Immunomodulatory effect of cimetidine on the proliferative responses of splenocytes from T. cruzi-infected rats.

The immunomodulatory effect of cimetidine (CIM), a histamine type-2 receptor antagonist, was evaluated in respect to the blastogenic response to Con A of Wistar Furth (WF) rats infected by the Y strain of Trypanosoma cruzi (T. cruzi). Enhancement of blastogenesis of normal splenocytes was observed at a concentration of 10(3) M. However, the splenocytes from infected animals responded to concentrations of CIM ranging from 10(-8) to 10(-3) M. The mitogenic response to Con A of cells from infected animals was restored in the presence of CIM. The results show that CIM modulates the "in vitro" proliferative response of cells from T. cruzi-infected rats and suggest an immunoregulatory role of histamine and/or of cells that express H2 receptors in this infection.     

Effect of retinoids on the induction of colon cancer in F344 rats by N-methyl-N-nitrosourea or by 1,2-dimethyihydrazine

The possible modifying effect of synthetic and natural retinoidson the incidence of colon cancer in rats induced by 2 intrarectaldoses of 2.5 mg of N-methyl-N-nitrosourea (MNU) given once aweek for 2 successive weeks or a single 150 mg/kg body weightdose of 1,2-dime-thylhydrazine (DMH), s.c. was investigated.Emphasis was on the effect of the development of early tumorsas visualized by endoscopy. With the retinoids N-ethyl-retinamide,N-2-hydroxyethylretinamide, N-(4-hydro- xyphenyl)-all-trans-retinamide(RAHA), and retinyl acetate (RA) administered orally after thecarcinogens, significant differences in early developing tumorswere not found. At histopathological examination of the tumorsthe RAHA + DMH group had significantly fewer adenomas per animal.The percentage of adenoma bearing rats was significantly lowerin groups receiving RAHA + DMH or RA + DMH. However, food consumptionwas lower in rats consuming either RAHA or RA. Retinyl palmitate(RP) and RAHA was administered intrarectally to MNU-inducedrats either before or after the carcinogen. When administeredbefore MNU, RP caused a significant increase in the percentageof tumor bearing animals and the average number of tumors peranimal as visualized endos copically. At histopathological examination,all retinoid groups except RAHA given after the carcinogen,produced significantly more adenomas per animal and a significantlygreater adenoma incidence than did the control groups. Thus,in two systems, the oral administration of retinoids did notclearly inhibit the early or later stages of colon tumor development.Inirarectal infusion of two retinoids had no effect on colonicmor phology but at histopathological examination of later stagetumors there was an enhanced adenoma response.     

Ureterointestinal anastomosis in ileal conduit in single kidney. New surgical technique

Introduction of a new approach for uretero-ileal implantation when only one kidney is available. The technique follows the same approach as the Wallace-type re-implantation but in this case the uretero-ileal anastomosis plate is formed with the far en 2-3 cm of ureter. All cases performed with this technique have been highly successfull as reported in this clinical account.     

Restoration of impaired T-cell proliferation after parathyroidectomy in hemodialysis patients

BACKGROUND/AIMS: Severe secondary hyperparathyroidism is not infrequent in hemodialysis patients and recent studies suggest that parathyroid hormone (PTH) may play a role in the genesis of cell immunity abnormalities in uremia. The aim of the present study is to describe the effect of parathyroidectomy on T- and B-cell functions in hemodialysis patients. METHODS: The study was performed on 6 patients with severe secondary hyperparathyroidism. iPTH, B, CD4(+), CD8(+), total number of lymphocytes, lymphoproliferative response to PHA, PWM and Candidin, and IgG, IgM, IL-2 production in vitro were determined 1 day before and 4 months after parathyroidectomy. RESULTS: The lymphoproliferative response to PHA increased significantly after parathyroidectomy. We also observed a trend to an increase in production of IgG and IgM after PWM stimulation before therapy. CONCLUSION: The present study suggests that patients with extremely high levels of PTH show a complete restoration of impaired T-cell proliferation after parathyroidectomy.     

Dose-Volume Histograms for bladder and rectum

: A careful examination of the foundation upon which the concept of the Dose-Volume Histogram (DVH) is built, and the implications of this set of parameters on the clinical application and interpretation of the DVH concept has not been conducted since the introduction of DVHs as a tool for the quantitative evaluation of treatment plans. The purpose of the work presented herein is to illustrate problems with current methods of implementing and interpreting DVHs when applied to hollow anatomic structures such as the bladder and rectum.

: A typical treatment plan for external beam irradiation of a patient with prostate cancer was chosen to provide a data set from which DVH curves for both the bladder and rectum were calculated. The two organs share the property of being shells with contents that are of no clinical importance. DVHs for both organs were computed using a solid model and using a shell model. Typical treatment plans for prostate cancer were used to generate DVH curves for both models. The Normal Tissue Complication Probability (NTCP) for these organs is discussed in this context.

: For an eight-field conformal treatment plan of the prostate, a bladder DVH curve generated using the shell model is higher than the corresponding curve generated using the solid model. The shell model also has a higher NTCP. A six-field conformal treatment plan slo results in a higher DVH curve for the shell model. A treatment plan consisting of bilateral 120-degree arcs, results in a higher DVH curve for the shell model, as well as a higher NTCP.

: The DVH concept currently used in evaluation of treatment plans is problematic because current practices of defining exactly what constitutes “bladder” and “rectum.” Commonly used methods of tracing the bladder and rectum imply use of a solid structure model for DVHs. In reality, these organs are shells and the critical structure associated with NTCP is obviously and indisputably the shell, as opposed to its contents. Treatment planning algorithms for DVH computation should thus be modified to utilize the shell model for these organs.     

Development of the multi-attribute Pediatric Asthma Health Outcome Measure (PAHOM).

OBJECTIVE: To develop a multi-attribute outcome measure for children with asthma that allows for the calculation of quality-adjusted life years in cost-effectiveness studies and can also be used to assign preference weights to asthma-symptom-free days. STUDY DESIGN: A literature review and two interviewer-administered surveys. SETTING: Homes or community centers of participants in Seattle, United States. MAIN MEASURE: Visual analog scale (VAS), standard gamble (SG), and relative risk attitude equation techniques were used to estimate two sets of preference weights for 10 health states. The PAHOM was used to record health states of pediatric asthma patients. RESULTS: A total of 94 subjects provided complete responses without any illogical ratings to VAS questions and 101 provided the same to SG questions. The VAS preference weights of the health states range from a maximum of 1 for perfect health to a minimum of 0.03 for severe asthma symptoms, emotional problems, and activity limitations. Those based on the relative risk attitude equation constructed with both VAS and SG preference weights range from 1 to 0.06. The mean PAHOM scores of pediatric asthma patients based on VAS and converted SG preference weights were 0.70 and 0.83, respectively. CONCLUSIONS: The PAHOM calendar can be used to identify asthma patients' health outcomes, to calculate the preference weights of asthma patients' health states, and to estimate the number of symptom-free days. These factors make the PAHOM a promising instrument for use in effectiveness and cost-effectiveness studies in children with asthma.