Jerry I. Hirsch

Encapsulation of a Radiolabeled Cluster Inside a Fullerene Cage, 177LuxLu(3−x)N@C80: An Interleukin-13-Conjugated Radiolabeled Metallofullerene Platform

In this communication, we describe the successful encapsulation of (177)Lu into the endohedral metallofullerene (177)Lu(x)Lu(3-x)N@C(80) (x = 1-3) starting with (177)LuCl(3) in a modified quartz Kraschmer-Huffman electric generator. We demonstrate that the (177)Lu (beta-emitter) in this fullerene cage is not significantly released for a period of up to at least one-half-life (6.7 days). We also demonstrate that this agent can be conjugated with an interleukin-13 peptide that is designed to target an overexpressed receptor in glioblastoma multiforme tumors. This nanoparticle delivery platform provides flexibility for a wide range of radiotherapeutic and radiodiagnostic multimodal applications.

Conjugation of functionalized gadolinium metallofullerenes with IL-13 peptides for targeting and imaging glial tumors.

BACKGROUND Glioblastoma multiforme is the most common and most lethal primary brain tumor in humans, with median survival of approximately 1 year. Owing to the ability of glioma cells to aggressively infiltrate normal brain tissue and survive exposure to current adjuvant therapies, there is a great need for specific targeted nanoplatforms capable of delivering both therapeutic and imaging agents directly to invasive tumor cells. METHOD Gadolinium-containing endohedral fullerenes, highly efficient contrast agents for MRI, were functionalized and conjugated with a tumor-specific peptide and assessed for their ability to bind to glioma cells in vitro. RESULTS We report the successful conjugation of the carboxyl functionalized metallofullerene Gd(3)N@C(80)(OH)(-26)(CH(2)CH(2)COOH)(-16) to IL-13 peptides and the successful targeting ability towards brain tumor cells that overexpress the IL-13 receptor (IL-13Rα2). CONCLUSION These studies demonstrate that IL-13 peptide-conjugated gadolinium metallofullerenes could serve as a platform to deliver imaging and therapeutic agents to tumor cells.

Increased morbidity with increased pulmonary albumin flux in sepsis-related adult respiratory distress syndrome

ObjectiveTo determine the feasibility of utilizing a scintigraphic technique to differentiate patients with adult respiratory distress syndrome due to sepsis syndrome from control volunteers and patients with congestive heart failure. Gamma scintigraphy was compared with chest roentgenograms to predict mortality rate and morbidity in adult respiratory distress syndrome (ARDS) patients. DesignProspective study. SettingUniversity hospital ICUs. PatientsThirty-five control volunteers, 19 patients with congestive heart failure, 30 patients with a diagnosis of sepsis. Measurements and Main ResultsAll patients were infused iv with technetium 99m-labeled albumin and underwent computerized gamma-scintigraphic analysis with a portable gamma camera. Lung-to-heart ratio of tracer was calculated and expressed as the slope index. Increase in slope index indicated increased pulmonary albumin flux. Slope index was no different in controls compared with congestive heart failure patients, unless the pulmonary artery occlusion pressure (PAOP) was >30 mm Hg. Patients with a diagnosis of sepsis had an overall increased slope index compared with the other groups. A subgroup of patients in the septic group had a normal slope index. Septic patients with an increased slope index had a significantly (p < .01) longer duration of mechanical ventilation (36 ± 5 vs. 7 ± 1 days), spent longer in the ICU (67 ± 9 vs. 11 ± 1 days), and had a longer hospital stay (113 ± 20 vs. 35 ± 5 days) than septic patients with a normal slope index. ConclusionsGamma scintigraphy successfully differentiated between control volunteers and patients with congestive heart failure with PAOP <30 mm Hg from patients with sepsis-induced ARDS. Although all of the patients with a clinical diagnosis of septic ARDS had similar impairments in oxygenation and chest roentgenograms, those patients with a significantly increased pulmonary albumin flux (>2 SD above control mean) had a markedly increased morbidity. (Crit Care Med 1992; 20:28)

