Biomedical subjects

G Marshall

Publications and source records attributed to G Marshall.

7 recordsLinked to original sources

PubMed1992

Salvage angioplasty: an alternative to high risk surgery for unstable angina?

This prospective, Human Subjects Committee and Ethics Committee approved investigation was performed to determine if coronary angioplasty (PTCA) might be a reasonable alternative revascularization method for unstable angina patients thought to be at high risk for operative (CABG) mortality. Between March 1990 and October 1991, thirty-four consecutive patients with medically refractory rest angina were deamed to have high risk of surgical mortality and underwent PTCA without surgical backup. Predicted operative mortality was calculated for each patient based upon the VA Surgical Risk Assessment model. Angioplasty of 52 vessels was attempted. Reduction in lumenal narrowing to < 50% and improved angiographic flow was obtained in 47 vessels. There were four complicating infarctions. One death occurred in the lab, and three patients with unsuccessful angioplasty died within 30 days of pump failure. Relief of angina occurred in 30/34. Thirty patients were discharged home. In follow-up from 1 to 12 months, there have been 2 late sudden deaths at 4 months and 9 months, 1 death from lung cancer; 4 patients have stable exertional angina; 2 are awaiting heart transplant but are pain free, and one patient who had PTCA during cardiogenic shock from acute myocardial infarction had elective coronary artery bypass surgery. There have been no late myocardial infarctions. The observed angioplasty 30-day mortality of 11.8% (95% confidence limit 1% to 22.6%) compares favorably with the predicted operative mortality of 23.8% for this group. This prospective but non-randomized series supports the concept that balloon angioplasty may be a reasonable alternative to surgical intervention in some patients with unstable angina and high risk for surgery. A prospective randomized trial is warranted.

Adult↗

PubMed1992

Comparison of tensile strength of solder joints by infrared and conventional torch technique.

Fabrication of a fixed partial denture may require a soldering step. This study compared soldering by a conventional torch procedure with an infrared soldering technique. Comparisons were made for tensile strength, porosity, and time efficiency between the two methods. No significant difference was found in ultimate tensile strength between the two types of solder joints and the nonsoldered control samples. Random samples photographed with a scanning electron microscope revealed no difference in joint porosity between the two techniques. Torch soldering took consistently less time that infrared soldering.

Dental Alloys↗

PubMed1992

Prevention of post-ischemic brain lipid conjugated diene production and neurological injury by hydroxyethyl starch-conjugated deferoxamine.

Hydroxyethyl starch conjugated deferoxamine (DFO) was administered to rats following resuscitation from 6.5 min cardiac arrest (CA) in an attempt to prevent the iron-catalyzed production of oxygen free radicals which may lead to neurologic injury and ultimately death following restoration of spontaneous circulation (ROSC). Brain conjugated dienes were analyzed spectrophotometrically 4 and 24 hr following ROSC, and were found to be significantly elevated when compared to non-ischemic controls. Hydroxyethyl starch-DFO treated rats demonstrated no increased conjugated diene production at either period. Neurologic injury was significantly less in drug treated rats surviving 24 or 72 hours when compared to controls. While mortality was similar in drug treated or control rats for the first 24 hours following ROSC, delayed mortality (days 1-10) was significantly less in drug treated animals, presumably as a result of neurologic protection afforded by post-ischemic drug administration. Administration of DFO conjugated to hydroxyethyl starch appears to modulate the neurologic injury which occurs during brain ischemia and reperfusion.

Alkenes↗

PubMed1991

Prophylactic use of ganciclovir in allogeneic bone marrow transplantation: absence of clinical cytomegalovirus infection.

Ganciclovir was given prophylactically to 25 patients receiving allogeneic bone marrow transplants for haematological malignancy. Patients who were seropositive for cytomegalovirus (CMV) pre-transplant were given ganciclovir both pre- and post-transplant. Those who were CMV seronegative, but who received marrow from a CMV seropositive donor, received ganciclovir post-transplant. No nonhaemopoietic toxicity was observed. Toxicity was restricted to late reversible haematological toxicity in four of the 19 evaluable patients (one thrombocytopenia, one pancytopenia, two leucopenia). No CMV interstitial pneumonitis (IP) was observed, nor were any other clinically manifest CMV infections detected. Sixteen patients remain alive at greater than 84 to greater than 518 d post-transplant. In a retrospective comparison of 152 recipients of allogeneic transplants for haematological malignancy not given prophylactic ganciclovir, and in whom either the recipient or the donor or both were CMV seropositive, the incidence of all clinically manifest CMV infections was 23% (P = 0.02) and that of CMV IP 17% (P = 0.05). If only patients in the study group and the control group receiving the same cyclosporin/short methotrexate prophylactic immune suppressive regimen, the same prophylactic acyclovir regimen and the same CMV and leucocyte-filtered blood product transfusion strategy were considered, the incidence of all clinically manifest CMV infections in the control group was 24% (P = 0.01) and that of CMV IP 13% (P = 0.07). Ganciclovir appears to reduce the incidence of CMV infections in allogeneic marrow transplant recipients even in those given immune suppressive regimens associated with adequate control of acute graft-versus-host disease.

Acute Disease↗

PubMed1979

Recruitment for the Coronary Primary Prevention Trial.

A preliminary account of some aspects of recruitment for the Coronary Primary Prevention Trial is provided. Extension of recruitment sources to include various forms of community screening resulted in more rapid acquisition of potential participants than was possible when recruitment was restricted to the more traditional sources of physician and laboratory referral. Extended recruitment was supported by augmented data feedback and by the development of the job of recruitment coordinator at each participating clinic. The identification of delays in reaching the maximal recruitment rate from particular sources points to the need for detailed planning of a recruitment campaign before large-scale clinical trials are begun.

Clinical Trials as Topic↗

PubMed1978

Roll over test.

Explore the source record for details and available documents.

Evaluation Studies as Topic↗

PubMedDate not supplied

Elevation of resting and exercise blood pressures in subjects with type I diabetes and relation to albuminuria.

The etiology of diabetic nephropathy is currently unknown, but blood pressure is believed an important risk factor. A total of 173 subjects with type I diabetes who participated in two or more exercise tests with simultaneous measurements of blood pressure (BP) and heart rate were studied. Subjects with diabetes had significantly elevated resting and exercise diastolic and systolic BPs when compared with controls. This was not related to the presence of albuminuria. During exercise, elevation of diastolic BP was present in 65 (38%) of the 173 test subjects. Elevated exercise diastolic BPs among the subjects with diabetes (excluding controls) was present only for subjects with elevated exercise and overnight albuminuria. It is concluded that factors other than early diabetic nephropathy are likely related to elevated resting and exercise BPs in subjects with diabetes compared with controls. Early renal damage, however, is related to further elevations in resting and exercise diastolic BPs within the group of subjects with diabetes.

Adolescent↗