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Biomedical subjects

B Carter

Publications and source records attributed to B Carter.

At least 73 records · Page 4Linked to original sources

Purification of transforming growth factor type e.

Transforming growth factor type e (TGFe) is a heat- and acid-stable polypeptide with an apparent molecular weight of 22,000, which stimulates the proliferation of certain epithelial and mesenchymal cells in monolayer and soft agar. TGFe has been purified to homogeneity. Initial acid-ethanol extraction of bovine kidney was followed by batch ion-exchange chromatography utilizing Bio Rex 70 resin. The activity eluted from the Bio Rex 70 resin was concentrated and diafiltered using an Amicon concentrator equipped with an S1Y10 spiral membrane, then was further purified by Bio-Gel P-60 molecular sieve chromatography. Active fractions from molecular sieve chromatography were pooled and purified by heparin-Sepharose affinity chromatography, followed by reverse-phase high-performance liquid chromatography using a microbore C-8 column. The final purification step involved electro-elution of TGFe separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purity of TGFe was assessed to be greater than 90%.

Animals↗

PC-based system for retrospective cardiac and respiratory gating of NMR data.

A method and a means for retrospectively clustering NMR k-space measurement profiles with respect to both cardiac and respiratory phases were developed to explore strategies for (1) reducing cardiovascular and respiratory flow/motion image artifacts and (2) improving T1 and T2 characterization of the heart. The image data are collected at a uniform rate so that echo (TE) and repetition (TR) times are independent of the varying cardiac cycle R-R interval and/or respiratory motions. Cardiac (C) time, respiratory (R) time or diaphragm position, and NMR data acquisition (A) cycle time are collected by microcomputer in parallel with free running (untriggered) image collection on a standard magnetic resonance imager. After the raw data equivalent of multiple images are collected, the C-A-R phase timing data are uploaded from the microcomputer to the scanner's minicomputer for use in a normalized C-R phase plane clustering of the image raw data. Each profile's position in the C-R phase plane is determined and then clustered into a new set of data, one image being equivalent for each desired C-R phase combination. These raw data are then zero-filled and (optionally) filtered to compensate for the nonuniform k-space sampling and, finally, reconstructed. Cardiac "cines" made from these retrospectively gated images are comparable to similarly phased triggered images. When high time resolution is required, retrospective gating can be expected to show improvements over triggering, especially toward the critical latter part of the cardiac cycle, where coronary artery filling occurs. The system described can readily be assembled from generally available components.

Electrocardiography↗

Elderly clients' perceptions of public health nursing care.

Although the health benefits of illness prevention and health promotion are accepted, little is known about the reasons for which elderly clients attend public health programs or the benefits they perceived from public health nursing care. This study reports the major reasons for which men and women age 60 and over sought care in a public health nursing program and the major benefits they perceived. The sample included 137 new and 360 returning clients. Responses to open-ended questions were content analyzed into categories of like statements, which in turn were placed into overall groups. The results suggest that most clients realized significant benefits from receiving public health care and were able to articulate these benefits. Eliciting client's perceptions can assist public health nurses to implement and market programs in a way that is acceptable and accessible to the recipients.

Aged↗

Fetal rights--a technologically created dilemma.

Fetal rights have always been a contentious issue, raising passions on either side of the debate. As technology moves on, however, decisions will have to be made on more wide ranging issues than when life itself begins.

Child Advocacy↗

Switching monoamine oxidase inhibitors.

Substituting one monoamine oxidase inhibitor for another is recommended only after a drug-free interval to avoid hypertensive emergencies. The evidence and mechanism firmly supporting this caution is lacking. We report a case where monoamine oxidase inhibitors were substituted without apparent adverse consequences.

Adult↗

The effect of d-amphetamine and ephedrine on smoking attitude and behavior.

Using a double blind, randomized, latin square design, 17 light smokers and 6 heavy smokers were given three times per day doses of placebo, 5 mg amphetamine sulfate, 7.5 mg amphetamine sulfate, 25 mg ephedrine hydrochloride or 50 mg ephedrine hydrochloride. Compared to placebo, active drug produced a statistically significant drop in feeling of addiction to cigarettes (p = 0.022). Ephedrine was reported to be more effective than amphetamine (p = 0.046). Subjects reported similar changes in feeling of enjoyment of smoking. Active drug produced a statistically significant drop in the actual amount of tobacco smoked in heavy smokers (p = 0.028), but not in light smokers. Only two smokers were able to quit completely during the experiment, and one of those people resumed smoking after she stopped taking medication. Possible explanations of these findings are discussed.

Attitude↗

The use of computerized tomography scan in the staging and follow-up study of carcinoma of the rectum.

