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Biomedical subjects

W C Johnson

Publications and source records attributed to W C Johnson.

At least 127 records · Page 7Linked to original sources
PubMed1985

In situ saphenous vein bypass grafts for limb salvage. A current fad or a viable alternative to reversed vein bypass grafts?

Revascularization of the lower extremity using the in situ saphenous vein bypass graft has resurfaced as a clinical alternative to reversal of the saphenous vein. Early patency rates have been excellent, however, concern has been raised about the durability of the in situ technique. Our total experience with this technique has been reviewed to evaluate its effectiveness on a teaching vascular service. Seventy-six limbs in 71 patients were revascularized using the in situ technique. The distal anastomosis was created at the below-the-knee popliteal level in 26 limbs and at the infrapopliteal level in 50 limbs. Operative assessment of the vein quality showed 42 percent to be phlebitic or less than 4 mm in diameter. Hospital mortality was 0 and late mortality was 8 percent. Cumulative life table analysis showed the graft patency rate to be 89 percent 1 month postoperatively, 82 percent at 1 year, 77 percent at 2 years, and 72 percent up to 4 year postoperatively. Patency was independent of runoff to the pedal arch and the level of the distal anastomosis. Limb salvage at 4 years was 83 percent for distal popliteal grafts and 79 percent for infrapopliteal reconstructions. Our results indicate that the long-term durability of the in situ saphenous vein graft is excellent despite suboptimal veins and poor runoff. When performed properly, it is the preferred technique for arterial reconstruction below the knee joint.

Adult↗
PubMed1985

Intrahepatic pyogenic abscesses: treatment by percutaneous drainage.

During a 6 year period, 18 liver abscesses in 12 patients were identified by computerized tomography. Five patients had presumed hematogenous seeding. Five patients previously had bilioenteric anastomoses, stents, or both to relieve obstructive jaundice. Four patients with abscesses had recent abdominal operations. Diagnosis was established by guided needle aspiration and treatment was provided by percutaneous catheter drainage. Organism-specific antibiotics were administered to all patients. Patients were evaluated for recurrence by serial computerized tomographic studies and were clinically followed up for a minimum of 15 months. Ten of 12 patients (83 percent) and 16 of 18 abscesses (89 percent) were successfully treated by percutaneous catheter drainage. Two failures required operative intervention. In summary, the low morbidity and high success rate in treating hepatic abscesses by percutaneous drainage suggests that this therapy be tried before operative intervention is considered.

Adult↗
PubMed1985

Transcriptional control of synthesis of acid-soluble proteins in sporulating Bacillus subtilis.

The major acid-soluble spore proteins (ASSPs) isolated from mature spores of Bacillus subtilis are designated alpha, beta, and gamma (about 60, 60, and 100 amino acids in length, respectively). Alpha and beta are very similar, and gamma is very similar to a less predominant ASSP called delta (about 115 amino acids). A minor and very basic ASSP called epsilon is the same size as alpha and beta but is unrelated antigenically. These and several minor ASSPs comprise at least three related families of sporulation-specific gene products. Expression of the alpha and beta genes, detectable as functional mRNA in vitro, coincides with the time of synthesis of all of the major ASSPs in vivo. This apparently coordinate expression is dependent on at least the spo0A, spoIIA, and spoIIIA loci, but not on the spoIVA or spoVA loci, consistent with the late stage of this expression (initiating at 3.5 h after the start of sporulation and peaking at 5 h after start of sporulation). A few minor ASSPs may be asynchronously expressed.

Bacillus subtilis↗
PubMed1985

Cutaneous delayed hypersensitivity, T cell subsets, and IL-2 secretion in patients with peripheral vascular disease.

To determine whether anergy in patients with peripheral vascular disease is related to an abnormality of their T cells, the distribution of T-cell subsets and monocytes in peripheral blood was studied in relation to the delayed hypersensitivity response following the intradermal injection of 7 recall antigens. Positive correlation coefficients were observed between either the sum of the induration at 48 hr or the number of antigens giving a positive response and the percentage of total T cells (OKT 3) and helper T cells (OKT 4). The percentages of suppressor/cytotoxic T cells (OKT 8) and monocytes (OKM 1) showed no correlation with skin reactivity to the recall antigens. In vitro secretion of IL-2 by purified T cells was similar in anergic patients and in patients with normal delayed hypersensitivity responses. Addition of IL-2 to unstimulated T cells or T cells stimulated in vitro with either tetanus toxoid or PPD sometimes potentiated incorporation of 3H-thymidine into the cells after 6 days of culture.

Adult↗
PubMed1985

Development of an indirect fluorescent antibody test, using microfluorometry as a diagnostic test for bovine anaplasmosis.

