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Biomedical subjects

R Zimmerman

Publications and source records attributed to R Zimmerman.

At least 109 records · Page 6Linked to original sources
PubMed1981

Characterization of human cells transformed by chemical and physical carcinogens in vitro.

Several different classes of chemical carcinogens induced the transformation of human fibroblasts grown in vitro. Characteristics of the events that occur from time of treatment through the expression of neoplastic transformation are presented. The S-phase appeared to be the portion of the cell cycle most vulnerable to insult. Staging of the cells by blocking them in G1 before releasing them to proceed through scheduled DNA synthesis (S) was required to induce reproducible transformation. Compounds such as insulin were added to the cells upon release from the block to sensitize the cells to the carcinogen that was added during S. Growth of the transformed cells as distinct from nontransformed cells was promoted by growth in medium supplemented with 8X nonessential amino acids. Carcinogen-treated cells in the early stage of transformation exhibited abnormal colony morphology and were able to grow at 41 degrees C, in air atmosphere, and in medium supplemented with only 1% serum. In addition, the transformed cells were insensitive to KB cell lysate and exhibited density independent, as well as anchorage independent, growth (i.e., growth in 0.33% agar). Cells that grew in soft agar also produced undifferentiated mesenchymal tumors in preirradiated nude mice.

Animals↗
PubMed1981

Ultraviolet radiation-induced neoplastic transformation of normal human cells, in vitro.

Human foreskin cell cultures in scheduled DNA synthesis (S phase) of the cell cycle were exposed to UV irradiation at a dose of 10 J . m-1 in the presence of insulin. These treated cell populations, when selectively passaged in a high amino acid supplemented complete growth medium (CM) after 20 Dulbecco's phosphate buffered saline (pH 6.8) (PDL), were able to be grown in soft agar. These treated cell populations were also grown in 1% serum supplemented growth medium and at 41 degrees C in 10% serum supplemented growth medium. Cell populations 4--5 PDL after treatment exhibited altered colony morphology and altered lectin agglutination profiles but would not grow in soft agar. These events appeared to be associated with the early stages in the expression phase of the transformed phenotype. After 20 PDL, we observed that these cells would grow in soft agar at a frequency of 20 colonies/10(5) cells seeded in soft agar. The cell populations derived from these colonies, when propagated and injected into the nude mice, formed myxofibromas at the injection sites rather than the type of tumor (fibrosarcoma) previously described for chemical carcinogen-induced neoplasms.

Animals↗
PubMed1980

Assessment of serial CEA determinations in urine of patients with bladder carcinoma.

Carcinoembryonic antigen (CEA) levels in urine and serum from 294 patients with bladder cancer in varying stages have been clinically evaluated. All urine samples were obtained from patients with intact renal function and without bacterial infection in the bladder. The samples were collected before, during, and at follow-up examination after radiotherapy. They were perchloric acid extracted before being assayed in a double-antibody radioimmunoassay. The geometric mean of urine CEA levels for patients with primary tumors of Stage T1 or T2 was significantly lower than that for those with Stage T3 or T4 disease. The urine CEA levels for patients with tumors of various histologic grades did not differ. The urine CEA levels decreased from before to after radiation treatment of the primary tumor. Patients with recurrence within six months after undergoing primary treatment had higher initial mean urine CEA levels than did those without evidence of recurrence. The prognostic information for recurrence was limited to the more advanced tumors. Differences were also found between the means of samples taken before recurrence and after treatment of recurrent tumors; with regression of the tumor, a lower mean urine CEA level was found; with progression, a higher value. Urine CEA levels before any treatment were higher when the patients had a short survival time. Serum CEA levels were not related to stage or grade of the primary bladder tumor but levels were slightly elevated with metastases. The determination of urine CEA levels seems to be useful in the follow-up of patients with bladder carcinoma because when initially high, it adds to the information of the T classification and predicts early recurrence, and the monitoring of individual patients after primary treatment is useful for detecting recurrence.

Aged↗
PubMed1980

Prosthodontic and speech rehabilitation after partial and complete glossectomy.

