Hypothalamic expression of ART, a novel gene related to agouti, is up-regulated in obese and diabetic mutant mice

We have isolated cDNA clones that encode a novel human gene related to agouti. Sequence analysis of this gene, named ART, for agouti-related transcript, predicts a 132-amino-acid protein that is 25% identical to human agouti. The highest degree of identity is within the carboxyl terminus of both proteins. Like agouti, ART contains a putative signal sequence and a cysteine rich carboxyl terminus, but lacks the region of basic residues and polyproline residues found in the middle of the agouti protein. Both agouti and ART contain 11 cysteines, and 9 of these are conserved spatially. ART is expressed primarily in the adrenal gland, subthalamic nucleus, and hypothalamus, with a lower level of expression occurring in testis, lung, and kidney. The murine homolog of ART was also isolated and is predicted to encode a 131-amino-acid protein that shares 81% amino acid identity to humans. The mouse was found to have the same expression pattern as human when assessed by RT-PCR. Examination by in situ hybridization using mouse tissues showed localized expression in the arcuate nucleus of the hypothalamus, the median eminence, and the adrenal medulla. In addition, the hypothalamic expression of ART was elevated approximately 10-fold in ob/ob and db/db mice. ART was mapped to human chromosome 16q22 and to mouse chromosome 8D1-D2. The expression pattern and transcriptional regulation of ART, coupled with the known actions of agouti, suggests a role for ART in the regulation of melanocortin receptors within the hypothalamus and adrenal gland, and implicates this novel gene in the central control of feeding.

Motion parallax as an independent cue for depth perception

The perspective transformations of the retinal image, produced by either the movement of an observer or the movement of objects in the visual world, were found to produce a reliable, consistent, and unambiguous impression of relative depth in the absence of all other cues to depth and distance. The stimulus displays consisted of computer-generated random-dot patterns that could be transformed by each movement of the observer or the display oscilloscope to simulate the relative movement information produced by a three-dimensional surface. Using a stereoscopic matching task, the second experiment showed that the perceived depth from parallax transformations is in close agreement with the degree of relative image displacement, as well as producing a compelling impression of three-dimensionality not unlike that found with random-dot stereograms.

Lymphotoxin and tumor necrosis factor-alpha production by myelin basic protein-specific T cell clones correlates with encephalitogenicity

Lymphokine activity in seven myelin basic protein (MBP)-specific T cell clones was examined. All of the clones recognize MBP peptide 1-9 in the context of I-Au. A strong positive correlation was found between levels of lymphotoxin (LT) and tumor necrosis factor alpha (TNF-alpha) mRNA and biological activity on L929 cells and their capacity to induce paralysis, the clinical hallmark of experimental allergic encephalomyelitis (EAE). No correlation was found between interleukin-2 or gamma interferon production and encephalitogenicity. LT and/or TNF-alpha may play a central role in the pathogenesis of EAE.

Similarities between motion parallax and stereopsis in human depth perception

Random dot techniques were used to investigate the human visual system's sensitivity to sinusoidal depth modulations specified by motion parallax information. Thresholds for perceiving depth were found to be smallest when the spatial frequency of the depth corrugations was between 0.2 and 0.5 c/deg visual angle. These data were compared with the equivalent thresholds for perceiving depth corrugations specified by binocular disparity using similar apparatus and psychophysical procedures. The similarity between the sensitivity functions is suggestive of a closer relationship between the two systems than has previously been thought.

Antibody targeting in metastatic colon cancer: a phase I study of monoclonal antibody F19 against a cell-surface protein of reactive tumor stromal fibroblasts

PURPOSE

To define the toxicity, imaging, and biodistribution characteristics of iodine 131-labeled monoclonal antibody F19 (131I-mAbF19). MAbF19 recognizes the fibroblast activation protein (FAP), a cell-surface glycoprotein not present in most normal tissues, but abundantly expressed by reactive stromal fibroblasts of epithelial cancers, including more than 95% of primary and metastatic colorectal carcinomas.

