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Biomedical subjects

W C Johnson

Publications and source records attributed to W C Johnson.

At least 145 records · Page 8Linked to original sources
PubMed1984

Effect of anergy on short-lived suppressor cells in patients with cirrhosis or peripheral vascular disease.

In order to determine whether or not abnormal suppressor cell function correlates with the absence of a delayed hypersensitivity reaction (DHR) in anergic patients, Con A reactivity and the short-lived suppressor cell activity of peripheral blood lymphocytes (PBL) were studied in 4 groups of patients: (1) Those with peripheral vascular disease (PVD) who reacted with a normal DHR to the intradermal injection of one or more recall antigens; (2) patients with PVD who did not respond with a DHR to any of these antigens; (3) patients with alcohol-related cirrhosis and normal DHR; and (4) cirrhotics who showed no DHR. The data for both short-lived suppressor cell activity and Con A reactivity were not significantly different between anergic patients, patients with normal DHR, and a group of normal controls. Although cirrhotic patients have been reported to show abnormalities in cellular immunity, short-lived suppressor cell activity and Con A reactivity were not significantly different between cirrhotics with normal DHR, PVD patients with normal DHR, and normal controls.

Concanavalin A↗
PubMed1983

Two RNA polymerase sigma factors from Bacillus subtilis discriminate between overlapping promoters for a developmentally regulated gene.

A developmentally regulated gene (spoVG) from the spore-forming bacterium Bacillus subtilis is expressed from two overlapping promoters, which direct transcription initiating from sites separated by 10 base pairs. Utilization of the upstream promoter is determined by an RNA polymerase sigma factor of molecular weight 37,000 (sigma 37). We report the isolation of a 32,000-molecular weight species of sigma factor (sigma 32), which exclusively dictates transcription initiation from the downstream promoter, and suggest a model for the way in which sigma-specific recognition sequences are intermeshed within the spoVG transcription initiation region.

Bacillus subtilis↗
PubMed1983

Direct venous surgery for venous valvular insufficiency of the lower extremity.

Seven patients had severe deep venous insufficiency and recurrent ulceration in eight lower extremities. All incompetent perforating veins had been previously ligated. All limbs were evaluated by dynamic venous pressure measurements. The venous pressure reduction with exercise was recorded, as well as the recovery time. The most accurate indicator of venous valvular incompetence was a short postexercise recovery time. Abnormal hemodynamic findings were correlated with ascending and descending venographic findings. Based on these anatomic and pathophysiologic abnormalities, patients underwent valvular transposition, superficial femoral vein valvuloplasty, or superficial femoral vein ligation. Immediate postoperative recovery time (mean +/- SEM) was improved to 34.5 +/- 18.3 s from 7.9 +/- 2.9 s preoperatively. Postoperative venography demonstrated patency of all anastomoses and absence of reflux into previously incompetent venous systems. All limbs were symptomatically improved after operation, and no venous thrombosis or pulmonary emboll developed. Persistent ulceration, however, continued in one limb.

Femoral Vein↗
PubMed1983

Prevalence of normal serum amylase levels in patients with acute alcoholic pancreatitis.

Acute alcoholic pancreatitis is uncommonly diagnosed when the serum amylase level is normal. We defined acute alcoholic pancreatitis as a clinical syndrome in which hyperamylasemia was not a necessary component and sought support for the diagnosis by ultrasonography and computed tomography of the pancreas. In 68 episodes of acute alcoholic pancreatitis identified in a one-year period, the serum amylase level was normal at the time of hospital admission in 32%. In 40 episodes, we performed ultrasonography and computed tomography within 48 hr of admission. The diagnosis was supported by ultrasonography in 43%, by computed tomography in 68%. Ultrasonography and computed tomography supported the diagnosis as frequently in patients with normal serum amylase levels as in patients with hyperamylasemia. We conclude that patients with acute alcoholic pancreatitis frequently have normal serum amylase levels. The widespread clinical practice of relying solely on hyperamylasemia to establish the diagnosis of acute alcoholic pancreatitis is unjustified and should be abandoned.

Acute Disease↗
PubMed1983

Flow dichroism evidence for tilting of the bases when DNA is in solution.

Flow linear dichroism studies of DNAs from Clostridium perfringens, Escherichia coli, and Micrococcus luteus are extended into the vacuum UV region to 175 nm. The short-wavelength pi pi region shows a less negative reduced linear dichroism than the well-studied long-wavelength pi pi region. These results are independent of the type of DNA and the concentration of salt over the range 0.001 to 1.0 M. This proves that the bases are not perpendicular to the flow orientation. Assuming that the DNA tends to align along its helix axis, the largest angle that the bases can make with the helix axis is 73 +/- 3 degrees.

Clostridium perfringens↗
PubMed1982

Subunit interactions of transcarboxylase as studied by circular dichroism.

