Correlation between adrenal function, growth hormone secretion, and insulin sensitivity in children with idiopathic growth hormone deficiency.

PURPOSE: Patients with growth hormone deficiency (GHD) demonstrate an increased cortisol/cortisone ratio which could potentially explain the metabolic features of GHD, while GH treatment (GHT) could increase the cortisol metabolism. METHODS: In 35 children (27 M, mean age 10.1 years) with idiopathic GHD at baseline and after 12 months of GHT and in 25 controls, in addition to metabolic parameters, we assessed adrenal function by morning serum cortisol, its peak, and its area under the curve (AUCCOR) during insulin tolerance test (ITT). RESULTS: A cortisol peak <18 µg/dl was shown in 22 and 31% of GHD children at baseline and after GHT, respectively. At baseline, GHD children had lower fasting glucose (p < 0.001) and ISI-Matsuda (p = 0.042), with concomitant higher Homa-IR (p = 0.006) and morning cortisol (p = 0.012) than controls. Morning cortisol was negatively correlated with GH (p < 0.001), fasting glucose (p < 0.001) and ISI-Matsuda (p < 0.001) and positively with Homa-IR (p = 0.010). Both cortisol peak and AUCCOR were negatively correlated with GH (all p < 0.001) and ISI-Matsuda (p = 0.016 and p = 0.001, respectively). After 12 months of GHT, a significant increase in fasting glucose (p < 0.001), and Homa-IR (p = 0.011) was documented, with a concomitant decrease in morning cortisol (p = 0.002), AUCCOR (p = 0.038), total (p = 0.003) and LDL-cholesterol (p = 0.016). No significant correlations were found among cortisol levels and all parameters were investigated. CONCLUSIONS: Cortisol levels correlate with GH secretion and with many metabolic parameters in GHD children, while the metabolic effects during GHT are mainly due to GHT per se and less to cortisol reduction.

Radiosensitisation by olaparib through focused ultrasound delivery in a diffuse midline glioma model.

BACKGROUND AND PURPOSE: Diffuse midline glioma H3K27-altered (DMG) is an aggressive, inoperable, predominantly paediatric brain tumour. Treatment strategies are limited, resulting in a median survival of only 11 months. Currently, radiotherapy (RT), often combined with temozolomide, is considered the standard of care but remains palliative, highlighting the urgency for new therapies. Radiosensitisation by olaparib, an inhibitor of PARP1 and subsequently PAR-synthesis, is a promising treatment option. We assessed whether PARP1 inhibition enhances radiosensitivity in vitro and in vivo following focused ultrasound mediated blood-brain barrier opening (FUS-BBBO). METHODS: Effects of PARP1 inhibition were evaluated in vitro using viability, clonogenic, and neurosphere assays. In vivo olaparib extravasation and pharmacokinetic profiling following FUS-BBBO was measured by LC-MS/MS. Survival benefit of FUS-BBBO combined with olaparib and RT was assessed using a patient-derived xenograft (PDX) DMG mouse model. RESULTS: Treatment with olaparib in combination with radiation delayed tumour cell proliferation in vitro through the reduction of PAR. Prolonged exposure of low olaparib concentration was more efficient in delaying cell growth than short exposure of high concentration. FUS-BBBO increased olaparib bioavailability in the pons by 5.36-fold without observable adverse effects. A Cmax of 54.09 µM in blood and 1.39 µM in the pontine region was achieved following administration of 100 mg/kg olaparib. Although RT combined with FUS-BBBO mediated olaparib extravasation delayed local tumour growth, survival benefits were not observed in an in vivo DMG PDX model. CONCLUSIONS: Olaparib effectively radiosensitises DMG cells in vitro and reduces primary tumour growth in vivo when combined with RT. Further studies are needed to investigate the therapeutic benefit of olaparib in suitable preclinical PDX models.

Photo-cross-linked poly(ethylene carbonate) elastomers: synthesis, in vivo degradation, and determination of in vivo degradation mechanism.

