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Biomedical subjects

K Rogers

Publications and source records attributed to K Rogers.

At least 91 records · Page 5Linked to original sources

Mechanical cardiopulmonary resuscitation choice of patients on chronic peritoneal dialysis.

Fifty-five adult patients (5 women, 50 men) on chronic peritoneal dialysis, mostly continuous ambulatory peritoneal dialysis (CAPD), for 2 to 155 mon were asked whether or not they wanted to have mechanical cardiopulmonary resuscitation (CPR) in case of sudden death. Thirty-five patients (65%) opted for CPR and 20 (36%) declined. Statistically, sex (although the number of women interviewed was too small for a valid sample) and duration of dialysis had no effect on choice of CPR, whereas older age, the presence of diabetes, advanced medical disability, and advanced socioeconomic disability were associated with a tendency to decline CPR. Among the 10 patients who had CPR, 5 developed flail chest, 4 had multiple rib fractures, and only 1 had no chest wall trauma from CPR. Two patients left the hospital alive. One third of the patients on chronic peritoneal dialysis do not want CPR. Advanced age, diabetes, and poor medical and socioeconomic states predispose peritoneal dialysis patients to decline CPR.

Adult↗

Initial evaluation of a human immunoglobulin M monoclonal antibody (HA-1A) in humans.

A human monoclonal antibody (HA-1A) directed against bacterial endotoxin was administered to 15 patients with incurable malignant disease. No adverse effects were noted following single intravenous infusions of 0.05 to 100 mg. Pharmacokinetics were evaluated in nine patients receiving 10 mg (n = 3), 25 mg (n = 3), and 100 mg (n = 3). Seven of these patients had initial peak serum concentrations greater than 80% of predicted values with plasma disappearance curves fitting a one-compartment system and a plasma half-life of 31.5 h (range of 20.3-44.6 h). The peak serum concentrations and area under the curve values were proportional to the dose of HA-1A administered. One patient had a hypercatabolic state with low levels of serum albumin and IgM. He achieved 65% of the predicted value for peak serum concentration of HA-1A with a plasma half-life of 12.3 h. A second patient had detectable serum HA-1A for only 15 min following infusion without an adequate technical or biologic explanation. We were unable to demonstrate antibody to HA-1A in sera from these nine patients either prior to therapy or during 28 days postinfusion using a "double-antigen" radiometric assay. This study suggests that HA-1A human monoclonal antibody administration is well tolerated by patients. Phase I trials will need to be carried out to characterize further the pharmacokinetics and toxicity of HA-1A in patients with gram-negative sepsis.

Adult↗

The influence of interferon alpha and gamma, singly or in combination on human natural cell mediated cytotoxicity.

The influence of interferon alpha and gamma alone or in combination on the augmentation of human natural cytotoxicity was studied. Treatment of peripheral blood lymphocytes with IFN- alpha led to a rapid augmentation of NK activity, in contrast to IFN-gamma where target cell killing was observed only following 18 hrs exposure of lymphocytes to IFN-gamma. The results of the single cell assay paralleled those obtained using the Chromium release test, but neither interferon type caused an increase in the number of target binding lymphocytes. The combined effect of IFN-alpha and IFN-gamma in stimulating human natural cytotoxicity demonstrated individual lymphocyte responses to be variable. Exposure of lymphocytes to IFN-alpha and IFN-gamma for 18 hrs prior to assay for cytotoxicity usually decreased the level of cytotoxicity compared with control values, whereas other treatment regimes gave an additive and sometimes synergistic effect. Only treatment with IFN-alpha for 18 hrs and IFN-gamma for one hr produced a synergistic response in the majority of individuals tested. We conclude from this study that individual responses to IFN-alpha and IFN-gamma alone or in combination are variable and dependent upon timing of exposure of lymphocytes to individual interferon types, and possibly reflects the donor status at the time of sampling.

Cytotoxicity, Immunologic↗

Mouse/human chimeric monoclonal antibody in man: kinetics and immune response.

