Breast fibroadenoma: mapping of pathophysiologic features with three-time-point, contrast-enhanced MR imaging--pilot study

The capability of three-time-point, gadolinium-enhanced magnetic resonance imaging to depict vascular permeability and extracellular volume fraction of breast fibroadenoma was evaluated with histopathologic correlation. This method demonstrated an even distribution of high extracellular volume fraction and low to moderate microvascular permeability in these common breast lesions, providing a nonsurgical means of improving the accuracy of diagnosis of fibroadenoma.

Analysis of clustered microcalcifications by using a single numeric classifier extracted from mammographic digital images

RATIONALE AND OBJECTIVES

The authors prospectively tested the performance of a single numeric classifier constructed from a discriminative analysis classification system based on automatic computer-extracted quantitative features of clustered microcalcifications.

MATERIALS AND METHODS

Mammographically detected clustered microcalcifications in patients who had been referred for biopsy were digitized at 600 dpi with an 8-bit gray scale. A software program was developed to extract features automatically from digitized images to describe the clustered microcalcifications quantitatively. The significance of these features was evaluated by using the Wilcoxon test, the Welch modified two-sample t test, and the two-sample Kolmogorov-Smirnov test. A discriminant analysis pattern recognition system was constructed to generate a single numeric classifier for each case, based on the extracted features. This system was trained on 137 archival known reference cases and its performance tested on 24 unknown prospective cases. The results were evaluated by using receiver operating characteristic analysis.

RESULTS

Thirty-seven extracted parameters demonstrated a statistically significant difference between the values for the benign and for the malignant lesions. Seven independent factors were selected to construct the classifier and to evaluate the unknown prospective cases. The area under the receiver operating characteristic curve for the prospective cases was 0.88.

CONCLUSION

A pattern recognition classifier based on quantitative features for clustered microcalcifications at screen-film mammography was found to perform satisfactorily. The software may be of value in the interpretation of mammographically detected microcalcifications.

Stimulation of p53-mediated transcriptional activation by the p53-binding proteins, 53BP1 and 53BP2

p53 is a tumor suppressor protein that controls cell proliferation by regulating the expression of growth control genes. In a previous study, we identified two proteins, 53BP1 and 53BP2, that are able to bind to wild type but not to mutant p53 via the DNA-binding domain of p53. We isolated cDNAs expressing a full-length human 53BP1 clone, which predicts a protein of 1972 residues that can be detected in the H358 human lung carcinoma cell line. The 53BP1 and 53BP2 genes were mapped to chromosomes 15q15-21 and 1q41-42, respectively. Immunofluorescence studies showed three types of staining patterns for 53BP1 as follows: both cytoplasmic and nuclear, homogeneous nuclear, and a nuclear dot pattern. In contrast, 53BP2 localized exclusively to the cytoplasm, and this pattern did not change upon coexpression of wild type p53. Although our previous study revealed that p53 is not able to bind simultaneously to either 53BP1 or 53BP2 and to DNA carrying a consensus binding site, both 53BP1 and 53BP2 enhanced p53-mediated transcriptional activation and induced the expression of a p53-dependent protein, suggesting that these proteins might function in signal transduction pathways to promote p53 activity.

Unusual gallbladder findings in two brothers with metachromatic leukodystrophy

Characteristic biliary tree abnormalities in metachromatic leukodystrophy (MLD) include gallbladder polyposis and haemobilia. We report two brothers with MLD, who presented with uncommon biliary complications. One presented with gastric outlet obstruction secondary to gallbladder enlargement, which was treated by percutaneous aspiration. He later developed gallbladder carcinoma with liver metastases. His brother demonstrated US findings consistent with gallstones.

Mutation detection by a two-hybrid assay

Yeast-based assays have been developed to detect inactivating mutations in human genes, but these assays generally rely on the human protein having a biological function in yeast. We describe a simple method to detect mutations by virtue of their ability to abolish a protein-protein interaction in the yeast two-hybrid assay. By the use of direct recombinational cloning in yeast of a reverse transcription-PCR product followed by a simple growth selection this method distinguished both homozygous and heterozygous mutations in the p53 tumor suppressor gene. This approach should be applicable to many human genes whose encoded proteins have suitable partners in the two-hybrid assay.