A multidisciplinary approach to the rehabilitation of four glossectomy patients has been presented. Points emphasized were the anatomic defects, their effect on the three oral functions of mastication, deglutition, and speech, and the various prosthetic modifications found most effective to restore the impaired oral functions.

Aged↗
PubMed1980

Iridium- 191 angiocardiography for the detection and quantitation of left-to-right shunting.

An osmium- 191 leads to iridium- 191 generator that can deliver multiple doses of Ir- 191m for first-pass radionuclide angiography has been developed. Iridium- 191m has a physical half-life of 4.96 sec and decays with emission of 65-keV and 129-keV photons in 58 and 30% abundance, respectively. Using a gamma camera, Ir- 191m radionuclide angiography was carried out, in dogs and ten patients, for the detection and quantitation of left-to-right shunting. In a one-year-old patients, 25 mCi of Ir- 191m results in a whole-body radiation absorbed dose of 35 mrad. Multiple Ir- 191m angiograms can be performed, seconds to minutes apart, without interference from background. The 15.4-day half-life of Os- 191 permits transportation of the generator to centers far from the production facility. With the low radiation dose, high information density, and the ability to repeat studies with Ir- 191m, clinical use of radionuclide angiography should be expanded.

Adolescent↗
PubMed1979

Improved performance of a double antibody radioimmunoassay for carcinoembryonic antigen.

A new double antibody solid-phase radioimmunoassay (RIA) for carcinoembryonic antigen (CEA) is critically analyzed. The aim of the study was 4-fold: (a) to define the level of sensitivity (a comparison of 3 different assay procedures revealed that our sequential assay was more sensitive than most previously reported RIAs, while competitive and non-equilibrium assay had wider measuring ranges); (b) to analyze recoveries of CEA in either serum, plasma or urine (the recovery, even in urine, was very close to expected values, indicating that no CEA is lost or degraded during brief storage or in the extraction procedure); (c) to evaluate inter- and intra-assay variations, since most clinical management is dependent on serial assays rather than single determinations. The coefficients of variation were low both within and between assays. A change of 3 ng CEA is required for significant change (greater than 2 S.D.) at the normal serum level which is 16 ng CEA/ml in our assay. At levels above normal, a change of 4 ng is required; (d) the assay was also developed for determination of CEA levels in a large series of perchlorid acid treated serum, plasma or urine samples. This forms the basis for an assay suitable for serial assays with high sensitivity and accuracy in various neoplastic diseases.

Animals↗
PubMed1979

Cell-free synthesis of the mitochondrial ADP/ATP carrier protein of Neurospora crassa.

ADP/ATP carrier protein was synthesized in heterologous cell-free systems programmed with Neurospora poly(A)-containing RNA and homologous cell-free systems from Neurospora. The apparent molecular weight of the product obtained in vitro was the same as that of the authentic mitochondrial protein. The primary translation product obtained in reticulocyte lysates starts with formylmethionine when formylated initiator methionyl-tRNA (fMet-tRNAfMet) was present. The product synthesized in vitro was released from the ribosomes into the postribosomal supernatant. The evidence presented indicates that the ADP/ATP carrier is synthesized as a polypeptide with the same molecular weight as the mature monomeric protein and does not carry an additional sequence.

Animals↗
PubMed1978

Isolation of CEA-like material from urinary bladder carcinoma.

Carcinoembryonic antigen (CEA)-like material from urinary bladder carcinoma was purified and compared with the immunological and physico-chemical properties of CEA isolated from colon cancer. After immunoadsorbent purification, the final step in a purification procedure similar to that adopted for colon cancer CEA, two main molecular species were identified: 1) Material identical with colon cancer CEA with respect to molecular size, PCA solubility, ability to bind to Con A, and most important the ability to bind to specific monkey anti-CEA serum. 2) Material with the same chromatographic and immunological properties as NCA.

Carcinoembryonic Antigen↗
PubMed1978

Arterio-venous shunting in renal transplant rejection.

The angiographic appearance of arterio-venous shunting has been reported in one previous case of a patient with acute severe transplant rejection. Two additional cases are presented here. In the first the arteriovenous shunting is massive, and the venous filling is within the first second of the study. In the second the shunting is less severe, and the venous filling occurs later in the arterial phase. Shunting is probably caused by multiple microscopic arterio-venous fistulae secondary to the vasculitis of rejection. We propose that the presence of arterio-venous shunting suggests renal transplant rejection and may indicate a poor prognosis for reversal of this rejection.