A mouse/human chimeric monoclonal antibody (mAb) composed of the variable regions of murine 17-1A mAb and the constant regions of human IgG-1K immunoglobulin was administered to 10 patients with metastatic colon cancer. Four patients received single infusion of 10 mg (n = 2) or 40 mg (n = 2). Six patients received three infusion of 10 mg (n = 3) or 40 mg (n = 3) at 2-week intervals. The pharmacokinetics were similar at both dose levels and at the second and third infusions. The plasma disappearance curves were best fit by a two-compartment model having a mean alpha T1/2 of 17.5 hr (range 13-23 hr) and a mean beta T1/2 of 100.5 hr (range 65-139 hr). One patient who received three 40-mg doses of chimeric IgG-1K 17-1A mAb (day 0, 14, and 28) was the only patient to exhibit a detectable but modest antibody reactivity to chimera on days 63 and 84. The antibody reactivity was inhibited by murine 17-1A mAb, indicating that the antibody response was directed to the murine variable region of the chimera. The patients had no toxic or allergic reactions. This chimeric form of 17-1A mAb has an approximate 6-fold longer circulation time and appears to be substantially less immunogenic than its murine counterpart. These characteristics may provide an advantage in the clinical application of such chimeric molecules in therapeutic trials in humans.

Adenocarcinoma↗

Relationship of benzyl alcohol to kernicterus, intraventricular hemorrhage, and mortality in preterm infants.

Intraventricular hemorrhage and death in preterm neonates has been associated with the use of fluid containing benzyl alcohol, a bacteriostatic agent, to flush intravascular catheters. The hospital and autopsy records of infants admitted to a nursery during the last 18 months that benzyl alcohol was in use (218 patients) were reviewed and compared with those of infants admitted in the first 18 months after benzyl alcohol was withdrawn (232 patients). The volume of flush solution administered to each patient was estimated. Exposure to benzyl alcohol was significantly associated with the development of kernicterus (P less than .005), and intraventricular hemorrhage (P less than .000,000,5). Kernicterus did not develop in any patient after benzyl alcohol was withdrawn. Many patients with kernicterus or intraventricular hemorrhages received small daily volumes of fluid containing benzyl alcohol. Withdrawal of benzyl alcohol from clinical use had no demonstrable effect on mortality. Medications intended for neonatal use should not contain benzyl alcohol. Our data indicate that patients not exposed to benzyl alcohol have a greatly reduced risk of kernicterus. If this finding is confirmed by other investigators, present indications for exchange transfusions in preterm infants with moderate elevations of serum bilirubin should be reconsidered.

Benzyl Alcohol↗

Cardiac transplantation: University of South Florida--Tampa General Hospital experience.

Cardiac transplantation has evolved from an experimental procedure to an accepted mode of therapy that prolongs life in patients with severe heart failure. The University of South Florida-Tampa General Hospital began performing cardiac transplantation for the treatment of end-stage cardiac disease in June 1985. Since then 42 heart transplantations have been performed and 30 patients are alive and well. The one-year actuarial survival is 78.73% and the two-year actuarial survival is 72.15%. Multiple complications have been encountered most notably rejection and infection. The recent approval of the USF/TGH program as a Medicare funded cardiac transplantation center is expected to greatly expand the number of potential recipients and will provide the residents of Florida, and the Southeastern United States, with an additional health care resource.

Adult↗

Comparison of excision versus cryosurgery of an HSV-2-induced fibrosarcoma. I. Survival, extent of metastatic disease and host immunocompetence following surgery.

Cryosurgery and excision were used to treat primary tumours of HSV-2-transformed hamster tumour sublines, and post-operative survival and the extent of metastatic disease were compared in the two groups. An inferior prognosis was observed following cryosurgery although the extent of metastatic disease was similar in both groups. Using this model it would appear that cryosurgery enhances the development of micrometastases rather than affecting the number of cells shed from the primary tumour during surgery. To investigate the underlying causes of the decrease in survival following cryosurgery, in vitro assays were used to monitor host immunocompetence following surgery. The results showed that whilst natural killer cell cytotoxicity was only marginally depressed, mitogen responsiveness and lymphocyte participation in a mixed lymphocyte reaction were severely reduced 3-7 days post-cryosurgery. In parallel with immunosuppression, extensive cell proliferation in the spleen of cryosurgically treated tumour-bearing animals was observed. Histological examination of the spleen demonstrated the presence of large numbers of transformed cells which correlated with the loss of mitogen responsiveness and the ability to participate in a mixed lymphocyte reaction. Further studies (manuscript submitted for publication) have demonstrated that spleen cells from animals whose tumour is treated by cryosurgery are capable of suppressing immunocompetence in vitro, implying they have a role in the uncontrolled growth of micrometastases in vivo.

