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Biomedical subjects

R Coombs

Publications and source records attributed to R Coombs.

36 records · Page 2Linked to original sources
PubMed1994

The safety and efficacy of combination N-butyl-deoxynojirimycin (SC-48334) and zidovudine in patients with HIV-1 infection and 200-500 CD4 cells/mm3.

We conducted a double-blind, randomized phase II study to evaluate the safety and activity of combination therapy with N-butyl-deoxynojirimycin (SC-48334) (an alpha-glucosidase I inhibitor) and zidovudine versus zidovudine alone. Patients with 200 to 500 CD4 cells/mm3 who tolerated < or = 12 weeks of prior zidovudine therapy received SC-48334 (1000 mg every 8 h) and zidovudine (100 mg every 8 h) or zidovudine and placebo. Sixty patients received combination therapy and 58, zidovudine and placebo. Twenty-three patients (38%) and 15 (26%), in the combination and zidovudine groups, respectively, discontinued therapy (p = 0.15). The mean SC-48334 steady-state trough level (4.04 +/- 0.99 micrograms/ml) was below the in vitro inhibitory concentration for human immunodeficiency virus (HIV). The mean increase in CD4 cells at week 4 was 73.8 cells/mm3 and 52.4 cells/mm3 for the combination and zidovudine groups, respectively (p > 0.36). For patients with prior zidovudine therapy, the mean change in CD4 cells in the combination and zidovudine groups was 63.7 cells/mm3 and 4.9 cells/mm3 at week 8 and 6.8 cells/mm3 and -45.1 cells/mm3 at week 16, respectively. The number of patients with suppression of HIV p24 antigenemia in the combination and zidovudine groups was six (40%) and two (11%) at week 4 (p = 0.10) and five (45%) and two (14%) at week 24 (p = 0.08), respectively. Diarrhea, flatulence, abdominal pain, and weight loss were common for combination recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Deoxynojirimycin↗
PubMed1994

Percutaneous computed tomography-guided stabilization of posterior pelvic fractures.

Nineteen patients with 21 unstable fractures of the posterior pelvic complex were treated with percutaneous computed tomography (CT)-guided posterior stabilization. CT allowed satisfactory visualization of the fracture and direction and length of the screw. It also allowed the authors to perform the procedure percutaneously, while causing only minimal blood loss. CT cuts that showed the best and safest sites for screw placement were selected. The length and direction of the screw was identified, and the skin entry site was determined. The guide pin was inserted across the fracture or disrupted sacroiliac joint; its correct position was confirmed and a cannulated screw was inserted over the pin. In the majority of patients, a pelvic external fixator was applied in the CT suite. Although assessing the deformity was possible, reduction was difficult but ultimately acceptable. All patients maintained reduction of their sacroiliac complex without loss of fixation, and all fractures healed without clinical or radiographic signs of pelvic instability. This technique was not associated with neurologic injury or deep infection. All but 2 patients returned to preinjury levels of activity and function. Two patients had associated injuries that affected their final functional outcome.

Adolescent↗
PubMed1994

Photodynamic inactivation of free and cell-associated HIV-1 using the photosensitizer, benzoporphyrin derivative.

The photosensitizer benzoporphyrin derivative monoacid ring A (BPD) has been investigated regarding its ability to destroy free and cell-associated human immunodeficiency virus type 1 (HIV-1) when activated by light. Experiments with free virus in tissue culture medium indicate that light-activated BPD was effective in rendering HIV uninfectious. Azidothymidine (AZT)-resistant strains of HIV appear equally susceptible to photodynamic inactivation under drug and light conditions that proved effective in inactivating AZT-sensitive strains of HIV. Experiments conducted on whole blood from individuals infected with HIV demonstrate that BPD and light treatment could significantly reduce cell-associated virus, under conditions that appear not to damage red blood cells. The amount of culturable virus from infected leukocytes surviving photodynamic treatment could be further reduced by the addition of AZT to the culture.

Cells, Cultured↗
PubMed1992

Top down, bottom up.

Explore the source record for details and available documents.

Diagnosis-Related Groups↗
PubMed1991

Pharmacokinetic disposition of zidovudine during pregnancy.

Zidovudine pharmacokinetics was determined in three human immunodeficiency virus type 1-seropositive women receiving zidovudine (200 mg orally every 4 h) from 19 to 39 weeks of pregnancy and postpartum. Zidovudine concentrations were measured using high-pressure liquid chromatography, and pharmacokinetic analyses were done using model-independent methods. For the pregnant versus postpartum periods, peak zidovudine levels (mean +/- 1 SD) were 3.9 +/- 1.7 mumol/l versus 4.3 +/- 0.04 mumol/l (P = .56); elimination half-lives were 1.3 +/- 0.6 versus 1.0 +/- 0.3 h (P = .41); areas under the concentration curve were 4.5 +/- 1.0 mumol/l x h and 6.8 +/- 0.5 mumol/l x h (P = .02); apparent total body clearances were 2.5 +/- 0.6 l/h/kg and 1.7 +/- 0.4 l/h/kg (P = .05); and apparent steady state volumes of distribution were 3.9 +/- 1.0 l/kg and 2.6 +/- 0.8 l/kg (P = .07), respectively. Umbilical cord serum levels ranged from 113%-127% of maternal levels. No persistent adverse effects of zidovudine therapy were seen in the three women or their babies.

Adult↗
PubMed1991

Anatomical and radiological considerations in compressive bar technique for posterior pelvic disruptions.