Adult↗
PubMed1978

Psychiatric treatment. General implications and lessons from recent court decisions in California.

The California legislature enacted tight constraints on the use of psychosurgery and electroconvulsive therapy in 1974. In April 1976 a State Court of Appeals declared part of the law to be unconstitutional. In doing so, the court enunciated several principles for regulating medical procedures. It affirmed the inherent police powers which permit the state to safeguard the public, especially incompetent, involuntary or confined persons, with respect to intrusive and hazardous medical procedures and to procedures which affect thought or feeling. Although limited to legislation concerning two psychiatric procedures, the court's decision, and subsequently enacted legislation governing these procedures, has implications for other medical procedures and for other parts of the nation.

Adolescent↗
PubMed1977

Characterization of urothelial carcinoma with respect to the content of carcinoembryonic antigen in exfoliated cells.

A sutstance immunologically similar to carcinoembryonic antigen (CEA) was demonstrated in urothelial bladder carcinoma cells. When indirect immunofluorescence with specific anti-CEA antisera was used, CEA-containing cells were seen in 18 out of 40 cases in 5% to 30% of the cells. Among patients with tumor cells of well differentiated morphology, 61% had CEA-containing cells, compared with only 24% of patients with a poorly differentiated tumor. Microfluorometry of single cells was performed in six cases to estimate the range of CEA content. The mean fluorescence intensity with anti-CEA antiserum was three to six times that of the same tumor cell population stained with non-immune rabbit sera. This fluorescence was decreased when the anti-CEA anti-sera were incubated with CEA but not with nonspecific cross-reactive antigen. The results show a wide range of CEA antigen content in exofoliated bladder tumor cells. In addition to proliferative status and differentiation, quantitative CEA measurements give further possibilities to study characteristics of tumor cell populations.

Carcinoembryonic Antigen↗
PubMed1977

Priorities and indications of computed tomography in clinical practice.

Because of its technical capabilities, its rapidity and its non-invasive nature, computed tomography (CT) has given a new scope to neurological diagnosis and to the understanding of various aspects of neurological science. The availability of this test is determined by the patient load. If precise clinical indications are not considered, patients requiring CT the most may be denied immediate examination because less urgent cases may be occupying valuable diagnostic time. Moreover, the test is relatively expensive for the individual patient and for the community; this presents another facet of its use that should be taken into account. The technical limitations and clinical priorities to be considered when a physician is entertaining this test for a patient have been outlined. The indications have been divided into absolute and relative, according to the degree of clinical urgency. As a result, a priority guideline for diagnostic CT has been provided.

Brain Abscess↗
PubMed1977

Radionecrosis of the brain presenting as a mass lesion: a case report.

A case of radionecrosis of the brain in a patient previously treated for squamous cell carcinoma of the scalp is presented. Cerebral angiography revealed a mass effect primarily in the right frontal area. Computed tomography showed extensive hemispheric oedema. A frontal lobectomy was performed, and the recovery was excellent. The lower limit for brain tolerance for irradiation is about 5000 rads given in five weeks. This dose should not be exceeded when extracranial lesions are treated. Although computed tomography cannot diagnose brain necrosis, specifically, it should, along with the clinical history, be very helpful.

Brain↗
PubMed1976

Intraocular copper foreign bodies. Use of dexamethasone to suppress inflammation.

In an attempt to prevent the intense inflammatory response to intravitreal copper foreign bodies in the rabbit eye, varying dosages of dexamethasone sodium phosphate were administered daily via the subconjunctival route. The steroid appeared to behave systemically and had similar effects in both the injected and the noninjected eyes. Its effect was similar also regardless of the concentration of copper within the foreign body. Nine days of dexamethasone therapy prevented a substantial number of copper foreign bodies from becoming totally encapsulated during that time. Furthermore, a delay in the onset of the inflammatory response to the foreign body was noted. In a few instances, inflammation was completely suppressed during the entire course of therapy.

Alloys↗