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Biomedical subjects

G R Burrus

Publications and source records attributed to G R Burrus.

At least 19 recordsLinked to original sources

Characterization of the human myeloid cell nuclear differentiation antigen: relationship to interferon-inducible proteins.

The human myeloid cell nuclear differentiation antigen (MNDA) is expressed specifically in cells of the granulocyte/monocyte lineage. The MNDA has been isolated by using a monoclonal antibody affinity matrix and reversed-phase high performance liquid chromatography. Its NH2-terminal sequence has been obtained, as well as additional sequence information derived from peptides produced by cyanogen bromide and SV8 protease cleavages. Meaningful similarities were observed in extended regions between the MNDA and the reported beta interferon-inducible proteins, 202 and 204, from Ehrlich ascites mouse tumor cells. An amphipathic, basic alpha-helical region, showing no similarity to the 202 and 204 proteins, exhibited close similarity to a region in the interferon response factor-2, a protein which binds the interferon stimulated response element. The relatively high number of S(T)PXX motifs present in the partial amino acid sequence of the MNDA, described herein, suggests that the MNDA binds DNA and is a transcription factor.

Amino Acid Sequence

Cloning and expression of the human myeloid cell nuclear differentiation antigen: regulation by interferon alpha.

The human myeloid cell nuclear differentiation antigen (MNDA) is a protein of 406 amino acids that is expressed specifically in granulocytes, monocytes and earlier stage cells of these lineages. Degenerate oligonucleotides that could encode regions of MNDA amino acid sequence were used to amplify the MNDA cDNA sequence using the polymerase chain reaction. The amplified cDNA product was sequenced to confirm that it encoded the MNDA protein. It was then used as a probe to isolate five clones from a human bone marrow lambda gt10 cDNA library. A clone containing a 1,672 base pair cDNA insert was sequenced and found to encode the entire MNDA open reading frame, as well as 5' and 3' untranslated regions. The primary structure of the MNDA contains extensive regions of sequence similarity with the protein products of the interferon-inducible genes: 204 and interferon regulatory factor 2. In addition, a 12-base sequence matching the interferon-stimulated response element consensus sequence [GAAAN(N)GAAA] is located in the 5' untranslated region of the MNDA cDNA. The 1.8 kb MNDA mRNA was detected only in cells that express the antigen and the level of MNDA mRNA was elevated in cells treated with either recombinant or natural interferon alpha. The MNDA mRNA was not induced by interferon alpha in cells that do not exhibit a constitutive level of the MNDA mRNA. The MNDA contains sequence motifs found in gene regulatory proteins. The expression and the primary structure of the MNDA indicates that it plays a role in the granulocyte/monocyte cell-specific response to interferon.

Amino Acid Sequence

Videothoracoscopy: improved technique and expanded indications.

Current videoendoscopic technology and percutaneous techniques of exposure and dissection have been successfully applied to abdominal surgery with favorable results. Application of this technology to our practice of thoracoscopy is the basis of this report. Videothoracoscopy has been performed in 39 patients for the following indications: chronic pleural effusion, interstitial lung disease, mediastinal lymphadenopathy in lung cancer, persistent air leak after decortication, mediastinal mass, recurrent spontaneous pneumothorax, hydropneumothorax with persistent air leak, and pleural-based mass. The technique we employ includes lateral decubitus positioning and double-lumen endotracheal intubation with ipsilateral lung collapse. The videoscope, retractors, and instruments are introduced through separate 10-mm incisions. Percutaneous manipulation of instruments and the videoscope is guided by images produced on television screens without dissection, and if resection is performed, the incision is enlarged to allow specimen retrieval. Procedures performed using this technique include pleural biopsy, partial pleurectomy, lysis of adhesions, lung biopsies, staging lymph node biopsy, lung nodule biopsy, pleural-based mass resection, and mediastinal mass biopsy and resection. This videoendoscopic technique greatly improves visualization of thoracic anatomy, facilitating thoracoscopy and enhancing exploration of the chest. It is preferred over conventional thoracoscopy and, in some patients, reduces the magnitude of operation by avoiding thoracotomy.

