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D Armstrong

Publications and source records attributed to D Armstrong.

At least 271 records · Page 15Linked to original sources
PubMed1994

Relationship between plasma concentrations of 3'-deoxy-3'-fluorothymidine (alovudine) and antiretroviral activity in two concentration-controlled trials.

Two concentration-controlled trials (CCTs) defined the relationship between plasma concentrations of 3'-deoxy-3'-fluorothymidine (alovudine) and changes in surrogate markers of antiretroviral activity. In an initial open-label CCT involving 14 subjects infected with human immunodeficiency virus (HIV), unacceptable hematologic toxicity occurred when the area under the concentration-time curve during a 12-h dosing interval (AUC12) was > or = 300 ng*h/mL. Consequently, 46 subjects were assigned to AUC12s of 50, 100, or 200 ng*h/mL for up to 16 weeks in a prospective, randomized, double-blind CCT. Alovudine caused a concentration-dependent reduction in p24 antigen and peripheral blood mononuclear cell HIV titers within 4 weeks of start of treatment. The AUC12 producing a 50% reduction in p24 (108 ng*h/mL) had a trough concentration identical to the reported IC50 of alovudine in HIV-infected H9 cells. It may be possible to predict the antiretroviral activity of certain nucleoside analogues as a function of plasma drug concentration.

Adult↗
PubMed1994

General practitioners' views of clinical guidelines for the management of asthma.

OBJECTIVES: To assess the views of GPs on the value of clinical guidelines for the management of asthma. DESIGN: Structured questionnaire survey. SETTING: Bromley Health District. SUBJECTS: All (160) GPs in health district. MAIN OUTCOME MEASURES: Evaluation of each item of clinical guidelines as to whether 'obvious', 'useful' or 'controversial'. RESULTS: Ninety-four (59%) of GPs responded. There was considerable variation in views on all 26 guideline items in the questionnaire. The average GP thought that 11.5 items were obvious, 8.5 useful and 5.7 controversial, but these views showed no relationship to the GP's age, sex, ethnicity or partnership size. CONCLUSION: Clinical guidelines are usually written to be of value to a wide number of clinicians, but it appears that GPs at least have more individual needs on issues of clinical management. This may explain the reported limited impact of guidelines on clinical practice.

Analysis of Variance↗
PubMed1994

Sepsis caused by Flavimonas oryzihabitans.

Previous reports of F. oryzihabitans sepsis involving central venous access devices reveal a relatively high rate of complications, including device removal, despite a course of broad-spectrum anti-microbials with compatible in vitro susceptibility results. In the present report of 22 cases of F. oryzihabitans sepsis treated at Memorial Sloan-Kettering Cancer Center from February 1986 through September 1993, the majority of CVAD-related infections with F. oryzihabitans were successfully treated with a 14-day course of antimicrobials with antipseudomonal activity, and removal of the device was usually not required. Factors that may complicate successful treatment of CVAD-related sepsis caused by F. oryzihabitans include polymicrobial infections and premature discontinuation of antibiotic therapy.

Adult↗
PubMed1994

Restriction fragment length polymorphism analysis of clinical isolates of Mycobacterium haemophilum.

Mycobacterium haemophilum is an emerging opportunistic pathogen, and since 1989, infections caused by this organism have been identified more frequently in the New York City area than in any other region of the United States. A DNA fingerprinting method, based on restriction fragment length polymorphisms (RFLPs) was developed. A genomic library of M. haemophilum isolate 1A was constructed; screening the library yielded a recombinant strain that incorporated a genetic element present in multiple copies in the M. haemophilum genome. This clone was used to produce a probe for RFLP analyses of PvuII digests of genomic DNA. We used this probe to determine the RFLP patterns of 43 clinical isolates of M. haemophilum from 28 patients. A total of six distinct patterns were observed. Two patterns, designated types 1 and 2, accounted for 91% of the infections in patients from the New York City area. Two isolates from Arizona had identical patterns but were distinct from those of New York isolates, and an isolate from Israel, the type strain, had another distinct pattern (type 6). The type 6 pattern was also seen in a recent isolate from Norway. All of the type 1 isolates and 60% of the type 2 isolates were recovered from patients with AIDS in the New York City area. This molecular subtyping method should provide a useful tool for epidemiological studies and may help identify the associated risk factors, vehicles, and possible reservoirs of this newly emerging pathogen.