Low-molecular-weight poly(ethylene carbonate) diols of varying molecular weight were generated through catalyzed thermal degradation of high-molecular-weight poly(ethylene carbonate). These polymers were then end functionalized with acrylate groups. The resulting α,ω-diacrylates were effectively photo-cross-linked upon exposure to long-wave UV light in the presence of a photoinitiator to yield rubbery networks of low sol content. The degree of cross-linking effectively controlled the in vivo degradation rate of the networks by adherent macrophages; higher cross-link densities yielded slower degradation rates. The cross-link density did not affect the number of adherent macrophages at the elastomer/tissue interface, indicating that cross-linking affected the susceptibility of the elastomer to degradative species released by the macrophages. The reactive species likely responsible for in vivo degradation appears to be superoxide anion, as the in vivo results were in agreement with in vitro degradation via superoxide anion, while cholesterol esterase, known to degrade similar poly(alkylene carbonate)s, had no affect on elastomer degradation.

Hypereosinophilic syndrome with characteristic left ventricular thrombus demonstrated by contrast echocardiography.

Hypereosinophilic syndrome (HES) is a rare condition characterised by idiopathic eosinophilia with organ system involvement. The condition is far more common in males, with a typical onset in the third to sixth decade. Cardiac damage may result in the formation of a characteristic apical thrombus readily visualised on two-dimensional echocardiography. Cardiac involvement portends a less favourable prognosis as it can be complicated by acute embolic events and progressive development of restrictive cardiomyopathy, valvular dysfunction, and heart failure. In this case report, we describe a middle-aged gentleman with HES and characteristic apical thrombus identified on contrast echocardiography. Although the use of contrast agents for assessment of left ventricular thrombus is documented in the literature,1 this case illustrates the application of contrast echocardiography in the evaluation of eosinophilia. (Neth Heart J 2009;17:169-70.).

Time-course analyses addressing the acquisition of DBA lectin reactivity in mouse lymphoid organs and uterus during the first week of pregnancy.

Terminal differentiation of uterine natural killer (uNK) cells is induced in humans and mice at the time of endometrial decidualization. In mice, commitment to this lineage is first recognized at gestation day (gd)5.5 when small, non-granulated lymphocytes in the mesometrial decidua basalis become histochemically reactive with the lectin Dolichlos biflorus agglutinin (DBA). Transplantation experiments in mice have shown that the self-renewing progenitors of uNK cells are present in peripheral rather than uterine tissues. While lymphoid tissues of virgin mice lack DBA lectin reactive putative uNK cell precursors or progenitors, peripheral organs have not been systematically examined in female mice during early pregnancy while the uNK cell population is becoming established. Here we report such a study in gd0.5-7.5 random bred mice. Only mesenteric lymph nodes showed a transient gain in DBA lectin reactive lymphocytes between gd0.5 and 4.5. These cells had cytoplasmic but almost no surface DBA lectin reactivity. This study indicates that the decidual environment is unique and locally promotes DBA lectin surface expression in terminally differentiating uNK cells.

Neurotrophin expression in the adult olfactory epithelium.

Published reports of neurotrophin expression in the olfactory system are incomplete because of missing data and conflicting results. Previous studies used a variety of fixation procedures and antibodies on different species and different ages. The aim of the present study was to examine expression of neurotrophins and their receptors using optimized methodologies: five methods of fixation, multiple antibodies, a variety of immunochemical protocols, and RT-PCR. We show here that (i) transcripts for all neurotrophins and their receptors are found in the adult olfactory epithelium; (ii) all neurotrophins are expressed in the supporting cells and the neuronal layers of the undisturbed adult olfactory epithelium while NT4 is found additionally in the horizontal basal cells; (iii) neurotrophin immunoreactivity required a fixative that included parabenzoquinone (not used in previous studies of olfactory tissue); (iv) TrkB and TrkC are restricted to the globose basal cell and neuron layers while TrkA is found in the horizontal basal cells and in the supporting cells where it co-localizes with the low affinity receptor for NGF (p75NTR). These findings confirm that neurotrophins are produced within the olfactory epithelium, suggesting autocrine and paracrine regulation of olfactory neurogenesis.

Experimental myocardial infarction. IV. Reduction of left ventricular compliance in the healing phase.

