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Biomedical subjects

R Hoppe

Publications and source records attributed to R Hoppe.

At least 19 recordsLinked to original sources
PubMed1995

Treatment planning for Hodgkin's disease: a patterns of care study.

PURPOSE: To conduct a survey of the process of treatment planning for the radiation treatment of Hodgkin's Disease in the United States, and to compare survey results with consensus guidelines as determined by recognized experts. METHODS AND MATERIALS: A consensus committee developed guidelines for the radiotherapeutic management of Hodgkin's Disease. A series of survey forms were designed to evaluate the standards of practice and compare these with the consensus guidelines. A total of 61 facilities divided evenly into the strata of academic, hospital based, and free standing had eligible Hodgkin's Disease cases. There were 275 eligible cases of Hodgkin's Disease evaluated. Data collected from the radiation oncology records included treatment-specific parameters such as energy, dose, blocking, and calculations, as well as treatment planning practices. Statistical analysis was performed on each data element and for all institution strata. RESULTS: For a number of treatment parameters, there were some discrepancies note between the current United States practice and the consensus guidelines. Some significant differences were found in practice between the stratified institution types. A representative sample of results are: the majority of Hodgkin's Disease patients are treated with x-ray energies in the recommended range, between 4 and 10 MV. Standard mantle (for upper extended field treatment) and modified spade (for lower extended field treatments) are the fields of choice for all types of facilities. The consensus guidelines recommended that dose calculations at multiple points be obtained; however, 15% of patients in the survey received only a single point calculation. Current irregular field dosimetry calculation software does not take account of inhomogeneities. Thirty percent of Hodgkin's Disease patients do not receive a gap calculation for the abutment of upper and lower extended fields. In 70% of treatment fields, no compensation is used. Very few patients receive any kind of in vivo dosimetry check. CONCLUSION: The survey served to verify that, in general, Hodgkin's Disease treatment planning at all strata of institution has kept pace with recommended practice as delineated in current literature and texts. Small pockets of practice still need improvement in technique and equipment. Changes in practice were identified that can contribute to improved dose uniformity and accuracy.

Consensus Statements as Topic↗
PubMed1995

A non-ionic vesicle lipid enhances mastoparan-stimulated GTPase activity of heterotrimeric G-proteins.

Isolated heterotrimeric G-proteins exhibit full biological activity when reconstituted into liposomes. Here, we investigated the non-ionic surfactant macrogol-260-cetylstearylether (TA 6) as an efficient vehicle for the reconstitution of G-proteins. Reconstitution efficiency of G-proteins was recorded by GTP gamma S-binding. Their biological potency was measured as basal and mastoparan-stimulated GTPase-activity. G-proteins were fully active when associated with liposomes. On the other hand, G-proteins solubilized by TA 6 micelles or reconstituted into pure TA 6 vesicles exhibited impaired biological activity. However, vesicles containing different ratios of azolectin and non-ionic TA 6 showed about 50% higher reconstitution efficiency as compared to pure liposomes. In addition, basal and mastoparan-stimulated GTPase-activity in vesicles containing an axolectin/TA 6 ratio of 3:1 were 2.7 and 9.1 fold higher than in pure liposomes, respectively. These data emphasize that the composition of the lipid membranous environment significantly influences G-protein activity.

Animals↗
PubMed1995

Treatment of rat arthritides with clodronate-containing liposomes.

Large multilamellar liposomes containing dichloro-methylene-bisphosphonate (clodronate; Clo), a bisphosphonate that becomes toxic when intracellularly concentrated, were used to therapeutically target macrophages (M phi) in rats with established adjuvant arthritis (AA; i.v. on days 10,11,12) or antigen-induced arthritis (AIA; i.v. or i.a. on 3 h, days 1,2). In established AA, i.v. injection of Clo-liposomes led to significant, long-lasting amelioration of clinical parameters, and to reduced destruction of the ankle joint even several weeks after termination of treatment. In the acute phase of established AIA, intravenous treatment induced transient clinical amelioration, but did not counteract joint destruction. I.a. treatment in AIA was ineffective. Systemic treatment with anti-M phi principles induces amelioration of both AA and AIA; the improvement appears more profound in AA, i.e., the model with a more systemic character. Preliminary data indicate that depletion of M phi occurs in the liver rather than in spleen, draining lymph nodes or synovial membrane. In addition, local treatment with the same principle is ineffective in AIA. Therefore, systemic elimination of M phi in different sites may be crucial for effective therapy of arthritis with anti-M phi agents.

Animals↗
PubMed1991

Observations on the effect of chimeric anti-CD4 monoclonal antibody in patients with mycosis fungoides.

