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Biomedical subjects

C B Anderson

Publications and source records attributed to C B Anderson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Serological differentiation between past and present infection in hepatic amoebiasis.

The indirect fluorescent antibody (IFA) test and the amoebic gel diffusion (AGD) test were assessed as tools for differentiating between past and present infection in invasive amoebiasis; in the case of the IFA test the Entamoeba histolytica-specific IgG and IgM were monitored. In a pilot study in which sera from 56 patients with suspected invasive amoebiasis were tested the IgM was positive in 40% of confirmed intestinal and 83% of confirmed hepatic cases, the IgG and AGD were positive in all confirmed cases. A subsequent study was then carried out, in which the tests were used to monitor longitudinally antibody levels of patients with confirmed amoebic liver abscess, from the time of admission to hospital, to one year after successful treatment. The specific IgM levels became negative sooner than the IgG or AGD, with more than half the subjects giving negative results at six months and all cases becoming negative 46 weeks after treatment. The results of this study suggest that the presence of specific IgM, together with specific IgG and a strongly positive AGD test, is indicative of an active infection; conversely, when the IgM is negative, while the other tests are positive, active disease was usually absent.

Dysentery, Amebic↗
PubMed1984

Prostaglandin synthesis associated with renal allograft rejection in the dog.

Vasospasm and intrarenal thrombosis are characteristics of acute renal allograft rejection. A possible mediator of these phenomena is thromboxane A2. Single kidneys were exchanged between nonimmunosuppressed mongrel dogs. At intervals after transplantation, rejecting and normal kidneys were removed and slices of cortex and medulla were prepared for incubation. The in vitro release of thromboxane B2 (TxB2), prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1a (6-keto-PGF1 alpha) into the incubation media was measured by radioimmunoassay. Within 72 hr of transplantation the cortex of rejecting kidneys synthesized 10 to 30 times as much PGE2 and TxB2 as normal controls. A similar increase was not observed for 6-keto-PGF1 alpha synthesis. In the medulla there was a selective reduction in 6-keto-PGF1 alpha production within five days of transplantation. In both cortex and medulla there was a significant increase in the ratio of TxB2 to 6-keto-PGF1 alpha production. Reversal of the normal TxB2:6-keto-PGF1 alpha ratio could induce the widespread intrarenal thrombosis and vasospasm that characterizes acute renal allograft rejection.

Animals↗
PubMed1984

Pretreatment of renal allograft recipients with immunosuppression and donor-specific blood.

The induction of immunologic unresponsiveness to improve renal allograft survival was attempted in 64 patients by the pretransplant administration of donor-specific whole blood or buffy coat in conjunction with continuous azathioprine immunosuppression. All donor/recipient combinations were at least one-haplotype-disparate. Presensitization, defined as a positive Amos or antiglobulin crossmatch or a high-titer (greater than 1:8) B-cell-positive crossmatch, was present in 6 patients and not present in 58 patients. Attempts at desensitization of the already sensitized group were uniformly unsuccessful. Treatment of the 58 nonpresensitized patients resulted in transient sensitization in 2 patients, permanent sensitization in 1 patient, and no evidence of sensitization in 55 patients. Fifty-three patients underwent renal transplantation from the specific blood donor, and only two have experienced renal allograft rejection loss during a mean follow-up period of 22 months (5-45 months); 57% have never experienced a rejection episode. The two-year renal allograft survival rate was 85%. This is significantly (P less than 0.01) better than our historical experience of 64% with one-haplotype living-related transplants. The low rate of sensitization (5%) has permitted almost all patients to undergo eventual renal transplantation from the specific blood donor. This and the low rate of rejection (4%) argues for a modification of the immunologic response, rather than a selecting-out process as the mechanism for improved allograft survival.

Adolescent↗
PubMed1984

Prostaglandin production and platelet reactivity of small-diameter grafts.

This article examines the relationship of platelet deposition to thromboxane and prostacyclin (PGI2) production in arterial autografts (n = 8), para-anastomotic native artery (n = 40), nonseeded control (n = 6), and endothelial cell-seeded (n = 17) small-diameter Dacron grafts implanted in the carotid and femoral arteries of dogs. Platelet deposition was measured by a dual-isotope subtraction platelet-imaging technique that expresses platelet deposition as percent indium excess (%IE). PGI2 and thromboxane assays were performed with the use of an immunoreactive assay. The %IE in the nonseeded grafts was significantly higher than in the seeded prostheses (p less than 0.001). Arterial autografts accumulated significantly less platelets than did seeded grafts (p less than 0.05) or nonseeded grafts (p less than 0.001). The thromboxane A2 (TXA2) production in nonseeded grafts was significantly higher than in seeded grafts (p less than 0.001), arterial autografts (p less than 0.001), or in para-anastomotic native artery (p less than 0.001). The PGI2 production by the arterial autografts was significantly higher than by the nonseeded grafts (p less than 0.005), seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). The PGF1 alpha/TXB2 ratio was significantly higher in the arterial autografts when compared with the nonseeded grafts (p less than 0.001), endothelial cell-seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). We conclude that platelet deposition can be significantly decreased by endothelial cell seeding of small-diameter grafts. The transmural production of TXA2 by native arteries and prosthetic grafts may have an important influence on platelet deposition and patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Renal graft irradiation in acute rejection.

