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Biomedical subjects

E B Silberstein

Publications and source records attributed to E B Silberstein.

At least 55 records · Page 3Linked to original sources
PubMed1993

Colorectal cancer imaging with iodine-123-labeled CEA monoclonal antibody fragments.

This prospective, randomized multicenter study in 62 patients was designed to evaluate the efficacy and safety of radioimmunodetection (RAID) with 123I-labeled fragments, F(ab')2 and Fab', of IMMU-4, an anti-CEA monoclonal antibody (Immu-RAID-CEA). It was found that ImmuRAID-CEA was safe and disclosed colorectal cancer sites at least 1 cm in size. The positive predictive value by lesions was 77% initially, and increased to 91% after 7 mo of follow-up. Only one patient developed a low level of HAMA. In 17 patients with 32 surgically confirmed lesions, there were 9% true-positive lesions for CT when RAID was false-negative, and 22% for RAID when CT was false-negative. Either CT or RAID detected all 32 lesions. In this small series, therefore, RAID was shown to complement CT findings by confirming suspected tumors and disclosing new lesions which had previously been occult.

Adult↗
PubMed1992

Phosphorus-32 radiopharmaceuticals for the treatment of painful osseous metastases.

Phosphorus-32, employed as the orthophosphate or polyphosphate, can reduce or relieve the pain of osteoblastic metastases without serious hematologic toxicity, especially if used as a single injection. Uptake of this beta-emitter by osteoblastic-reactive bone and possibly by tumor and other cells can lead to pain reduction and often to cell killing. Efficacy has been demonstrated for the treatment of pain in 84% of 322 breast cancer patients and 77% of 444 prostate cancer patients found in a review of the literature. These results match those of the newer radiopharmaceuticals currently under investigation.

Bone Neoplasms↗
PubMed1992

Synthesis and renal excretion of technetium-99m-labeled organic cations.

Organic cations are excreted more efficiently than organic anions in uremia suggesting superiority as renal imaging agents. In this study, three 99mTc-labeled cationic cyclam complexes were synthesized and their renal clearance quantified in rats. The complexes are cleared at a rate of about 2.5-3 times that of inulin and about 60% that of p-amino-hipurate. Inhibition of 99Tc-cyclam excretion by quinine indicates transport by the organic cation process. Comparative in vivo imaging experiments demonstrated that in normal rats 99mTc-cyclam reached peak renal activity 1.8 +/- 0.6 min after injection, a value intermediate between that for [131I]OIH (1.0 +/- 0) and 99mTc-MAG3 (2.8 +/- 0.6). In rats injected with the acute nephrotoxin cisplatin, the times to peak were lengthened with the relative order being 99mTc-cyclam > 99mTc-MAG3 > [131I]OIH. The results demonstrate that cationic complexes may be useful for renal imaging diagnostic applications.

Animals↗
PubMed1992

Cyclic oral phosphate and etidronate increase femoral and lumbar bone mineral density and reduce lumbar spine fracture rate over three years.

We have performed a study of the safety and efficacy of cyclic sequential oral phosphate, diphosphonate and calcium carbonate. Forty-two postmenopausal women with osteoporosis diagnosed by dual-photon absorptiometry were treated with a sequential cyclic regimen of oral phosphate for 3 days, etidronate for 2 wk, and then a calcium salt for 12 wk. This was repeated cyclically for 3 yr. They were rescanned after every two 101-day cycles. A control group of 20 patient receiving only the calcium salt was matched for age, time since menopause, race and sex. The group treated with cyclic phosphate, etidronate, and calcium regimen had 80% fewer fractures than the control group over 3 yr of follow-up. Significant response in halting bone mineral loss and increasing bone mineral density was seen in none of the controls but in 90% of treated patients' lumbar spine and 70%-80% of the three regions of the femoral neck examined.

Bone Density↗
PubMed1989

Clinical and radiographic correlates of femoral artery visualization on bone scan.

In order to determine if the linear pattern of thigh uptake medial to the femur often seen on a 99mTc diphosphonate bone scan (DiP) is caused by calcification of the femoral artery, 42 patients with and without this pattern were studied by a combination of conventional radiographs, radioisotope angiography and/or computed tomography. Risk factors for arteriosclerotic disease were recorded for all patients. These techniques identified the postulated femoral artery pattern on bone scan as always corresponding to calcified femoral arteries. The prevalence of diabetes, cigarette use, hypertension and a family or clinical history of arteriosclerotic vascular disease was the same in the groups with or without DiP uptake.