Animals↗

Characterisation of suppressor cells generated following cryosurgery of an HSV-2-induced fibrosarcoma.

Cryosurgery of a primary HSV-2-induced hamster fibrosarcoma resulted in the generation of a population of suppressor cells. These cells were detectable in the spleen 1-10 days post-cryosurgery by their ability to suppress the proliferation of immunocompetent splenic T-lymphocytes following exposure to concanavalin A (Con A). The spleens of tumour-bearing (t.b.) animals which received cryosurgery 3 days previously displayed gross splenomegaly due to the generation of large numbers of highly proliferative erythroblasts. The erythroblast cells were unlikely to be the source of suppression since time course studies have demonstrated the presence of suppressor cells before and after their appearance in the spleen. The erythroblasts therefore probably reflected a response by the host to regenerate the erythrocytes lost during surgery and their presence was independent of the appearance of suppressor cells. Characterisation of the suppressor cell has revealed it to be non-adherent and esterase negative making it unlikely to be of macrophage (MO) lineage. This was confirmed by the ability of splenic MOs from day 3 t.b. cryosurgery-treated animals to completely restore Con A-dependent T-lymphocyte proliferation following MO depletion. As nylonwool column-eluted cells are able to suppress Con A-dependent T-lymphocyte proliferation, it seemed unlikely that B-lymphocytes play a role in cryosurgery-induced immunosuppression. These findings suggest that cryosurgery of a t.b. animal results in the generation of a population of T-lymphocytes capable of suppressing Con A-dependent T-lymphocyte proliferation, and infers that these cells contribute to the inferior prognosis following cryosurgery as compared to excision of a metastatic tumour.

Animals↗

Immuno-electron microscopy of chondrocyte-derived cells in the rheumatoid cartilage-pannus junction.

Immuno-electron microscopy has been utilised to examine the cartilage-pannus junction in seven patients with rheumatoid arthritis. Using a monoclonal antibody, keratan sulphate was localised to cells with the ultra-structural appearance of fibroblasts within a transitional fibroblastic zone in the pannus in two cases. This confirms previous light microscopy evidence that this area (which is clearly separate from articular cartilage) contains cells which produce keratan sulphate, and strengthens the hypothesis that these cells are derived from cartilage rather than from the adjacent synovial membrane.

Antibodies, Monoclonal↗

Loss of polymorphic A and B locus HLA antigens in colon carcinoma.

In the present study we have confirmed that approximately one third of human colorectal carcinomas fail to express the HLA - A,B,C monomorphic determinant reactive with the W6/32 MAb, and 44% express class II HLA antigens as shown by reactivity with NFK-1 MAb. Reduced staining with the W6/32 MAb was not always associated with the loss of beta 2m. In addition, the expression of HLA-A2 and Bw4 class I specific haplotypes on normal colon epithelium and tumour biopsy tissue was assessed. All normal colonic epithelia stained positively with MAb against A2 and Bw4 antigens, but a loss of these determinants was shown on tumour biopsies from patients tissue typed for the respective specificities. Loss of the A2 haplotype was shown in 4 of 15 tumour tissue samples, and loss of Bw4 specificities in 5 out of 7 tissue samples. The failure to detect specific loci determinants was not necessarily associated with loss of reactivity with W6/32 MAb.

Adenocarcinoma↗

Immunohistological demonstration of progesterone receptor in breast carcinomas: correlation with radioligand binding assays and oestrogen receptor immunohistology.

The validity of determining the progesterone receptor status of breast carcinomas with a monoclonal antibody was investigated by comparison with data from a radioligand binding assay on adjacent cryostat sections of 103 tumours. Significant nuclear staining for progesterone receptor was observed in 37 (36%) of the tumours studied and this showed a close correlation with the results of radioligand binding assays for progesterone receptor. In three progesterone receptor positive tumours there was an apparent paradoxical absence of oestrogen receptor; progesterone receptor normally depends on the presence of oestrogen receptor, but these rare tumours may be essentially progesterone receptor positive. It is concluded that this monoclonal antibody is an appropriate reagent for use in the immunohistological determination of progesterone receptor status of breast carcinomas; that it advantageously identifies both the occupied and unoccupied receptor sites; and that it provides information about tumour cell heterogeneity with respect to receptor status.

Antibodies, Monoclonal↗