Adult

Internal mammary artery graft at reoperation: risks, benefits, and methods of preservation.

To determine the effect of a prior internal mammary artery (IMA) graft on coronary artery bypass reoperation (CABR), we reviewed our experience with 410 consecutive patients: 313 received only saphenous vein grafts at initial coronary artery bypass grafting (CABG), and 97 received at least one IMA graft at CABG. Cardiac catheterization data before CABG were available in 110 patients (56 received only saphenous vein grafts, 54 received at least one IMA graft), allowing comparison of left ventricular function at CABG and CABR. Injury of the IMA graft occurred in 5 patients (1 death), but presence of an IMA graft was not an independent predictor of morbidity or mortality. Overall, the incidences of complications and deaths were higher in patients with saphenous vein grafts than in patients with IMA grafts, though not significantly so. Internal mammary artery grafts better preserved cardiac function: patients with IMA grafts had worse left ventricular function before CABG but better left ventricular function before CABR than patients with saphenous vein grafts. Left ventricular function deterioration from before CABG to before CABR was significantly less in patients with IMA grafts. We conclude that the risk of CABR is not increased by a previously constructed IMA graft and that left ventricular function is better preserved at CABR when an IMA graft was constructed at the initial operation.

Confounding Factors, Epidemiologic

Lectin-binding proteins in nuclear preparations from rat liver and malignant tumors.

Lectin binding [concanavalin A, biotinylated ricinus communis agglutinin, and biotinylated succinylated wheat germ agglutinin (B-SWGA)] was used to detect the glycosylated proteins associated with a residual protein fraction [insoluble in 4% sodium dodecyl sulfate and termed the nuclear residual fraction (NRF)] or with nuclear matrix preparations from normal rat liver, azo dye (3'-MeDAB)-induced rat hepatoma, and Walker 256 transplantable carcinosarcoma. One- and two-dimensional gel electrophoresis were used with lectins, polyclonal antisera, and monoclonal antibody binding to characterize some of the glycoconjugates. Two polypeptide bands with approximate molecular weights of 95,000 and 55,000, shown previously to be present only in the induced tumor cells and the Walker 256 tumor, were reactive with lectins. In addition, a Mr 62,000 protein reacted only with B-SWGA in the nuclear matrix fractions from normal rat liver and the induced hepatoma. A polypeptide band (approximate molecular weight, 213,000) in the Walker 256 NRF reacted with concanavalin A and biotinylated ricinus communis agglutinin. One polypeptide band (approximate molecular weight, 182,000) reacted with concanavalin A in all three tissues, with biotinylated ricinus communis agglutinin and B-SWGA in the Walker NRF, and with B-SWGA in the hepatoma NRF. Another polypeptide band (approximate molecular weight, 138,000), reactive with all three lectins, was present in all three tissues. Our findings are consistent with previous reports of lectin binding proteins in the eukaryotic cell nucleus and indicate that certain glycoproteins isolated in nuclear preparations are found specifically in 3'-MeDAB-induced hepatoma and Walker 256 transplantable carcinosarcoma.

Animals

Internal mammary artery grafts: technical factors influencing patency.

Eight hundred fourteen patients with internal mammary artery (IMA) coronary artery bypass grafts have been restudied 961 times with coronary arteriography, primarily to evaluate the patency of the grafts in the setting of symptomatic coronary occlusive disease. Their records were reviewed to assess graft patency as related to the technical aspects of coronary artery bypass surgery. Patency was evaluated using life-table analysis of the data. The method of harvesting the IMA played no role in patency. The left anterior descending coronary artery was the recipient coronary artery with the highest patency rate. The left IMA had a significantly higher patency rate than the right IMA. As a group, the IMAs had a significantly higher patency rate than saphenous vein grafts. However, there was no difference between right IMA grafts and saphenous vein grafts. The mammary artery grafts that remained patent throughout the study had a significantly higher blood flow after bypass than did those that became occluded (43.0 +/- 0.9 versus 28.9 +/- 1.8 ml/min; p less than .001).