To evaluate the effect of graft irradiation in the treatment of acute rejection of renal transplants, a randomized study was conducted from 1978 to 1981. Patients with acute rejection were given standard medical management in the form of intravenous methylprednisolone, and were chosen randomly to receive either graft irradiation (175 rads every other day, to a total of 525 rads) or simulated (sham) irradiation. Eighty-three rejections occurring in 64 grafts were randomized to the protocol. Rejection reversal was recorded in 84.5% of control grafts and 75% of the irradiated grafts. Recurrent rejections were more frequent and graft survival was significantly lower in the irradiated group (22%) than in the control group (54%). Graft irradiation does not appear to be beneficial in the treatment of acute rejection of renal transplants when used in conjunction with high-dose steroids.

Female↗
PubMed1983

Salvage operations for malfunctioning polytetrafluoroethylene hemodialysis access grafts.

During the study period a cohort of 170 of patients receiving long-term hemodialysis treatment required placement of 214 polytetrafluoroethylene grafts for vascular access; within this period 74 of these patients had significant graft malfunction that required 149 salvage operations. The most common failure/malfunction was thrombosis, and the most commonly appreciated mechanical cause of graft failure was outflow venous stenosis. Complex revisions were required to address this problem. First, second, and third revisions were successful in 65%, 53%, and 44% of cases, respectively. Multiple revisions, including thrombectomy, were required in some, but the functional life of these salvaged grafts was nearly equal to that of grafts that did not require revision. Abandonment of grafts because of secondary infection exacted a toll in both groups.

Adolescent↗
PubMed1982

Effect of hyaluronidase treatment on the distribution of cranial neural crest cells in the chick embryo.

The cranial paraxial mesoblast is patterned into segmental units termed somitomeres. Recently we demonstrated the morphological relationship between the migratory pathways of cranial neural crest cells and the patterned primary mesenchyme of chick embryos (Anderson and Meier, '81). Since extracellular matrix, particularly hyaluronate, is also distributed in cranial crest pathways, embryos were given sub-blastodisc injections of hyaluronidase just prior to neural tube fusion and neural crest migration to remove matrix. Histological sections of enzyme-treated embryos showed that Alcian blue staining of hyaluronate was significantly reduced. Surface ectoderm appeared collapsed on the subjacent mesoderm as well. Examination of embryos with the scanning electron microscope (SEM) revealed that paraxial mesoderm remained segmentally patterned even though it appeared more condensed because of a reduction in intercellular space between mesenchymal cells. In enzyme-treated embryos, the rostral crest cells spread over the dorsal surfaces of the first four somitomeres, as they would do normally. This distribution of neural crest cells occurs even when enzyme treatment interferes with neural tube fusion at that level. We conclude that 1) neural tube fusion is not a prerequisite for the timely release of cranial crest in the chick embryo and 2) that much of the organized hyaluronate-rich matrix that lies in the path of cranial crest is not essential for crest emigration or patterned distribution.

Animals↗
PubMed1982

Preliminary studies on bovine embryo survival following short-term storage at 4 degrees C.

A total of 113 non-surgically collected bovine embryos, 5-8 days of age, were stored for 48 hours at 4 degrees C in a modified phosphate-buffered saline solution (PBS). Following storage, embryos were cultured for 8-12 hours at 37 degrees C, and those which were morphologically normal were transferred to synchronized recipients by several methods designed to achieve twin pregnancies. Embryos which were collected and transferred on the same day served as controls. Of 113 embryos stored, 47 (42%) appeared to be transferable after the brief culture period. There was a marked breed effect on viability after refrigeration, with Hereford embryos surviving significantly better than Angus embryos (71% vs. 12%, respectively, p < .001). Post-transfer embryo survival of stored and control embryos, based on actual calvings, was 34 and 48 percent, respectively, a difference which was not significant (p=0.3). A marked difference in pregnancy rate following non-surgical transfer by 2 different technicians was noted (50% vs. 21.7%, respectively).

Journal Article↗
PubMed1982

Graft irradiation in the treatment of acute rejection of renal transplants: a randomized study.

A randomized study of graft irradiation in the treatment of acute rejection of renal transplants was conducted from 1978 to 1981. Patients developing clinical signs of an acute graft rejection received customary antirejection treatment in the form of intravenous administration of high-dose (1 gm per day) of methylprednisolone. They were at the same time randomized to either receive therapeutic irradiation (175 rad every other day to a total of 525 rad) or sham irradiation. Neither the patient nor the Transplant Service surgeons knew at any time whether the radiation treatment had been given. Eight-three rejection episodes occurring in 64 grafts were entered into the study. Acute rejection was reversed in 84.5% of grafts in the control and 75% in the treated group. The incidence of recurrent rejection was higher in the treated group (66 vs. 46%) and graft survival was lower (22% vs. 54%). The study failed to demonstrate a beneficial effect of graft irradiation in the treatment of acute renal allograft rejection, when used in conjunction with high dose steroids.