We have reviewed the CT scans of 30 patients who were evaluated for either primary or recurrent carcinoma of the colon and rectum in the pelvis. The results of our experience have shown that pelvic CT scans can provide accurate information regarding the extramural extension of carcinoma of the rectosigmoid undetected by other means. CT scans can detect significant ureteral pathology as accurately as can IVP and have essentially replaced the IVP in the preoperative evaluation of carcinoma of the rectum. Inflammation of the perirectal musculature, either by the effect of the local tumor or secondary to preoperative radiation, can make it difficult to determine if these structures are invaded by tumor. Tumor involvement, however, can be proved using CT localization and percutaneous fine needle aspiration biopsy techniques. During radiation therapy and chemotherapy, CT scans may also assist in treatment planning and may be the most reliable way of observing the objective response of the recurrent tumor in the pelvis. Finally, in the patient in whom the recurrent tumor does not produce abnormally high levels of CEA, the CT scan may be the only method by which the early and treatable recurrence may be detected. It is, therefore, appropriate to recommend that pelvic CT scan be a routine test for every patient who has had abdominoperineal resection or low anterior resection for carcinoma of the rectum and rectosigmoid.

Anus Neoplasms↗

A coordinating center in a clinical trial: the Hypertension Detection and Followup Program.

Multicenter clinical trials are often larger and more complex than other methods of clinical inquiry. They tend to involve a number of research or clinical centers and several formal committees. In many of these trials a coordinating center is one of the participating organizational units. This article describes one such coordinating center, that of the Hypertension Detection and Follow-up Program (HDFP). In 1971 the HDFP Coordinating Center was established to assist in planning and implementing this National Heart, Lung, and Blood Institute (NHLBI)-sponsored, multicenter, community-based, randomized, controlled clinical trial. The HDFP Coordinating Center is a large, intricate organization comprised of personnel who perform a wide variety of functions. From 1972 to 1979 it supervised the adherence to a common protocol among the cooperating centers and reported the Program's progress to the various monitoring and review committees, the Steering Committee, and the NHLBI Program Office. The Program screened approximately 159,000 persons ages 30 to 69 years, identifying and following 10,940 hypertensive participants. It has been the responsibility of this Coordinating Center to institute, coordinate, and monitor the data-gathering activities of the study as a whole and to process, store, and analyze the large, multifaceted set of data that were collected.

Clinical Trials as Topic↗

Sclerosing lesions of the temporal bone.

Sclerosis of the mastoid portion of the temporal bone is often seen on radiographs of patients who have or have had chronic otitis media. Occasionally lesions are seen that cause sclerosis of the entire temporal bone. The otolaryngologist must be alert to the fact that these findings may signify important pathology beyond that of chronic otitis media and indeed may be indicative of life threatening problems in adjacent or distant areas. In this paper the differential diagnoses of sclerotic lesions of the temporal bone will be discussed. These include fibrous dysplasia, osteopetrosis, meningioma, ossifying fibroma and metastatic lesions to the temporal bone. Three representative cases with sclerotic temporal bones are presented. The first is a patient with a conductive hearing loss secondary to stenosis of the external auditory canal. He was found to have a fibrous dysplasia of the temporal bone. The second case is an elderly male with a draining ear and a facial nerve paresis. He was found to have adenocarcinoma of the prostate gland metastatic to the temporal bone. The third case is that of a woman with a meningioma who demonstrated a sclerotic temporal bone on routine radiographs of the skull.

Adenocarcinoma↗

An assessment of radioimmunoassay procedures for determination of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis.

A reproducible radioimmunoassay procedure for the determination of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis is described and examined in detail. The assay combines features of a number of methods previously outlined and allows repeat determinations of antibody titre in a given myasthenic serum sample with coefficient of variation 6%. The mean +/- standard deviation for normal human serum anti-acetylcholine receptor antibodies was found by this procedure to be 0.024 +/- 0.033 nmol/l alpha-bungarotoxin binding sites whereas the range for myasthenic patients was 0-139.14 nmol/l with a mean value of 7.55 nmol/l alpha-bungarotoxin binding sites.

Acetylcholine↗

Mammalian cell function mediating recombination of genetic elements.

Recombination of segments of the SV40 genome by a variety of mechanisms is described. These include the faithful joining of linear segments that have flush termini as opposed to previously described cohesive or resected termini. Lack of involvement of viral proteins has been demonstrated for recombination of segments with homologous overlapping termini, but probably applies also to the other joining reactions. Segments of the genome that have been cleaved in such a manner as to be unable to manufacture any known viral proteins are neutral elements of genetic information, incapable of selection by replication or biological function until recombined. These recombination functions presumably are available to the host cell and any element of genetic information that can be generated in that cell.

Animals↗

Analysis of recombination in mammalian cells using SV40 genome segments having homologous overlapping termini.

Segments of SV40 DNA having homologous overlapping termini recombine to produce viable genomes in monkey cells. Frequencies of recombination on either side of a deletion marker are non-random; replication and palindromes do not appear to be essential. Since recombination involves host enzymes, a suitable system has been devised for analysing host cell recombination functions.

Animals↗

Anti-acetylcholine receptor antibody titres in the sera of myasthenia patients treated with plasma exchange combined with immunosuppressive therapy.

Anti-acetylcholine receptor antibody titres have been monitored in the sera of 19 myasthenic patients treated with plasma exchange combined with a three month period of immunosuppressive therapy. In general the post-exchange titres stabilised at below pre-exchange levels for prolonged periods which were associated with clinical improvement. In seven instances recurrence of symptoms occurred and in six of these cases relapse was shown to be associated with a rise in anti-acetylcholine receptor antibody titre.

Acetylcholine↗