AIDS-Related Opportunistic Infections↗
PubMed1994

Effect of omeprazole on intragastric bacterial counts, nitrates, nitrites, and N-nitroso compounds.

Previous studies have suggested that profound inhibition of gastric acid secretion may increase exposure to potentially carcinogenic N-nitroso compounds. The aim of this study was to find out if the proton pump inhibitor omeprazole (20 mg daily) is associated with increased concentrations of potentially carcinogenic N-nitroso compounds in gastric juice. The volume of gastric contents, number of bacteria, and concentrations of nitrates, nitrites, and N-nitroso compounds was determined in gastric aspirates obtained after an overnight fast in 14 healthy volunteers (7M:7F) after one week of treatment with placebo, and one and two weeks' treatment with omeprazole. Median bacterial concentrations were 1.0 x 10(4) (range 5.0 x 10(3)-5.0 x 10(6)) colony forming units (CFU)/ml after one weeks' treatment with placebo and increased significantly to 4.0 x 10(5) (0-3.3 x 10(7)) CFU/ml after two weeks' treatment with omeprazole (p < 0.05). A similar increase was seen in the concentration of nitrate reducing bacteria. There was no difference in the volume of gastric aspirates after treatment with omeprazole when compared with placebo (65 (29-155) ml v 42 (19-194) ml). The concentration of N-nitroso compounds was 0.13 (0-1.0) mumol/l after two weeks of omeprazole, which was not significantly different from that seen with placebo (0.15 (0-0.61) mumol/l). There was also no increase in the concentrations of nitrates or nitrites. It is concluded that omeprazole (20 mg once daily) for two weeks in healthy volunteers is associated with gastric bacterial proliferation but does not increase concentrations of N-nitroso compounds.

Adult↗
PubMed1994

Effects of omeprazole and lansoprazole on 24-hour intragastric pH in Helicobacter pylori-positive volunteers.

BACKGROUND: The comparative effects of omeprazole and lansoprazole on gastric acidity in Helicobacter pylori-positive subjects and the clearance of H. pylori are unknown. METHODS: Eighteen asymptomatic H. pylori-positive subjects were studied. Each volunteer received 7 days of omeprazole, lansoprazole, or placebo in a randomized, double-blind, crossover study, with a washout period of 4-6 weeks between treatments. At the end of each treatment period 24-h dual-point intragastric pH-metry was performed, and H. pylori clearance was assessed. RESULTS: Both omeprazole (corpus/antrum pH: 5.5/5.5) and lansoprazole (5.4/5.4) increased intragastric pH compared with placebo (1.5/1.3). Over the 24-h recording there was no difference between the two treatments with regard to control of intragastric pH or clearance of H. pylori. CONCLUSION: Omeprazole, 20 mg once daily, and lansoprazole, 30 mg once daily, are comparably effective antisecretory agents in H. pylori-positive subjects. Both agents provide only transient clearance of H. pylori in a few subjects.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

Cryptococcosis.

Cryptococcal disease is the most common life-threatening fungal infection in patients with AIDS. The most common manifestation, meningitis, has an indolent presentation that may lead to a delay in diagnosis. Although clinical trials have demonstrated efficacy with fluconazole in some patients, amphotericin B, with or without flucytosine, is the treatment of choice. Lifelong suppression of cryptococcal disease after initial therapy, however, is best achieved with fluconazole. Prognostic staging systems and primary prophylaxis of cryptococcal disease are also discussed.

AIDS-Related Opportunistic Infections↗
PubMed1994

Apert syndrome: quantitative assessment by CT scan of presenting deformity and surgical results after first-stage reconstruction.