PATIENTS AND METHODS

131I-mAbF19 was administered intravenously to 17 patients with hepatic metastases from colorectal carcinoma who were scheduled for resection of localized metastases or insertion of hepatic artery catheter for regional chemotherapy. Seven to 8 days before surgery, patients received 131I-mAbF19 at three dose levels, with at least four patients entered at each level.

RESULTS

No toxicity associated with intravenous 131I-mAbF19 administration was observed. Tumor images were obtained on planar and single-photon emission tomography (SPECT) scans in 15 of 17 patients with hepatic metastases, tumor-infiltrated portal lymph nodes, and/or recurrent pelvic disease. The smallest lesion visualized was 1 cm in diameter. The optimal time for tumor imaging was 3 to 5 days after 131I-mAbF19 administration. The use of image registration techniques allowed precise anatomic localization of 131I-mAbF19 accumulation. Immunohistochemical analysis of biopsy tissues showed expression of FAP in the tumor stroma (but not in normal liver) in all patients studied and confirmed that the FAP-positive tumor stromal fibroblasts were interposed between the tumor capillaries and the malignant colon epithelial cells. At the time of surgery, tumor-to-liver ratios up to 21:1 and tumor-to-serum ratios up to 9:1 were obtained. The fraction of the injected 131I-mAbF19 dose per gram tumor (%ID/g tumor) localized to hepatic metastases at the time of surgery ranged from 0.001% to 0.016%.

CONCLUSION

The FAP tumor fibroblast antigen is highly expressed in primary and metastatic colorectal carcinomas and shows limited expression in normal adult tissues. This highly selective expression pattern allows imaging of colorectal carcinoma lesions as small as 1 cm in diameter on 131I-mAbF19 scans. Because of the consistent presence of FAP in the stroma of epithelial cancers and the accessibility of FAP-positive tumor stromal fibroblasts to circulating monoclonal antibodies (mAbs), this study suggests possible diagnostic and therapeutic applications of humanized mAbF19 and mAbF19 constructs with novel immune and nonimmune effector functions.

Frequency and duration of handwashing in an intensive care unit

The effects on hand decontamination of the introduction of an antiseptic handrub lotion in an intensive care unit was studied. To obtain baseline data, nursing, medical, physiotherapy, radiology, and orderly staff members were observed. Further observations were carried out after the introduction of the handrub lotion. Patient care activities were classified as high or low, according to the degree of contact with the patients or their equipment. A total of 884 patient contacts and 341 hand decontamination episodes was observed: 440 contacts and 140 handwashes in stage one (32%) and 444 contacts and 201 handwashes in stage two (45%). There was an increase of 13% in hand decontamination frequency after the introduction of the handrub lotion. The data indicate that the frequency of hand decontamination is below levels recommended by infection control authorities. Increasing the accessibility of hand decontamination facilities did result in a slight increase in handwashing compliance.

Expression of basic fibroblast growth factor, FGFR1 and FGFR2 in normal and malignant human breast, and comparison with other normal tissues

The expression of basic fibroblast growth factor (bFGF) and two of its receptors, FGFR1 and FGFR2, was detected using the polymerase chain reaction, and quantified by comparison to the relative amount of product obtained following co-amplification of the ubiquitous glyceraldehyde phosphate dehydrogenase transcript. Varying levels were found in the vast majority of both cancer and non-malignant breast biopsies as well as in samples of several other normal human tissues. Significantly less bFGF was present in cancers (P less than 0.0001). Similarly, FGFR2 product was also much less in cancer tissues (P = 0.0078), as was FGFR1 (P = 0.002). FGFR1 levels in cancers tended to be higher in those which were oestrogen receptor positive (P less than 0.06). Amplification of different coding regions showed evidence of variant forms of FGFR1 RNA. Cancers appeared to have a significantly greater proportion of PCR product corresponding to the region between the third immunoglobulin like domain and the tyrosine kinase domain (P = 0.046). Differential expression was observed in breast cell lines, with bFGF in the normal derived HBL100, HBR SV1.6.1 and 184A1 but little or none in ZR-75-1, MCF-7, T47D and MDA-MB-231. FGFR1 was present in most of these but FGFR2 was absent from T47D, MDA-MB-231 and HBL100. ZR-75-1 cells had a marked preponderance of FGFR1 variants lacking part of the coding sequence. Aberrant receptor processing may provide clues concerning the role of FGF's and their potential involvement in malignancy.

