Search PubMed⌕ Search

Biomedical subjects

M Hunt

Publications and source records attributed to M Hunt.

At least 91 records · Page 5Linked to original sources
PubMed1991

[D-Pen2,4'-125I-Phe4,D-Pen5]enkephalin: a selective high affinity radioligand for delta opioid receptors with exceptional specific activity.

[D-Pen2,4'-125I-Phe4,D-Pen5]enkephalin ([125I]DPDPE) is a highly selective radioligand for the delta opioid receptor with a specific activity (2200 Ci/mmol) that is over 50-fold greater than that of tritium-labeled DPDPE analogs. [125I]DPDPE binds to a single site in rat brain membranes with an equilibrium dissociation constant (Kd) value of 421 +/- 67 pM and a receptor density (Bmax) value of 36.4 +/- 2.7 fmol/mg protein. The high affinity of this site for delta opioid receptor ligands and its low affinity for mu or kappa receptor-selective ligands are consistent with its being a delta opioid receptor. The distribution of these sites in rat brain, observed by receptor autoradiography, is also consistent with that of delta opioid receptors. Association and dissociation binding kinetics of 1.0 nM [125I] DPDPE are monophasic at 25 degrees C. The association rate (k + 1 = 5.80 +/- 0.88 X 10(7) M-1 min-1) is about 20- and 7-fold greater than that measured for 1.0 nM [3H DPDPE and 0.8 nM [3H] [D-Pen2,4'-Cl-Phe4, D-Pen5]enkephalin, respectively. The dissociation rate of [125I]DPDPE (0.917 +/- 0.117 X 10(-2) min-1) measured at 1.0 nM is about 3-fold faster than is observed for either of the other DPDPE analogs. The rapid binding kinetics of [125I]DPDPE is advantageous because binding equilibrium is achieved with much shorter incubation times than are required for other cyclic enkephalin analogs. This, in addition to its much higher specific activity, makes [125I]DPDPE a valuable new radioligand for studies of delta opioid receptors.

Animals↗
PubMed1990

Esorubicin (deoxydoxorubicin) has low grade activity in malignant melanoma. Results of an Eastern Cooperative Oncology Group study (EST 2685).

In this phase II trial, twenty patients with advanced, measurable melanoma from ECOG institutions were treated with esorubicin 30 mg/m2 iv every three weeks. Doses were escalated or reduced based on nadir counts. The dose limiting toxicity was leukopenia with no significant thrombocytopenia or anemia. Other toxicities were mild. One patient had skin necrosis with extravasation. Two patients with soft tissue disease had partial remissions and were treated with 9 and 17 courses. One patient was stable for 8 courses. No cardiac toxicity was seen in three patients receiving more than 150 mg/m2. The response rate was 10% (90% CI = 2 to 30%). Low level activity was seen, but it is unlikely that this drug has sufficient activity to warrant further development in melanoma.

Adult↗
PubMed1990

Furosemide-induced disturbances of renal function in patients undergoing TURP.

Furosemide remains the drug of choice for patients with the transurethral resection syndrome. Furosemide is often used intraoperatively to treat patients suspected of having excessive irrigant absorption. To examine the efficacy of such therapy, a randomized study was performed in which furosemide was administered to patients undergoing routine transurethral resection of the prostate (TURP) to determine the effect of furosemide on electrolyte and fluid volume conservation in these patients. Seven patients treated with furosemide on completion of TURP had a statistically significant delayed drop in serum sodium values after normal initial values (139 mEq/L to 134 mEq/L). Seven untreated control patients did not have a similar drop in sodium values, and the difference between groups was significant. We suggest that furosemide be used with caution in patients undergoing routine TURP, and when given it should be accompanied by the infusion of an isotonic balanced salt solution.

Aged↗
PubMed1990

Evidence for the presence of angiotensin II-type 1 receptors in brain.

Angiotensin II receptor subtypes have been localized in brain by using a novel nonpeptide AII-type 1 receptor antagonist to compete with [125I]AII binding in an autoradiographic study. These data contrast with results obtained using the AII-type 2 antagonist PD123177. Both receptor subtypes appear to exist in the brain, but the type 1 receptor predominates in the small regions of brain where AII binding is highly concentrated. DUP 753 may have a central action involved in its unique antihypertensive effect.

Angiotensin II↗
PubMed1990

Hepatic venoocclusive disease in autologous bone marrow transplantation of solid tumors and lymphomas.

