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Biomedical subjects

T J Yeh

Publications and source records attributed to T J Yeh.

At least 37 records · Page 2Linked to original sources

Sequential production of IFN-alpha and immune-specific IFN-gamma by human mononuclear leukocytes exposed to herpes simplex virus.

Both viral-induced interferon (IFN-alpha) and immune interferon (IFN-gamma) were produced in cultures of human peripheral mononuclear leukocytes (PML) exposed to ultraviolet (UV) light-inactivated herpes simplex virus (HSV). Comparable IFN titers (100 to 300 U) were present in supernatant media from PML of HSV-seropositive and -seronegative donors maintained for 2 days in culture. This "early" IFN was not immunologically specific and had the characteristics of IFN-alpha. In contrast, PML from 20 of 21 (95%) seropositive donors, but only 2 of 22 (9%) seronegative subjects, produced IFN in day-5 cultures that had been washed on day 2 followed by the addition of fresh media without UV-HSV (p < 0.0001). In addition,the geometric mean IFN titer of 35 U present in media from day 5 cultures of seropositive donors was significantly higher (p < 0.0001) than those from seronegative subjects (<10 IFN U). This "late" IFN was defined as immunologically specific by virtue of its being present almost exclusively in PML cultures from seropositive donors. Late-appearing, HSV-induced, immunospecific IFN-gamma had antigenic characteristics of both viral-induced IFN-aand mitogen-induced IFN-gamma. A considerable degree of overlapping sensitivity to anti-IFN-alpha and anti-IFN-gamma antibody existed in late IFN, but was not seen in standard, control specimens. The latter finding suggests that the possible existence of an IFN of antigenic character intermediate to IFN-alpha and IFN-gamma. Late IFN was not induced in PML cultures by UV-inactivated Newcastle disease virus (NDV). NDV did, however, induce high titers of early IFN-alpha in PML cultures of both HSV-seropositive and HSV-seronegative donors. HSV-stimulated lymphocyte blastic transformation occurred only in cultures of seropositive individuals, whereas none occurred in response to NDV. Delayed appearance of antiviral activity with the characteristics of IFN-gamma in HSV-stimulated PML cultures is a sensitive and specific measure of the human immune IFN response. Sequential synthesis of IFN-alpha and IFN-gamma in individual PML cultures provides an opportunity to examine regulation of IFN production in response to virus with intrinsic IFN-inducing properties.

Humans↗

Sensitivity of herpes simplex virus types 1 and 2 to three preparations of human interferon.

Ten isolates of herpes simplex virus (HSV) type 1 and nine isolates of HSV type 2 were tested against virus-induced (alpha), fibroblast (beta), and mitogen-induced (gamma) preparations of human interferon (HuIFN). HSV type 2 was slightly more sensitive and HSV type 1 somewhat less sensitive to all three preparations of HuIFN than Sindbis and vesicular stomatitis virus-both considered to be quite sensitive to HuIFN. HSV type 2 was significantly more sensitive than HSV type 1 to each of the HuIFN preparations (P less than 0.01; Mann-Whitney ranksum test). Clinical isolates did not appear to differ from laboratory strains. These results indicate that both HSV types 1 and 1 are sensitive to the three different preparations of HuIFN. HuIFN may have a role in natural recovery from and may have potential as an antriviral chemotherapeutic agent in HSV infections in humans.

Humans↗

Rapid, quantitative, semiautomated assay for virus-induced and immune human interferons.

An improved human interferon (IF) assay is described. This procedure is based on the ability of encephalomyocarditis virus to replicate in WISH cell microcultures with the production of discrete plaques in the presence of a liquid tissue culture medium. Performance of 50% plaque reduction endpoint assays in micro-culture required only 0.1 ml of specimen for determinations using duplicate dilutions beginning at 1:3. Semiautomated equipment facilitated simultaneous in situ dilution and distribution of multiple IF samples in cultures containing preformed WISH cell monolayers. An incubation period of 5 to 6 h was adequate for development of maximal antiviral activity by both virus- and immune-induced IF. Sensitivity of the encephalomyocarditis microplaque reduction assay was comparable to that of other commonly used techniques. The method is rapid, can be completed within 30 h from the beginning of the IF assay, and is able to accommodate as many as 40 to 50 samples at a single time. Encephalomyocarditis microplaque reduction is suitable for the quantitation of IF as an antiviral agent or a lymphokine.

Cell Line↗

Y-grafts and sequential grafts in coronary bypass surgery: a critical evaluation of patency rates.

In a series of 584 patients undergoing coronary bypass, 425 patients received Y-grafts, sequential grafts, or a combination of the two. The saphenous veins from the legs frequently had Y- or double Y-branches suitable for bypasses. As many as 5 grafts have been served satisfactorily by a single proximal anastomosis. Simultaneous procedures included 45 left ventricular aneurysmectomies, 18 valve replacements, 7 carotid endarterectomies, repairs of a ventricular septal defect, an acute dissection, and coronary arteriovenous fistulas, with a total surgical mortality of 6 (1.4%). Restudy to determine graft patency was undertaken only in the 59 patients with unsatisfactory surgical results. These patients represent the worst 10% of the series in terms of surgical results. The patency rate for proximal anastomoses was 93%; Y-branchings, 93%; distal end-to-side anastomoses, 89%; and distal side-to-side anastomoses, 89%. Fifty-eight patients (98%) had at least 1 patient graft, and in 47 patients (80%) all anastomoses were patent up to six years after operation. Six patients underwent reoperation without any deaths.

Coronary Artery Bypass↗

Blood loss and bank blood requirement in coronary bypass surgery.

With the use of nonblood prime and refinement in perfusion and surgical techniques, blood requirement for coronary bypass operations has been reduced to a minimum. Of 240 patients (average number of bypasses, 3.07; average pump time, two hours and 22 minutes), no blood was used in pump prime or before perfusion. During perfusion, 29 patients (12%) received 34 units of blood in the pump-oxygenator, and after bypass 64 patients (27%) received 65 units of blood in the operating room (average intraoperative use, 203 ml per patient). For the total hospital stay, the blood requirement was 728 ml per patient. For the last 60 patients operated on, the figure was 328 ml. There were no surgical deaths, and only 1 reexploration for postoperative hemorrhage (0.4%). Discharge hemoglobin level averaged 11.8 gm, whereas the admission hemoglobin level had averaged 13.8 gm. Autotransfusion, avoidance of entry into the pleural space, shorter perfusion time, postoperative platelet count of more than 150,000, and normal partial thromboplastin time tend to reduce blood requirement, but not to a striking degree. Bank blood requirement for the coronary bypass program accounted for 3.7% of the hospital need and 2% of the community need.

Adult↗