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Biomedical subjects

D Cory

Publications and source records attributed to D Cory.

12 recordsLinked to original sources
PubMed2000

Experimental demonstration of fully coherent quantum feedback.

In the conventional picture of quantum feedback, control sensors make measurements on a quantum system, a classical controller processes the results of the measurements, and semiclassical actuators act back on the system to alter its behavior. We describe and provide an experimental demonstration of an alternative method for quantum feedback control, in which the sensors, controller, and actuators of conventional feedback control are replaced with quantum systems that interact coherently with the system to be controlled. The resulting control system represents a fully coherent quantum feedback loop.

Alanine↗
PubMed2000

Tat peptide-derivatized magnetic nanoparticles allow in vivo tracking and recovery of progenitor cells.

The ability to track the distribution and differentiation of progenitor and stem cells by high-resolution in vivo imaging techniques would have significant clinical and research implications. We have developed a cell labeling approach using short HIV-Tat peptides to derivatize superparamagnetic nanoparticles. The particles are efficiently internalized into hematopoietic and neural progenitor cells in quantities up to 10-30 pg of superparamagnetic iron per cell. Iron incorporation did not affect cell viability, differentiation, or proliferation of CD34+ cells. Following intravenous injection into immunodeficient mice, 4% of magnetically CD34+ cells homed to bone marrow per gram of tissue, and single cells could be detected by magnetic resonance (MR) imaging in tissue samples. In addition, magnetically labeled cells that had homed to bone marrow could be recovered by magnetic separation columns. Localization and retrieval of cell populations in vivo enable detailed analysis of specific stem cell and organ interactions critical for advancing the therapeutic use of stem cells.

Animals↗
PubMed1999

Omeprazole plus antibiotics in the eradication of Helicobacter pylori infection: a meta-regression analysis of randomized, controlled trials.

This article presents a meta-regression analysis of published studies of omeprazole plus antibiotics (amoxicillin, clarithromycin, or an imidazole derivative) in the treatment of Helicobacter pylori. Eligible studies were all randomized, controlled trials published through April 1996 with 10 or more patients receiving omeprazole plus antibiotics for 5 or more days and testing for H. pylori eradication 4 weeks or more after treatment. Probability of eradication was calculated for each treatment arm, and logistic regression was performed using study characteristics as covariates. Seventy-four studies involving 117 treatment arms with 4,769 patients were identified. The eradication rate was 76% for omeprazole plus clarithromycin and 65% for omeprazole plus amoxicillin dual regimens (P <.0001). Eradication rates for triple regimens were 82%, omeprazole plus amoxicillin plus clarithromycin; 83%, omeprazole plus amoxicillin plus imidazole; and 89%, omeprazole plus clarithromycin plus imidazole. In a multiple logistic regression analysis, significant factors were antibiotic, disease, omeprazole dose, and whether treatment was followed by maintenance omeprazole. A systematic overview of the best available evidence suggests that dual therapy with omeprazole plus clarithromycin is superior to omeprazole plus amoxicillin. Triple therapy is better than dual therapy. Treatment works better on ulcers than on nonulcer dyspepsia. Higher doses of omeprazole give better results. Additional trials exploring higher omeprazole doses for varying durations as well as cost, side effects, and compliance trade-offs with efficacy are recommended.

Anti-Bacterial Agents↗
PubMed1999

Safety of nifedipine in angina pectoris: a meta-analysis.

-Our objective was to compare cardiovascular event rates in patients with stable angina receiving nifedipine as monotherapy or combination therapy and in active drug controls. A MEDLARS search of published articles from 1966 to 1995 in English, French, German, Italian, or Spanish, supplemented by a manual search of bibliographies, identified 60 randomized controlled trials that met protocol criteria. Blinded articles were extracted by 2 physicians. The pooled risks of death, withdrawal, and cardiovascular event were computed and expressed as odds ratios (ORs) for all nifedipine formulations and relative to same study control drug regimens. Thirty cardiovascular events were reported in 2635 nifedipine exposures (1.14%) and 19 events in 2655 other active drug exposures (0.72%). Unadjusted ORs for nifedipine versus controls were 1.40 (95% CI, 0.56 to 3.49) for major events (death, nonfatal myocardial infarction, stroke, revascularization procedure), 1.75 (95% CI, 0.83 to 3.67) for increased angina, and 1.61 (95% CI, 0.91 to 2.87) for all events (major events plus increased angina). Episodes of increased angina were more frequent on immediate-release nifedipine (OR, 4.19 [95% CI, 1.41 to 12.49]) and on nifedipine monotherapy (OR, 2.61 [95% CI, 1.30 to 5.26]). The OR for immediate-release nifedipine was significantly higher than that for sustained-release/extended-release nifedipine (P=0.001), and the OR for nifedipine monotherapy was higher than that for nifedipine combination therapy (P=0.03). Increased risks of cardiovascular events in patients with stable angina on nifedipine were due primarily to more episodes of increased angina, confined to the immediate-release formulation and to nifedipine monotherapy.