The indirect fluorescent antibody test for the diagnosis of Anaplasma marginale infection in cattle was modified for use with microfluorometry. The test was standardized by use of a fluorometer that measures intensity of fluorescence. Standardization included A marginale-infected blood smears on microscope slides as antigen, serum from an inoculated calf as a positive control containing specific antibody, and an affinity-purified fluorescein-conjugated anti-bovine immunoglobulin as 2nd antibody. The modified test and microfluorometry allowed for titration of sera from A marginale (Florida isolate)-inoculated cattle with a degree of accuracy exceeding visual determinations. In addition, the fluorometric test was more sensitive than the complement fixation or card agglutination tests in identifying cattle that had previous Anaplasma infections.

Agglutination Tests↗
PubMed1985

A prospective double-blind comparison of piperacillin, cephalothin and cefoxitin in the prevention of postoperative infections in patients undergoing intra-abdominal operations.

Piperacillin has been shown to be as safe and effective an agent as cephalothin and cefoxitin when used in patients undergoing elective intra-abdominal surgical procedures. Enterococcus species have been shown in other studies to be susceptible to piperacillin, perhaps making it the preferred antibiotic for prophylaxis in clinical settings when enteric flora will be encountered.

Abdomen↗
PubMed1984

Prediction of secondary structure for Eco RI endonuclease.

The circular dichroism of Eco RI restriction endonuclease was measured to 178 nm and analyzed for secondary structure. The results (33% alpha-helix, 25% beta-sheet, 17% turns, and 25% other structures) compare well with our joint prediction from sequence data.

Circular Dichroism↗
PubMed1984

Prediction structure type for human leukocyte interferon subtype A from circular dichroism.

Vacuum UV circular dichroism studies were carried out on human leukocyte interferon subtype A. The secondary structure analysis for the CD spectrum shows 59% alpha-helix, 16% antiparallel beta-sheet, no parallel beta-sheet, 18% beta-turns and 13% other structures. The analysis of the CD features for the prediction of tertiary structural class reveals that it is an all-alpha type protein.

Amino Acid Sequence↗
PubMed1984

Percutaneous drainage of infected pancreatic pseudocysts.

After diagnostic needle aspiration guided by computed tomography and/or ultrasound, 11 infected pseudocysts in ten patients were treated nonoperatively by percutaneous catheter drainage and intravenously administered antibiotics. Nine infected pseudocysts resolved after 11 to 37 days (mean, 21 days) with no recurrences at follow-up 16 to 42 months (mean, 24.4 months) later. All were confirmed by Gram's stain, culture, and elevated amylase levels. Ten of the pseudocysts were acute; one was chronic; five were polymicrobial; six had a single organism. There were no major complications. There was one failure when a pancreatic abscess developed in a patient who died following operative drainage. There was one successful palliation of a postoperative-infected pseudocyst in a patient with an obstructing nonresectable carcinoma of the head of the pancreas. A trial of percutaneous catheter drainage is indicated in patients with infected pancreatic pseudocysts.

Adult↗
PubMed1984

Stroke after carotid endarterectomy: risk as predicted by preoperative computerized tomography.

In patients undergoing carotid endarterectomy, the role of preoperative computerized tomographic head scanning in predicting the risk of postoperative neurologic deficit was determined by a retrospective evaluation of a select group of 107 consecutive patients with preoperative scans. Patients with infarction determined preoperatively by computerized tomography were found to be at a significantly higher risk for postoperative neurologic deficit than patients with a normal preoperative computerized tomographic scan. History and physical examination alone detected only 66 percent of the infarctions found with preoperative computerized tomographic scanning in these patients. Because the incidence of infarction revealed computerized tomography in patients with symptoms of a reversible ischemic neurologic deficit was 22 percent, we have proposed a new definition of reversible ischemic neurologic deficit to include the necessary finding of a normal computerized tomographic scan. Patients who presented with transient ischemic attack and the unexpected finding of a subclinical infarction on the preoperative scan were at the same significantly higher risk for postoperative stroke and a permanent neurologic deficit. Computerized tomographic scanning of potential carotid endarterectomy patients is of benefit not only to rule out other sources of neurologic symptoms, but also to predict more accurately the risk of postoperative neurologic deficit.

Adult↗
PubMed1984

Radiologic aspects of diagnosis and treatment of abdominal abscesses.

The precise anatomic display by computed tomography and ultrasonography provides the guidance to make diagnostic needle aspiration a safe routine procedure. Percutaneous catheter drainage of abdominal abscesses now offers an alternative to surgery and has already become a well-established radiologic procedure in many centers.

Abdomen↗
PubMed1984

Concepts of granulomatous inflammation.

Table 8 lists the patterns of the five discrete tissue reaction patterns of granulomatous inflammation and relates them to the predominant microscopic tissue reaction as well as to the dominant cell type present in the infiltrate. The possibility of a sixth group, granulation tissue, was also considered for this classification schema. The term "granulation tissue" was used by Virchow to define granulomatous inflammation. He probably used this term in a broader context than our present definition of granulation tissue (ie, fibrocapillary proliferation). Using the more narrow and perhaps more precise definition, we think that granulation tissue does not constitute a form of granulomatous inflammation.

Dermatitis↗