Search PubMed⌕ Search

Biomedical subjects

J B Marmor

Publications and source records attributed to J B Marmor.

At least 19 recordsLinked to original sources
PubMed1998

Medical marijuana.

Although many clinical studies suggest the medical utility of marijuana for some conditions, the scientific evidence is weak. Many patients in California are self-medicating with marijuana, and physicians need data to assess the risks and benefits. The only reasonable solution to this problem is to encourage research on the medical effects of marijuana. The current regulatory system should be modified to remove barriers to clinical research with marijuana. The NIH panel has identified several conditions for which there may be therapeutic benefit from marijuana use and that merit further research. Marijuana should be held to the same evaluation standards of safety and efficacy as other drugs (a major flaw in Proposition 215) but should not have to be proved better than current medications for its use to be adopted. The therapeutic window for marijuana and THC between desired effect and unpleasant side effects is narrow and is a major reason for discontinuing use. Although the inhaled route of administration has the benefit of allowing patients to self-titrate the dose, the smoking of crude plant material is problematic. The NIH panel recommended that a high priority be given to the development of a controlled inhaled form of THC. The presence of a naturally occurring cannabinoid-receptor system in the brain suggests that research on selective analogues of THC may be useful to enhance its therapeutic effects and minimize adverse effects.

Analgesics↗
PubMed1984

Impact of adjuvant chemotherapy on cosmesis and complications in stages I and II carcinoma of the breast treated by biopsy and radiation therapy.

Cosmesis and complication rates were examined in patients with early stage carcinoma of the breast treated by biopsy and radiation therapy with and without adjuvant chemotherapy in an attempt to determine the effect of chemotherapy upon these parameters. Between April 1, 1975 and June 1, 1980, 51 patients were treated with radiation therapy and adjuvant chemotherapy (XRT + ACT) and 83 patients with radiotherapy alone (XRT). Chemotherapy usually consisted of cytoxan, methotrexate and 5-fluorouracil for 6 or 12 cycles. Minimum follow-up was 36 months. Cosmetic results deteriorated with time in both groups but to a greater extent in the XRT + ACT group. At 36 months, excellent cosmetic results were obtained in 73 of the 83 patients (88%) in the XRT group compared to 37 of 51 patients (73%) in the XRT + ACT group (p = less than .05). Comparison of the two treatment groups revealed that complication rates were significantly increased in the XRT + ACT group. Of the 51 patients in the XRT + ACT group, 21 patients (41%) suffered complications compared to 8 (10%) of the 83 patients in the XRT group (p = less than .001). This difference in complication rates resulted primarily from an increased incidence in the XRT + ACT group of wet desquamation in the electron beam portal used to treat the internal mammary lymph nodes and a trend towards a higher incidence of spontaneous nonpathologic rib fractures, myositis and arm edema. An increased incidence of nonbreast primary cancers was not seen. Our preliminary conclusions are that adjuvant chemotherapy has a negative impact upon cosmesis and complication rates in patients being treated with definitive radiotherapy. However, cosmetic results remain satisfactory and complication rates are maintained at an acceptable level. Continued close follow-up will be required before definitive conclusions can be reached as to the overall incidence and severity of the changes noted.

Adult↗
PubMed1983

Work in progress: serial evaluation of tumor volume using computed tomography and contrast kinetics.

Computed tomography can be used to evaluate tumor volume changes after therapy. Pre- and posttreatment results are presented for nine human neoplasms. Volume changes are correlated with the behavior of intravenous diatrizoate contrast material. The five-minute diatrizoate distribution volume appears to be a potential contrast material marker for therapeutically induced tumor volume changes. Neoplasms decreasing in volume demonstrate a decrease in the diatrizoate distribution volume; those increasing in volume demonstrate an increase.

Carcinoma, Squamous Cell↗
PubMed1982

Clinical studies with ultrasound-induced hyperthermia.

