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Biomedical subjects

F R Kirchner

Publications and source records attributed to F R Kirchner.

At least 19 recordsLinked to original sources
PubMed1985

Quantitative assessment of rabbit alveolar macrophage function by chemiluminescence.

Rabbit alveolar macrophages (RAM) were cultured for 24 hr with concentrations ranging from 3 to 12 micrograms/ml of vanadium oxide (V2O5), a known cytotoxic agent, or with high-molecular-weight organic by-products from coal gasification processes. After culture the cells were harvested and tested for functional capacity using three types of indicators: (1) luminol-amplified chemiluminescence (CL), which quantitatively detects photon emission due to respiratory burst activity measured in a newly designed instrument with standardized reagents; (2) the reduction of nitro blue tetrazolium-saturated polyacrylamide beads, a semiquantitative measure of respiratory burst activity; and (3) phagocytic efficiency, defined as percentage of cells incorporating immunoglobulin-coated polyacrylamide beads. Chemiluminescence declined linearly with increasing concentrations of V2O5 over the dose range tested. Dye reduction and phagocytic efficiency similarly decreased with increasing V2O5 concentration, but were less sensitive indicators of functional impairment than CL as measured by the amount required to reduce the response to 50% of untreated cells. The effect of coal gasification condensates on RAM function varied, but in general these tests also indicated that the CL response was the most sensitive indicator.

Animals↗
PubMed1983

Toxicological effects on mice following inhalation exposures to fluidized-bed coal combustor fly ash.

Toxicological effects of exposure to reaerosolized fly ash from a fluidized-bed coal combustor were evaluated in mice following 500- and 1000-hr inhalation exposures. Alveolar macrophage function, organ histology, and hematopoiesis were assessed following 24-hr/day exposures in two 500-hr experiments. There was little mutagenicity detected by the Ames assay in the samples of the fly ash tested. The chemical characteristics of the fly ash were very similar to those of fly ash produced during conventional coal combustion. However, physical characterization revealed that the fluidized-bed combustion fly ash was not fused as is commonly the case in conventionally combusted fly ash, and as a result had a very large surface area. The function of the alveolar macrophages of exposed mice was impaired, and there were significant changes in the histology of the lung, including cellular infiltration and hyperplasia of bronchiolar and alveolar epithelium. These changes are characteristic of pulmonary responses to chronic irritation of the lung.

Animals↗
PubMed1983

The action of selected agents on the accumulation of 18F by Streptococcus mutans.

The action of certain substances known to induce cellular alterations, or encounted in the oral cavity, on the accumulation of 18F by Streptococcus mutans GS-5 has been investigated. A 62-67% inhibition in the number of 18F atoms bound per mg dry weight of cells could be induced by a 15 min pretreatment with 2.7 X 10(-4) M cetyltrimethylammoniumbromide, 1 X 10(-1) M acetic anhydride, or 7 X 10(-2) M HCl. Plate counts indicated that alteration of the cellular composition rather than viability was responsible for this diminution in 18F accumulation. Prior exposure for 15 min of this organism to 1 M HCHO or 0.1 M NaOH did not alter 18F accumulation. Of the common salts encountered in the oral cavity, CaCl2 enhanced 18F binding. Pretreatment of the assay cells for 15-160 min with 0.1-10 mg/ml of trypsin, pronase, protease, alpha-glucosidase, dextranase, or lactoferrin had no significant effect on the accumulation of 18F. However, pre-exposure of cells for 60 min to 1-10 mg/ml of either amylase or lipase induced a 40-67% inhibition in the binding of 18F, while lysozyme enhanced the binding of 18F by the cells. It would appear then that the binding of 18F by S. mutans may be altered by certain substances encountered in the oral cavity.

Acetic Anhydrides↗
PubMed1981

Suturing techniques in endolaryngeal surgery.

In the past 15 years surgery of the endolarynx has been greatly expanded. This development has been the product of three main factors: technological advancements such as the microcautery, improved knowledge about the healing properties of the endolarynx, and new surgical techniques. These types of approaches are being increasingly used in the treatment of complex reconstructive procedures of the larynx. An integral part of these new procedures are special suturing techniques. At present suturing techniques are being used to fulfill a number of requirements, including approximation and lateralization of anatomical structures for operative or exposure purposes, intraoperative retraction of endotracheal tubes, closure of wounds and securement and fixation of skin grafts, intralaryngeal molds, and interfacing Silastic sheeting materials. With amazing simplicity the above requirements can be met if a few basic steps are comprehended and followed.