Retrospective review of 291 solid tumor and lymphoma patients undergoing autologous bone marrow transplantation (BMT) was performed to determine the influence of pretransplant characteristics and preparative regimen to the development of hepatic venoocclusive disease (VOD). Twelve patients (4.1%) developed a clinical syndrome of right upper quadrant (RUQ) tenderness or hepatomegaly, jaundice, and ascites, with or without encephalopathy, within 40 days of marrow reinfusion. Evidence of metastatic liver disease was the only pretransplant characteristic predictive for VOD (P = .0002). Sex, age, histology, hepatitis B serology, and elevated liver function tests were not predictive. No individual preparative agent had a significant effect on the development of VOD. However, a single 2-hour infusion of carmustine (BCNU) (greater than or equal to 450 mg/m2) led to an increased incidence of VOD when compared with the same dose administered in a fractionated schedule (P = .0258) when given with two other chemotherapeutic agents. Seven of eight autopsy specimens confirmed the clinical diagnosis of VOD. The four patients in whom clinical VOD resolved had lower median peak bilirubins (7.3 v 15.9 mg/dL), lower median peak creatinines (2.1 v 4.1 mg/dL), and relatively quick engraftment of neutrophils (mean, 18.7 days). One of the four patients in whom VOD resolved had other grade 4 (life-threatening) toxicities in contrast to eight of eight who succumbed. In summary, VOD is an uncommon complication in autotransplantation of solid tumors and lymphomas. Our data suggest caution in selecting patients with known metastatic liver disease and consideration of a fractionated BCNU schedule especially in combination with other alkylating agents.

Adult↗
PubMed1990

A phase I-II study of cyclophosphamide, thiotepa, and carboplatin with autologous bone marrow transplantation in solid tumor patients.

The principles of dose-response and combination chemotherapy were basic to the design of the initial curative standard-dose treatment regimens for leukemias, lymphomas, and testis cancer. Agents were selected with different dose-limiting toxicities, resulting in subadditive toxicity in combination. A fourth principle in the design of curative regimens was to combine agents with different mechanisms of action to avoid cross-resistance. Based on these principles, combinations of the highest tolerated doses of active noncross-resistant agents are required to decrease the emergence of drug resistance and achieve optimum cytotoxicity. Hematopoietic stem-cell support provides a mechanism for significantly increasing the doses of active agents, a strategy that has resulted in the cure of 10% to 50% of selected patients with lymphoma who could not be cured with standard-dose therapy. The lack of sufficiently effective cytoreductive conditioning regimens remains the major impediment to improving the high-dose therapy of patients with solid tumors. In this study, 27 patients with solid tumors were treated with a combination of cyclophosphamide, thiotepa, and carboplatin (CTCb) in a phase I-II study. Severe mucositis and neurotoxicity were dose-limiting. The maximum-tolerated dose (MTD) of the combination was 6.0 g/m2 of cyclophosphamide, 500 mg/m2 of thiotepa, and 800 mg/m2 of carboplatin. There were two deaths (7%) of sepsis, and an overall response rate of 72% in refractory tumors (81% in breast cancer). CTCb is a combination with low morbidity and high cytoreductive efficacy designed to exploit the principles of curative cancer chemotherapy.

Adult↗
PubMed1990

Familial Wolf-Hirschhorn syndrome associated with Rieger anomaly of the eye.

The authors report the case of a male infant who presented with growth retardation and multiple congenital anomalies including bilateral cleft lip and palate, large glabella and broad nasal bridge. Eye examination revealed Rieger anomaly, nasolacrimal duct obstruction and mild microphthalmia bilaterally. In addition, shawl scrotum, nail hypoplasia and linear skin hypoplasia of the lower extremities were noted. Two G-banded chromosome studies were normal; prophase analysis showed 4p monosomy and 10q trisomy derived from a paternal balanced translocation. The clinical recognition of Wolf-Hirschhorn syndrome in this child, despite the two normal chromosome studies, allowed for the recognition of the cytogenetic aberration and identification of other family members who carry the balanced translocation.

Abnormalities, Multiple↗
PubMed1989

Neoadjuvant chemotherapy in marginally resectable stage III M0 non-small cell lung cancer: long-term follow-up in 41 patients.