Results obtained in clinical studies in which ultrasound was used for hyperthermia induction are reviewed. High intensity ultrasound has certain advantages for the induction of local hyperthermia: Well-collimated beams can be produced, which makes good localization possible; ultrasound can be focused; and absorption in tissue is proportional to frequency, hence the depth of penetration can be controlled. Limitations include the fact that ultrasound is reflected from tissue-air interfaces and thus cannot be used to heat tumors in the lung. Local "hot spots" due to impedance mismatches that result in standing wave patterns may occur near bone. During clinical treatments, this latter problem is frequently associated with a patient's complaint of pain. The temperature generated depends both on ultrasound absorption coefficients, which vary among different tissues, and dissipation of heat, which varies due to local differences in blood flow rates. Thus inhomogeneities of heating in tissue may be observed despite uniform ultrasound fields. Clinical results with ultrasound-induced hyperthermia have been reported by groups at Stanford, M.D. Anderson Hospital, and Massachusetts Institute of Technology-Harvard. Approximately 40-50% of the superficial tumors showed an objective response to ultrasound hyperthermia in the range of 43 degrees -50 degrees C. Responses to heat alone were partial and transitory. Some radiation responses appeared to be improved by concomitant ultrasound hyperthermia.

Adenocarcinoma↗
PubMed1981

Anthracycline-associated cardiac and renal damage in rabbits. Evidence for mediation by vasoactive substances.

We tested the hypothesis that anthracycline-induced cardiac and renal damage is mediated by vasoactive substances. A 1-minute exposure to 5 micrograms per ml. of doxorubicin (DXR, Adriamycin) produced cardiac histamine release in isolated rabbit hearts. Under conditions in which histamine uptake and metabolism were impaired, the administration of DXR, 2 mg. per kg., over 1 minute was associated with elevations in arterial histamine and catecholamines. The chronic weekly administration of DXR produced severe cardiac and renal damage. The administration of combined histaminic and adrenergic blockade with diphenhydramine, cimetidine, phentolamine, and propranolol (DCPP) pre- and immediately post-DXR resulted in near total protection against DXR-mediated cardiac damage and prevented the majority of the renal lesions. The combined administration of diphenhydramine, cimetidine, phentolamine, and propranolol did not appear to be acting by mechanisms other than blockade of vasoactive amine receptors as cardiac uptake of DXR and the DXR antitumor response were not altered by diphenhydramine, cimetidine, phentolamine, and propranolol. This study demonstrates that anthracycline-associated cardiac and renal toxicity may be mediated by vasoactive substances and that anthracycline cardiomyopathy is potentially preventable.

Animals↗
PubMed1981

Induction of hyperthermia by ultrasound.

Induction of hyperthermia by ultrasound is facilitated by the characteristics of sound absorption in tissue: at frequency of 500 kHz the penetration distance in muscle is about 12.5 cm. Energy deposition patterns can be shaped by focussing or by the use of multiple transducers. An initial clinical study has demonstrated the safety and efficacy of the heating technique. Temperatures of 43-45 degrees for 30-45 min were obtained in surface accessible tumors. 50 per cent of the treated tumors regressed either partially or totally. Normal tissue damage was minimal even in sites that had previously been heavily irradiated. A few patients given relatively small doses of X-irradiation in addition to the hyperthermia responded very well. Based upon these encouraging results, a new ultrasound system designed for heating of deep seated lesions has been built and tested.

Animals↗
PubMed1980

Combined radiation and hyperthermia in superficial human tumors.