Sacral bar fixation is a well-recognized technique for the treatment of posteriorly unstable pelvic injuries, particularly sacral fractures. The sacral bars are placed in the iliac crest posterior to the sacrum. We reviewed 103 pelvic computed tomography (CT) scans and three cadaver pelves to measure the iliac crest prominence and its spatial relationship to the lamina of the sacrum. It was found that the best bony purchase for the bars is at the level of the L5-S1 junction. Lower placement of the bar increases the risk of violating the sacral canal and may also decrease the bony purchase of the bars. Some patients have an inadequate iliac crest posteriorly for proper placement; therefore, the pelvic CT scans should always be carefully evaluated preoperatively. The study also includes a description of a technique for percutaneous placement of sacral bars using fluoroscopic guidance.

Female↗
PubMed1990

CT-guided biopsy of metastatic sacral tumors.

Between June 8, 1985 and January 29, 1986, the authors performed five CT-guided needle biopsies of suspicious sacral lesions. In each of the five cases, these biopsies allowed the acquisition of specimens suitable for definitive pathologic diagnosis. Three cases of metastatic adenocarcinoma, one case of desmoplastic fibroma, and one case of chronic inflammatory changes were noted. In the case involving chronic inflammatory changes, subsequent open biopsy was performed, confirming the inflammatory changes and absence of neoplasm. The authors conclude that percutaneous CT-guided biopsy of sacral lesion can be performed safely and rapidly, and allows accurate diagnosis and treatment of sacral lesions.

Adenocarcinoma↗
PubMed1990

Reduction of postoperative CT artifacts of pelvic fractures by use of titanium implants.

The value of CT scanning for both preoperative and postoperative assessment of pelvic and acetabular fractures has been demonstrated. Previous attempts at our institution to obtain useful pelvic CT scans following internal fixation with stainless steel implants have been impaired by metal artifacts that degraded the transaxial CT images. Our use of titanium, instead of stainless steel implants, produced identical fixation and ultimate fracture healing, but yielded minimal artifacts. We recommend the use of titanium implants as substitutes for stainless steel implants in pelvic fixation to maximize the information obtained on subsequent CT exams.

Bone Screws↗
PubMed1989

Isolation of human immunodeficiency virus from genital ulcers in Nairobi prostitutes.

Recent epidemiologic studies have implicated genital/anorectal ulcer disease as an important cofactor for acquisition and transmission of human immunodeficiency virus (HIV) during sexual intercourse. To better understand the mechanism for the association between genital ulcers and HIV, exudates from 62 genital ulcers of 56 HIV-seropositive prostitutes in Nairobi (Kenya) were cultured for HIV. Twenty-six ulcer cultures could not be evaluated for the presence of HIV because of bacterial or fungal contamination. HIV was isolated from 4 (11%) of the 36 remaining uncontaminated ulcer cultures (2 introital, 1 vaginal, and 1 cervical) from 4 separate women. HIV was isolated from the cervical os from only 2 of the 4 women. HIV p24 antigen was detected in exudate from 1 of the 4 culture-positive ulcers and 0 of 32 culture-negative ulcers. Genital ulcers in seropositive patients should be regarded as potential sources of HIV, which could be important in transmission of HIV during intercourse. Public health measures aimed at controlling sexually transmitted genital ulcer diseases should be an integral part of acquired immunodeficiency syndrome (AIDS) prevention programs.

Adult↗
PubMed1989

Major surgery in von Willebrand's disease.

Two patients with von Willebrand's disease underwent major surgery, the first had aortic valve replacement and the second a total hip replacement. Clinically, the best practical test for monitoring the dose of cryoprecipitate necessary to maintain haemostasis was the bleeding time. The response to coagulation factor replacement in von Willebrand's disease is extremely variable, and it is necessary to maintain close coagulation monitoring until the patient's surgical condition is satisfactory for discharge from hospital.

Aged↗
PubMed1988

Implementing a value improvement process.

At Foothills Hospital in summer 1984, physicians, nurses and administrators began working toward a new interdisciplinary partnership and more effective management of resources through a hospital-wide initiative--the Value Improvement Program (VIP). The program has been enormously successful. VIP has helped to streamline procedures, promote teamwork and reduce costs, while simultaneously improving patient care.

Alberta↗
PubMed1987

Impedance imaging in the newborn.

We have been investigating the use of electrical impedance methods for the study of cerebral haemodynamics in the newborn for many years. Of particular interest has been the early detection of intraventricular haemorrhage, which is a major cause of death or handicap in low birthweight infants. Several problems exist in obtaining representative impedance measurements from the newborn, most notably movement artefact, respiratory-based modulation and a blood-flow related pulsatile component. Movement artefact is by far the most significant problem; in order to perform long-term monitoring we have developed an effective algorithm for rejection of corrupted data. To remove the respiratory component, which can be 1-2% of the impedance measurement, we link to the output of a respiratory monitor (standard in intensive care units) as a means of synchronising measurements to a fixed point in the respiratory cycle. Similarly, to remove the blood-flow pulsatile component, measurements are gated from the R-wave of the recorded ECG. Our total system consists of a front-end measurement system that passes image data over a serial link to a host computer. Data storage, image reconstruction and display is performed on the host, which can be any of a wide range of personal computers. The front-end contains the impedance measurement circuit, electrode switching electronics and a microprocessor for control, and is of a sufficiently small size to fit into the incubator next to the baby. Incorporating a microprocessor into the front-end produces a very flexible system that has many benefits, including: asynchronous operation from host, 'intelligent' pre-processing of measurements, command driven operation from host, etc. Software development for the front-end is performed on the host with program down-load for interactive debugging. Details of the front-end electronics and software, system performance, preliminary clinical results and other application areas of the impedance imaging technique to the care of the newborn are presented.

Cerebral Hemorrhage↗