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A J Milligan

Publications and source records attributed to A J Milligan.

At least 19 recordsLinked to original sources
PubMed1991

Effect of hyperthermia on normal tissue toxicity and on adriamycin pharmacokinetics in dogs.

This study examined the effects of Adriamycin (ADR) (30 mg/m2), whole-body hyperthermia (WBH) (42 degrees C for 1 h), and the combination of the two (ADR plus WBH) on gastrointestinal and hematopoietic toxicity and the effects of WBH on ADR pharmacokinetics in the normal dog (n = 5/treatment group). Duodenal biopsies were collected from animals in each group via endoscopy and were incubated in the presence of [3H]thymidine as an index of cell turnover. Additional duodenal biopsies were assayed for the enzymes gamma-glutamyltranspeptidase, N-acetyl-beta-D-glucosaminidase, and succinate dehydrogenase. Complete blood chemistry profiles and differential blood cell counts were done prior to and following treatment. Cell turnover was most depressed 3 days after ADR or ADR plus WBH; WBH alone had little effect on cell turnover. Neither gamma-glutamyltranspeptidase, N-acetyl-beta-D-glucosaminidase, nor succinate dehydrogenase activities were significantly altered by any of the treatment protocols. High performance liquid chromatography was used to quantify Adriamycin and adriamycinol in samples collected up to 6 h after drug administration. Duodenal biopsies were collected immediately and 1 h after drug administration for measurement of tissue concentrations of Adriamycin. A significant increase in the apparent volume of distribution and whole-body clearance and decrease in area under the plasma Adriamycin concentration versus time curve occurred when drug was administered concurrently with WBH. This differs from results reported in some other mammalian species.

Animals↗
PubMed1990

Rat liver tolerance for partial resection and intraoperative radiation therapy: regeneration is radiation dose dependent.

We studied the feasibility of delivering a large single dose of intraoperative radiation as an adjuvant to partial hepatic resection. Intraoperative radiation therapy (IORT) was delivered to the remaining liver of 84 rats after partial hepatectomy to determine the acute and chronic effects of treatment on blood chemistry values, histology, survival, hepatic regeneration, and cellular appearance of the normal liver. Transient elevations in SGOT, SGPT, and alkaline phosphatase were attributed both to hepatectomy and to liver parenchymal damage induced by IORT. Microscopic examination upon necropsy, performed at frequent intervals post-treatment revealed hepatic capsular thickening with some alteration of liver architecture mainly underneath the capsule, with localized inflammation and some areas of necrosis. Survival in all groups was 100% at 45 days. Liver weight increase proved to be dose-dependent and displayed a bisphasic pattern. This study demonstrated that IORT is a feasible adjunct to surgical resection of the liver in the rat model.

Alanine Transaminase↗
PubMed1990

Nd:YAG laser-induced interstitial hyperthermia using a long frosted contact probe.

The heating potential of a closed loop interstitial hyperthermia system employing 1,064 nm laser light in conjunction with a long frosted contact probe was investigated in hind limb muscle of anesthetized dogs. The laser system was an Nd:YAG surgical laser modified with a single channel thermometry unit, a computer, a printer, and a computer-controlled laser exposure shutter. The long frosted laser probe was implanted into the muscle, and 3.12-5.00 Watts of laser power was delivered interstitially. Temperature distribution was measured in three dimensions around the frosted probe. The temperature distributions generated by this technique were satisfactory for producing desired hyperthermia temperatures in an approximately 3.5 cm3 cylindrical tissue volume. A multiple laser delivery system is needed to induce interstitial hyperthermia in large tumors. A significant potential for the long frosted contact probe may be its use in combining interstitial hyperthermia and interstitial photodynamic therapy. Using this technique, both modalities may be delivered while employing the same treatment setup.

Animals↗
PubMed1989

Treatment of cancer of the pancreas by intraoperative electron beam therapy: physical and biological aspects.

Radiation therapy has had a significant and an expanded role in the management of cancer of the pancreas during the last decade. In particular, for locally advanced disease, radiation therapy has improved the median survival of patients to 1 year. Intraoperative electron beam therapy has been applied to unresectable and resectable pancreatic cancer in an attempt to enhance local control of disease and to improve patient survival. This paper presents a survey of the role of radiation therapy in treatment of cancer of the pancreas, provides information on the radiobiological aspects of this treatment modality and details the physical and dosimetric characteristics of intraoperative radiation therapy with electrons. Presented are the design specifics of an applicator system, central axis beam data, applicator parameters, dose distribution data, shielding, treatment planning and means of verification. Emphasis is placed on the collaboration and cooperation necessary for all members of the intraoperative radiation therapy team including surgeons, radiation therapists, medical physicists, anesthesiologists, technologists, and nurses.