Five days of oral topotecan (Hycamtin), a phase I and pharmacological study in adult patients with solid tumours

Topotecan is a specific inhibitor to topoisomerase I. An oral formulation of topotecan is available with a bioavailability of 32-44% in humans. A phase I and pharmacological study of the oral formulation of topotecan administered daily for 5 days every 21 days was performed in adult patients with solid tumours to determine the maximum tolerated dose (MTD). Adult patients with a WHO performance status < or = 2 adequate haematological, hepatic and renal functions, with malignant solid tumours refractory to standard forms were entered into the study. Pharmacokinetics were performed on days 1 and 4 of the first course using a validated high performance liquid chromatographic assay. 29 patients entered the study, all patients were evaluable for toxicity and response. The doses studied in the 29 patients were 1.2, 1.8, 2.3, 2.7 mg/m2/day and a fixed dose of 4 mg/day without surface area adjustment. A total of 109 courses were given. Dose limiting toxicity (DLT) was reached at a dose of 2.7 mg/m2/day and consisted of CTC (NCI-Common Toxicity Criteria) grade IV granulocytopenia. The regimen was well tolerated. Non-haematological toxicities were mild, including fatigue, anorexia, nausea, vomiting and diarrhoea. A significant correlation was observed between the percentage decrease in white blood cells versus the area under the curve (AUC(t)) of topotecan lactone (R = 0.76 P < 0.01) which was modelled by a sigmoidal Emax function. The correlation coefficient between the absolute topotecan dose administered and the AUC(t) was R = 0.52 (P = 0.04). Pharmacokinetics of the fixed dose of 4 mg/day were comparable to the 2.3 mg/m2/day dose. DLT in this phase I study of five daily doses of oral topotecan every 21 days was granulocytopenia. The recommended dose for phase II studies is 2.3 mg/m2/day or alternatively, a fixed dose of 4 mg/day.

Oral topotecan given once or twice daily for ten days: a phase I pharmacology study in adult patients with solid tumors

Prolonged exposure to topotecan (TPT) in in vitro experiments and in vivo studies in animals yielded the highest antitumor efficacy. An oral bioavailability of TPT of 32-44% enables convenient prolonged administration. Because of unpredictable diarrhea in the third week of the twice daily (b.i.d.) 21-day schedule of p.o. administered TPT and the finding of optimal down-regulation of topoisomerase I level after 10-14 days in mononuclear peripheral blood cells, a shorter period of administration (10 days) was chosen for Phase I and pharmacological studies of oral administration of TPT. Adult patients with malignant solid tumors that were refractory to standard forms of chemotherapy were entered. Two dose schedules were studied: once daily (o.d.) and b.i.d. administration for 10 days every 3 weeks. TPT o.d. for 10 days was studied at dose levels 1.0, 1.4, and 1.6 mg/m2/day, and dose levels were 0.5, 0.6, 0.7, and 0.8 mg/m2 with the 10-day b.i.d. schedule. Pharmacokinetics were performed on days 1 and 8 of the first course using a validated high-performance liquid chromatographic assay and noncompartmental pharmacokinetic methods. Nineteen patients were entered in the 10-day o.d. schedule, with a total of 48 courses given. Dose-limiting toxicity (DLT) was reached at 1.6 mg/m2/day and consisted of common toxicity criteria (CTC) grade IV thrombocytopenia and CTC grade III diarrhea. The maximum tolerated dose was 1.4 mg/m2/day. In the 10-day b.i.d. administration of TPT, a total of 64 courses were studied in 20 patients. DLT was reached at a dose of 0.8 mg/m2 b.i.d. and consisted of CTC grade IV myelosuppression and CTC grade IV diarrhea. The maximum tolerated dose was 0.7 mg/m2 b.i.d. Nonhematological toxicities with both schedules included mild nausea and vomiting, fatigue, and anorexia. Pharmacokinetics revealed a substantial variation of the area under the plasma concentration-time curve of TPT lactone in both schedules. Significant correlations were observed between the myelotoxicity parameters and the area under the plasma concentration-time curve at day 1 of TPT lactone o.d. and b.i.d. The DLT of 10 daily administrations of oral topotecan every 3 weeks consisted of a combination of myelosuppression and diarrhea for both schedules studied. The recommended doses for Phase II studies are 1.4 mg/m2/day for 10 days for the o.d. administration and 0.7 mg/m2 for the b.i.d. schedule.