A change in the secondary structure of transcarboxylase from quaternary interactions is monitored by circular dichroism spectroscopy. The change is traced to interactions among the six polypeptides that make up the 12SH subunit. It is fully reversible and is not a result of the conditions used to dissociate the enzyme. Our new method of analyzing circular dichroism spectra for secondary structure works well for this enzyme and its subunits. Even the odd circular dichroism of the 1.3SE subunit analyzes well. There is an increase of 19% in alpha helix and a concomitant decrease of 8% in antiparallel beta sheet and 7% in random structure on association to form the hexameric 12SH subunit.

Carboxyl and Carbamoyl Transferases↗
PubMed1982

Lethal complications associated with nonrestrictive treatment of abdominal aortic aneurysms.

Five high-risk patients received nonresective treatment of abdominal aortic aneurysms (AAAs). This treatment included ligation of the iliac arteries to induce acute thrombosis of AAA and a simultaneous axillobifemoral bypass for restoration of arterial flow to the lower extremities. Of these five patients, lethal complications associated with this procedure developed in four. The complications included rupture, infection of the thrombotic aortic aneurysm, visceral ischemia, and consumptive coagulopathy. This high incidence of lethal complications and the unacceptably high patient mortality in these five patients indicates extreme precaution in the application of nonresective treatment for AAA.

Aged↗
PubMed1982

Cause of wound complications in elderly patients with above-knee amputation.

Seventy-six above-knee amputations performed on elderly debilitated patients were reviewed. Fifty-one wounds healed without complications; 25 amputation wounds developed postoperative complications. The quality of the femoral pulse has a significant effect on wound healing after an above-knee amputation. Other significant conditions that appear to influence the frequency of wound complications are hypertension, a failed bypass procedure to the groin, and angiographic evidence of stenosis or occlusion of the common femoral or the profunda femoral artery. Multiple variable analysis suggests a beneficial effect of antibiotics in patients with a diminished or absent femoral pulse. Age, presence of cardiac disease, diabetes, associated diseases and the use of drains have no significant effect on the outcome. Before an above-knee amputation, patients with a diminished femoral pulse should undergo arteriography and perhaps reconstructive surgery. Primary hip disarticulation may be the initial procedure of choice in the presence of multiple risk factors.

Adult↗
PubMed1982

Home ultraviolet phototherapy of early mycosis fungoides: preliminary observations.

Thirty-one patients with early mycosis fungoides (MF) and three patients with parapsoriasis en plaques were treated with ultraviolet phototherapy (280 to 350 nm) at home using a commercially available light source containing four Westinghouse FS40 lamps. A complete clinical and histologic remission of disease, lasting for a median duration in excess of 18 months, was achieved in nineteen patients (61%) with MF. Although higher complete response rates generally are achieved with other therapeutic modalities, ultraviolet phototherapy with its minimal adverse effects may be indicated for selected patients. Controlled studies are encouraged to evaluate the full potential of conventional phototherapy in the management of MF.

Adult↗
PubMed1982

Bleeding esophageal varices: treatment with vasopressin, transhepatic embolization and selective splenorenal shunting.

The fate of 359 consecutive alcoholic cirrhotic male patients with bleeding esophageal varices was determined through chart review and personal interview. Three historical periods (1966-70; 1971-75; 1976-80) were defined based on availability of different therapeutic modalities. Management of acutely bleeding varices by conservative, nonsurgical means, including embolization, was preferable to emergency surgery when considering 30-day mortality rates. Percutaneous transhepatic embolization of esophagogastric varices significantly improved the rate of control of hemorrhage and 30-day survival over previously employed nonsurgical methods. The combination of nonsurgical management of acute variceal hemorrhage followed by selective distal splenorenal shunting resulted in maximum salvage of the alcoholic cirrhotic patient.

Embolization, Therapeutic↗
PubMed1981

Percutaneous catheter drainage of abdominal abscesses: a five-year experience.

We used computed tomography (CT) and ultrasonography for detection and localization of intra-abdominal abscesses. On the basis of these images, safe routes for diagnostic aspiration and percutaneous drainage were planned. Over these routes indwelling catheters were inserted to provide immediate decompression, evacuation, and continuous drainage until the abscess resolved. All patients received concomitant intravenous antibiotics. The treatment was used for 71 abscesses in 67 patients. Sixty-one abscesses (86 per cent) were satisfactorily drained. There were 11 complications (15 per cent). Six deaths were attributable to sepsis, three of which (4 per cent) were related to inadequate drainage. There was one recurrence (1 per cent) during a follow-up period ranging from one month to five years (means, 22.3 months). The mean duration of treatment was 20.2 days (range, five to 120 days). We conclude that percutaneous drainage is an effective method for treatment of abdominal abscesses and is indicated when sectional imaging demonstrates an accessible unilocular lesion.

Abdomen↗