Forty-one patients with marginally resectable stage III M0 non-small cell lung cancer (NSCLC) were entered into a study evaluating neoadjuvant cyclophosphamide, adriamycin, and cisplatin chemotherapy (CAP) followed by radiotherapy and subsequent resection. Postoperative radiotherapy and additional CAP were also administered. The objective disease regression rate prior to surgery was 72% (2 complete, 12 partial, and 7 minimal responses). Thoracotomy was carried out in 37 patients (90%), with resection of all gross disease in 36 patients (97%). Relapse occurred in 22 (61%) of the resected patients, involving chest only (four patients), chest and extra thoracic (nine patients), and extra thoracic only (nine patients). Subsequent CNS relapse developed in 9 (25%) of 36 postop patients in association with other sites of relapse (five patients) or as a solitary location (four patients). Only one of seven patients receiving prophylactic cranial irradiation (PCI) developed CNS relapse compared with 7 (26%) of 27 patients not receiving PCI. The median long-term follow-up for 14 living patients is 53+ months, with a rang of 38+ to 71+ months. Median survival for all patients is 32 months, with 1-year survival being 75%. The survival curve shows a plateau of 31% from 3 to 5+ years. Using a log rank test, no prognostic subgroups could be identified that significantly affected response rate, disease-free survival, or overall survival. While neoadjuvant CAP followed by radiotherapy appears to improve survival, more effective chemotherapy along with randomized studies are needed to determine the role of initial chemotherapy in marginally resectable NSCLC.

Adult↗
PubMed1988

Myocardial risk area and peak gray level measurement by contrast echocardiography: effect of microbubble size and concentration, injection rate, and coronary vasodilation.

Contrast agents were injected via the intracoronary route in eight dogs during two-dimensional echocardiographic imaging to determine the influence of microbubble size and concentration, injection rate, and coronary vasodilation on risk area and peak gray level measurement. At an injection rate at 13 cc/sec, the average background-subtracted peak gray level intensity of hand-agitated diatrizoate meglumine/diatrizoate sodium was significantly (p less than 0.01) higher than that of hand-agitated diatrizoate meglumine/diatrizoate sodium + 0.9% saline, sonicated diatrizoate meglumine/diatrizoate sodium, and sonicated 70% sorbitol. These differences were abolished by the use of 38 cc/sec injection rates and intracoronary injection of adenosine. Perfusion area determinations as assessed by planimetry were unaffected by the contrast agent used, the injection rate, or by intracoronary administration of adenosine. We conclude that risk area measurement by the ultrasound contrast technique is not affected by varying contrast agents, injection rates, or vasodilation. However, peak gray level intensity is variable among contrast agents and may result in variability of time-activity curve analysis.

Animals↗
PubMed1988

Applicator for optimum cobalt-60 primary breast treatments.

A breast applicator has been designed to optimize 3 field breast treatments for 60Co. The device has a six half value layer beam splitting block constructed in two sections. The larger permanently mounted section is sufficient for treating 90% of the patients. Slots are available for mounting cerroband blocks, and any of five brass half field wedges. A magnetically attached front and back-pointer assembly readily breaks away in the event of a collision between pointer and patient. With this design the breast applicator with wedges and blocks has in-field surface doses reduced to that of an open field without accessory devices. The 50-90% dose decrement of the radiation penumbra for the half field block is comparable to that for the field edge of a typical 6 MV X ray unit, although the 50-10% decrement is larger. The average out-of-field dose at the surface is 8% and is 5% at the depth of dose maximum. The combination for this applicator of sharp penumbra and low out-of-field dose leads to reduced lung and opposite breast doses. The latter was confirmed with TLD measurements on 10 patients, and yielded an average opposite breast dose of 230 cGy for a 4600 cGy prescription. Thus, half-field blocking devices do not preclude, as has been stated in the literature, acceptable opposite breast doses. In addition, proper design of these devices can significantly improve the radiation characteristics for primary breast treatments.

Breast Neoplasms↗
PubMed1988

Failure patterns and survival in pediatric soft tissue sarcoma.

We retrospectively analyzed 44 patients with localized soft tissue sarcomas who were seen and treated at the JCRT, DFCI, and TCH between 1970-1984. Patients with rhabdomyosarcoma were excluded. Primary tumors were located in the following sites: extremities 19 (43%), head and neck 9 (20%), and trunk 16 (37%). Median follow-up for survivors was 7.7 years (range 24 mo-16 years). Surgery was the initial aspect of treatment for all patients. All patients also received post-operative irradiation, 43 at presentation and one at local relapse, and 26 received adjuvant chemotherapy. Radiation was delivered to a dose of 4000 cGy (median) followed by a boost to a median dose of 5760 cGy (range 4500-7000 cGy). Actuarial 5- and 10-year disease-free survivals (DFS) were 70% and 59% while the actuarial 5- and 10-year overall survivals (OS) were both 75%. All parameters were assessed for significance by univariate analysis. OS was significantly affected by presenting stage when analyzed according to both the Intergroup Rhabdomyosarcoma Staging System (IRS) and the American Joint Committee on Cancer system (AJCC). For the IRS, OS at 10 years was 100% for Stage I, 72% for Stage II, and 54% for Stage III (p = 0.04). For the AJCC, OS at 10 years was 100% for Stage I and 65% for Stage II and III (p = 0.05). Primary site, histology, and use of adjuvant chemotherapy did not influence OS or DFS. Fourteen patients failed: 8 local, 1 distant, and 5 combined local and distant. There was no LF among the 9 pts. with primary lesions less than 5 cm compared to 11/29 (39%) whose tumor was greater than 5 cm (p = 0.04). Pts. with gross residual disease had a local DFS of 42%, but those with no residual or microscopic residual had a local DFS of 71% (p = 0.02). In conclusion, childhood STS has an excellent OS (75% at 10 years). Tumor size and residual tumor after surgery strongly predicted for local failure. Of interest, the pattern of failure is predominantly local in our series. This suggests that more aggressive local treatment is indicated in management of children with STS. Higher doses of irradiation as used for adult STS are probably indicated for patients with gross residual disease.