Chimeric (murine/human) anti-CD4 monoclonal antibody was infused into seven patients with mycosis fungoides. Successive patients received doses of 10, 20, 40, and 80 mg of antibody twice a week for 3 consecutive weeks. All patients had some clinical improvement, but responses were of relatively short duration. Serum levels of chimeric antibody varied as a function of dose. At the 80-mg dose level, antibody was readily observed in biopsied skin lesions. Although there was coating by antibody of most CD4 positive cells in the blood, there was no significant depletion of CD4 positive cells. Low-level antibody responses against the mouse Ig variable region and human Ig allotypic constant region determinants were observed in several patients, but none were of clinical significance. All but two patients made primary antibody and T-cell proliferative responses to a simultaneously administered foreign protein test antigen. However, there was marked suppression of the mixed lymphocyte reaction. We conclude that at the dose levels studied, a chimeric anti-CD4 monoclonal antibody (1) had some clinical efficacy against mycosis fungoides; (2) was well tolerated; (3) had a low level of immunogenicity; (4) had immediate immunosuppressive effects; and (5) did not induce tolerance to a co-injected antigen.

Adult↗
PubMed1989

The effect of controlled reperfusion in porcine hearts submitted to three hours of cold global ischemia.

At present, many investigations of myocardial function following ischemic insults concentrate on the modalities of reperfusion rather than on the mode of preservation. In this study, we tried to define the effect of reperfusion using warm blood cardioplegia (WBC) after medium-term (3 h) cold global ischemia, as required in cardiac transplantation. Twenty-one porcine hearts were harvested after preservation with cold cardioplegia (St. Thomas Hospital solution) and topical cooling. Normothermic reperfusion with blood was initiated after 3 h of ischemia utilizing a special extracorporeal pump circuit. Twelve hearts served as controls (group A), while substrate-enriched WBC was applied during the initial 20 min of reperfusion in nine hearts (group B). Hearts in both groups were then studied for myocardial function and metabolism under both working and nonworking conditions for a maximum of 180 min. In the nonworking mode, left ventricular dp/dt was significantly higher in group B than in group A at 15 min (2201 +/- 785 mm Hg/sec vs 1515 +/- 732 mm Hg/sec) and at 180 min (1730 +/- 471 mm Hg/sec vs 836 +/- 147 mm Hg/sec; P less than 0.05). After 3 h, lactate production was significantly higher in group A (371 +/- 45 mg/dl) than in group B (108 +/- 44 mg/dl; P less than 0.05). Creatine kinase release into the coronary sinus was also significantly elevated in group A at 15 min (2807 +/- 1478 IU/l vs 1148 +/- 1272 IU/l; P less than 0.05). Similarly, the hemodynamic data obtained under working conditions in group B were superior to those in group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Outcome of the acute glomerular injury in proliferative lupus nephritis.

Treatment with total lymphoid irradiation (TLI) and corticosteroids markedly reduced activity of systemic lupus erythematosis in 10 patients with diffuse proliferative lupus nephritis (DPLN) complicated by a nephrotic syndrome. Physiologic and morphometric techniques were used serially before, and 12 and 36 mo post-TLI to characterize the course of glomerular injury. Judged by a progressive reduction in the density of glomerular cells and immune deposits, glomerular inflammation subsided. A sustained reduction in the fractional clearance of albumin, IgG and uncharged dextrans of radius greater than 50 A, pointed to a parallel improvement in glomerular barrier size-selectivity. Corresponding changes in GFR were modest, however. A trend towards higher GFR at 12 mo was associated with a marked increase in the fraction of glomerular tuft area occupied by patent capillary loops as inflammatory changes receded. A late trend toward declining GFR beyond 12 mo was associated with progressive glomerulosclerosis, which affected 57% of all glomeruli globally by 36 mo post-TLI. Judged by a parallel increase in volume by 59%, remaining, patent glomeruli had undergone a process of adaptive enlargement. We propose that an increasing fraction of glomeruli continues to undergo progressive sclerosis after DPLN has become quiescent, and that the prevailing GFR depends on the extent to which hypertrophied remnant glomeruli can compensate for the ensuing loss of filtration surface area.

Acute Disease↗
PubMed1989

Characterization of splenic structure in Hodgkin disease by using narrow-band filtration of backscattered ultrasound.

A preliminary study was performed to evaluate the effectiveness of narrow-band filtration of backscattered ultrasound for the detection of splenic involvement in patients with Hodgkin disease. Regions of interest were identified in the spleens of 14 normal volunteers and eight Hodgkin disease patients before staging laparotomy. An analysis of the narrow-band-filtered waveforms showed that the mean amplitudes of the filtered ultrasonic signals received correlated with the presence of extensive splenic involvement with Hodgkin disease (defined as more than four grossly visible nodules on cut section) (p = .0004). Conversely, mean amplitudes of unfiltered ultrasonic backscatter, employed in conventional sonographic imaging, did not correlate with splenic involvement (p = .5). Phantom studies were performed to develop a tissue model for the observed phenomena; images of the phantoms and of the involved and uninvolved spleens were made by using techniques involving narrow-band filtration of backscattered ultrasound. Our results indicate that narrow-band-filtered sonography holds promise for detecting lymphomatous involvement of the spleen, although larger studies, with equipment allowing real-time implementation of narrow-band filtering, are needed.

