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Biomedical subjects

R P Anderson

Publications and source records attributed to R P Anderson.

At least 19 recordsLinked to original sources
PubMed1992

Hepatobiliary excretion of bacterial formyl-methionyl peptides in rat. Structure activity studies.

The bacterial chemotactic peptide formyl-met-leu-phe and its radioiodinated analog formyl-met-leu-[125I]tyr are rapidly excreted by the liver into bile following portal or systemic venous infusions in rats or after absorption from the gut lumen. To determine the molecular structural requirements for hepatobiliary excretion of formyl-methionyl peptides, structure-activity studies using portal venous infusions of 24 structural analogs of formyl-met-leu-tyr were performed in rats with biliary cannulae. Hepatic extraction of peptides was studied in vivo using external gamma counting after portal infusion. Efficient hepatobiliary excretion was not restricted to bioactive formyl peptides, but showed a broad specificity for different amino-acylated (formyl, acetyl, propionyl, carbobenzoxy) di- and tripeptides and no requirement for methionine in position one or for a free carboxy terminus. However, nonacylated peptides and an acyl-amino acid showed little excretion. Hepatic extraction of peptide was also related to N-acylation. Hepatic extraction and excretion of N-acyl peptides were also related to hydrophobicity. Thus, the presence of an N-acyl group is the key determinant of biliary excretion of inflammatory bacterial f-met peptides in the rat.

Animals↗
PubMed1992

Mitral valve reconstruction.

Modern repair techniques allow reconstruction rather than replacement of the mitral valve (MV) in the majority of patients requiring operation. Such patients are now older and more likely to have nonrheumatic MV disease than those treated in former years. A continuing experience with MV reconstruction was reviewed to determine its safety and efficacy. In 50 patients undergoing isolated MV reconstructions, there have been no postoperative deaths. In 36 patients undergoing mitral reconstruction combined with other cardiac procedures, there have been 5 deaths (14%). Three patients have required MV replacement for an inadequate repair as determined by evaluation during the repair or by intraoperative transesophageal echocardiography (TEE) following cardiopulmonary bypass. Overall complications have included five reoperations for bleeding, two perioperative myocardial infarctions, two strokes, and one aortic dissection. The majority of patients maintain an improved functional state after operation. Multiple reconstructive maneuvers are now available, and the elements of any given reconstruction depend on the pathoanatomy of the valve. Intraoperative TEE has been invaluable in planning, evaluating, and modifying repairs. At present, over 70% of all MV operations are reconstructions, and the most common recent indication for MV replacement is a malfunctioning prosthetic MV rather than native valve disease.

Adult↗
PubMed1992

Continuing experience with the automatic implantable cardioverter defibrillator.

The automatic implantable cardioverter defibrillator (AICD) is now used commonly in the management of malignant ventricular arrhythmias. Its use may obviate the need for antiarrhythmic drugs or endocardial resection. We reviewed our continuing experience with the AICD to determine its safety and efficacy. Since June 1987, 102 patients (mean age: 63 years) who survived out-of-hospital ventricular fibrillation or hemodynamically unstable ventricular tachycardia not associated with acute myocardial infarction underwent implantation of an AICD. There were three operative deaths and nine complications. Eighty-nine patients are alive. No patient has experienced sudden cardiac death. Forty-two patients (43%) have had 1 or more AICD discharges associated with symptoms of cardiac arrest. During AICD implantation, it appears preferable to configure lead placement by individual patient characteristics rather than by a rigid protocol. The relative safety and efficacy of the AICD support its use as an alternative to toxic medications or more dangerous endocardial resection in suboptimal candidates.

Adult↗
PubMed1989

Early experience with the automatic implantable cardioverter defibrillator in sudden death survivors.

Medical management of life-threatening ventricular arrhythmias is difficult because of the toxicity and limited efficacy of antiarrhythmic drugs. The automatic implantable cardioverter defibrillator (AICD) offers protection against malignant ventricular arrhythmias and allows some patients to be managed without antiarrhythmic drugs. We reviewed our experience with the AICD to determine its safety and efficacy. Since June 1987, 24 patients (mean age 63 years) who survived out-of-hospital ventricular fibrillation or hemodynamically unstable ventricular tachycardia not associated with acute myocardial infarction had implantation of an AICD. None had inducible monomorphic ventricular tachycardia associated with ventricular aneurysm. Twenty-three had abnormal left ventricular function (mean ejection fraction 0.32). There were no operative deaths and three complications. At last follow-up (mean 8.9 months) 23 patients were alive. Eight patients had one or more AICD discharges associated with symptomatic or monitored cardiac arrest. AICD implantation can be performed with low risk and appears to be an effective alternative to antiarrhythmic therapy with toxic drugs.

Adult↗
PubMed1989

Fifteen- to twenty-year results after the Hill antireflux operation.