Phase I and pharmacokinetic study of GI147211, a water-soluble camptothecin analogue, administered for five consecutive days every three weeks

GI1147211 is a 7-substituted 10,11-ethylenedioxy-20(S)-camptothecin analogue that inhibits the nuclear enzyme topoisomerase I. In this Phase I and pharmacological study, 24 patients with advanced solid malignancies received a total of 72 courses of GI147211 as a 30-min infusion daily for 5 consecutive days, at doses ranging from 0.3 to 1.75 mg/m2/day. Severe neutropenia precluded dose escalation above 1.5 mg/m2/day in minimally pretreated patients, and both severe neutropenia and thrombocytopenia were dose limiting in heavily pretreated patients at doses above 1.0 mg/m2/day. These doses are, therefore, recommended for subsequent Phase II evaluations of GI147211 in patients with comparable prior therapy. Nonhematological toxicities, including nausea, vomiting, fatigue, and anorexia, were mild to moderate. The disposition of GI147211 in blood was described by a linear three-compartment model, with renal elimination accounting for only 11% of drug distribution. No relationship was observed between the pharmacological exposure to GI147211 and effects on neutrophils; however, patients who developed dose-limiting myelosuppression did experience greater exposure to both the lactone and total forms of the drug. The hydrolysis kinetics of GI147211 revealed not only a shift of the drug to the inactive carboxylate form in human serum albumin but also stabilization of the lactone in erythrocytes, perhaps accounting for the observed lactone:total area under the concentration-time curve ratio of 0.27. These results indicate that GI147211 exhibits predictable toxicities and that further studies are warranted to determine the distinct role of this compound among currently available camptothecin analogues.

A conserved RNA-binding protein that regulates sexual fates in the C. elegans hermaphrodite germ line

The nematode Caenorhabditis elegans has two sexes, males and hermaphrodites. Hermaphrodites Initially produce sperm but switch to producing oocytes. This switch appears to be controlled by the 3' untranslated region of fem-3 messenger RNA. We have now identified a binding factor (FBF) which is a cytoplasmic protein that binds specifically to the regulatory region of fem-3 3'UTR and mediates the sperm/oocyte switch. The RNA-binding domain of FBF consists of a stretch of eight tandem repeats and two short flanking regions. This structural element is conserved in several proteins including Drosophila Pumilio, a regulatory protein that controls pattern formation in the fly by binding to a 3'UTR. We propose that FBF and Pumilio are members of a widespread family of sequence-specific RNA-binding proteins.

The complete set of predicted genes from Saccharomyces cerevisiae in a readily usable form

Nearly all of the open reading frames (ORFs) of the yeast Saccharomyces cerevisiae have been synthesized by PCR using a set of approximately 6000 primer pairs. Each of the forward primers has a common 22-base sequence at its 5' end, and each of the back primers has a common 20-base sequence at its 5' end. These common termini allow reamplification of the entire set of original PCR products using a single pair of longer primers-in our case, 70 bases. The resulting 70-base elements that flank each ORF can be used for rapid and efficient cloning into a linearized yeast vector that contains these same elements at its termini. This cloning by genetic recombination obviates the need for ligations or bacterial manipulations and should permit convenient global approaches to gene function that require the assay of each putative yeast gene.

Transcriptional activation upon pheromone stimulation mediated by a small domain of Saccharomyces cerevisiae Ste12p

In the yeast Saccharomyces cerevisiae, Ste12p induces transcription of pheromone-responsive genes by binding to a DNA sequence designated the pheromone response element. We generated a series of hybrid proteins of Ste12p with the DNA-binding and activation domains of the transcriptional activator Gal4p to define a pheromone induction domain of Ste12p sufficient to mediate pheromone-induced transcription by these hybrid proteins. A minimal pheromone induction domain, delineated as residues 301 to 335 of Ste12p, is dependent on the pheromone mitogen-activated protein (MAP) kinase pathway for induction activity. Mutation of the three serine and threonine residues within the minimal pheromone induction domain did not affect transcriptional induction, indicating that the activity of this domain is not directly regulated by MAP kinase phosphorylation. By contrast, mutation of the two tyrosines or their preceding acidic residues led to a high level of transcriptional activity in the absence of pheromone and consequently to the loss of pheromone induction. This constitutively high activity was not affected by mutations in the MAP kinase cascade, suggesting that the function of the pheromone induction domain is normally repressed in the absence of pheromone. By two-hybrid analysis, this minimal domain interacts with two negative regulators, Dig1p and Dig2p (also designated Rst1p and Rst2p), and the interaction is abolished by mutation of the tyrosines. The pheromone induction domain itself has weak and inducible transcriptional activity, and its ability to potentiate transcription depends on the activity of an adjacent activation domain. These results suggest that the pheromone induction domain of Ste12p mediates transcriptional induction via a two-step process: the relief of repression and synergistic transcriptional activation with another activation domain.

