Gastric ulcer localization by direct in vivo labeling of sucralfate. Work in progress

We developed and evaluated a new procedure for imaging gastric ulcer disease with technetium 99m-labeled sucralfate. The new method employs direct in vivo labeling of sucralfate instead of in vitro labeling using human serum albumin, as previously reported in the literature. Tests using hydrochloric acid and a rabbit ulcer model showed the efficacy of the direct in vivo labeling technique and the ability of the tagged material to bind to ulcers, respectively. In 26 studies using humans with sucralfate labeled directly in vivo, 15 gave true-negative results and 11 gave true-positive results. Of 14 studies using humans with in vitro labeled sucralfate, three gave true-negative results, three gave true-positive results, and the results of eight were either false-negative or could not be interpreted because of high levels of activity remaining in the stomach. We suggest that the direct in vivo labeling method significantly improves the sucralfate gastric ulcer imaging technique.     

High-dose cytosine arabinoside therapy for refractory leukemia

Fifty-seven patients with refractory acute leukemia were treated with high-dose cytosine arabinoside to establish the maximum tolerated dose and duration and to determine the antileukemic activity. The maximum tolerated regimen was found to be 3 g/sq m every 12 hr for 6 days. At this dose, nonhematologic toxicity was limited to conjunctivitis in approximately half of the patients, and liver toxicity (transient elevations in transaminase, alkaline phosphatase, or bilirubin) was frequently observed, but neither was dose-limiting. Extending the duration of treatment to 8 days resulted in excessive diarrhea and skin toxicity (painful erythema with bullae), while increasing the dose to 4.5 g/sq m q. 12 hr for 6 days resulted in severe cerebellar toxicity. Myelosuppression was severe, but was not related to the intensity of treatment; granulocyte recovery occurred a median of 28 days (range 22- 40 days) after initiating therapy, and platelet recovery occurred after a median of 25 days (range 16-41 days). Antileukemic activity was evaluable in the 46 patients who survived at least 3 wk. Complete remissions were obtained in 1 of 6 patients with chronic myelogenous leukemia (CML) in accelerated phase and 1 of 3 acute lymphoblastic leukemia (ALL) patients. A more detailed analysis of response was possible for the 37 evaluable patients with acute nonlymphoblastic leukemia: 70% of these patients responded, with 51% complete remissions. The median unmaintained response was 4 mo (range 2-26+ mo). The complete response rate was higher in patients who received at least 12 doses of high-dose cytosine arabinoside compared to shorter regimens [17/28 (61%) versus 2/9 (22%), p less than 0.05]. Resistance to cytosine arabinoside in conventional doses was documented in 11 patients, 5 of whom responded (2 complete remissions) to high-dose regimens. We conclude that high-dose cytosine arabinoside in the maximally tolerated regimen of 3 g/sq m every 12 hr for 6 days has substantial antileukemic activity in patients refractory to standard therapy. Durable unmaintained remissions can be achieved, even in patients who fail to respond to cytosine arabinoside in conventional doses.     

Death in CHARGE syndrome after the neonatal period

Bergman JEH, Blake KD, Bakker MK, du Marchie Sarvaas GJ, Free RH, van Ravenswaaij‐Arts CMA. Death in CHARGE syndrome after the neonatal period. CHARGE syndrome is a multiple congenital anomaly syndrome that can be life‐threatening in the neonatal period. Complex heart defects, bilateral choanal atresia, esophageal atresia, severe T‐cell deficiency, and brain anomalies can cause neonatal death. As little is known about the causes of death in childhood and adolescence, we studied post‐neonatal death in patients with CHARGE syndrome. We collected medical data on three deceased children from a follow‐up cohort of 48 CHARGE patients and retrospectively on an additional four deceased patients (age at death 11 months to 22 years). We analyzed the factors that had contributed to their death. In five patients respiratory aspiration had most likely contributed to premature death, one died of post‐operative complications, and another choked during eating. From our findings and a literature review, we suggest that swallowing problems, gastro‐esophageal reflux disease, respiratory aspiration and post‐operative airway events are important contributors to post‐neonatal death in CHARGE syndrome. Cranial nerve dysfunction is proposed as the underlying pathogenic mechanism. We recommend every CHARGE patient with feeding difficulties to be assessed by a multidisciplinary team to evaluate cranial nerve function and swallowing. Timely treatment of swallowing problems and gastro‐esophageal reflux disease is important. Surgical procedures on these patients should be combined whenever possible because of their increased risk of post‐operative complications and intubation problems. Finally, we recommend performing autopsy in deceased CHARGE patients in order to gain more insight into causes of death.     

Digital processing of radiographic images from PACS to publishing

Several studies have addressed the implications of filmless radiologic imaging on telemedicine, diagnostic ability, and electronic teaching files. However, many publishers still require authors to submit hard-copy images for publication of articles and textbooks. This study compares the quality digital images directly exported from picture archive and communications systems (PACS) to images digitized from radiographic film. The authors evaluated the quality of publication-grade glossy photographs produced from digital radiographic images using 3 different methods: (1) film images digitized using a desktop scanner and then printed, (2) digital images obtained directly from PACS then printed, and (3) digital images obtained from PACS and processed to improve sharpness prior to printing. Twenty images were printed using each of the 3 different methods and rated for quality by 7 radiologists. The results were analyzed for statistically significant differences among the image sets. Subjective evaluations of the filmless images found them to be of equal or better quality than the digitized images. Direct electronic transfer of PACS images reduces the number of steps involved in creating publication-quality images as well as providing the means to produce high-quality radiographic images in a digital environment.     

Germline mutations in the PTEN/MMAC1 gene in patients with Cowden disease

Cowden disease, also known as multiple hamartoma syndrome, is an autosomal dominant cancer syndrome with a high risk of breast and thyroid cancer. The gene involved has been localized to chromosome 10q22-23. Recently, the tumour suppressor gene PTEN/MMAC1, encoding a putative protein tyrosine or dual-specificity phosphatase, was cloned from that region and three mutations were detected in patients with Cowden disease. We confirmed that the PTEN/MMAC1 gene is indeed the gene for Cowden disease by a refined localization of the gene to the interval between D10S1761 and D10S541, which contains the PTEN/MMAC1 gene and, by mutation analysis in eight unrelated familial and 11 sporadic patients with Cowden disease. Eight different mutations were detected in various regions of the PTEN/MMAC1 gene. One mutation was detected twice. All detected changes in the gene can be predicted to have a very deleterious effect on the putative protein. Five of the nine patients have a mutation in exon 5 coding for the putative active site and flanking amino acids. Evaluation of the clinical data of the patients in which a mutation could be detected gives no clear indications for a correlation between the genotype and phenotype. In 10 patients no mutation could be detected so far. In support of the linkage data, no evidence has emerged from the phenotype of these patients suggestive for genetic heterogeneity.      

The effects of growth factors on human normal placental cytotrophoblast cell proliferation

The effects of growth factors were investigated on the proliferation of a normal placental cytotrophoblast cell line (NPC). Epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and insulin- like growth factor-I (IGF-I) stimulated NPC cell proliferation. In contrast, TGFbeta1 was found to be a negative regulator, inhibiting EGF- induced cell proliferation. When EGF/TGF alpha receptor was analysed by radio-ligand binding, two binding sites of different affinities were revealed in the proliferating NPC cells but only the low affinity binding site was detected in the non-proliferating cytotrophoblast cells in primary cultures. The results suggest that EGF stimulates cytotrophoblast proliferation through high affinity binding sites.