Blood Flow Velocity

The cost of coronary bypass procedures.

We reviewed the financial records of 200 succesive patients who had coronary artery bypass surgery in the first three months of 1976. The average hospital bill was $7,690 and the average length of stay was 18 days. The highest bill was $28,329 (79 days) and the lowest was $6,126 (11 days). The average total physician charge to the patient was $3,240. The total average hospital and physician cost was $10,930.

Coronary Artery Bypass

Median sternotomy dehiscence.

Sternal dehiscence requiring reoperation occurred in 36 out of 4,531 patients who had a sternotomy incison within an eight-year period. Twisted sternal wire sutures were used for the first four years and a crimped steel plate fixation was used during the second four years with a marked and significant decrease in the incidence of dehiscence from 17 out of 1,000 patients to 3 out of 1,000 patients. Thirty-five of the 36 patients were men, and 4 required reoperation for bleeding. Other factors such as mammary artery dissection, tracheostomy, and body weight of more than 82 kg were not significant. Although infection was noted in 20 patients, it was thought to be secondary. Early reoperation with antibiotic irrigation achieved wound stability in the 34 survivors with only 3 patients requiring additional procedures for chronic osteomyelitis of the sternum.

Anti-Bacterial Agents

The effectiveness of surgical treatment of acute aortic dissection.

Ten consecutive patients have undergone operative repair of acute aortic dissection at St. Thomas Hospital in the last three years. Two died. To assess the status of the residual aorta, all 8 survivors were evaluated by postoperative aortography. Only the patient with a clotted dissection on preoperative study showed no residual dissection of the distal aorta. Analysis of postoperative aortograms suggests that the original dissection reentry points become sites of inflow following removal of the original intimal tear. No death resulted from these residual abnormalities. Retrograde dissection and aortic insufficiency were obliterated. The major sites of aortic rupture were removed. It is concluded that surgical therapy for acute aortic dissection is effective in that it avoids the major sources of mortality. The resultant surviving population must be carefully observed in view of the high frequency of residual aortic abnormality.

Aortic Dissection

Further evaluation of the surgical treatment of obstructive disease of the left main coronary artery.

A protocol for the operative management of two patient groups with left main coronary artery disease has been evaluated. The period prior to and during induction of anesthesia is managed without using aortic balloon counterpulsation. Of the 86 patients undergoing coronary artery bypass for left main coronary artery disease from 1970 to 1973, there was a surgical mortality of 8.1%. Follow-up of the survivors from 48 to 87 months revealed three coronary and five non-coronary related deaths with survival to seven years of 75.6 +/- 5%. If the operative mortality is excluded, there is an observed survival to seven years of 82.4 +/- 4.8%, almost the same as a "normal" population of similar age and sex. Utilizing the same protocol, 90 similar patients undergoing coronary artery bypass in 1976 had an operative mortality of 4.4%. The deaths were not related to induction of anesthesia. The perioperative infarction rate (2%) and postoperative cardiac enzyme determinations were no greater in a random group having the same operation for less severe forms of coronary artery disease during the same time period. This method of management for patients with significant left main coronary artery disease is judged superior to other more complex techniques.

Coronary Artery Bypass

The natural history of long-term cardiac pacing.

During the past ten years, 504 patients have received one or more pacemakers for complete heart block or other arrhythmia. Of these patients, 306 (61%) are alive. Actuarial analysis shows a steady attrition of 9.4% per year for the first five years, decreasing to 7% per year for the second five years. The overall survival was decreased for patients with congestive heart failure and advanced age and was not affected by the history of Stokes-Adams attacks, initial pulse rate below 50 per minute, or a QRS duration greater than 0.12 second prior to pacing. Cardiac problems were the primary cause of death in 71% of the patients. The natural history of patients with permanent pacemakers depends, more than any other factor, on the function of the left ventricle.