Compliance of the infarcted left ventricle was studied in dogs 3-5 days after occlusion of the left anterior descending coronary artery. Compliance was assessed from postmortem pressure-volume curves and from pressure-length measurements (mercury-in-silastic segment length gauges) made both in vivo and postmortem. Postmortem pressure-volume curves showed reduced compliance compared to sham-operated animals. Postmortem pressure-length curves of infarcted and adjacent normal myocardium indicated that the diminished total compliance could be attributed to an increase in stiffness of the infarcted area. This was confirmed by in vivo end-diastolic pressure-length changes produced by transient aortic occlusion. The infarcted area was akinetic, showing neither contraction nor aneurysmal bulging. In addition, anesthetized dogs with infarcts, when compared with sham-operated animals, had similar left ventricular end-diastolic volumes (indicator dilution method), but higher left ventricular end-diastolic pressures. Taken with previous observations, which show that systolic aneurysmal bulging is uniformly present at the onset of ischemia, these results indicate that stiffening of the ischemic myocardium occurs during the first 5 days after infarction, and show that elevation of left ventricular filling pressure does not necessarily signify ventricular dilatation. The results also suggest a mechanism whereby ventricular performance may improve during recovery from acute myocardial infarction.

Injectable nanomedicine hydrogel for local chemotherapy of glioblastoma after surgical resection.

Glioblastoma (GBM) treatment includes, when possible, surgical resection of the tumor followed by radiotherapy and oral chemotherapy with temozolomide, however recurrences quickly develop around the resection cavity borders leading to patient death. We hypothesize that the local delivery of Lauroyl-gemcitabine lipid nanocapsule based hydrogel (GemC12-LNC) in the tumor resection cavity of GBM is a promising strategy as it would allow to bypass the blood brain barrier, thus reaching high local concentrations of the drug. The cytotoxicity and internalization pathways of GemC12-LNC were studied on different GBM cell lines (U251, T98-G, 9L-LacZ, U-87 MG). The GemC12-LNC hydrogel was well tolerated when injected in mouse brain. In an orthotopic xenograft model, after intratumoral administration, GemC12-LNC significantly increased mice survival compared to the controls. Moreover, its ability to delay tumor recurrences was demonstrated after perisurgical administration in the GBM resection cavity. In conclusion, we demonstrate that GemC12-LNC hydrogel could be considered as a promising tool for the post-resection management of GBM, prior to the standard of care chemo-radiation.

Phase Ib trial of pentoxifylline and ciprofloxacin in patients treated with interleukin-2 and lymphokine-activated killer cell therapy for metastatic renal cell carcinoma.

The dose of interleukin 2 (IL-2) which can be administered to cancer patients is limited largely by a capillary leak syndrome. Pentoxifylline (PTX) is a methylxanthine which reduces IL-2 toxicity in animals. Ciprofloxacin (Cipro) modifies the metabolism of methylxanthines and, when coadministered with PTX, increases levels of PTX and certain of its metabolites. We conducted a phase Ib trial in patients receiving IL-2 and lymphokine-activated killer cell (LAK) cell therapy for metastatic renal cell carcinoma to identify the maximum tolerated dose of PTX which could be coadministered with Cipro in this setting. Eighteen patients received IL-2 (Roche) by continuous infusion at 6 x 10(6) units/m2/day on days 1-5 and underwent leukapheresis on days 7-9. LAK cells were infused on days 12-14. IL-2 was administered at 2 x 10(6) units/m2/day on days 10-20. Cohorts of patients received PTX at 2.5 (n = 3), 3.1 (n = 6), 3.9 (n = 6), and 4.9 (n = 3) mg/kg by 30 min i.v. infusion every 4 h on days 0-5 and 10-20 and Cipro (500 mg p.o. every 12 h) on days 1-5 and 10-20. Toxicity was compared with that observed in 33 historical control patients who received 37 cycles of an identical regimen of IL-2/LAK without PTX/Cipro. PTX at 2.5-3.9 mg/kg and Cipro were well tolerated. The maximum tolerated dose of PTX was 3.9 mg/kg. Dose-limiting emesis (n = 1) and atrial fibrillation (n = 2) occurred at 4.9 mg/kg and were reversible. Two complete, one partial and one minor, responses were observed. Patients treated with 3.9 mg/kg PTX received 95.0% of the planned dose of IL-2 as compared to 72.8% in the control patients (P < 0.025), primarily due to a lower incidence of azotemia and metabolic acidosis in PTX/Cipro recipients than had been seen in the historical control patients. The results of this study demonstrate that PTX/Cipro can be administered to patients receiving IL-2/LAK without apparent loss of therapeutic efficacy. Moreover, PTX/Cipro recipients exhibited less toxicity than historical controls. Therefore, treatment with PTX/Cipro may allow delivery of higher doses of IL-2, which might induce more responses in IL-2-responsive tumors and regression of tumors unresponsive to conventional doses of IL-2.

