Search PubMed⌕ Search

Biomedical subjects

L R Kaiser

Publications and source records attributed to L R Kaiser.

At least 181 records · Page 10Linked to original sources
PubMed1981

Radio frequency hyperthermia of advanced human sarcomas.

Hyperthermia greater than or equal to 42 degrees C is tumoricidal in vitro and in many animal models, although such temperatures have only recently been achieved experimentally in some human cancers. A recently developed radio frequency device that provides safe hyperthermia to any depth without surface tissue injury now permits evaluation of the effects of hyperthermia on advanced human sarcomas. Twelve patients with large sarcomas located intraabdominally [7], in the chest wall [2], proximal extremity [2], and the neck [1], were evaluated in this study. Tumor types include liposarcoma [3], rhabdomyosarcoma [2], leiomyosarcoma [2], neurofibrosarcoma [2], and one each malignant mesothelioma, undifferentiated sarcoma, and osteosarcoma. Intratumor temperatures greater than or equal to 42 degrees C were observed in all tumors, with virtually no normal tissue injury. Selective tumor heating greater than or equal to 45 degrees C occurred in 9/12 (75%) and greater than or equal to 50 degrees C in 6/12 (50%). One to five weekly treatments greater than or equal to 50 degrees C and ten daily treatments greater than or equal to 45 degrees C resulted in significant tumor necrosis and pain relief in some patients. Hyperthermia of advanced sarcomas is possible with little host toxicity and may be of potential therapeutic benefit.

Adult↗
PubMed1981

Skeletal metastases of melanoma: radiographic, scintigraphic, and clinical review.

The radiographic manifestations of 127 skeletal metastases in 50 patients with melanoma were reviewed and correlated with the scintigraphic findings. Although the features of most of the metastases were nonspecific and appeared similar to those of other osteolytic metastases, several of them had unusual features, including expansion, subarticular location, osteosclerosis, and a thin, sclerotic rim. These features could result in some of the metastases being mistaken for other lesions. The radionuclide bone scans were more sensitive in that they detected the lesions earlier and in greater numbers than the radiographs. Prognosis was poor once skeletal metastasis was diagnosed, the mean survival time being 4.7 months.

Adolescent↗
PubMed1981

In vitro assessment of antineoplastic therapy. New indication for thoracotomy?

Selection and determination of the efficacy of antineoplastic agents has been dependent upon the trial and error method of observing measurable disease. Such methods subject the patient not only to loss of precious time but to needless toxicity if the drug is ineffective. The clonogenic assay, an in vitro assessment of tumor cell sensitivity to antineoplastic agents, has the potential for individualizing therapy. In this assay, tumor cells exposed to various drugs are cloned in soft agar. In the 16 primary and 24 metastatic pulmonary tumors tested with this technique, a growth rate of 80% was achieved. Fifty-five percent of the primary tumors and 60% of the metastatic lesions responded in vitro to one or more of the test drugs. There were twelve possible correlations between in vitro and in vivo results. In four of 12 assays, in vivo sensitivity was predicted and three of four patients demonstrated a clinical response. No drug that was inactive in vitro had activity in vivo. Prior knowledge of in vitro sensitivity may dictate a more aggressive surgical approach to pulmonary metastatic disease, whereas in vitro resistance would call for more conservative treatment. Just as with estrogen receptor status in breast cancer, data derived from the clonogenic assay may ultimately be of such import that thoracotomy would be warranted solely for the purpose of obtaining tissue for the assay.

Antineoplastic Agents↗
PubMed1978

The future of health planning.

What is the future of health planning? Will the profession survive? What will health planners be doing thirty years from now? The answers to these questions depend in part on prognostication and in part on the collective will of the profession to shape its own destiny. You ought to be doing something about the future in addition to waiting around for it. If by nature you are impatient for the good life, don't wait for it--invent it. The science of design is the sovereign science of the 21st century. A design for health requires us to answer three questions: (1) What should be done? (values) (2) How can it be done? (knowledge) (3) Who can do it? (power) To the degree health planners help society in its search for answers to these three questions, it will secure its own future as a profession. To the degree it fails in this quest, it will continue in its current mechanistic preoccupations and will eventually pass into irrevelance and obscurity. The impact of twenty-four societal trends are projected, as are the effects of the trends on the health planning profession and the images of its practitioners.

Delivery of Health Care↗
PubMed1977

Effects of probenecid on methotrexate exchange between the blood and the cerebrospinal fluid.

In rabbits anesthetized with urethane, only a small fraction of 3H-methotrexate administered by an i.v. infusion reached an artificial cerebrospinal fluid solution perfused through the cerebroventricular system. This movement was not altered significantly by probenecid administered either i.v. or in the perfusing artificial cerebrospinal fluid. When the 3H-methotrexate was perfused through the cerebroventricular system, one third of the amount normally lost during the perfusion was retained when probenecid was also added to the solution. Therefore, at least a portion of the apparent blood-brain barrier that exists for methotrexate is due to removal from the cerebrospinal fluid by a process that can be inhibited by probenecid.

Animals↗
PubMedDate not supplied

The evaluation of adenoviral p53-mediated bystander effect in gene therapy of cancer.

Because many tumors have mutated p53, one potential strategy proposed for cancer gene therapy is the introduction of the wild-type p53 gene into tumor cells. One puzzling aspect of this approach is that currently available gene transfer protocols result in a small percentage of tumor cells being transduced in vivo, thus implicating a "bystander effect" to achieve therapeutic efficacy. Because bystander effects in the context of p53-mediated gene therapy have not been well characterized, we evaluated the role of in vitro and in vivo bystander effects of adenovirally delivered p53 (AdWTp53). Using human tumor cell lines that did not express p53 protein but were infectible with adenovirus and showed sensitivity to p53-mediated apoptosis, we were unable to demonstrate an AdWTp53-mediated in vitro bystander effect, despite seeing strong bystander effects when cells were infected with an adenovirus containing the suicide gene herpes simplex virus thymidine kinase and treated with ganciclovir. In contrast, in vivo flank mixing studies using one of these cell lines showed a weak but significant p53-mediated bystander effect (a 40% inhibition of tumor growth). This bystander effect translated into a small survival advantage in an established intraperitoneal tumor model when tumor burden was low at the time of viral instillation. The survival advantage was lost, however, when tumor burden was increased. This study indicates that treatment of human tumors using AdWTp53 may be possible; however, because of the weak bystander effect in vivo, effective treatment will likely require a large percentage of tumor cells to be transduced.

Adenoviridae↗
PubMedDate not supplied

Severe acute extrinsic airway compression by mediastinal tumor successfully managed with extracorporeal membrane oxygenation.

The successful use of femoral venoarterial extracorporeal membrane oxygenation to support an adult patient with extrinsic airway compression secondary to a large mediastinal tumor is presented. Extracorporeal membrane oxygenation was continued until a combination of chemotherapy and radiation therapy allowed sufficient tumor shrinkage to permit decannulation. This method should be considered and available before manipulation of the airway in similar patients.

Adult↗
PubMedDate not supplied

The extrapleural fat sign: CT characteristics.

Three cases of medially displaced extrapleural fat are presented. In these cases displacement is secondary to tumor, thoracic wall edema, and hematoma. When significantly displaced, and especially when distorted, the extrapleural fat may present a confusing CT picture. The recognition of this finding may aid in establishing differential diagnosis and staging.

Adenocarcinoma↗