Antireflux surgery, specifically the Hill procedure, has been shown to be effective management of refractory reflux when assessed in the relatively short term. This study follows 441 patients from the time of their initial operation and reports on assessments conducted after 5 to 10 years and 15 to 20 years. The late study group comprises 167 patients (mean age 71 years) with an average follow-up of 17.8 years; 15.6% of patients had undergone a previous antireflux operation. Overall subjective good and excellent results, as determined by the patients themselves, were seen to improve significantly (p less than 0.02) between the two follow-up periods, 82% and 88%, respectively. No serious late complications such as fistula, bleeding, or obstruction were observed in this series. The Hill antireflux operation, properly performed, provides durable long-term results.

Adolescent↗
PubMed1988

Introducer insertion of mini-thoracostomy tubes.

Introducer insertion of a small caliber chest tube is easily mastered, fast, and nearly painless. Outpatient management of spontaneous pneumothorax with a 12 F. polyvinylchloride catheter and a Heimlich valve appears both safe and economical in a selected group of patients. Introducer chest tube insertion is well tolerated, in contrast to the discomfort experienced during insertion of chest tubes by means of blunt dissection or trocar. In addition, the high risk of injury to the lung or other viscera by trocars is avoided.

Adult↗
PubMed1988

Acrocyanosis due to imipramine.

An 11 year old girl who was being treated for enuresis with imipramine developed acrocyanosis of the hands and feet. All biochemical and haematological investigations gave normal results. When imipramine was stopped the girl recovered within three days.

Adolescent↗
PubMed1988

Improved results of surgical treatment for esophageal and gastroesophageal junction carcinomas after preoperative combined chemotherapy and radiation.

Combined treatment with chemotherapy and radiation (chemoradiation) preceding surgical exploration for esophageal or gastroesophageal squamous cell carcinoma or adenocarcinoma was compared with surgical exploration alone to determine if there was an influence on tumor status at exploration, tumor resectability, disease recurrence, and patient survival. Preoperative chemoradiation resulted in significant tumor response as measured by decreased nodal involvement and 36% incidence of no residual tumor at resection (total response) and was reflected by an improvement in resectability. Local tumor recurrence was eliminated by preoperative chemoradiation preceding resection. Distant recurrence was not reduced and remained the major cause of death. The 2-year survival rate after tumor resection alone was 33% versus 66% after preoperative chemoradiation and resection (p = 0.13). Patient survival after resection alone was predicted by pathologic extent of local disease as measured by lymph node status. In contrast, survival after chemoradiation and resection was not predicted by pathologic extent of local disease. Surgical resection appears to have been an important component of therapy, primarily because survival was improved in patients after resection of residual local disease.

Actuarial Analysis↗
PubMed1987

Tests of the ribosome editor hypothesis. III. A mutant Escherichia coli with a defective ribosome editor.

Peptidyl-tRNA dissociates from the ribosomes of Escherichia coli during protein biosynthesis. The ribosome editor hypothesis states that incorrect peptidyl-tRNAs dissociate preferentially. Editing would therefore prevent the completion of proteins containing misincorporated amino acids. We have isolated a mutant strain of E. coli that dissociates some peptidyl-tRNAs at a fivefold lower rate than its parent strain, and that synthesizes significantly more erroneous complete proteins. This strain is also partially resistant to the antibiotic erythromycin, which in wild-type E. coli stimulates the dissociation of peptidyl-tRNA from ribosomes. The data suggest that in this mutant all peptidyl-tRNAs are bound to the ribosome more tightly than normally during protein synthesis. Because of the inverse correlation between the accuracy of synthesis of complete proteins and the rate of dissociation of peptidyl-tRNA from the ribosome, we propose that the mutant contains a defective ribosomal editor.

Escherichia coli↗
PubMed1986

Memory evaluation of alcoholics with Russell's revised Wechsler Memory Scale.

Fifty-four alcoholics and 30 nonalcoholics were tested on Russell's (1975) revision of the Wechsler Memory Scale (RWMS). Subjects were dichotomized into groups of old and young, and alcoholics were divided further into groups of short- and long-term abusers. Groups were matched on socioeconomic status. Significant group differences were found on three of the four RWMS measures as a function of abuse status and on two of the measures as a function of age. In terms of severity of impairment, alcoholics were found to demonstrate only mild verbal and figural memory deficits when compared to age-matched controls. Results are discussed with regard to the clinical utility of the RWMS as a memory screening instrument with alcoholic patients and in terms of treatment implications.

Adult↗
PubMed1986

Cardiovascular perfusion: evolution to allied health profession and status 1986.

The occupation of cardiovascular perfusion has evolved from a technical to a professional status during the past 25 years. The national thoracic surgical organizations, The American Association for Thoracic Surgery and the Society of Thoracic Surgeons, have supported this process of development through participation on various boards and committees of the perfusionist organizations. The rapid growth of cardiac surgical services in the past decade produced concern about the availability of perfusionist manpower. This concern was exacerbated by creation of formal processes for the certification of perfusionists and the accreditation of perfusion educational programs. Today, these issues are largely resolved and cardiovascular perfusion is recognized as an allied health profession.

Accreditation↗