Prediction of cerebral palsy in very low birthweight infants: prospective ultrasound study

The value of regular cerebral ultrasound scanning in predicting cerebral palsy (CP) was assessed in very low birthweight infants. The infants were scanned before discharge, and their vision and hearing were assessed at age 9 months and neurodevelopment was assessed at 18 months. Ultrasound abnormalities, defined before the study, were periventricular haemorrhage (PVH), "prolonged flare" (echodensity persisting in the periventricular white-matter for more than 2 weeks without cavitating), and cystic periventricular leukomalacia (PVL). The incidence of these three conditions in surviving infants was 49%, 15%, and 8%, respectively. 158 infants survived to be discharged from hospital and 156 had neurodevelopmental assessment at 18 months of corrected age. All infants with PVH alone and confined to the lateral ventricles were normal at follow-up. The presence of cysts accurately predicted abnormal outcome (94%) and was highly specific (96%). Prolonged flare predicted adverse outcome but the accuracy (79%) was less good than for cystic PVL. 12 infants had CP, and 10 of these had ultrasound evidence of PVL. 8 of the 13 infants with cysts had spastic CP. 4 of these were walking independently and had mild CP. No infant with ultrasound evidence of a single cyst or with cysts confined to the frontal region or centrum semiovale had severe CP. Cysts involving the periventricular white-matter in the occipital region were associated with a poor prognosis. Echolucent cystic lesions detected by ultrasound in the neonatal period accurately predict adverse outcome, and if multiple and present in the occipital region, confer a very high risk of severe CP.

Variant (6;15) translocations in murine plasmacytomas involve a chromosome 15 locus at least 72 kb from the c-myc oncogene

The variant (6;15) translocations in murine plasmacytomas join the myc oncogene-bearing band of chromosome 15 and the immunoglobulin kappa band of chromosome 6. We recently cloned a region from chromosome 15 linked to C kappa and have now used probes from that region to define the major locus of plasmacytoma variant translocations, which we denote pvt-1. In five of nine plasmacytomas we analysed, the 6;15 translocation resulted from reciprocal recombination between the C kappa locus and a 4.5-kb region of pvt-1. Moreover, nearby we located the region shown by others to have undergone a complex (15;12;6) translocation in plasmacytoma PC7183. All the chromosome 6 breakpoints fell between 1 and 3 kb 5' to C kappa but only two were near J kappa genes. Thus the J kappa -C kappa region appears to be a recombination 'hot spot' in lymphocytes, but the breaks are unlikely to be mediated via V/J recombination enzymes. Comparison of a cloned 108-kb region across pvt-1 and another of 52 kb across c-myc established that the pvt-1 breakpoints lie at least 72 kb from the c-myc promoters. Since c-myc is expressed at a substantial level, the 6;15 translocation apparently activates c-myc. Activation may occur directly, at a remarkable distance along the chromosome, or indirectly, via a putative pvt-1 gene product.

A prospective randomized trial of triage angiography in acute coronary syndromes ineligible for thrombolytic therapy. Results of the medicine versus angiography in thrombolytic exclusion (MATE) trial

OBJECTIVES

The purpose of this study was to determine if early triage angiography with revascularization, if indicated, favorably affects clinical outcomes in patients with suspected acute myocardial infarction who are ineligible for thrombolysis.