Cancer Care Facilities↗
PubMed1988

Blood flow values.

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Blood Flow Velocity↗
PubMed1988

Biochemical and cellular effects of radiofrequency induced interstitial hyperthermia on normal canine liver.

Interstitial hyperthermia (44.0 +/- 0.5 degrees C for 40 minutes) was delivered to the livers of 16 dogs to determine acute effects of treatment on blood chemistry, histology, and cellular appearance of normal liver. SGOT in treated animals peaked immediately at 300 +/- 21 U/L (within 2 hrs) and returned to control value within 7 days. LDH levels peaked at 1 day post-treatment and again at 2 weeks (300 +/- 16 U/L and 340 +/- 25 U/L respectively) and returned to pre-treatment values by week 4. SGPT remained elevated for 6 to 7 days following hyperthermia, but returned to control value at 2 weeks. There was also a rise in alkaline phosphatase (200 +/- 14 U/L 1 day post-treatment), which returned to a pre-treatment level by week 3. Changes in serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactate dehydrogenase, and alkaline phosphatase were attributed to both liver parenchymal damage induced by hyperthermia and to surgery. Other deviations in the blood chemistries and hematological parameters measured were ascribed to the stress response from surgical intervention, or to the resultant hemodilution from fluids during surgery. Microscopic examination upon necropsy, performed 4 weeks post-operatively, displayed limited fibrosis with some alteration of liver architecture, generalized sinusoidal dilation and red blood cells in the space of Disse. Cellular ultrastructure changes showed an increase of myelin figures, but mitochondria and other cellular organelles remained essentially normal. Localized tissue inflammation and some loss of function occurred in response to localized hyperthermia for this volume of tissue at therapeutic temperatures. This study showed that the technique was feasible and confirmed that the parenchymal damage caused by interstitial hyperthermia did not produce the severe loss of function that might have been expected.

Alanine Transaminase↗
PubMed1987

Intraoperative interstitial hyperthermia in conjunction with intraoperative radiation therapy in a radiation-resistant carcinoma of the abdomen: report on the feasibility of a new technique.

The application of a new technique of intraoperative interstitial hyperthermia (IOHT) and intraoperative radiation therapy (IORT) was investigated for unresectable abdominal carcinoma. A 43-year-old white male presented with severe back pain due to metastatic adenocarcinoma in the left paravertebral area, producing erosion of the body of T12. The disease had not responded to external beam radiation therapy. The tumor was approached through a thoraco-abdominal incision and IOHT was delivered via interstitial electrodes. Temperature was monitored at 16 locations within the tumor. An LCF hyperthermia unit was utilized to deliver RF power and produced a treatment temperature of 43 degrees C for 60 minutes uniformly throughout the treatment volume. Immediately following hyperthermia treatment, the lesion was treated with 15 meV electrons via IORT to a tumor dose of 25Gy. The patient recovered without complication and had complete relief from pain. Posttreatment CT scans have demonstrated control of disease over a 5-month follow-up period. A clinical pilot study has been established to further investigate the application of this combination therapy.

Adenocarcinoma↗
PubMed1985

Canine normal and tumor tissue estimated blood flow during fractionated hyperthermia.

Time-temperature relationships are of critical importance in hyperthermia effects on tumors. Knowledge of temperature distributions within tumors is necessary to achieve maximal tumor response, and because blood flow is the major determinant of heat dissipation within tissue, knowledge of blood flow parameters is equally important. A mathematical model has been developed which estimates a parameter that may be related to regional tissue blood flow and is readily adaptable to clinical observations. Eight canine mast cell tumors were heated with interstitial radiofrequency (100 mHz) hyperthermia to a temperature range of 44 degrees C, +/- 0.5 degrees C, for 40 minutes. Estimated blood flow increased over the 40-minute treatment interval from 81 ml/min/100 gm of tissue at 10 minutes post-initiation of treatment to a maximum of 101.2 ml/min/100 gm of tissue at 30 minutes post-initiation of treatment. Over a 9-day period, during which both tumor and normal tissues were treated four times, values increased within the volume of interest. Maximum estimated blood flow within normal tissue increased from 115.7 ml/min/100 gm of tissue after 10 minutes of heating to a maximum of 121.7 ml/min/100 gm of tissue at 40 minutes. In contrast to normal tissue, eight canine mast cell sarcomas showed little change in estimated blood flow during 40 minutes of treatment. However, tumor tissue appears to undergo compensatory changes over the 9-day treatment interval with increases occurring in blood flow over that time period. These data underscore the importance of knowing blood flow characteristics within tumor and normal tissue.