Adrenergic beta-Antagonists↗
PubMed1996

Searching for signals: mortality and cardiovascular events in published randomized control trials of nifedipine in ischemic heart disease and hypertension.

UNLABELLED: META-ANALYSIS: A meta-analysis of published randomized control trials of nifedipine in hypertension and stable angina pectoris was performed. RESULTS: The results suggest a formulation-dependent increased risk of mortality and adverse cardiovascular outcomes for monotherapy use in patients with stable angina pectoris. No increased risk was seen in the hypertension studies.

Humans↗
PubMed1992

The potential role of custody facilities in controlling sexually transmitted diseases.

BACKGROUND: The National Commission on Correctional Health Care recommends that medical screening, including tests for syphilis and other sexually transmitted diseases, be performed by the 14th day after initial booking procedures. Because the average length of stay in detention is usually less than 14 days, most detainees are not screened or treated for asymptomatic communicable diseases. METHODS: In order to determine the incidence and prevalence of syphilis among those booked through a large county jail, a rapid screening procedure to test newly incarcerated inmates and treat those infected was implemented over a 3-week period. RESULTS: Among 6309 detainees eligible for testing during the 3-week period of the study, 129 (2%) were diagnosed with syphilis. During the preceding month when only those reporting symptoms or high-risk behaviors were screened, 20 cases were diagnosed. The sensitivity and predictive value of self-reported risk factors for syphilis infection were low. Among the first 110 diagnosed cases, 17 (15.5%) were released within 3 days and 86 (78%) were released within 6 days. CONCLUSIONS: If screening and treatment for syphilis are delayed until the 14th day after booking, the majority of infected inmates will be released prior to evaluation and treatment. Rapid screening and treatment for selected sexually transmitted diseases are likely to be an effective public health measure when implemented in custody settings.

Adolescent↗
PubMed1992

Controlling a syphilis epidemic.

In 1986 the rate of infectious syphilis (primary and secondary) in Los Angeles County began to rise from previously stable levels of about 23.5 per 100,000 to peak at 55.6 per 100,000 in 1987. The incidence of congenital syphilis increased from 205 cases in 1987 to 575 cases in 1989. The county's Sexually Transmitted Disease Program instituted a disease-specific plan to address the epidemic. Factors considered in designing the program included the high morbidity and mortality associated with congenital infection, the existence of latent infection, self-limiting symptoms, and the availability of an inexpensive screening test and curative treatment. Policy changes implemented comprised expanded screening, expanded surveillance, increased contact tracing, and the initiation of condom promotion programs. To evaluate the relative effectiveness of Los Angeles County's syphilis control efforts, the epidemic curve for infectious syphilis was compared with trends in other urban areas. Although the rate of infectious syphilis climbed a year earlier in Los Angeles than in other cities, it returned to baseline levels when other cities' rates remained at epidemic levels.

Health Education↗
PubMed1991

Magnetic resonance imaging of a seminal vesicle cyst and a review of the imaging modalities.

Magnetic resonance imaging (MRI) is invaluable in the diagnosis of pelvic pathology as demonstrated here by its use in the diagnosis of a seminal vesicle cyst. Comparison is made with computed tomography, ultrasonography and voiding cystourethrography (VCUG). MRI provides precise, anatomical detail, far superior to other modalities. The advantages and disadvantages of older diagnostic modalities, such as intravenous pyelogram, VCUG and seminal vesiculography, are discussed in this article.

Adolescent↗
PubMed1990

Failure of percutaneous drainage in children with traumatic pancreatic pseudocysts.

Recent reports have documented the successful use of percutaneous drainage (PD) in the management of traumatic pancreatic pseudocysts in children. This study presents four cases of pancreatic pseudocyst in which percutaneous catheter drainage was performed. In one instance, no operative therapy was required. However, in the other three cases PD failed to resolve the problem and distal pancreatectomy with splenic salvage was performed when contrast studies (endoscopic retrograde cholangiopancreatography or catheter injection) demonstrated disruption of the main pancreatic duct. This report suggests that children with pancreatic pseudocysts unresponsive to PD require prompt investigation of ductal anatomy to rule out transection or other major injury.

Abdominal Injuries↗
PubMedDate not supplied

Percutaneous feeding tube method for use in children.

Surgical gastrostomy has been a widely accepted method for introducing a percutaneous feeding tube for many years. However, complications are frequent, and many children who need them are not good surgical candidates. This study examines imaging guided percutaneous placement of feeding gastrostomy catheters as a safe and effective alternative to surgery.

Barium Sulfate↗