Lisofylline inhibits transforming growth factor beta release and enhances trilineage hematopoietic recovery after 5-fluorouracil treatment in mice.

The effectiveness of endogenous or exogenously administered colony-stimulating factors may be modulated by the presence of hematopoietic inhibitory molecules. Cytotoxic therapy may result in the induction of hematopoietic inhibitors contributing to prolonged myelosuppression, whereas preventing the induction of such inhibitors may accelerate multilineage recovery. Lisofylline [LSF; (R)-1-(5-hydroxyhexyl)-3,7, dimethyl-xanthine], inhibits the signaling and/or release of certain hematopoietic inhibitory molecules such as tumor necrosis factor alpha, macrophage inflammatory protein 1 alpha, transforming growth factor beta, and IFN-gamma. Treatment of murine bone marrow cells with the cytotoxic agent 5-fluorouracil (5-FU) results in the release of a nondialyzable inhibitor of progenitor (colony-forming unit-granulocyte macrophage; CFU-GM) proliferation. When murine bone marrow cells were treated with 5-FU plus LSF, release of this inhibitor of CFU-GM proliferation was blocked. Neutralizing antibody and Western blot analysis indicated that the inhibitor was TGF-beta. We tested the effect of LSF (100 mg/kg i.p., b.i.d.) on multilineage regeneration after high-dose 5-FU or thiotepa treatment in BALB/c mice. In 4 of 5 experiments, LSF significantly accelerated neutrophil recovery (P < or = 0.05, Wilcoxon paired-signed test). In addition, platelet, reticulocyte, and CFU-GM regeneration were significantly accelerated in mice treated with LSF compared to control mice (P < or = 0.05). LSF had no significant effects on the ability of 5-FU to kill hematopoietic progenitor cells, nor did LSF stimulate or inhibit proliferation of CFU-GM. LSF had no effect on chemotherapy-induced killing of tumor cells in vitro, nor on the antitumor activity of 5-FU or thiotepa in BALB/c mice implanted with P388 leukemia cells. Inhibition of hematopoietic inhibitor release may accelerate multilineage recovery after cytotoxic therapy and, as such, may represent an alternative or additional therapy to the use of positively acting lineage specific colony-stimulating factors.

High-dose cyclophosphamide, carmustine, and etoposide followed by autologous bone marrow transplantation in patients with lymphoid malignancies who have received dose-limiting radiation therapy.

PURPOSE: To evaluate high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) in patients with lymphoid malignancy who had received prior radiation therapy. PATIENTS AND METHODS: Fifty-seven patients with non-Hodgkin's lymphoma (NHL; n = 23), Hodgkin's disease (HD, n = 32), or acute lymphoblastic leukemia (ALL; n = 2) with a history of previous radiation therapy were treated with cyclophosphamide (Cy; 7.2 g/m2), carmustine (300 mg/m2 or 600 mg/m2), and etoposide (2,400 mg/m2) (CBV) followed by ABMT. RESULTS: The projected 2-year probabilities of survival, event-free survival (EFS), and relapse were .31, .24, and .76, respectively. For patients with intermediate- and high-grade lymphoma and HD the probabilities were .27, .10, and .14 for EFS and .57, .90, and .77 for relapse. The probability of nonrelapse mortality in the first 100 days post-ABMT was 33%. Idiopathic pneumonia syndrome (IPS) was observed in no patients who received carmustine 300 mg/m2 and 23% of patients who received carmustine 600 mg/m2 (P = .05). Eight-three percent of patients who received mediastinal radiation therapy less than 3 months before transplant developed IPS, compared with 13% who received radiation therapy more than 3 months before transplant (P = .001). CONCLUSION: ABMT following high-dose CBV resulted in long-term disease-free survival in 25% of patients with lymphoid malignancies who had previously received dose-limiting radiation therapy. Fatal IPS and a high relapse rate were major factors limiting successful outcome following ABMT. The morbidity and mortality rates associated with the administration of carmustine 600 mg/m2 were prohibitively high, especially in patients who received mediastinal radiation immediately before ABMT, and were not associated with a decrease in post-ABMT relapse.