Hyperthermia (42--43 C) appears to potentiate the effects of radiation therapy in experimental tumor models. In addition, some studies indicate that tumors may be sensitized to a greater extent than normal tissue. This study was designed to test whether the effectiveness of irradiating human tumors was enchanced significantly by concomitant heating. We also examined skin to see if heating enhanced the response to radiation of normal tissues. Nineteen patients with multiple metastatic superficial tumor masses of various histologies were studied. All were considered incurable and an independent clinical decision had been made to irradiate for palliation. Two or more masses in the same patient were matched for size and location, so that one of the patient's own tumors was a control to monitor the effect of irradiation alone. On each patient the tumors were treated with identical fractions and to the same total dose of radiation. One of the matched nodules was given hyperthermia (43 C) for 15 minutes before and 30 minutes after each radiation fraction. The response of the tumor that received radiation alone was compared with that of the tumor receiving hyperthermia and radiation. In seven of 15 evaluable patients the tumor that received heat in addition to radiation had a greater objective response than the tumor receiving radiation alone (P < .065). Of the remaining eight patients, four had complete tumor regression in both areas without later regrowth, two failed to respond in either area, and two partially responded in both areas. Two patients had increased cutaneous reaction to radiation in the heated area; one of these was a severe desquamative reaction, which conformed to the size and shape of the ultrasound field. These results suggest that hyperthermia improves the objective response to radiation in some human tumors; in two cases it appeared to sensitize skin as well.

Dose-Response Relationship, Radiation↗
PubMed1979

Tumor eradication and cell survival after localized hyperthermia induced by ultrasound.

This study was designed to test the effect of localized ultrasound-induced hyperthermia on experimental mouse tumors. Transducers operating at 5.17 MHz with relatively uniform output over an area 1 cm in diameter were used to heat EMT6 and KHJJ tumors in 407 BALB/cKa mice. Treatments were at 43, 43.5, 44, and 44.5 degrees. At each temperature level, treatments were applied for 15, 30, or 45 min. Temperature profiles measured in tumors treated by ultrasound hyperthermia indicated that heating was not completely uniform. In general, both rate of tumor eradication and growth delay increased as temperature and/or time of exposure increased. The EMT6 and KHJJ tumors had comparable rates of eradication for the same temperatures and times of exposure. Cell survival studies indicated that there was considerable variation in cell killing between individual EMT6 tumors exposed to the same hyperthermic dose. In addition, cell death appeared to be progressive over a period 2 to 48 hr after hyperthermic exposure. The mechanism of this delayed cell death is not known but may be important in eradicating the tumors. Ultrasound was a relatively safe and effective method of heating tumor volumes up to 44 degrees, and hyperthermia alone resulted in high rates of tumor eradication in the EMT6 and KHJJ systems.

Animals↗
PubMed1979

Effects of systemically administered bleomycin or adriamycin with local hyperthermia on primary tumor and lung metastases.

Exposure of cells in tissue culture to bleomycin or Adriamycin during 43 degrees C hyperthermia increased cytotoxicity dramatically compared to exposure at 37 degrees C. This study was designed to test whether this interaction was useful in tumor-bearing animals. C3H mice bearing the KHT tumor were treated with bleomycin (7 or 15 mg/kg) or with Adriamycin (2.5 or 5 mg/kg) with or without local heating of the tumor to 43 degrees C for 30 minutes by 13.56 MHz radiofrequency fields. The effects were assessed by growth delay (mean tumor diameter doubling time) and cure rate. In separate experiments, BALB/c mice bearing EMT6 tumors were treated identically, but tumors were excised 2 hours after treatment and tumor cell survival was assayed by colony formation. Antitumor effects of systemic bleomycin were potentiated by local hyperthermia. The two modalities had to be administered close together in time to observe the potentiation, suggesting a true interaction. There was a "threshold" for bleomycin potentiation in vivo between 42 degrees C and 43 degrees C, just as observed in tissue culture experiments. The antitumor activity of Adriamycin was not potentiated in vivo in these tumor systems except in cell survival experiments at doses higher than those compatible with survival of the host. The toxicity of drug combined with heat was greater than that of either modality alone. Hyperthermia did not adversely affect the incidence or severity of spontaneous lung metastases from KHT tumors. In fact, groups treated with heat and bleomycin had less severe lung metastases than groups treated with bleomycin alone. We conclude that local heating of tumors may be a useful adjunct to systemic bleomycin therapy. In vivo potentiation of Adriamycin by heat, however, could not be demonstrated in these tumor systems.

