosis to SRS was shorter for the NSC lung patients (11 mo) compared to the non-lung patients (35 mo). SRS was given for recurrence of metastases after XRT for 11/14 NSC lung patients and 13/16 non-lung patients. The doses (cGy) of SRS were 1579+/-484 vs. 1682+/-476 (p=0.45) for the NSC lung and non-lung groups, respectively. After SRS a decrease in metastasis diameter was observed in 10 of 14 NSC lung patients vs. 12 of 16 non-lung patients (p=0.85 Chi-square). Twenty-seven of the 30 patients have died. For all patients, the median survival after diagnosis of the primary and after radiosurgery was 31.3 and 8.4 months, respectively. The median survival (95% CI) from primary diagnosis was 24.3 months (13.2-27.3) for NSC lung patients and 46.5 months (39.2-65.5) for non-lung patients (p=0.005 logrank test). The median survival (95% CI) after SRS was 7.9 months (3.0-14.3) for the NSC lung patients and 8.4 (2.9-11.9) months for the non-lung patients (p=0.98 logrank test). Within the two groups, no difference in survival was observed for patients who had SRS sooner (< 1 yr for NSC lung; < 3 yr for non-lung) after primary diagnosis: 9.3 vs. 6.5 mo for NSC lung (p=0.21) and 10.5 vs. 7.2 mo for non-lung (p=0.87). In this series, the shortened intervals from primary diagnosis to SRS for NSC lung metastases was associated with post-SRS survivorship that was equivalent to the more favorable non-lung group.

Adult↗

PubMed1998

Inhibited apoptosis and drug resistance in acute myeloid leukaemia.

Despite extensive investigation into mechanisms of drug resistance in acute myeloid leukaemia (AML), the aetiology of therapeutic resistance is unclear. We found that five leukaemia cell lines (K562, HL-60, CEM. CEM induced to overexpress bcl-2, and REH) displayed parallel sensitivity to four antileukaemia drugs with different mechanisms of action, with K562 generally being the least sensitive and REH being the most sensitive. The amount of spontaneous apoptosis in the cell lines after serum-free culture paralleled their drug sensitivity: K562 cells displayed the least apoptosis at 24h (2.50 +/- 0.24%) and REH the most (24.47 +/- 8.22%). The extent of spontaneous apoptosis of leukaemic blasts from 39 patients with newly diagnosed de novo AML also correlated with the success of the intensive, infusional cytarabine-based induction therapy. There was a median of 19.5% (range 3.6-64%) apoptotic AML cells after 24 h of serum-free culture in patients who entered a complete remission compared with 4.2% (1.8-7.0%) apoptotic AML cells in patients who did not achieve a complete remission (P = 0.0007). Thus, inhibited apoptosis was associated with both in vitro and in vivo pan-resistance to antileukaemic chemotherapy. The cause of inhibited apoptosis in AML is probably a function of interactions among multiple signals that influence apoptosis. Assessment of spontaneous apoptosis may serve as an important prognostic factor for AML.

Acute Disease↗

PubMed1998

Cytomegalovirus retinitis and viral resistance: ganciclovir resistance. CMV Retinitis and Viral Resistance Study Group.

Cytomegalovirus (CMV) retinitis is among the most common opportunistic infections in patients with AIDS and a substantial cause of visual loss. With long-term therapy, resistant CMV may develop. In a prospective study of 108 patients with CMV retinitis, 80.6% of patients were found to have either a positive blood culture or positive urine culture for CMV at the diagnosis of retinitis. At diagnosis of retinitis, 0.9% and 2.7% of patients had a ganciclovir-resistant blood culture isolate and urine culture isolate, respectively. Of 76 patients initially treated with ganciclovir, 11.4% had a resistant blood or urine culture isolate by 6 months of treatment and 27.5% by 9 months. The development of ganciclovir resistance during follow-up correlated with the occurrence of CMV retinitis in the contralateral eye (odds ratio = 9.06, P = .003).

AIDS-Related Opportunistic Infections↗

PubMed1998

Incidence of foscarnet resistance and cidofovir resistance in patients treated for cytomegalovirus retinitis. The Cytomegalovirus Retinitis and Viral Resistance Study Group.

Cytomegalovirus (CMV) retinitis is a common opportunistic infection in patients with AIDS. With long-term therapy for CMV retinitis, resistant CMV may develop. In a prospective study of 122 patients with CMV retinitis, 2.4 and 0.8% of patients had foscarnet-resistant blood culture isolates (50% inhibitory concentration [IC50], >400 microM) and urine culture isolates, respectively, at diagnosis of CMV retinitis prior to treatment, whereas 4.1 and 6.6% had cidofovir-resistant (IC50, >2 microM) blood and urine culture isolates, respectively. Patients were treated according to best medical judgement. Of 44 foscarnet-treated patients, 26% had a resistant blood or urine culture isolate by 6 months of treatment and 37% had a resistant isolate by 9 months; of 13 cidofovir-treated patients, 29% had a resistant blood or urine culture isolate by 3 months of therapy. The probabilities of developing foscarnet resistance while on foscarnet and developing cidofovir resistance while on cidofovir were not significantly different from that for developing ganciclovir resistance while on ganciclovir (odds ratios, 1.87 [P = 0.19] and 2.28 [P = 0.15], respectively).

Adult↗

PubMed1998

Oltipraz chemoprevention trial in Qidong, People's Republic of China: modulation of serum aflatoxin albumin adduct biomarkers.

In 1995, 234 adults from Qidong, People's Republic of China, were enrolled and followed in a Phase IIa 4-methyl-5-(N-2-pyrazinyl)-1,2-dithiole-3-thione (oltipraz) chemoprevention trial. Residents of this area are at high risk for development of hepatocellular carcinoma, in part due to consumption of aflatoxin-contaminated foods. The intervention was a randomized, placebo-controlled, double-blind study. Elements of the study design and clinical outcomes have been recently published (Jacobson et al, Cancer Epidemiol. Biomark. Prev., 6: 257-265, 1997). The primary objective was to conduct a preliminary assessment of the ability of oltipraz to modulate levels of a validated biomarker of aflatoxin exposure and of the risk of hepatocellular carcinoma by determining levels of aflatoxin-albumin adducts in sera. Healthy eligible individuals were randomized into three arms to receive p.o. 125 mg of oltipraz daily, 500 mg of oltipraz weekly, or placebo for 8 weeks. There were no consistent changes in biomarker levels in the placebo arm over the 16-week observation period, nor was any apparent effect observed in the arm receiving 125 mg of oltipraz each day. However, individuals receiving 500 mg of oltipraz once a week for 8 weeks showed a triphasic response to oltipraz. No effect was observed during the 1st month of the intervention, whereas a significant (P = 0.001) diminution in adduct levels was observed during the 2nd month of active intervention and during the lst month of follow-up. A partial rebound in adduct levels toward baseline values was observed during the 2nd month postintervention. Linear regression models up to week 13 confirmed a significant (P = 0.008) weekly decline of biomarker levels in the group receiving 500 mg of oltipraz once a week. However, despite these effects relative to baseline values within the 500-mg weekly arm, there were no statistically significant differences in biomarker trajectories between treatment arms. The genotype for glutathione S-transferase M1, an oltipraz-inducible isoform involved in the detoxification of aflatoxin B1, did not appear to affect either baseline levels or rates of decline in the biomarker. A follow-up Phase IIb trial with a longer intervention period will be necessary to determine the full extent to which aflatoxin biomarker burden can be reduced and whether diminution of biomarkers can be sustained over the long term.

Adult↗