We reviewed our experience with eight infants or young children (less than 2 years of age) who presented sequentially with Apert syndrome. Using a method of 14 measurements taken from the cranio-orbitozygomatic region in preoperative and postoperative CT scans of these patients, we documented their presenting skeletal morphology and the results of surgical correction at least 1 year after surgery. Significant preoperative findings included a wide anterior cranial vault at 110 percent of normal, a maximum cranial length that averaged only 90 percent of normal, a substantially widened anterior interorbital distance of 117 percent of normal, an increased lateral interorbital distance (112 percent of normal), and a widened bitemporal width at 122 percent of normal. Globe protrusion was significant at 121 percent of normal, and the medial orbital wall distance (length) was less than normal at 92 percent. In the upper midface (zygomatic) region, both the distance between the zygomatic buttresses and the interarch distance were found to be increased at 109 percent of normal, while the zygomatic arch lengths were substantially shortened at 79 percent of normal. Results of surgical correction, as documented by CT scan measurements, showed that more than a year after surgery, skeletal morphology had changed from preoperative measurements but that none of the craniofacial measurements had significantly improved (p < 0.05) in comparison with those of age-matched controls. Quantitative measurement of CT scans of the cranio-orbitozygomatic region confirmed clinically observed findings in these patients before cranio-orbital reconstruction in infancy and early childhood and proved useful in assessing the surgical results over time.

Acrocephalosyndactylia↗
PubMed1994

Metopic synostosis: quantitative assessment of presenting deformity and surgical results based on CT scans.

Our study applied a method of using 14 clinically relevant measurements of CT scan images to document skeletal dysmorphology in patients with metopic synostosis to determine the effectiveness of their surgical procedure after a minimum of 1 year. Ten consecutive patients with metopic synostosis who underwent a standard surgical procedure were reviewed. Preoperative and postoperative (> 1 year) CT scans were compared with those of age-matched controls. Percentages of normal were then compared for significant differences. Preoperative cranial vault measurements revealed a narrowed anterior intercoronal distance at 92 percent of normal. Orbital measurements showed a narrowed anteromedial wall interorbital distance at 79 percent of normal, a narrowed lateral orbital wall distance at 94 percent, and an elevated medial orbital wall protrusion beyond the plane of the lateral orbital walls at 115 percent. After surgery, the intercoronal distance was significantly corrected to 101 percent, the anteromedial wall interorbital distance was improved but remained undercorrected at 90 percent, and the medial wall protrusion was significantly decreased to 98 percent of normal. Quantitative measurements of CT scan images confirmed clinically observed physical findings in unoperated trigonocephaly to be orbital hypotelorism, retruded lateral orbital rims, and a narrowed bitemporal width. The surgical technique corrected the lateral orbital wall aspects of the deformity as well as the narrowed anterior cranial vault width and improved the orbital hypotelorism.

Cephalometry↗
PubMed1993

Infectious morbidity associated with long-term use of venous access devices in patients with cancer.

OBJECTIVE: To evaluate infectious morbidity associated with long-term use of venous access devices. DESIGN: Prospective, observational study. SETTING: Comprehensive cancer center at a university hospital. PARTICIPANTS: 1431 consecutive patients with cancer requiring 1630 venous access devices for long-term use inserted between 1 June 1987 and 31 May 1989. MEASUREMENTS: Quantitative microbiologic tests to identify device-related bacteremia and fungemia, catheter tunnel infection, pocket infection in implantable port devices, and site infections; number of days the device remained in situ and time until infectious morbidity; vessel or device thrombosis and device breakage. RESULTS: At least one device-related infection occurred with 341 of 788 (43% [95% CI, 39% to 47%]) catheters compared with 57 of 680 (8% [CI, 6% to 10%]) completely implanted ports (P < or = 0.001). Device-related bacteremia or fungemia is the predominant infection occurring with catheters, whereas ports have a more equal distribution of pocket, site, and device-related bacteremia. The predominant organisms isolated in catheter-related bacteremia were gram-negative bacilli (55%) compared with gram-positive cocci (65.5%) in port-related bacteremia. The number of infections per 1000 device days was 2.77 (95% CI, 2.48 to 3.06) for catheters compared with 0.21 (CI, 0.16 to 0.27) for ports (P < or = 0.001). Based on a parametric model of time to first infection, devices lasted longer in patients with solid tumors than in those with hematopoietic tumors. Ports lasted longer than catheters across all patient groups. CONCLUSIONS: The incidence of infections per device-day was 12 times greater with catheters than with ports. Patients with solid tumors were the least likely to have device-related infectious morbidity compared with those with hematologic cancers. The reasons for the difference in infectious complications is uncertain but may be attributable to type of disease, intensity of therapy, frequency with which devices are accessed, or duration of neutropenia.