Adolescent↗
PubMed1982

Natural history of extraperitoneal gas after renal transplantation: CT demonstration.

The natural history of extraperitoneal gas present in the operative bed was prospectively evaluated with serial computed tomography in 25 renal transplant patients. While 73% (11/15) of patients studied within the first 4 days after drain removal had residual gas in the operative bed, 90% (9/10) of patients examined after the 5th day had no demonstrable gas in the peritransplant area. Of 12 patients with gas present on the initial scans, follow-up studies documented resolution of the gas in 10 with subsequent benign clinical courses. In the remaining two patients, the gas collections increased in volume on serial examinations followed shortly by wound dehiscence. Our data suggest that gas present later than 1 week following drain removal should prompt careful scrutiny and that an increase in the volume of gas collections on serial studies must be considered pathologic. The incidence and significance of peritransplant fluid collections in these patients are also discussed.

Abscess↗
PubMed1982

Anti-erythrocyte antibodies, leukocytotoxins and human renal allograft survival.

ABO blood group compatibility is generally required for successful human kidney transplants and new data suggest donor-recipient incompatibility for the Lewis or multiple minor blood groups is detrimental. This is of special importance in the setting of liberal transfusions prior to transplant. To assess the impact of immunizing exposure to disparate blood groups of ABO-matched transfusions and kidney transplants, we studied the interrelationships of anti-erythrocyte antibodies, leukocytotoxins and graft survival in 42 kidney transplant recipients. Three hundred forty-four sera were screened for anti-erythrocyte antibodies using standard hemagglutination techniques and leukocytotoxins, using the antiglobulin method. Statistical analysis by computer used a 2 x 2 x 2 contingency table with model fitting. Only 13 of 42 patients had anti-erythrocyte antibodies at some time: anti-I (4); anti-Kell (1); cold panagglutinin (7); unidentifiable agglutinin (1). Of 42 patients, 16 had no detectable leukocytotoxins. By computer analysis, immunizations to blood group and HLA antigens were independent phenomena. Analysis showed that leukocytotoxins, but not anti-erythrocyte antibodies, were associated with poor graft survival. A computer generated probability of graft survival by antibody status is presented. We conclude that immunization to blood group antigens is not common, is largely non-specific, and is not detrimental to kidney graft survival.

Antilymphocyte Serum↗
PubMed1982

Successful revascularization of early posttransplant renal arterial occlusion.

A case involving immediate postoperative prolonged warm ischemia in a transplanted kidney from a living related donor is presented. Repair of the renal artery after 3 hours 15 minutes of complete occlusion resulted in an 18-day course of acute tubular necrosis followed by full return of normal renal function. Significant collateral circulation has been present in all previously salvageable cases of transplant renal artery obstruction. This case demonstrates that a kidney from an optimally prepared donor can withstand more than 3 hours of posttransplant warm ischemia despite the absence of collateral circulation. An aggressive surgical approach to restoring circulation is indicated.

Adult↗
PubMed1982

Pretreatment of renal allograft recipients with azathioprine and donor-specific blood products.

Improvement of renal allograft survival by induction of immunologic unresponsiveness was attempted in 24 patients by the pretransplant administration of donor-specific whole blood or buffy coat under continuous azathioprine immunosuppression. All patients and their donors had one or two disparate HLA haplotypes. Crossmatch (CM) testing (22 degrees C) for T cells (Amos and antiglobulin enhanced) and B cells identified sensitization in two patients (8%). One developed a low titer (1:2) positive B-cell CM, which did not preclude successful transplantation. The second, with a preexisting high titer (1:16) positive B-cell CM, developed a low titer (1:1) T-cell antiglobulin CM and had hyperacute graft rejection. Twenty-one recipients received kidneys from their blood donors. Except for one patient who had hyperacute rejection (across positive T-cell CM), none have rejected their kidneys. Three patients died at 2, 13, and 23 months, respectively, with good renal function. Seventeen patients are alive at 3 months to 10 years with a mean serum creatinine concentration of 1.3 +/- 0.4 mg/dl. Donor-specific transfusion with immunosuppressive coverage improves renal allograft survival without significant sensitization.

Adolescent↗
PubMed1981

Intestinal parasitic infections in black scholars in northern KwaZulu.

Faecal specimens were collected form a total of 7569 scholars at 45 different localities in northern KwaZulu and screened for the presence of intestinal helminth and protozoan parasites. The soil-transmitted nematodes Ascaris lumbricoides, Trichuris trichiura and hookworm sp. were extremely common, with prevalences in certain localities ranking among the highest to be recorded in South Africa. Entamoeba coli was by far the commonest (60%) of the protozoa;p all the other species had prevalences of less than 10%. The distribution age-specific prevalence and the influence of the variables-sex, ara and age-on the occurrence of the various intestinal parasites are described.

Adolescent↗