BACKGROUND

The majority of patients with acute myocardial infarction and other acute coronary syndromes are considered ineligible for thrombolysis and therefore are not afforded the opportunity for early reperfusion.

METHODS

This multicenter, prospective, randomized trial evaluated in a controlled fashion the outcomes following triage angiography in acute coronary syndromes ineligible for thrombolytic therapy. Eligible patients (n=201) with <24 h of symptoms were randomized to early triage angiography and subsequent therapies based on the angiogram versus conventional medical therapy consisting of aspirin, intravenous heparin, nitroglycerin, beta-blockers, and analgesics.

RESULTS

In the triage angiography group, 109 patients underwent early angiography and 64 (58%) received revascularization, whereas in the conservative group, 54 (60%) subsequently underwent nonprotocol angiography in response to recurrent ischemia and 33 (37%) received revascularization (p=0.004). The mean time to revascularization was 27+/-32 versus 88+/-98 h (p=0.0001) and the primary endpoint of recurrent ischemic events or death occurred in 14 (13%) versus 31 (34%) of the triage angiography and conservative groups, respectively (45% risk reduction, 95% CI 27-59%, p=0.0002). There were no differences between the groups with respect to initial hospital costs or length of stay. Long-term follow-up at a median of 21 months revealed no significant differences in the endpoints of late revascularization, recurrent myocardial infarction, or all-cause mortality.

CONCLUSIONS

Early triage angiography in patients with acute coronary syndromes who are not eligible for thrombolytics reduced the composite of recurrent ischemic events or death and shortened the time to definitive revascularization during the index hospitalization. Despite more frequent early revascularization after triage angiography, we found no long-term benefit in cardiac outcomes compared with conservative medical therapy with revascularization prompted by recurrent ischemia.

Murine T lymphomas with retroviral inserts in the chromosomal 15 locus for plasmacytoma variant translocations

The frequent trisomy of murine chromosome 15 in T lymphomas suggests that it bears one or more genes conducive to T-cell neoplasia. One such gene seems to be c-myc, the oncogene frequently activated in B-lymphoid tumours either by retroviral insertion, as in the avian bursal lymphomas, or by a translocation to the immunoglobulin heavy-chain locus, as in the predominant t(12; 15) of murine plasmacytomas and the analogous t(14; 8) of human Burkitt lymphomas. The c-myc gene was strongly implicated in T-cell neoplasia when 15-25% of T lymphomas arising in AKR mice, a strain prone to leukaemia, were found to have retroviral inserts near c-myc. Proviruses near c-myc were also found in several T lymphomas induced by murine leukaemia viruses (MuLV) in both mice and rats, but many of the rat thymomas bear an insert instead at one of several other common sites, at least two of which have murine homologues on chromosome 15. We show here that some murine T lymphomas contain proviral inserts in the recently identified chromosome 15 locus for plasmacytoma variant (6; 15) translocations, which we have denoted pvt-1. Although 6; 15 breakpoints map cytogenetically to the same chromosome band as c-myc, the alterations of pvt-1 in tumours occur at least 72 kilobases (kb) from the c-myc promoters. The insertions in T lymphomas suggest that an altered pvt-1 locus is conducive to neoplasia in T cells as well as B cells, possibly via long-range effects on c-myc expression.

Nanoencapsulation of phase change materials for advanced thermal energy storage systems

Phase change materials (PCMs) allow the storage of large amounts of latent heat during phase transition. They have the potential to both increase the efficiency of renewable energies such as solar power through storage of excess energy, which can be used at times of peak demand; and to reduce overall energy demand through passive thermal regulation. 198.3 million tons of oil equivalent were used in the EU in 2013 for heating. However, bulk PCMs are not suitable for use without prior encapsulation. Encapsulation in a shell material provides benefits such as protection of the PCM from the external environment and increased specific surface area to improve heat transfer. This review highlights techniques for the encapsulation of both organic and inorganic PCMs, paying particular attention to nanoencapsulation (capsules with sizes <1 μm). We also provide insight on future research, which should focus on (i) the development of multifunctional shell materials to improve lifespan and thermal properties and (ii) advanced mass manufacturing techniques for the economically viable production of PCM capsules, making it possible to utilize waste heat in intelligent passive thermal regulation systems, employing controlled, "on demand" energy release/uptake.