Animals↗
PubMed1985

Hematoporphyrin derivative photochemotherapy of experimental bladder tumors.

Recent studies have shown that disruption of tumor blood flow is a major consequence of hematoporphyrin derivative photochemotherapy. A series of experiments was undertaken on the transplantable N-(4-(5-nitro-2-furyl)-2-thiazolyl)-formamide induced urothelial tumor in Fischer 344 rats to determine a dose response for both hematoporphyrin derivative and light. Tumor blood flow was used as the biologic criteria of response. Hematoporphyrin derivative doses of 10 micrograms./gm. body weight or above were necessary to cause a significant decrease in tumor blood flow when the tumors were illuminated with 360 joules/cm.2 of noncoherent red light (greater than 590 nm.). With a constant hematoporphyrin derivative dose of 20 micrograms./gm. body weight, significantly lower tumor blood flows were observed with fluences of 240 joules/cm.2 and above. In order to correlate dose response to tumor regression, experiments were done in which tumor dry weights were determined 3 weeks after completion of photochemotherapy (360 joules/cm.2). Hematoporphyrin derivative doses of 10 micrograms./gm. body weight or above were necessary to induce tumor regression. These studies support the hypothesis that disruption of tumor blood flow is a tumoricidal mechanism of hematoporphyrin derivative photochemotherapy.

Animals↗
PubMed1985

Effect of hyperthermia on the radiation response of Chinese hamster small intestine.

The Chinese hamster small intestine was surgically exteriorised from the ligament of Trietz to the ileocaecal junction and heated for 8 min at 44.3 degrees C (a non-lethal dose) at various intervals before or after whole-body 60Co irradiation. Hyperthermia exposure immediately after irradiation reduced the LD50/7 from the control of 1,230 cGy to 798 cGy (thermal enhancement ratio, TER, of 1.5). At an interval between irradiation and hyperthermia of 2 h the LD50/7 was 935 cGy, and it remained at that value for intervals of 2-24 h. The increase in the LD50/7 by 2 hours after irradiation probably represents the repair of radiation damage that can interact with hyperthermia, and after two hours the two modalities interact independently. When the small intestine was exposed to 44.3 degrees C hyperthermia immediately prior to irradiation, the LD50/7 was reduced to 658 cGy (TER = 1.8). As hyperthermia and radiation treatments were separated the LD50/7 returned to the control value by 24 h and was unchanged over 24-72 h. This indicates that by 24 h, recovery from hyperthermia damage that could interact with radiation damage was complete. For the sequence hyperthermia----radiation, 33% of the hyperthermia damage was repaired by 1 h; whereas for radiation----hyperthermia, 85% of the radiation damage was repaired by 1 h. The sequence-dependent interaction of hyperthermia and radiation damage in normal tissues is complex, but the kinetics of interaction for the sequence radiation----hyperthermia seem to be predictable for several normal tissues in different species.

Animals↗
PubMed1984

Effect of intestinal hyperthermia in the Chinese hamster.

If hyperthermia is to become a useful cancer therapeutic modality, normal tissue response must be thoroughly understood. The hyperthermia response of Chinese hamster intestine was studied by immersion of the exteriorized small intestine in heated tissue culture medium. After heating, the small intestine was reinserted, the incision closed, and animals observed until death. Animals exposed to 42.5 degrees, 43.5 degrees, or 44.5 degrees C intestinal hyperthermia exhibited LD50/7 values (including 95% intervals) of 56 min (52.9-59.3), 29 min (26.4-31.8), or 14 min (13.2-14.6), respectively. An Arrhenius plot of LD50/7 vs 1/T degree K exhibited an inactivation energy of 139 kcal/mole, which corresponds well with values generally reported for cellular inactivation. Hamster intestine conditioned with a sublethal exposure of 8 min at 44.5 degrees C developed thermotolerance to subsequent 44.5 degrees C hyperthermia. Thermotolerance induction was maximal by 24 hr; the LD50/7 for the second dose of hyperthermia increased from 6 min at 44.5 degrees C at zero time to 21 min at 44.5 degrees C after a treatment interval of 24 hr (thermotolerance ratio of 3.5). The LD50/7 subsequently decreased from 21 min to 12 min at 44.5 degrees C (the control value) by 96 hr. The hyperthermia response of this tissue was predicated by previous results from the Chinese hamster ovary (CHO) fibroblast cell line in tissue culture, and is also similar to several mouse normal tissues.

Animals↗
PubMed1984

The effect of lucanthone on sublethal radiation damage, in vivo.