Gamma camera detection of oleic acid alveolar-capillary albumin leak

Abstract The computerized gamma camera was able to record and quantitate the alveolar-capillary membrane leak of radioactive technetium-99m-tagged human serum albumin in two dogs following intravenous oleic acid. In dog 1, given 0.1 ml/kg oleic acid, the increase in lung: heart radioactivity ratio, following oleic acid, became statistically significant within 12 (P

Premicellar taurocholate enhances calcium uptake from all regions of rat small intestine

BACKGROUND/AIMS The specific components of bile, which is necessary for normal calcium absorption, are unknown. We have previously shown that Ca2+ is bound with high affinity by premicellar taurocholate. The current studies examined the effects of taurocholate on intestinal calcium transport. METHODS Intestinal Ca2+ uptakes were measured from proximal, mid, and distal small intestinal segments perfused with solutions containing 45CaCl2 (0.1-1 mmol/L), taurocholate (0-10 mmol/L), trihydroxymethylaminomethane buffer (pH 7), phenolsulfonpthalein (nonabsorbable marker), and NaCl (total ionic strength, 0.16 mol/L) for four randomized perfusion periods. In other studies, the proximal small intestine was divided into two equal segments and perfused with either 45CaCl2 or 45CaCl2 plus taurocholate (2.5-5 mmol/L). Calcium absorption was measured from the difference in uptake and calcium concentration retained in mucosa. Finally, effects of taurocholate on Ca2+ uptake across isolated brush border membrane vesicles were measured. RESULTS Premicellar taurocholate produced an approximately 1.7-2-fold enhancement (P < 0.01) in Ca2+ uptake in all regions, with lesser contributions from micellar taurocholate. These effects resulted in a net increase in calcium absorption. Premicellar taurocholate also significantly increased calcium uptake across brush border vesicles. CONCLUSIONS Premicellar taurocholate significantly enhances calcium uptake into, and absorption across, enterocytes. The mechanisms remain to be experimentally verified.

Ex vivo expansion of tumor-draining lymph node cells using compounds which activate intracellular signal transduction. I. Characterization and in vivo anti-tumor activity of glioma-sensitized lymphocytes

It has been shown that adoptive immunotherapy can be curative for established malignant tumors. The key to this treatment lies in obtaining sufficient numbers of lymphocytes which are sensitized to recognize tumor antigens and carry out immunological reactions to destroy tumor cells. Reported here are the results of experiments to: 1) sensitize lymphocytes to the antigens of rat glioma cells and expand them ex vivo for use in adoptive immunotherapy, 2) characterize the cells of the expanded population, and 3) evaluate antitumor activity in a cohort of rats with well-established intracranial gliomas.Viable RT-2 glioma cells were injected into the hind foot pads of syngeneic Fischer 344 rats. After 10 days, the tumor draining lymph nodes (DLN) were harvested from the injected limbs and mechanically dissociated. The cells of the DLN were then suspendedin culture medium supplemented with low dose interleukin-2 (IL-2)and incubated for 18 hours with Bryostatin-1 and ionomycin (Bryo/Io)to stimulate expansion. The cells were next washed to remove the Bryo/Io and resuspended in culture medium and IL-2. Population expansions of 40- to 100-fold were seen after 8 days. Flow cytometric analysis showed these cells to be a nearly pure population of T lymphocytes of the CD3+CD8+ phenotype. Intravenous injection of the ex vivo expanded DLN cells didnot significantly improve survival of rats with a seven-day intracerebral RT-2 glioma, although, compared to untreated controls, the tumors of the treated animals were smaller, showed no necrosis, and appeared to be less infiltrative. Furthermore, the treated animals had a pronounced lymphocytic infiltration of their tumors with greater associated degrees of hemorrhagic change and peritumoral edema. When the ex vivo expanded DLN cells were intravenously injected into three-day intracerebral RT-2 gliomamodels, tumors were almost always eliminated and the animals survived their tumor challenge. We conclude that successful expansion of glioma-sensitized DLN lymphocytes is possible and that adoptive immunotherapy using these cells is capable of effectively limiting the progression of large gliomas, while totally eradicating small ones.