Impairment of muscle function caused by mutations of phosphorylation sites in myosin regulatory light chain

Myosin regulatory light chain is phosphorylated by myosin light chain kinase at conserved serine and threonine residues in a number of species. Phosphorylation of myosin regulatory light chain regulates smooth muscle contraction, but appears to have a modulatory role in striated muscle contraction. We assessed the in vivo role of myosin regulatory light chain phosphorylation in the striated muscles of Drosophila melanogaster by substituting alanine at each or both conserved myosin light chain kinase-dependent phosphorylation sites, serine 66 and serine 67. We report here that myosin light chain kinase-dependent phosphorylation is not required for myofibrillogenesis or for the development of maximal isometric force in indirect flight muscles. However, mutants with substitutions at the major phosphorylation site (serine 66) or with the double substitutions had reduced power output in isolated flight muscle fibres and reduced flight ability, showing that myosin regulatory light chain phosphorylation is a key determinant of the stretch activation response in Drosophila.

Randomized placebo-controlled study of recombinant human interleukin-11 to prevent chemotherapy-induced thrombocytopenia in patients with breast cancer receiving dose-intensive cyclophosphamide and doxorubicin

PURPOSE

Thrombocytopenia may compromise cancer treatment, causing chemotherapy dose reductions, schedule alterations, or the need for platelet transfusions. We evaluated the efficacy and safety of recombinant human interleukin-11 (rhIL-11; Neumega, Genetics Institute, Inc, Cambridge, MA), a novel thrombopoietic growth factor, in reducing the need for platelet transfusions in patients who undergo dose-intensive chemotherapy.

PATIENTS AND METHODS

Women with advanced breast cancer received cyclophosphamide (3,200 mg/m2) and doxorubicin (75 mg/m2) plus granulocyte colony-stimulating factor (G-CSF; 5 microg/kg/d). Patients were randomized to blinded treatment with placebo or 50 microg/kg/d rhIL-11 subcutaneously for 10 or 17 days after the first two chemotherapy cycles.

RESULTS

Seventy-seven patients were randomized and constitute the intent-to-treat (ITT) population. Sixty-seven patients (the assessable subgroup) either completed both cycles without a major protocol violation (n = 62) or received a platelet transfusion before treatment was discontinued after the first cycle. In the ITT population, rhIL-11 significantly decreased the requirement for platelet transfusions; 27 of 40 (68%) patients who received rhIL-11 did not require transfusions, compared with 15 of 37 (41%) in the placebo group (P = .04). Treatment with rhIL-11 significantly reduced the total number of platelet transfusions required in the assessable subgroup (P = .03) and the time to platelet recovery to more than 50,000/microL in the second cycle (P = .01). Most adverse events associated with rhIL-11 were reversible, mild to moderate in severity, and likely related to fluid retention.

CONCLUSION

rhIL-11 is safe and effective in reducing treatment-associated thrombocytopenia and the need for platelet transfusions in patients who undergo dose-intensive chemotherapy, and thus may permit chemotherapy to be administered as planned at intended doses and thereby maximize the potential for a successful outcome.

Development and geometry of isotropic and directional shrinkage-crack patterns

We have studied shrinkage-crack patterns which form when a thin layer of an alumina/water slurry dries. Both isotropic and directional drying were studied. The dynamics of the pattern formation process and the geometric properties of the isotropic crack patterns are similar to what is expected from recent models, assuming weak disorder. There is some evidence of a gradual increase in disorder as the drying layer become thinner, but no sudden transition, in contrast to what has been seen in previous experiments. The morphology of the crack patterns is influenced by drying gradients and front propagation effects, with sharp gradients having a strong orienting and ordering effect.