Adult↗
PubMed1989

A comparison between fibronectin and Matrigel pretreated ePTFE vascular grafts.

Two distinct series of experiments were performed to compare the behavior of ePTFE vascular grafts coated with basement membrane gel to that of identical grafts coated with fibronectin. Bilateral carotid interposition grafts (10 cm long) were interposed in 16 conditioned mongrel dogs. In the first series of experiments (n = 10), each graft was seeded with radiolabeled endothelial cells and initial endothelial cell adherence was determined. Following restoration of blood flow in the grafts, endothelial cell retention was measured for 24 hours. Seeding efficiency was 66.48% (+/- 13.2) for fibronectin-coated grafts and 56.58% (+/- 13.51) for gel-coated grafts. There was a slow, constant loss of activity during the first 90 minutes of imaging, and at 24 hours of observation the activity remaining on the fibronectin-coated graft was 13.2 +/- 3.98% of the initial graft activity. Although the basement membrane gel had a higher mean activity at 24 hours (18.9 +/- 7.22%), the difference was not statistically significant at any interval. In the second series of animals (n = 6), radiolabeled platelets were injected within 60 minutes following restoration of flow. Total platelet activity on the explanted grafts was 3.36 (+/- 1.35) x 10(5) counts per gram/0.2 minute for the fibronectin-coated grafts. The gel-coated grafts had 2.74 (+/- 1.33) x 10(5) counts per gram/0.2 minute, a difference that was not statistically significant. Thus, despite its theoretical appeal, basement membrane gel was no better than fibronectin in increasing endothelial cell adherence and retention, and the resulting flow surface of grafts treated with either compound appeared to attract platelets to an equal degree.

Animals↗
PubMed1989

The potential unreliability of indium 111 oxine labeling in studies of endothelial cell kinetics.

The current widespread use of indium 111 oxine for labeling endothelial cells to study their interaction with various bioprosthetic flow surfaces presupposes a high retention of the radioisotope within the cell and a lack of significant adherence of any marker released from the cell to the surface under study. We measured the loss of indium 111 from freshly harvested, canine, venous endothelial cells, and their viability in cell culture, for varying intervals up to 24 hours. At prescribed intervals, aliquots of the radiolabeled endothelial cell suspension were centrifuged, and the supernatant was separated from the cell pellet. The relative radioactivity of each was measured in a gamma well counter and the spontaneous loss of marker from the endothelial cells was calculated. Spontaneous loss of indium 111 was 7.8% +/- 1.9% at 1 hour and 47.6% +/- 1.8% at 24 hours. Loss of activity was virtually constant between 14 and 24 hours. Endothelial cell viability was 80% at 24 hours. We next studied the in vitro affinity of indium 111 oxine and indium 111 transferrin for untreated expanded polytetrafluoroethylene vascular grafts and for similar grafts treated with two surfactants commonly used to increase the "wetability" of expanded polytetrafluoroethylene, a nonionic sufectant (Nonidet) and tridodecylmethylammonium chloride, and with two glycoproteins, fibronectin and basement membrane gel. A minimum of three graft segments were studied in each group. The affinity of graft material for indium 111, in both its oxine and transferrin complex, was significantly increased by treating the graft with a wetting agent, and it was further increased by the addition of a glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Red blood cell membrane microviscosity correlates with posttransfusion survival.

The cholesterol/phospholipid and sphingomyelin/phospholipid ratios of red blood cells stored for 42 days were unchanged after storage. However, the total phospholipid concentration in the red cells decreased suggesting a loss of red cell membrane during storage. The 24 h survival of the stored red cells was assessed by the Cr technique in homologous donors. A decrease in fluorescence polarization of diphenylhexatriene incorporated into the membrane was observed following storage which correlated with survival. Thus, molecular defects in the lipid bilayer are associated with long-term storage of red blood cells.

Blood Preservation↗
PubMed1988

Early burn wound excision and skin grafting postburn trauma restores in vivo neutrophil delivery to inflammatory lesions.