Animals↗
PubMed1978

Optic nerve head involvement with cytomegalovirus in an adult with lymphoma.

An optic nerve swelling that was thought clinically to represent a lymphomatous infiltrate of the nerve head developed in a 51-year-old man with histiocytic lymphoma. Histologic examination of the eyes showed the presence of cytomegalovirus (CMV) in the nerve head, but no lymphoma cells. Tru lymphomatous invasion of the nerve head in systemic lymphoma is probably very rare. This case points out an unusual manifestation of adult CMV infection, and a new concern in patients with compromised immune systems.

Adult↗
PubMed1977

Tumor cure and cell survival after localized radiofrequency heating.

Radiofrequency electromagnetic fields at 13.56 MHz were used to heat locally EMT-6 sarcomas and KHJJ carcinomas in BALB/cKa mice. Temperature profiles obtained in tumors during treatment showed uniform temperature distribution throughout the tumor volume with no systemic hyperthermia. Temperature could be maintained at a stable level throughout treatment by adjustment of power. Tumors were treated at 43 degrees, 43-5 degrees, and 44 degrees, for 5, 10, 20, 30, and 40 min. The EMT-6 tumor was highly sensitive to cure by radiofrequency heating: a 5-min exposure at 44 degrees resulted in cure of almost 50% of the tumors. Cure rate was a function of temperature and of duration of exposure. The KHJJ carcinoma was somewhat more resistant to cure by radiofrequency heating, although most of the animals treated at 43.5 degrees or above were cured of their tumors. In an effort to explain the remarkable effectiveness of radiofrequency heating, tumor cell survival studies were done on EMT-6 tumors treated in situ. Cell inactivation by radiofrequency heating was similar to that for hot water bath heating. However, direct cell killing cannot account for the observed cures, and an additional mechanism must be responsible for tumor eradication.

Animals↗
PubMed1976

Unregulated growth of murine leukemic cells and suppression of normal granulocyte growth in diffusion chamber cultures.

The patterns of proliferation of C1498 mouse acute leukemic cells have been studied using the diffusion chamber technique of cell culture. These malignant cells grow to the same maximal cell concentration irrespective of initial cell input. Leukemic cells proliferate equally well with or without the stimulus of prior host irradiation. When cells cultured for several days are diluted to the original input concentration and recultured, they rapidly proliferate back to maximal cell number. All of these findings are in sharp contrast to the behavior of granulocytes from normal mouse marrow grown in the same culture system. Co-culutre of equal numbers of normal marrow cells and leukemic cells results in virtually complete inhibition of normal marrow cells and leukemic cells results in virtually complete inhibition of normal granulocyte growth. These experiments provide a means of studying malignant growth of leukemic cells, as compared to the controlled growth and differentiation of normal granulocytes, and mechanisms by which leukemic cells suppress normal granulocyte development.

Animals↗
PubMed1975

Modulation of murine granulocyte proliferation in diffusion chamber cultures.

Normal mouse marrow cells were cultured in Millipore diffusion chambers for long periods of time and at a variety of cell concentrations. All cultures showed a pattern of granulocyte proliferation characterized by logarithmic growth followed by prolonged stabilization of cell number starting a 7 days thereafter. The height of this "plateau" varied in relationship to the level of cell input and characteristically was far lower than the maximum cell density that can be maintained in this culture system. Additional studies showed that the plateau represented a steady state of granulocyte turnover and was not due to alterations in the diffusion chambers or the host mice. Regulatory mechanisms intrinsic to the cultured cell population appeared to play a primary role in maintaining this stable plateau. Modulation of granulocyte proliferation was partly due to increasing cell density; particularly with high input concentrations. In addition, differential cell counts suggested that critical changes in the relationship between immature and mature granulocytes partially accounted for this apparent autoregulation of cell growth. The plateau period in diffusion chamber cultures in many ways resembles granulocyte proliferation in normal mouse bone marrow and is a useful model for the study of regulatory functions in granulocytopoiesis.

Animals↗