Phase I study of busulfan and cyclophosphamide in preparation for allogeneic marrow transplant for patients with multiple myeloma.

PURPOSE: To study the toxicity and potential efficacy of busulfan (BU) and cyclophosphamide (CY) as a conditioning regimen before allogeneic bone marrow transplantation (ABMT) in patients with multiple myeloma (MM). PATIENTS AND METHODS: Twenty patients with MM underwent conditioning, which was followed by ABMT from 16 HLA-identical donors, three one-antigen-mismatched donors, and one HLA A, B, D-identical unrelated donor. Four levels of BU plus CY were evaluated. RESULTS: Severe regimen-related toxicity occurred in two of five patients who received BU 16 mg/kg and CY 120 mg/kg, in none of the four patients who received BU 14 mg/kg and CY 120 mg/kg, in one of eight patients who received BU 14 mg/kg and CY 147 mg/kg, and in two of three patients who received BU 14 mg/kg and CY 174 mg/kg. Twelve of 15 (80%) assessable patients achieved a complete remission with the disappearance of M-protein and the return of normal marrow morphology. Ten patients died of complications related to the ABMT, and two patients died of progressive or relapsed MM. Overall, eight of 20 patients were alive; seven (35%) were in complete remission 190 to 1,271 days after ABMT. CONCLUSIONS: The maximum-tolerable dose given in this setting was BU 14 mg/kg and CY 147 kg/mg. These results suggest that this regimen may have significant antimyeloma activity. Further phase II studies are warranted.

Accumulation of radioiodinated 15-(p-iodophenyl)-6-tellurapentadecanoic acid in ischemic myocardium during acute coronary occlusion and reperfusion.

The myocardial uptake of 15-(p-iodophenyl)-6- tellurapentadecanoic acid ( TPDA ) was studied in dogs during coronary occlusion and after reperfusion. In eight dogs with a 3 hour occlusion (Group A) with (n = 5) and without (n = 3) 30 minutes of reperfusion, iodine-125 TPDA uptake correlated well with microsphere myocardial blood flow over a wide range of flow levels (n = 111, r = 0.94). In six dogs with a 20 minute occlusion of the left anterior descending coronary artery and 1 hour of reperfusion (Group B), iodine-125 TPDA uptake correlated equally well with myocardial blood flow (n = 37, r = 0.90). There was no difference between the slopes of regression lines for Groups A and B, indicating no release from the myocardium of radioiodinated TPDA . Dual radiolabeling of TPDA was employed in five Group A animals by intravenous injection of iodine-125 TPDA during coronary occlusion and iodine-131 TPDA after reperfusion. In 63 myocardial samples, microsphere reperfusion flow and iodine-131 TPDA uptake were closely correlated (r = 0.91). As with monovalent cations, at myocardial flows higher than control flows, iodine-131 TPDA uptake was flow-limited. It is concluded that: 1) radioiodinated TPDA accurately reveals severely ischemic areas of myocardium without myocardial release of the radionuclide in coronary occlusions lasting 20 to 180 minutes and followed by reperfusion, and 2) double radiolabeled TPDA allows assessment of both occlusion and reperfusion flows. This compound may find an application in the measurement of infarct size and the evaluation of interventional therapies in acute myocardial infarction.

Biochemical characterization of a unique canine myeloid antigen.

In marrow transplantation, radioisotope-labeled monoclonal antibodies may provide a way to selectively deliver high doses of radiation to target tissues (marrow in the case of myeloid malignancies) without significant toxicity to other normal organs. This paper describes the production and characterization of a novel monoclonal antibody, DM5, that we have developed for use in an animal model of radiotherapy targeted to the marrow. DM5 recognizes three glycosylation variants, gp19,21,23DM5, of a polypeptide core that is expressed on canine cells of the myeloid lineage, but not on lymphoid cells. The antigen recognized by DM5 is not present on most progenitor cells as determined by CFU-GM assays of DM5 positive and negative cell populations.

Diastolic function of the heart in clinical cardiology.