This study assessed the effect of early vs delayed postburn wound excision and skin grafting on the in vivo neutrophil delivery to a delayed-type hypersensitivity (DTH) reaction and a bacterial skin lesion (BSL). Male Lewis rats were presensitized to keyhole-limpet hemocyanin. Group 1 comprised sham controls. Groups 2 through 4 were given a 30% 3 degrees scald burn, but the burn wounds were excised, and skin was grafted on days 1, 3, and 7, respectively, after the burn. Group 5 comprised burn controls. Twelve days after burn trauma, all rats were injected at different intervals (during a 24-hour period) with a trio of intradermal injections of keyhole-limpet hemocyanin, Staphylococcus aureus 502A, and saline at different sites. In vivo neutrophil delivery to these dermal lesions was determined by injecting indium in 111 oxyquinoline-labeled neutrophils isolated from similarly treated groups of rats. Neutrophil delivery to DTH and BSL lesions was restored to normal by excision and skin grafting of the burn wound one day after burn trauma. Waiting three days after burn trauma to excise and skin graft the wound partially, but not completely, restored the in vivo neutrophil delivery to DTH and BSL lesions. Waiting one week to excise and skin graft a burn wound resulted in no improvement in neutrophil delivery to DTH and BSL dermal lesions. It was concluded that burn wound excision and skin grafting immediately after burn trauma restored in vivo neutrophil delivery to a BSL and DTH dermal lesion. This may, in part, explain the beneficial effect of early aggressive burn wound debridement in patients with burn injuries.

Animals↗
PubMed1988

Bacterial infectibility of chronically implanted endothelial cell-seeded expanded polytetrafluoroethylene vascular grafts.

Vascular prosthetic grafts become more resistant to infection as the interval between implantation and bacteremic challenge increases. Endothelial cell (EC) seeding of such grafts has been shown to improve measurably their ability to resist a bacteremic challenge several weeks after implantation, presumably by reducing the amount of thrombus-free area (TFA) on their luminal surface. However, no investigators have reported the impact of EC seeding on the ability of chronically implanted vascular prostheses to resist a late bacteremic challenge. Bilateral common carotid interposition grafts were placed in 15 adult mongrel dogs with a 4 mm internal diameter, experimental, expanded polytetrafluoroethylene (ePTFE) prosthesis. One animal died shortly after operation and the grafts in two dogs thrombosed, thereby leaving 12 animals with at least one patent graft for subsequent study. At a mean interval of 45 weeks after implantation, five dogs (seven patent grafts) were challenged with an intravenous infusion of 3 X 10(8) radiolabeled Staphylococcus aureus; bacterial adherence and the TFA of the graft's luminal surface were determined for each of the patent grafts. There was no statistically significant difference in bacterial adherence or TFA between EC-seeded and control grafts. At a mean interval of 53 weeks after implantation, the remaining seven dogs (14 patent grafts) received a similar bacterial infusion and the animals were allowed to recover. Five days later, the grafts were harvested and cultured. Once again, there was no significant difference in the infectibility of EC-seeded vs. control grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Incidental detection of obstructive uropathy during scrotal imaging.

The customary method for radionuclide imaging in patients with testicular pain is to image the scrotal region using Tc-99m pertechnetate. Acute obstructive uropathy was found to be the cause of the testicular pain in three adult patients with normal testicular perfusion using Tc-99m DTPA. Tc-99m DTPA is recommended for testicular imaging with concomitant imaging of the kidneys and ureters, particularly in the adult patient.

Adult↗
PubMed1987

The value of hepatobiliary scans in fasted patients receiving total parenteral nutrition.

Hepatobiliary scanning is considered to be a highly accurate method for the diagnosis of acute cholecystitis. False-positive scans (failure to visualize the gallbladder in the absence of cholecystitis) have been reported to occur in fasted patients receiving total parenteral nutrition (TPN). To determine the prevalence of false-positive scans in this patient population and identify factors that might be associated with scan outcome, hepatobiliary imaging was performed in fasted patients receiving TPN and without clinical evidence of acute cholecystitis. Gallbladder nonvisualization occurred in 18 of 50 (36%) patients. In the group whose gallbladders did not visualize, a significantly higher male to female ratio (15:3 versus 17:15; p = 0.016), alkaline phosphatase (346 +/- 84 IU/L versus 212 +/- 32 IU/L, p less than 0.04), total bilirubin (1.7 +/- 0.3 mg/dl versus 1.0 +/- 0.2 mg/dl, p less than 0.02), and lower serum albumin (2.4 +/- 0.01 gm/dl versus 2.8 +/- 0.2 gm/dl, p less than 0.02) levels were noted. In 18 patients, gallbladder ultrasonography was also performed, and the presence of sludge or a thickened gallbladder wall did not correlate with scan outcome. The prevalence of false-positive hepatobiliary scans in fasted patients receiving TPN is significant and does not always correlate with a syndrome of acute gallbladder inflammation. The results of such scans must therefore be interpreted with caution in these patients.

Adult↗