Purification and evaluation of the integral membrane protein H11 as a protective antigen against Haemonchus contortus

A detergent extract of adult Haemonchus contortus enriched in the integral membrane protein H11, previously shown to give protective immunity against the parasite, was fractionated by lectin and ion-exchange chromatography. The fractions were evaluated for their ability to immunize Clun Forest and Dorset Horn sheep against experimental haemonchosis. Most of the protective activity was associated with H11. Used in an approximately 95% pure form it gave a mean reduction in parasite egg output of 94.6% and reduced male and female worm numbers by 86.5 and 93.5%, respectively. Level of protection correlated with serum antibody titre to H11.

Chromosome 8 breakpoint far 3′ of the c-myc oncogene in a Burkitt's lymphoma 2;8 variant translocation is equivalent to the murine pvt-1 locus

The 2;8 variant translocation of human Burkitt's lymphomas is closely related cytogenetically to the t(6;15) of murine plasmacytomas; both involve a reciprocal exchange between the Ig kappa locus and a band region indistinguishable from that bearing the c-myc oncogene. To define their molecular relationship, we have compared cloned chromosome 8 DNA from the t(2;8) breakpoint in the human Burkitt's lymphoma JBL2 with cloned DNA from the murine pvt-1 locus, the major chromosome 15 breakpoint region in murine t(6;15). DNA sequencing and Southern blot analysis shows that these two regions are homologous. Thus the t(2;8) in JBL2 is the molecular equivalent of many murine t(6;15). The murine pvt-1 locus lies an unknown distance 3' of c-myc; analysis of DNA from several tumours with c-myc amplification reveals that pvt-1 is co-amplified in at least one case, placing pvt-1 approximately 100-500 kb 3' of c-myc. The significance of these results with respect to the role of pvt-1 in tumorigenesis is discussed.

Randomised placebo controlled trial of nebulised corticosteroids in acute respiratory syncytial viral bronchiolitis

OBJECTIVE

To evaluate short and long term effects of giving nebulised budesonide early in respiratory syncytial viral (RSV) bronchiolitis.

DESIGN

A multicentre randomised double blind placebo controlled trial.

SUBJECTS

Infants admitted to hospital with their first episode of RSV positive bronchiolitis.

INTERVENTION

Randomisation to receive either 1 mg of nebulised budesonide (Bud) or placebo (Pla) twice daily from admission until 2 weeks after discharge. Follow up was for 12 months.

MAIN OUTCOME MEASURES

Duration of hospital admission, time taken to become symptom free, re-admission rates, general practitioner consultation rates, and use of anti-wheeze medication during follow up.

RESULTS

161 infants were studied. Both arms were similar with respect to initial clinical severity, age, sex, socioeconomic class, and tobacco exposure. Median time from first nebulisation to discharge: Bud and Pla, 2 days. Median number of days for 50% of infants to be symptom free for 48 hours: Bud, 10 days; Pla, 12 days. Respiratory re-admission rates in the 12 month follow up: Bud, 16%; Pla, 18%; median difference (95% confidence interval (CI)), -2 (-14 to 10). Median respiratory related general practitioner attendances: Bud, 4.0; Pla, 4.5; median difference (95% CI), -1 (-2 to 0). Percentage of infants receiving at least one prescription for anti-wheeze medication during follow up, corticosteroids: Bud, 50%; Pla, 60%; difference (95% CI), -10 (-26 to 6); bronchodilators: Bud, 60%; Pla, 67%; difference (95% CI), -7 (-22 to 8).

CONCLUSIONS

There are no short or long term clinical benefits from the administration of nebulised corticosteroids in the acute phase of RSV bronchiolitis.

