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Biomedical subjects

F Chu

Publications and source records attributed to F Chu.

At least 73 records · Page 4Linked to original sources
PubMed1986

Pulmonary edema and acute upper airway obstruction.

Pulmonary edema following the relief of acute upper airway obstruction is unusual and unpredictable. The cause is usually attributed to pulmonary and hemodynamic changes resulting from high negative intrathoracic pressures during obstructed respiration. The incidence of this problem is not known. Why pulmonary edema develops in only certain patients is also unclear. We reviewed the records of 27 consecutive adult patients admitted and treated for acute upper airway obstruction. Three of 27 (11%) developed pulmonary edema. Age, sex, diagnosis, duration of obstruction, history of cardiopulmonary disease, and perioperative fluid administration were evaluated. No differences were noted between those who did and those who did not develop pulmonary edema. Pulmonary edema following acute upper airway obstruction appears to be more common than is generally appreciated, however, no specific factors seem related to its occurrence.

Adult↗
PubMed1986

Reuse and reprocessing of disposable medical devices. Legal liability issues.

Reuse and reprocessing of disposable medical devices raises issues of legal liability, especially among physicians, hospitals, and device manufacturers. The practice of reuse has been, at least informally, reported to be fairly widespread. However, the medical risks associated with reuse are unresolved in most cases, which may lead to circumstances conducive to litigation. In this paper, the characteristics of reuse pertaining to legal liability, the parties potentially subject to civil liability suits as a result of reuse, the legal theories underlying claims of injury, and the legal implications of possible policy actions will be examined.

Disposable Equipment↗
PubMed1985

Processing of the intron-containing thymidylate synthase (td) gene of phage T4 is at the RNA level.

The interrupted T4 phage td gene, which encodes thymidylate synthase, is the first known example of an intron-containing prokaryotic structural gene. Analysis of td-encoded transcripts provides evidence in favor of maturation at the RNA level. Northern blotting with T4 RNA and with region-specific probes revealed three classes of RNA: diffuse premessage (ca. 2.5 kb), a low-abundance mature mRNA (ca. 1.3 kb), and an abundant free intron RNA (ca. 1.0 kb). The existence of covalently joined mature mRNA was suggested by hybridization and S1 protection experiments and was confirmed by primer extension analysis of the splice junction. In analogy to expression of interrupted eukaryotic genes, these results are consistent with an RNA processing model that would account for the direct gene transcript serving as precursor for both free intron RNA and a spliced mRNA that is colinear with the thymidylate synthase product.

Base Sequence↗
PubMed1985

A clinical study of benzydamine for the treatment of radiotherapy-induced mucositis of the oropharynx.

A double-blind, randomized clinical study was undertaken to determine the analgesic and antiinflammatory effectiveness of benzydamine in patients with radiation-induced mucositis of the oropharynx. Of the 67 patients in the study, 37 patients were on benzydamine and 30 patients on a placebo. The results of the study showed that benzydamine possessed a significant analgesic activity as evidenced by relief of mouth and throat pain induced by radiation therapy. It is also noted that the patients on benzydamine exhibited a cumulative relief of oral pharyngeal pain and discomfort over the time of treatment, as compared to those on the placebo. These effects of benzydamine in the present study might be a result of the antiinflammatory property of the drug. The cumulative and prolonged effectiveness of benzydamine makes it of distinct value compared with the commonly available local anaesthetics such as lidocaine. Benzydamine appears to provide a useful addition to the therapeutic armamentarium for alleviating the symptoms of oral pharyngeal mucositis.

Adult↗
PubMed1983

Perception of moving, sounding objects by four-month-old infants.

Infants and adults were presented with two moving objects accompanied by a single percussive sound. In different experiments, the sound occurred when one object moved through a particular spatial position, when it abruptly changed its direction of movement, or when it made contact with a rigid surface. Infants responded to the sound-object relationship whenever the sound occurred as the object changed direction, irrespective of its impacts with the surface. Adults, in contrast, responded to the sound-object relationship most clearly when sounds were synchronized with impacts. In infancy, perception of auditory-visual relationships thus depends in part on detection of discontinuities in the movement of a visible object.

Auditory Perception↗
PubMed1980

Treatment of regionally advanced epidermoid carcinoma of the extremity and trunk.

