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Biomedical subjects

R Knapp

Publications and source records attributed to R Knapp.

At least 73 records · Page 4Linked to original sources
PubMed1987

Wrist: coronal and transaxial CT scanning.

Computed tomography (CT) of the wrist can be useful in selected clinical applications and is generally performed in the transaxial orientation. Coronal and transaxial CT scanning of the wrist were directly compared in three patients and in a normal, isolated cadaveric hand. Twenty other patients with wrist problems who underwent only transaxial or coronal CT examinations were also considered to assess the clinical indications of both techniques. A simple Lucite holder was designed and tested to simplify patient positioning with the coronal CT technique. In most clinical situations, coronal images were superior to transaxial images because the former were more detailed and easier to interpret. In some specific cases, however, especially fracture of the hamate hook and distal radioulnar subluxation, transaxial CT scanning was superior.

Adult↗
PubMed1987

Head nurses: their practice and education.

The head nurse has become a critical link in managing successful hospital units in this post-DRG (Diagnosis Related Group) era. As more nursing services move to a decentralized model, the head nurse role has grown in complexity and accountability far beyond entry level nursing preparation. This study explores the patterns of use of head nurses in United States hospitals and how they should be educated.

Clinical Competence↗
PubMed1986

Double-blind assessment of potential pergolide-induced cardiotoxicity.

Possible pergolide-induced cardiotoxicity has been reported in open trials. Over a 6-month period of observation, we prospectively analyzed ECGs and 24-hour ambulatory ECG in 23 patients with Parkinson's disease who were randomized in a double-blind fashion to pergolide or placebo treatments. Pergolide therapy was associated with a mild and transient bradycardiac effect, but no clinically significant cardiotoxicity.

Aged↗
PubMed1985

Circulating DF3 and CA125 antigen levels in serum from patients with epithelial ovarian carcinoma.

The murine monoclonal antibody (MAb), designated DF3, reacts with a 300-kilodalton (kd) mammary epithelial antigen. A sequential double-determinant enzyme-linked immunoassay (EIA) has been developed to monitor circulating DF3 antigen. Previous studies have demonstrated that the use of the DF3 EIA provides a new and potentially useful marker to follow the clinical course of patients with metastatic breast cancer. In the present study, we have monitored circulating DF3 antigen in the serum of patients with epithelial ovarian carcinomas and non-ovarian gynecologic malignancies. Twenty-one of 45 patients (47%) with ovarian carcinoma had elevated DF3 antigen levels (greater than or equal to 30 U/mL). In contrast, three of 20 patients (15%) with non-ovarian gynecologic malignancies, and only four of 59 control women (7%) had elevation of circulating DF3 antigen. The difference between DF3 antigen values from patients with ovarian cancer and from controls was significant (P less than .001). The elevation of circulating DF3 antigen in ovarian cancer patients has also been confirmed by transblot assays. MAb DF3 reactivity occurred predominately with circulating antigens of molecular weights (mol wt) ranging from 300 to 450 kd. Furthermore, DF3 antigen levels have been shown to correlate with progression of disease in six patients with ovarian cancer and after resection of disease in two others. The half-life of circulating DF3 antigen was approximately 45 to 60 days. The results also demonstrate that DF3 antigen is distinct from CA125, a glycoprotein associated with coelomic epithelium and developmental amnion. The use of both the DF3 EIA and the immunoradiometric assay previously described to detect circulating CA125 suggests that determining levels of both markers may enhance the sensitivity of monitoring the course of ovarian cancer. Furthermore, the use of both assays may be useful in distinguishing ovarian cancer from other malignancies.

Adult↗
PubMed1984

Bupivacaine protein binding in the term parturient: effects of lactic acidosis.

The effects of lactic acidosis on bupivacaine serum protein binding was studied in a group of term parturients and a group of nonpregnant female control subjects. Groups were matched in age and health. Distribution characteristics of bupivacaine in pregnancy were determined. Bupivacaine protein binding was best characterized by the model for two classes of binding sites in all studies. The parturients exhibited a lower capacity for the high-affinity, low-capacity (alpha 1-acid glycoprotein) site and higher affinity for the low-affinity, high-capacity (albumin) site. Lactic acidosis decreased the affinity constant for the high-affinity, low-capacity site in the control group but did not change binding characteristics in the parturients. Free concentration of bupivacaine (Cu) was elevated at low total bupivacaine concentrations (Ct) (less than 10 micrograms/ml). No differences in Cu were detected at concentrations in the cardiotoxic range (greater than 20 micrograms/ml). The Cu values predicted by the estimated binding parameters from in vitro experiments were compared with actual Cu measured in nine parturients at delivery; they correlated significantly (r = 0.94). Distribution changes for bupivacaine in the parturients were consistent with known physiologic changes in body composition associated with pregnancy. Alterations that occur in serum protein binding during pregnancy should not result in increased risk of central nervous system or cardiovascular system toxicity since these alterations do not increase free tissue concentration.