The capacity of the Chinese hamster jejunal crypt cell to accumulate and repair sublethal radiation damage was determined by analyzing the return of the shoulder of the radiation dose-crypt microcolony survival curve (Dr) after a priming dose of 1250 rad. The control split dose crypt cell survival curve exhibited a D0, Dr and "n" of 179 +/- 3 rad, 261 +/- 3 rad and 4.3 respectively; repair of sublethal radiation damage was completed by two hours post-irradiation. The effect of lucanthone (an antischistosomal DNA intercalating agent) on the crypt cell's capacity to accumulate and repair sublethal radiation damage was determined by injecting the drug (100 mg/kg, i.p.) at intervals before irradiation with a priming dose of 1250 rad, followed two hours later by graded doses. Injection coincident with the priming dose of radiation resulted in a 22 rad reduction of the Dr (compared to control Dr). Injection eight hours before the priming dose almost completely inhibited the accumulation and repair of sublethal radiation damage so that the resultant Dr two hours later was only 29 rad (a 232 rad reduction). At no time was the D0 of the crypt cell survival curve affected by lucanthone. These data confirm previous results from whole crypt analysis and LD50/7 analysis that non-toxic concentrations of lucanthone reversibly inhibit the accumulation and repair of sublethal radiation damage in a time-dependent manner with complete inhibition approximately eight hours post-injection. This drug is useful for the study of sublethal radiation damage in vivo and may be beneficial in radiation therapy of cancer when it is desirable to inhibit the repair of sublethal radiation damage.

Animals↗
PubMed1984

Whole-body hyperthermia induction techniques.

Currently, there are three techniques used for delivery of whole-body hyperthermia. The simplest of these is direct contact between skin and some surrounding fluid. The surrounding fluid can be either water, wax, air, or other fluid medium; heat is transferred from the surrounding fluid to the body surface. Vessels in the skin surface transfer heat to the perfusing blood, which uniformly distributes it throughout the body. The second technique uses irradiation of the body surface with nonionizing radiation to deliver heat to the first few cm from the surface. This heat can be picked up by local blood perfusion and distributed throughout the body. One advantage of this method over direct contact methods is that heat is deposited throughout the first few cm and therefore temperature increases at the surface are lower. The third technique is extracorporeal perfusion which seems the most promising method for delivery of whole-body hyperthermia. This allows for greater control of central temperature via rapid change in temperature of blood passing through the external heat exchanger. The increased ability to control temperature resulting from this advanced instrumentation allows accurate delivery of whole-body hyperthermia. This permits comparison studies of therapeutic effectiveness.

Clothing↗
PubMed1983

Predictions of blood flow from thermal clearance during regional hyperthermia.

In order to provide a method for estimation of regional blood flow during hyperthermia, a mathematical model has been developed which employs thermal clearance to measure this physiologic parameter. Limbs of mongrel dogs were heated with 2450 megaHertz microwaves to temperatures of 43 degrees C, 45 degrees C, or 47 degrees C and thermal washout was measured at five minute intervals throughout each treatment period. Calculated blood flow indicates that in response to heat challenge, normal tissue compensates by increasing regional blood flow within the treatment volume. This increase in blood flow continues to a maximum value after which the blood flow begins to decrease. Data indicate that the time for maximum increase in blood flow (induction time) decreases as treatment temperature increases. These induction times were 40 minutes, 25 minutes, and 15 minutes for treatment temperatures of 43 degrees, 45 degrees, and 47 degrees C, respectively. The data also show that the calculated value of peak blood flow is directly related to treatment temperature. Calculated peak blood flow values reached 37.8, 59.0, and 183.0 ml/minute/100 grams of tissue during 43 degrees, 45 degrees, and 47 degrees C, hyperthermia, respectively. It is suggested that a therapeutic advantage could be gained by treating tumors for a specific length of time during which the blood flow in adjacent normal tissues continues to increase. This would take maximum advantage of normal tissue's ability to compensate for increased temperature, and would exploit any decreased ability of tumor tissue to perform this same function.

Animals↗
PubMed1979

The effect of lucanthone on the radiation response of intestinal stem cells in Chinese hamsters.

Crypt microcolony assay was used to determine the effect of lucanthone on the radiation response of intestinal stem cells in Chinese hamsters . The Dq of the crypt microcolony radiation--survival curve was maximally reduced by 205 rads when lucanthone injection preceded irradiation by 10 hours and was reduced by 140 rads when injection followed irradiation by 5 hours. On simultaneous injection and irradiation, Dq was reduced by only 20 rads; when injection and irradiation were separated by approximately 30 hours, Dq returned to the control value. Lucanthone never affected Do. Thus at non-toxic concentrations, lucanthone reversibly modifies cellular ability to accumulate and repair sublethal radiation damage without affecting radiation sensitivity.

Animals↗