Adolescent↗
PubMed1993

Fever among outpatients with advanced human immunodeficiency virus infection.

BACKGROUND: Fever is common among persons with human immunodeficiency virus (HIV) infection. However, the clinical implications of fever in this population have not been evaluated. We therefore undertook a prospective study of fever in persons with advanced HIV infection to determine the incidence and etiology of fever in this patient group. METHODS: Prospective natural history study of 176 patients with advanced HIV infection followed up at Memorial Sloan-Kettering Cancer Center, New York, NY, from April 1, 1990, through December 31, 1990. RESULTS: Fever occurred in 46% of patients. A diagnosis was made in 83% of episodes, with acquired immunodeficiency virus-defining illnesses accounting for half of the diagnosed cases. Patients whose conditions required more than 2 weeks to diagnose most often had lymphoma, Mycobacterium avium-intracellulare bacteremia, or Pneumocystis carinii pneumonia. Four patients had persistent unexplained fever without a clear source. Only one patient had fever that clearly responded to antiretroviral therapy. CONCLUSIONS: Fever is common among outpatients with advanced HIV infection. Human immunodeficiency virus itself is rarely the cause of fever in such patients; the cause of the fever should be thoroughly evaluated.

AIDS-Related Opportunistic Infections↗
PubMed1993

A cluster of four cases of Mycobacterium haemophilum infection.

Four cases of infection with Mycobacterium haemophilum occurred at a single hospital in a seven-month period. Only 22 cases have been reported since 1976. All four patients were immunocompromised; two had AIDS and two were the first known recipients of allogeneic bone marrow transplants (BMT) to develop the infection. One BMT recipient died of Mycobacterium haemophilum pneumonia. The organism requires hemin or ferric ammonium citrate and incubation of media at 30 degrees C for optimum growth. Clinicians and microbiologists should consider infection with Mycobacterium haemophilum, particularly when specimens are from immunocompromised patients with unexplained illness and/or when acid-fast bacilli are seen on smear.

AIDS-Related Opportunistic Infections↗
PubMed1993

HIV-related emergencies: frequency, diagnoses, and outcome.

OBJECTIVE: To study the clinical epidemiology and outcome of HIV-related emergencies, and to identify clinical predictors of HIV-related emergency hospitalizations. DESIGN: Case series. SETTING: Emergency facility of a tertiary care teaching hospital. PATIENTS: 350 HIV/AIDS patients followed at the authors' center. MEASUREMENTS AND MAIN RESULTS: 69 of 356 patients made 92 emergency visits with a frequency of 8% per month and 20% per quarter in a three-month study period. Forty-three visits (47%) resulted in hospitalization and contributed to 70% of total AIDS hospitalizations in the period. The five most common acute diagnoses were pneumonia (n = 22; 24%), fever (n = 15; 16%), upper respiratory infection (n = 9; 10%), cellulitis (n = 6; 7%), and gastroenteritis (n = 6; 7%). Three diagnoses accounted for 70% of acute HIV hospitalizations: pneumonia (n = 19), fever (n = 4), and sepsis (n = 4). Analysis of patient disposition as it relates to the patient's clinical presentation and HIV history using multivariate analysis yielded 1) the presence of dyspnea or cough (p = 0.015) and 2) fever with an abnormal chest x-ray (p = 0.008) as independently predictive of hospitalization. CONCLUSION: The findings indicate that HIV/AIDS patients have a frequent need for emergency care and most HIV/AIDS hospitalizations are emergency-related. The acute problems of these patients are related to a limited number of diagnostic categories, and the presence of respiratory or constitutional symptoms with an abnormal chest radiograph are the only reliable factors predictive of hospitalization.

Adult↗