Acoustics↗
PubMed1987

Suppression of anti-mouse immunoglobulin antibodies in subhuman primates receiving murine monoclonal antibodies against T cell antigens.

Murine monoclonal antibodies stimulate the production of human anti-mouse immunoglobulin antibodies (AMIA) when administered to patients. This limits their long-term usefulness as therapeutic and diagnostic agents. We report the use of three maneuvers to suppress AMIA against T cell-specific monoclonal antibodies in cynomolgus monkeys. Twelve monkeys received daily i.v. infusions of 1 mg each of anti-Leu-2a, -3a, and -5 on days 1 through 10. One group (control) received no suppressive regimen. The second group received cyclosporine, 12.5 mg/kg daily on days -7 to +14. The third group (PI) were passively immunized with 0.4 ml of hyperimmune monkey AMIA serum on days -7, -1, 2, 4, 6, and 8. The fourth group (TLI) received 1700 rad fractionated total lymphoid irradiation ending on day -1. The animals treated with TLI were markedly delayed in the onset of AMIA, which was suppressed to less than 1% of the control group. The AMIA specific for the constant region of animals receiving PI was also suppressed to one-third of control. The majority of the AMIA in all the animals was anti-idiotypic and wholly anti-idiotypic in the TLI animals.

Animals↗
PubMed1986

The smoking problem.

Explore the source record for details and available documents.

Developing Countries↗
PubMed1985

A profile of the self-poisoner in Michigan.

We reviewed the charts of all patients (160) ages 15 and older discharged in 1981 from the four hospitals in Lansing, Michigan with a diagnosis of overdose. Females predominated (65 per cent) and the median age was 27 years. The most common reason for intentional self-poisoning was "significant-other" conflict (54.5 per cent), followed by family conflict and financial problems. Benzodiazepines were most commonly used followed by acetylsalicylic acid and ethanol.

Adolescent↗
PubMed1981

[Sociomedical aspects of cancer of the uterine cervix (author's transl)].

Statistics on long-term results in the treatment of cancer of the cervix are usually based on clinical data, so that they are not sufficiently randomized. The author attempted to follow up the subsequent fate of patients with cancer of the cervix who had been granted a disability pension from the sickness insurance fund of the workers' compensation board in North-Rhine Westphalia effective 1969/1970. In view of the fact that after a lapse of 8 to 9 years it is no longer possible to obtain medical data as completely as would be desirable, the inquiry was limited to finding out the amount paid out every month, the old-age pension, and the year of death. 30.5% of the 583 pensioners had died, whereas 30.5% were still recipients of disability pension because of this disease, and 17.0% had in the meantime become old-age pensioners (2.6% cancellations of pension payments and 19.4% pensions for a limited period). Of the 178 deceased, 76.5% died already within the first 3 years after having been granted the pension; thereafter, the annual death rates decreased continually by 6.5% to 2.8%. Attention is drawn to the advantages offered by a pension for a limited time with the possibility of getting it extended. The results of this study are supplemented by statistics on mortality, ability to work and amount of pension granted, as well as references from literature on the incidence and long-term results in carcinoma of the cervix.

Adult↗
PubMed1981

Survival of primates following orthotopic cardiac transplantation treated with total lymphoid irradiation and chemical immune suppression.

Fractionated total lymphoid irradiation (TLI) has been used for attempts at induction of a donor-specific tolerant-like state in allograft recipients and for immunosuppressive effects. Cyclosporin A (Cy A) has been shown to suppress rejection of organ grafts in many species including man. The present study was designed to test the effectiveness of TLI in combination with either CY A or rabbit anticynomolgus thymocyte globulin (ATG) and azathioprine. Thirty-one orthotopic cardiac allografts were performed using surface cooling and total circulatory arrest in outbred cynomolgus monkeys. TLI was administered preoperatively in fractions of 100 rad until a total of 600 or 1800 rad was achieved. Cy A was administered 17 mg/kg/day. All treatment groups demonstrated extended survival. Myocardial biopsies as early as 4 weeks were consistent with mild rejection in all treatment groups. No significant synergistic effect upon survival could be demonstrated utilizing TLI plus Cy A when compared with using Cy A alone. TLI (1800 rad) plus ATG and azathioprine was associated with a high incidence of early death attributable to leukopenia and infection. Cy A alone or in combination with TLI was associated with the development of lymphoid malignancy.

Animals↗
PubMed1980

[Social medicine and chronic liver disease (author's transl)].

Reports of 1,033 insured person in file of the Landesversicherungsanstalt Rheinprovinz, a public insurance agency, were evaluated; these individuals had started receiving annuities because of liver disease in the years 1969 and 1970. On evaluation 7-8 years later the following was found: annuities still running 21,3%, stop of annuities 1,3%, time limited annuities 3,5%, change to retirement annuities 34,8%, death 39,1%.

Female↗