Effects of ibuprofen on a pig Pseudomonas ARDS model

Abstract The effects of ibuprofen (I) were studied in the Pseudomonas (P) porcine ARDS model. Pigs, 14–26 kg (5 in each group), were anesthetized and ventilated with 0.5 FiO2 and 5 cm H2O PEEP. A control (C) group received saline only, a second group was given P, 1 × 108 org/ml at 0.3 cc/20 kg/min, and a third group was given P followed by 12.5 mg 1 at 20 and 120 min. Pulmonary arterial (PAP), wedge (PWP) and systemic arterial pressures, cardiac output (CO), and thermal-cardiogreen extravascular lung water (EVLW), thromboxane (TxB2), 6-keto-PGF1α, PaO2, PaCO2 were determined every 30 min. Albumin flux was measured with scintigraphic determination of lung:heart radioactivity ratios versus time, called slope index (SI). At 3 hr, P produced marked (P

Premicellar Taurocholate Enhances Ferrous Iron Uptake From All Regions of Rat Small Intestine

Inorganic iron is virtually insoluble at the pH of small intestinal contents. This severe solubility limitation has been partly overcome by intraluminal substances that bind and solubilize iron, thus increasing availability for absorption. While several dietary ligands capable of solubilizing Fe2+ in intestinal lumen have been described, an endogenous binding ligand has not been previously described. It has recently been shown that certain trihydroxy bile acids (taurocholate and glycocholate) show high-affinity premicellar and low-affinity micellar Fe(2+)-binding properties, resulting in the formation of soluble Fe(2+)-bile salt complexes. It was hypothesized that this binding would increase the intraluminal pool of soluble iron, increase delivery of soluble iron to mucosal carriers, and thus enhance intestinal Fe2+ uptake. As a first step toward testing this hypothesis, the effect of taurocholate on Fe2+ uptake from all regions of in vivo rat small intestine is reported. It is shown that taurocholate, at premicellar concentrations, produces a marked, stepwise increase in Fe2+ uptake from all regions of small bowel, with little further increase above the critical micellar concentration. Enhancement of intestinal Fe2+ uptake is a newly described effect, and potential physiological function, of premicellar bile salts.

Pitfall to modified in vivo method of technetium-/sub 99m/ red blood cell labeling. Iodinated contrast media

Suboptimal labeling of red blood cells with Tc–99m, using the modified in vivo technique, was observed in three patients in whom labeling was attempted following IV administration of iodinated contrast media in the previous 24 hours. The mechanism is not understood, but it may represent a change in either stannous ion distribution or redox potential. It is recommended that studies employing Tc–99m RBC labeling using this technique be performed prior to administration of iodinated contrast media. This effect should be kept in mind in gastrointestinal bleeding studies performed using Tc–99m RBC, as well as in cardiac imaging studies.

Single isotope evaluation of pulmonary capillary protein leak (Ards model) using computerized gamma scintigraphy

Using a canine oleic acid model, a computerized gamma scintigraphic technique was evaluated to determine 1) ability to detect pulmonary capillary protein leak in a model temporally consistent with clinical adult respiratory distress syndrome (ARDS), 2) the possibility of providing a quantitative index of leak, and 3) the feasibility of closely spaced repeat evaluations. Study animals received oleic acid (controls, n = 10; 0.05 ml/kg, n = 10; 0.10 ml/kg, n = 12; 0.15 ml/kg, n = 6) 3 hours prior to a tracer dose of technetium-990m (99mTc) HSA. One animal in each dose group also received two repeat tracer injections spaced a minimum of 45 minutes apart. Digital images were obtained with a conventional gamma camera interfaced to a dedicated medical computer. Lung: heart ratio versus time curves were generated, and a slope index was calculated for each curve. Slope index values for all doses were significantly greater than control values (P(t) less than 0.0001). Each incremental dose increase was also significantly greater than the previous dose level. Oleic acid dose versus slope index fitted a linear regression model with r = 0.94. Repeat dosing produced index values with standard deviations less than the group sample standard deviations. We feel this technique may have application in the clinical study of pulmonary permeability edema.