Adult

Ischemic cardiomyopathy: medical versus surgical treatment.

The natural history of patients with ischemic heart disease and depressed left ventricular function is dismal, and medical therapy has failed to alter its course. To assess the results of aorta-coronary bypass grafting in patients with coronary artery disease and decreased left ventricular ejection fraction (LVEF less than or equal to 0.3), we compared 70 medically treated patients to 46 patients having aorta-coronary bypass grafting. The duration of follow-up was 6 to 72 months (mean 19 months). All patients had angina pectoris. Congestive heart failure was present in 56 percent (39/70) of the medical and 43 percent (20/46) of the surgical group. The medical group had a mean LVEF of 0.20 and a mean left ventricular end-diastolic pressure (LVEDP) of 29 mm. Hg. The surgical group had a mean LVEF of 0.21 and a mean LVEDP of 24 mm. Hg. Three vessel disease was found in 60 percent (42/70) of the medical group and 83 percent (38/46) of the surgical group. The operative mortality rate in the surgical group was 4 percent (2/46). There were four late deaths. The 2 year actuarial survival rate for medical and surgical groups was 47 percent and 83 percent, respectively. Significant improvement in angina pectoris and/or congestive heart failure was found in 16 percent (11/70) of medically treated patients and 95 percent (38/40) of the surgically treated patients. Aorta-coronary bypass grafting can be performed in patients with poor left ventricular function with a low operative mortality rate, relief of angina pectoris, and improvement in symptoms of congestive heart failure.

Adult

Results of reoperation for failed aortocoronary bypass grafts.

Thirty-one patients underwent reoperation for failure of one or more previous aortocoronary bypass grafts. Thirty-nine grafts were replaced. Twenty-four grafts were constructed to vessels not thought to be significantly diseased at initial operation. There were no early or late deaths. Postoperative morbidity was comparable to initial prodecures. Of 24 patients followed up for more than six months., 62% clearly experienced improvement without evidence of perioperative or postoperative infarction. Reoperation for failed aortocoronary bypass grafts can be achieved without excess risk, but with long-term results less optimistic than initial procedures.

Arm

Cost of cardiac pacing.

The patient with a permanent pacemaker faces significant lifetime medical expenses. The financial records of 15 patients with more than 4 years' (average 73 months) of cardiac pacing were reviewed to establish the basic cost of pacing. Each pacemaker was electively replaced after 24 months of service. During the total of 1,096 months of pacing there were 65 hospital admissions. Medical expenses for the 15 patients totaled $112,160, of whic- $93,410 was for hospital expenses and $18,750 for physicians'fees. The average monthly cost per patient was $102 (range $84 to $130).

Aged

Unexpected death following aortocoronary bypass.

Since 1968, 1,800 aortocoronary bypass procedures have been performed with 37 operative or early postoperative deaths (2.1%). Twenty-one deaths (57%) occurred in patients with one or more of the following predetermined risk factors: ventricular aneurysm, decreased left ventricular contractility, left main coronary artery stenosis, valve replacement, recent infarction, or cardiogenic shock. The remaining 16 deaths (43%) were unexpected and occurred in patients with none of these risk factors.

Adult

The incidence of venous thrombosis following long-term transvenous pacing.

Long-term cardiac pacing with permanent transvenous electrodes has achieved wide acceptance with only occasional reports of venous obstruction and edema. To determine the incidence of venous abnormalities associated with transvenous electrodes, 34 venograms were obtained in 32 patients paced 18 months or longer. Eleven venograms demonstrated severe obstruction with collateral circulation communicating with the opposite cervical and innominate venous channels; 7 of these showed total occlusion. Seven venograms revealed no obstruction. The remaining 16 venograms showed venous stenosis without collaterals. It is concluded that venous abnormalities associated with permanent transvenous pacing occur commonly but are not usually associated with arm or facial edema.

Arm