Absorption↗
PubMed1983

Comparison of a rabbit heteroantiserum and a murine monoclonal antibody raised against a human epithelial ovarian carcinoma cell line.

An ovarian carcinoma cell line (OVCA 432) and a B-lymphocyte line (LAZ 446) were established from the same donor. A heteroantiserum (D-100) was prepared in rabbits against OVCA 432 and absorbed with LAZ 446, human AB erythrocytes, and the CX-1 colorectal cell line. After absorption, D-100 reacted by indirect immunofluorescence with six of six epithelial ovarian carcinoma cell lines and cryostat sections of 18 of 18 epithelial ovarian tumors but bound to zero of 12 nonovarian tumor cell lines. Despite a lack of reactivity with nonovarian tumor cell lines, D-100 reacted with epithelial components of normal ovary, fallopian tube, endometrium, endocervix, breast, colon, and epididymis. A murine monoclonal antibody (OC 133) was also raised against OVCA 432 and selected for lack of reactivity with the autologous B-lymphocyte line LAZ 446. OC 133 reacted with six of six ovarian carcinoma cell lines and cryostat sections of seven of 19 ovarian tumors, but it also reacted with five of five nonovarian tumor cell lines. Of 12 normal tissues examined, OC 133 reacted with endometrium and endocervix only. Whereas D-100 bound to serous, mucinous, endometrioid, and clear cell ovarian neoplasms, OC 133 bound only to serous tumors. In developing monoclonal reagents, cell lines may provide a useful source of antigen, but promising antibodies should be screened for reactivity with sections of normal and malignant human tissues.

Animals↗
PubMed1980

Chemical requirements of vasopressins for barrel rotation convulsions and reversal by oxytocin.

When vasopressin is administered into the lateral ventricles of rats it produces severe convulsive activity characterized by a rapid barrel rotation. Electrical recordings from the dorsal hippocampus indicate marked elevations in the amplitude and frequency at doses of 5 microliter of 2 x 10(-5) M vasopressin. No significant behavioral effects were noted with oxytocin, somatostatin, beta-melanophore-stimulating hormone, adrenocorticotropin, or leu-enkephalin. Pretreatment of the rats with intraventricularly administered oxytocin, beta-MSH, or systemically administered Dilantin prevented the vasopressin-induced seizures. With the use of chemical and enzymic modification procedures, the essential fragment and amino acids of vasopressin needed for the activity were determined. It was concluded that although the peptide could be acting by vasoconstricting blood arterioles and capillaries in the brain, it may also be exerting a direct excitatory action on neurons.

Animals↗
PubMed1980

Characteristics of patients with chronic pain.

We describe the characteristics which patients with chronic pain ascribe to themselves and present some of the data we have gathered in the areas of demographics, economic and family problems, difficulty in rehabilitation, and the failure of treatment methods such as surgery and medications to provide relief. We compared the responses of men and women and found significant differences in sexual difficulties and pain relief from nerve blocks.

Adult↗
PubMed1977

Chemotherapy of murine ovarian carcinoma by methotrexate-antibody conjugates.

Antibodies with specificity for an experimental ovarian carcinoma were coupled to methotrexate by two procedures. Water-soluble carbodiimide gave effective coupling, but a large proportion of the conjugate was rendered insoluble, presumably due to alteration or aggregation of the antibodies. A modification of the mixed anhydride procedure gave rise to products which were completely soluble and allowed a high degree of coupling to be achieved. In vivo testing of the conjugates revealed a significant increase in survival time in treated mice when compared to a variety of control groups; these included groups receiving antiserum or drug alone, mixtures of the two, and conjugates of normal gamma-globulin with methotrexate. Our results provide added support for the concept that tumor-associated antibodies coupled to cytotoxic agents are more effective than single agents or noncoupled mixtures of agents.

Anhydrides↗
PubMed1975

Ovarian tumor antigens: a new potential for therapy.

A murine tumor-associated alpha-globulin was identified by immunofluorescence, cytotoxicity, and immunoelectrophoresis. The antiserum resulting from heterologous immunization with the segregated antigen was tolerated in multiple injections and was therapeutic; host cell participation by macrophages and lymphocytes led to the therapeutic result. Investigation of human ovarian carcinoma demonstrated an alpha-globulin which shares antigenic specificity with other tumor-associated antigens. The successful scanning of a tumor mass with a heterologous antibody directed against a tumor-associated antigen demonstrated the feasibility of applying these techniques to clinical cancer.

Animals↗