During the last six years, there has been increased interest in the detection of abnormalities of left ventricular diastolic function in patients with heart disease. Before 1981, most studies on diastolic function were performed in the catheter laboratory using invasive techniques and complex methods. Recently, radionuclide angiograms and Doppler echocardiography have been employed to measure the dynamics of filling in normal individuals and in patients with heart disease. These methods are noninvasive, easy to perform, accurate, and reproducible. It is now clear that diastolic function may be altered globally and regionally, at rest and perhaps during exercise, in many patients with ischemic heart disease, hypertension, and hypertrophic cardiomyopathy. Interestingly, these diastolic abnormalities may even appear before systolic abnormalities are identified in these patients. Thus, diastolic abnormalities may permit assessment of presence of disease early in its evolution. Whether detection and quantitation of diastolic abnormalities will permit grading of disease severity or evaluation of therapeutic efficacy remains an important research question. At the present time, it appears that the decision to employ either radionuclide angiography or Doppler echocardiography for the assessment of diastolic abnormalities will depend on the local expertise to carry out the investigation. Both diagnostic modalities require standardization of accuracy and reproducibility with proper selection of control values from the appropriate populations of normal individuals. It is also important to remember that left ventricular diastolic abnormalities have to be identified after the elimination of the confounding influence of variables such as ejection fraction, heart rate, age, and preload (end-diastolic volume). Automation of the derivation of indexes of diastolic filling should provide an objective assessment of the dynamics of left ventricular filling. Although the value of measurement of diastolic filling in the individual patient remains controversial, we believe that the practice of cardiology is incomplete without consideration of the second half of cardiac function.

Pulmonary embolism from a venous thrombus located below the knee.

A patient with bronchogenic carcinoma developed acute thrombophlebitis below the knee followed by pulmonary embolism. Sequential nuclear venograms, perfusion lung scans, bilateral impedance plethysmography, and the patient's clinical course indicated that the below-knee thrombus had embolized in its entirety, causing clinically significant disease. This case demonstrates that below-knee thrombi are not always benign and, in certain circumstances, merit anticoagulation.

Specific marrow localization of an 131I-labeled anti-myeloid antibody in normal dogs: effects of a "cold" antibody pretreatment dose on marrow localization.

Tumor recurrence and regimen-related toxicity remain major obstacles in the successful use of marrow transplantation as therapy for hematologic malignancies. By attaching radionuclides to monoclonal antibodies (MoAbs) targeted at myeloid-associated antigenic determinants, a more effective and directed delivery of therapy may be possible without increasing toxicity. We investigated the biodistribution over time of an anti-myeloid antibody (DM-5) labeled with trace amounts of 131I in normal dogs. This study demonstrates the ability to target marrow with a high degree of selectivity, achieving marrow/blood ratios of 25-30:1 with the greatest concentration in any other organ being a tissue/blood ratio of 1.4:1 for stomach at 48 h. A pretreatment dose of unlabeled antibody effectively reduced early hepatic uptake by 80%, resulting in improved marrow localization with an estimated 58.6% of the injected dose localized in marrow within 2 h following infusion, compared to 32.8% without pretreatment. The marrow concentration clearance curve for the radioimmunoconjugate revealed an initial short half-life (4.75 h), suggesting rapid internalization, digestion, and release of free iodine (dehalogenation). This view was supported by a corresponding rise in trichloroacetic acid-non-precipitable activity during this period. Methods aimed at decreasing dehalogenation may result in longer residence time of the radionuclide within the marrow space, resulting in more effective tumor cell kill. This approach may provide a way to improve upon the current results obtained with marrow transplantation as treatment for patients with leukemia and other hematologic malignancies.

Oestrogens and prostate cancer.