Humans↗
PubMed1979

Endoscopic lateralization of the vocal cord in abductor paralysis of the larynx.

Endoscopic surgical operations of the larynx have many desirable features, including the conservative nature of these procedures, plus the ability to produce surgical changes predictable from the onset. For several years the direct lateralization of the vocal ligament after the removal of a preassessed amount of thyroarytenoid muscle appeared to be the simplest and most accurate surgical procedure. The resection of this wedge of muscle was easily performed with laryngeal microcautery. Posterior cicatricial webs can be easily removed with this instrument. Simple suturing techniques are also described, including the practicability of using padded buttons plus lead fishing sinkers to adjust the tension and secure these sutures on the surface of the neck. So far 16 patients have been rehabilitated using this technique, including 6 patients with posterior commissure webs. These anatomical techniques should be considered because of their obvious simplicity.

Cautery↗
PubMed1978

Failure to find a humoral factor which influences the compensatory response after resection of the rat small bowel.

Small bowel resection was performed in one parabiont of a parabiotic rat pair to determine whether there was a "humoral" or other circulating factor present which could influence the compensatory response seen in the remainder of the small bowel. Following intestinal resection in one parabiont, there was an increase in DNA synthesis in the intestine of that member provided at least 40% of the small intestine was removed. The compensatory response seen in a resected animal was not observed in its parabiotic partner, even though an attempt was made to make the potentially responding animal more sensitive to the influence of any circulating "factors" by resecting its intestine as well. The results obtained are in disagreement with the one closely related report in the literature; it is suggested that there is no good evidence for the existence of a resection-induced circulating factor with the capability of crossing a vascular anastomosis and controlling proliferation of small intestinal epithelium.

Animals↗
PubMed1978

Induction of colonic adenocarcinoma in the rat by X-irradiation.

In work to determine whether X-radiation could be used to induce tumors of the colon in outbred Holtzman rats, a technique was devised so that only the descending colon could be irradiated with a collimated X-ray beam and tumorigenic exposures in the kilo-Roentgen range were delivered. Ninety male Holtzman rats were divided into 6 exposure groups of 15 animals each. In the first group only the colon was exposed to 2500 R; in the second group the colon was exposed to 3500 R and the exposures were increased by 1000-R increments up through 6500 R; the sixth group was sham irradiated. Animals in each of the irradited groups developed mucoid adenocarcinomas with the highest incidence (47%) obtained inthe 4500-R group. Histopathologically, the induced tumors bear a close resemblance to human colon adenocarcinoma, and the development of pulmonary metastases in one of the animals with multiple primary tumors demonstrated their malignancy. The usefulness of the animal model is discussed.

Adenocarcinoma, Mucinous↗
PubMed1976

Aneurysms of the petrous portion of the internal carotid artery.

Aneurysms of the petrous portion of the internal carotid artery are rare lesions. One case is reported here and 18 others have been found in the literature. These lesions usually arise in young men who present with auditory dysfunction. The aneurysm is usually discovered as a pulsating purple mass in the middle ear and mistaken for a glomus jugulare tumor. A definitive diagnosis can be made by carotid angiography. Subtraction techniques are very helpful. Carotid ligation or trapping is the treatment of choice.

Adult↗
PubMed1975

Laryngeal structure following microcauterization.

This paper supports and reaffirms the objectives of contemporary laryngology in the treatment of cancer of this organmthese objectives are, first and foremost, the eradication of the tumor, and second, the preservation of function. A relatively recent contribution to the "state of the art" has been the development of the field of microlaryngology. The introduction of the surgical microscope has provided the laryngologist with better means to judge the type, localization and extent of neoplastic lesions. Reports indicate that superficial limited carcinomas of they larynx with good vocal cord mobility can be successfully treated by vocal cord stripping and/or radiotherapy. This paper presents the serious challenge posed by these limited tumors when they recur after radiotherapy. In a selected number of these patients radical surgery has been prevented by treating these recurrent tumors with the microcautery. Some of these patients, so treated, habe been free of disease for more than three years after their recurrent tumors were destroyed with the microcautery. During this time these patients have enjoyed adequate voices.

Aged↗