A retrospective study was made of 106 locally and regionally advanced epidermoid carcinomas of the trunk and extremity treated from 1949 to 1970. Forty-six of the tumors had a known cause, of which radiation exposure was the most common. In addition to axillary and inguinal nodal metastases, these cancers also manifested intransit, epitrochlear and popliteal lymphatic metastatic disease. Surgical treatment consisted of wide monobloc resection for the majority of the primary neoplasms, amputation being necessary for tumors fixed to skeletal or neurovascular structures. Clinically enlarged regional lymph nodes were subjected to biopsy, but elective regional node dissection did not offer therapeutic benefit. Patients with biopsy proved nodal metastases were treated by either radical nodal dissection or high exarticulation, with similar results. Actuarial five year survival rates after definitive surgical treatment were 71 per cent for patients with regional node-negative and 57 per cent for those with regional node-positive tumors. Local and regional recurrences of tumors were frequent in patients who had deep seated tumors of the trunk and postsacral region, or bulky nodal disease, despite pathologically negative resection margins. Uncontrolled recurrent tumor with sepsis and compromise of vital organ function was the most common cause of death. Radiation therapy achieved partial regression of the tumor in eight patients and complete regression in one of 15 patients. A critical analysis is made of the various clinicopathologic factors which affect prognosis, and the possible means of improving the results of treatment are discussed.

Adult↗
PubMed1979

Effect of deglycosylation of yeast invertase on its uptake and digestion in rat yolk sacs.

The uptake by rat yolk sacs of native invertase and invertase which was deglycosylated by treatment with endo-beta-N-acetylglucosaminidase was compared. The initial rate of uptake of the deglycosylated enzyme was severalfold greater and its accumulation leveled off much earlier than that of the native enzyme. Uptake rates of the deglycosylated and native forms of the enzyme were proportional to their concentration in the medium in the range employed and were inhibited about 85% by 10(-6) M glucagon in both cases. After preloading of yolk sacs with native invertase, the tissue level of activity remained relatively constant over a subsequent 6-h time period, while with the deglycosylated form, activity declined substantially. Since this difference appears not to be attributable to differences in thermal stability, it is suggested that the deglycosylated form of the protein is more susceptible to intracellular proteolytic digestion. In vitro studies on the digestion of these two forms of invertase by trypsin are consistent with this suggestion.

Animals↗
PubMed1978

The relationship between the spoT gene, the synthesis of stable RNA, ribosomal proteins, and the beta beta' subunits of RNA polymerase following a nutritional shiftup of Escherichia coli.

The level of ppGpp and rates of synthesis of stable RNA, ribosomal protein, and the beta and beta' subunits of RNA polymerase were measured following a nutritional shiftup in Escherichia coli strains, NF 929 (spoT+) and NF 930 (spoT-). In the spoT+ strain, ppGpp levels decreased 50% within 2 min following shiftup, and the rates of synthesis of stable RNA, ribosomal proteins, and the beta and beta' subunits of RNA polymerase increased with little or no lag. In contrast, in the spoT- strain, ppGpp levels transiently increased 40% during the first 6 min following shiftup. An inhibition in the rate of stable RNA synthesis and a delay in the increased synthesis of ribosomal proteins and beta and beta' subunits occurred concurrently with the transient increase in ppGpp. In addition, the DNA-dependent synthesis in vitro of the beta and beta' subunits of RNA polymerase was inhibited by physiological levels of ppGpp. Because of the timing and magnitude of the changes in ppGpp levels in the spoT- strain versus the timing when the new rates of stable RNA, ribosomal protein, and beta and beta' subunits synthesis are reached, it is concluded that ppGpp is not the sole element regulating the expression of these genes.

DNA-Directed RNA Polymerases↗
PubMed1977

Radiation treatment planning.

Radiation treatment planning has developed into a substantial and effective component of the entire radiation treatment approach. Over the last 2 decades, with the development of high energy electron and x-ray sources, and also with the availability of new radionuclides and techniques for internally applied radiation, all of which permit a high degree of concentration of radiation, treatment planning has been developed to make best use of these modalities. The use of automatic computation has proved necessary in order to handle the large amounts of radiation data involved in treatment dose calculation. Tumor and anatomical localization has been carried out with increasing precision. Several cases are described which illustrate planning and in particular the use of computerized transverse tomography. The use of moving shadow-shields is also described. For internally applied radiation, the features of iodine-125 are illustrated.

Adult↗