Androgens are essential for stimulating normal development, growth and secretory activities of the prostate whereas oestrogens are generally regarded as inhibitors of growth. Evidence for the local synthesis of oestrogens includes the detection of aromatase mRNA and protein in the stroma of human non-malignant tissues and in malignant tissue, where it is detected in epithelial tumour cells. As well, aromatase activity was measured by biochemical assay and protein was detected in prostatic non-malignant and tumour cell lines. Taken together with the identification of direct oestrogenic actions on the prostate, these results suggest that alterations in local oestrogen synthesis may have significant consequences in malignancy of these organs. Genetically modified mouse models were studied in order to evaluate the action of oestrogens alone or in combination with androgens on the prostate gland. Hypogonadal (hpg) mice are deficient in gonadotrophins and androgens but showed direct proliferative responses to oestradiol. The responses were characterised by discrete lobe-specific changes including smooth-muscle regression, fibroblast proliferation, inflammation, and basal epithelial cell proliferation and metaplasia. The aromatase knockout (ArKO) mouse, deficient in oestrogens due to a non-functional aromatase enzyme, developed prostatic hyperplasia during the lifelong exposure to elevated androgens, however, no malignant changes were detected in the prostate at any time. In contrast, combined androgen and oestrogen treatment has been shown to induce prostatic dysplasia and adenocarcinoma. These results demonstrate that malignant changes to the prostate gland are dependent upon both androgenic and oestrogenic responses and that neither hormone alone is sufficient to evoke aberrant patterns of growth, resulting in malignancy.

Prevalence of clinically relevant bacteremia after upper gastrointestinal endoscopy in bone marrow transplant recipients.

PURPOSE: To determine the prevalence of clinically relevant bacteremia after upper endoscopy in patients undergoing bone marrow transplantation. PATIENTS AND METHODS: We retrospectively reviewed the records of 151 patients who received an HLA-identical allogeneic bone marrow transplant (BMT) at the Seattle Veterans Affairs Medical Center between September 1983 and December 1988. Forty-seven patients who required esophago-gastroduodenoscopy (EGD) during their first 100 days after transplant were selected for evaluation. Clinically relevant bacteremia was defined as the development of hypotension, temperature greater than 38.5 degrees C, and a positive blood culture occurring within 24 hours after endoscopy. The presence of acute graft-versus-host disease (GVHD) at the time of endoscopy and the use of prednisone prior to endoscopy were considered possible risk factors for the development of bacteremia. The proportion of subjects who became bacteremic were compared using Fisher's exact test. RESULTS: Within 24 hours following endoscopy, nine patients (19%) developed clinically evident bacteremia (hypotension, temperature greater than 38.5 degrees C, and a positive blood culture). Eight of 14 patients receiving prednisone at the time of endoscopy developed bacteremia, compared to one of 33 not receiving prednisone (p less than 0.01). Nineteen patients had acute GVHD of at least grade 2 at the time of EGD, six of whom developed bacteremia. Although acute GVHD alone did not increase the risk of post-EGD bacteremia in patients not receiving prednisone (one of 21 versus zero of 12, p greater than 0.9), the risk of bacteremia was particularly high in patients with acute GVHD treated with prednisone at the time of EGD (six of seven). CONCLUSION: Allogeneic BMT recipients receiving prednisone for immunoprophylaxis after grafting or for treatment of acute GVHD are at high risk for clinically relevant bacteremia following EGD. Such patients are candidates for antibiotic prophylaxis prior to endoscopy.

Preferential radiosensitization of G1 checkpoint-deficient cells by methylxanthines.

PURPOSE: To develop a checkpoint-based strategy for preferential radiosensitization of human tumors with deficient and/or mutant p53. METHODS AND MATERIALS: A549 human lung adenocarcinoma cell lines differing in their expression of the p53 tumor suppressor gene were produced by transduction with the E6 oncogene from human papilloma virus type 16. The cells expressing E6 (E6+) lack a G1 arrest in response to ionizing radiation, are deficient in p53 and p21 expression, and exhibit a fivefold greater clonogenic survival following 10 Gy radiation. RESULTS: Postirradiation incubation with millimolar concentrations of the methylxanthine pentoxifylline (PTX) results in preferential radiosensitization of the E6+ cells compared to the LXSN+ vector transduced controls. There is a threefold sensitization of the LXSN+ cells and a 15-fold sensitization of the E6+ cells, which results in equal clonogenic survival of the two lines. Flow cytometry reveals PTX abrogation of the radiation induced G2 arrest for both cell lines. PTX also prolongs G1 transit for both cell lines. Preliminary results are presented using a novel methylxanthine, lisofylline (LSF), which has similar cell cycle effects on G1 and G2 and achieves differential radiosensitization at micromolar concentrations that are sustainable in humans. CONCLUSION: This checkpoint-based strategy is a promising approach for achieving preferential radiosensitization of p53- tumors relative to p53+ normal tissues.