Genital cancer in wives of penile cancer patients

We identified the wives or ex-wives of 227 males of the 256 reported with cancer of the penis to the New York State Cancer Registry from Upstate New York from 1960-64. Utilizing the Registry, death certificates, hospital and physician records, we ascertained those wives who developed cancer at any site from 1951-1975. We generated expected numbers of cases of cancer at each site by applying the age specific incidence rates experienced by women of a specific age in a specific year designated by the age of the wife of the index case in each year, estimating withdrawals from age-specific death rates. Thus, our expected numbers are based on the experience of the women in Upstate New York with traits like those of spouses of the men in the same population with cancer of the penis. We found significantly more cases of cancer of the cervix than expected. This was not true for other sites of cancer.

Dehydroepiandrosterone 7-hydroxylase CYP7B: predominant expression in primate hippocampus and reduced expression in Alzheimer's disease

Neurosteroids such as dehydroepiandrosterone (DHEA), pregnenolone and 17beta-estradiol are synthesized by cytochrome P450s from endogenous cholesterol. We previously reported a new cytochrome P450 enzyme, CYP7B, highly expressed in rat and mouse brain that metabolizes DHEA and related steroids by hydroxylation at the 7alpha position. Such 7-hydroxylation can enhance DHEA bioactivity in vivo. Here we show that the reaction is conserved across mammalian species: in addition to mouse and rat, DHEA hydroxylation activity was present in brain extracts from sheep, marmoset and human. Northern blotting using a human CYP7B complementary deoxyribonucleic acid (cDNA) probe confirmed the presence of CYP7B mRNA in marmoset and human hippocampus; CYP7B mRNA was present in marmoset cerebellum and brainstem, with lower levels in hypothalamus and cortex. In situ hybridization to human brain revealed higher levels of CYP7B mRNA in the hippocampus than in cerebellum, cortex, or other brain regions. We also measured CYP7B expression in Alzheimer's disease (AD). CYP7B mRNA was significantly decreased (approximately 50% decline; P<0.05) in dentate neurons from AD subjects compared with controls. A decline in CYP7B activity may contribute the loss of effects of DHEA with ageing and perhaps to the pathophysiology of AD.

Phase I/II study of iodine 131-labeled monoclonal antibody A33 in patients with advanced colon cancer

PURPOSE

A phase I/II study was designed to determine the maximum-tolerated dose (MTD) of iodine 131-labeled monoclonal antibody (mAb) A33 (131I-mAb A33) administered intravenously, its limiting organ toxicity, and its radioisotope retention in tumors, and to develop preliminary evidence of antitumor activity.

PATIENTS AND METHODS

Patients (N = 23) with colorectal cancer who had failed to respond to conventional chemotherapy but had not received prior radiotherapy were treated with escalating doses of 131I-mAb A33. Three or more patients were entered at each dose level, starting at 30 mCi/m2, with increments of 15 mCi/m2 to a maximal dose of 90 mCi/m2. Radiolabeling was performed to maintain a specific activity of 30 mCi/m2/4 mg mAb A33 (projected maximum, 15 mCi/mg). Patients were under strict isolation precautions until whole-body radiation levels decreased to less than 5 mrem/h at 1 m. Serial radioimmunoscintigrams were performed in some cases for up to 3 weeks after 131I-mAb A33 administration.

RESULTS

All 20 patients with radiologic evidence of disease showed localization of radioisotope to sites of disease. Two patients with elevated carcinoembryonic antigen (CEA) levels and negative radiologic tests did not have positive antibody scans. One patient with a small-bowel cancer also had a negative antibody scan. The major toxicity was hematologic and was more pronounced in patients with compromised bone marrow due to prior chemotherapy. Of five patients who received 78 to 84 mCi/m2 131I-mAb A33, one had grade 3 and one grade 4 toxicity; of six patients treated with 86 to 94 mCi/m2 131I-mAb A33, two had grade 4 and one grade 1 toxicity. The MTD was determined to be 75 mCi/m2 in these heavily pretreated patients. Although the isotope showed variable uptake in the normal bowel, gastrointestinal symptoms were mild (n = 8) or absent. No major responses were observed; however, three patients had evidence of mixed responses, and CEA levels decreased in two patients without clinical or radiologic measurable disease. Immunoreactivity of radiolabeled mAb A33 decreased at the highest dose levels in preparations in which specific activity exceeded 18 mCi/mg.