Adolescent↗
PubMed1988

A composite hip implant.

Composites are made of two or more different components that combine their properties into a new material. By modifying the type or structure or volume of the components, a theoretically endless number of new materials can be produced and their properties can be altered as desired. A composite hip implant made of carbon fiber and polysulfone is described.

Animals↗
PubMed1987

Delineation of the extent of coronary atherosclerosis by high-frequency epicardial echocardiography.

Postmortem studies suggest that coronary angiography does not always accurately delineate the extent of coronary-artery disease. We examined this problem in living human hearts by performing high-frequency epicardial echocardiography at the time of cardiac surgery. The ratio of the diameter of the lumen of the coronary artery to the thickness of its wall was used to quantify the severity of coronary lesions. In 11 patients with no angiographic evidence of coronary disease anywhere in the coronary tree, the mean (+/- SEM) ratio was 5.9 +/- 0.3. In 21 patients with angiographic disease at the site evaluated by echocardiography, the mean ratio was lower (2.3 +/- 0.2, P less than 0.05), reflecting encroachment into the arterial lumen by atherosclerotic plaque. In 15 patients with arterial segments that were angiographically normal but with arterial stenoses elsewhere in the coronary tree, the mean ratio was 4.1 +/- 0.3, with marked overlap with the values in the patients who had angiographic disease at the site of the echocardiographic evaluation. These results demonstrate, in living human hearts, that diffuse coronary atherosclerosis is often present when coronary angiography reveals only discrete stenoses. This finding suggests that coronary angiography may underestimate the severity and extent of coronary disease.

Adult↗
PubMed1987

Indium-111 platelet scintigraphy and two-dimensional echocardiography for detection of left ventricular thrombus: influence of clot size and age.

Two-dimensional echocardiography and indium-111 platelet scintigraphy were performed on 50 dogs to determine the influence of clot age and size on the detection of experimentally induced left ventricular mural thrombus. Thrombus was induced by apical infarction and injection of a sclerosing agent and thrombin. The animals were classified into four groups according to the time of indium-111 platelet injection after thrombus induction: Group I (17 dogs, 1/2 hour after induction; 3 dogs, before induction), Group II (12 dogs, 24 hours after induction) and Group III (12 dogs, 1 week after induction). In Group IV (six control dogs) apical infarction was produced, but thrombin was not injected; indium-111 platelets were injected 1/2 to 1 hour after infarction. The dogs were studied by indium-111 platelet scintigraphy and by two-dimensional echocardiography 1/2 to 5 hours (Group I) and 1 to 5 and up to 72 hours (Groups II to IV) after platelet administration and before death was induced. Two-dimensional echocardiography showed the best overall sensitivity for detection of acute thrombus (97%; 29 of 30). The sensitivity of indium-111 platelet scintigraphy was 86% (18 of 21) for clots greater than or equal to 0.08 ml in size, and 67% (20 of 30) for detection of all clots. Thrombus did not form in 14 dogs of Groups I to III and in 6 of 6 control dogs. The specificity of scintigraphy was 100% (20 of 20) compared with 80% (16 of 20) for echocardiography. Echocardiography was more sensitive than scintigraphy for detecting very small clots in this experimental model.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1987

The process of translating research findings into nursing practice.

Action research studies are described which involved nurse teachers, ward sisters and nurse managers in the processes of: nursing practice problem identification and the search for relevant research literature; the evaluation and synthesis of the collected literature; the identification of the need to change practice and the translation of the research synthesis into practice if warranted. The processes engaged in by the groups in each of the three phases in relation to the management of mouth care and preoperative fasting are analysed. The findings suggest that the demands of these processes are beyond the capacity of any one individual nurse and require systematic organizational approaches such as that proposed by quality assurance programmes. The need is emphasized for as much status and resources to be expended on the utilization of existing information as is given to the generation of new knowledge.

Education, Nursing↗