CONCLUSION

The A33 antigen appears to be a promising target for radioimmunotherapy of colon cancer. The modest antitumor activity of 131I-mAb A33 in heavily pretreated patients is encouraging because of its lack of toxicity in the bowel, the only antigen-positive normal tissue.

A phase I/II study of external beam radiation, brachytherapy and concurrent chemotherapy in localized cancer of the esophagus (RTOG 92-07): preliminary toxicity report

PURPOSE

A multi-institutional, prospective study was designed to determine the feasibility and tolerance of external beam irradiation plus concurrent chemotherapy and esophageal brachytherapy (EB) in a potentially curable group of patients with adenocarcinoma or squamous cell carcinoma of the esophagus.

METHODS AND MATERIALS

Planned treatment was 50 Gy external beam radiation (25 fractions/5 weeks) followed 2 weeks later by EB [either high dose rate (HDR) 5 Gy, weeks 8, 9, and 10, for a total of 15 Gy, or low dose rate (LDR) 20 Gy, week 8]. The protocol was later revised to delete the LDR alternative, owing to poor accrual, and to decrease the HDR dose to 10 Gy (i.e. 5 Gy, weeks 8 and 9). Chemotherapy was given weeks 1, 5, 8, and 11 with cisplatin 75 mg/m2 and 5-fluorouracil 1000 mg2/m per 24 h, 96-h infusion. The study closed in January 1995 after 56 patients had been entered on the HDR arm. Six patients were declared ineligible owing to tumor extension to the gastroesophageal junction (three patients) or involved celiac lymph nodes (three patients). Of the 50 eligible patients, the planned EB dose was 15 and 10 Gy in 40 and 10 patients, respectively. Forty-six (92%) of the eligible patients had squamous histology, and three (6%) adenocarcinoma.

RESULTS

Life-threatening toxicity or treatment-related death occurred in 13 (26%) and 4 (8%) of the 50 eligible patients, respectively. Treatment-related esophageal fistulas occurred in three patients (12% overall, 14% of patients starting EB) at 0.5-6.2 months from the first day of brachytherapy, leading to death in three. The fourth death was secondary to renal toxicity and infection attributed to chemotherapy. No correlation was found between the development of fistula and location of primary tumor, brachytherapy active length or applicator diameter. So far, 5 of the 6 treatment-related fistulas have occurred following 15 Gy EB. The other fistula occurred after only 5 Gy of a planned 15 Gy was delivered.

CONCLUSION

Thirty-five patients (70%) were able to complete external beam, EB, and at least two courses of chemotherapy. Estimated survival rate at 12 months is 48%, with an estimated 11-month median survival rate. Survival following external beam radiation plus concurrent chemotherapy and EB does not appear to be significantly different from survival seen following external beam radiation and chemotherapy only. The development of six fistulas in the 35 patients completing EB is of concern. Based on the high incidence of fistulas, we urge extreme caution in employing EB as a boost following concurrent external beam radiation and chemotherapy.

Properties of sea urchin embryo messenger RNA containing and lacking poly(A)

Various properties of nonhistone messenger RNA species containing poly(A), [+A]mRNA, and lacking poly(A), [-A]mRNA, are described: the rates of turnover of these mRNA classes are not significantly different, as indicated by their similar rates of entry into and decay from the cytoplasm; each mRNA class is essentially entirely transcribed from unique DNA sequences; the ratio of [+A] to [-A] nonhistone mRNA increases with increase in size of free polyribosome, although the average molecular weights of these mRNAs are similar in each polysomal size class. These results indicate that the [+A]mRNA species tend to be more fully loaded with ribosomes than the nonhistone [-A]mRNA species.