Mapping pathophysiological features of breast tumors by MRI at high spatial resolution

Magnetic resonance imaging (MRI) is a noninvasive method that reveals anatomical details in vivo and detects lesions for diagnosis. Although standard breast MRI cannot clearly delineate breast cancer, contrast-enhanced MRI enables the detection of breast masses with high sensitivity. Dynamic studies demonstrated that malignant lesions were characterized by a faster signal enhancement rate than benign ones. Dynamic MRI of human breast cancer in mice revealed high heterogeneity in the distribution of contrast-enhanced curves and derived pathophysiological features, indicating the importance of high spatial resolution. With clinical MRI, it is difficult to achieve simultaneously high spatial and temporal resolution. In previous dynamic studies, the emphasis was on high temporal resolution and mainly empiric analyses. We describe here a new model-based method that optimizes spatial resolution by using only three time points, and yet characterizes tumor heterogeneity in terms of microvascular permeability and extracellular fraction. Mapping these pathophysiological features may aid diagnosis and prognosis assessment, while the high spatial resolution may improve the capacity to detect smaller lesions. The method was tested in human breast tumors implanted in mice and in a limited number of benign and malignant breast lesions of patients.

[CT-guided core needle biopsy of abdominal, pelvic and retroperitoneal masses]

CT-guided core needle biopsy of abdominal, pelvic and retroperitoneal masses is accurate and safe and can be performed on an outpatient basis. Between 1987 and 1995, 809 patients (age range 1-87 years) underwent 851 biopsies (minimal lesion diameter 1 cm). Cutting needles were always used, facilitating both cytological and histological diagnosis while minimizing risk of complications. A positive result (malignant, inflammatory or infectious) was obtained in 69% of the 809 and a negative result (normal tissue) in 17.4%, while in 13.6%, material for diagnosis was insufficient. Biopsy was repeated in 42 of them in whom radiological or clinical suspicion of malignancy was high. In 24 (60%) a positive result was obtained after the second biopsy. Significant complications occurred in 7 (0.8%). 1 hemo-rrhaged following liver biopsy and required blood transfusion. Pancreatitis occurred in 6 (2.6%) following pancreatic biopsy. An intraabdominal fluid collection in 1 necessitated percutaneous drainage. There was no mortality following the procedure and no documented case of needle-tract seeding of tumor. All outpatients were discharged within 3 hours of completion of the biopsy, without ill effects.

Image-guided core-needle biopsy in malignant lymphoma: experience with 100 patients that suggests the technique is reliable

PURPOSE

In an initial evaluation of 1,500 computed tomography (CT)-guided core-needle biopsies performed at our institute during the period from 1989 to 1994, we encountered 100 patients with the diagnosis of lymphoma. Here, we review the clinical impact of 109 image-guided needle biopsies in these 100 patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD).

PATIENTS AND METHODS

NHL was diagnosed in 71 patients, and 29 had HD. Among the NHL patients, 17 (24%) had proven lymphoma diagnosed before the biopsy was performed; in 54 (76%) core-needle biopsy was performed as the first diagnostic procedure. Of 29 HD patients, nine (31%) were already established cases of HD, and in 20 (69%) core-needle biopsy was the first diagnostic procedure attempted. Most of the biopsies were performed under CT control using a 20- or 18-gauge Turner biopsy needle.

RESULTS

Eighty-six patients received therapy based on the results of the needle biopsy alone. Fourteen patients received therapy after undergoing surgical biopsy for a suspected diagnosis of lymphoma, which could not be established with certainty on the basis of an earlier core-needle biopsy alone. In 78% of the patients, the needle biopsy saved a further surgical procedure that may have been difficult to perform because of the primary location of the tumor.

CONCLUSION

From our experience in this study, image-guided core-needle biopsies provide sufficient information for the diagnosis of and subsequent therapeutic decision to treat most cases of lymphoma.

A three-hybrid system to detect RNA-protein interactions in vivo

RNA-protein interactions are pivotal in fundamental cellular processes such as translation, mRNA processing, early development, and infection by RNA viruses. However, in spite of the central importance of these interactions, few approaches are available to analyze them rapidly in vivo. We describe a yeast genetic method to detect and analyze RNA-protein interactions in which the binding of a bifunctional RNA to each of two hybrid proteins activates transcription of a reporter gene in vivo. We demonstrate that this three-hybrid system enables the rapid, phenotypic detection of specific RNA-protein interactions. As examples, we use the binding of the iron regulatory protein 1 (IRP1) to the iron response element (IRE), and of HIV trans-activator protein (Tat) to the HIV trans-activation response element (TAR) RNA sequence. The three-hybrid assay we describe relies only on the physical properties of the RNA and protein, and not on their natural biological activities; as a result, it may have broad application in the identification of RNA-binding proteins and RNAs, as well as in the detailed analysis of their interactions.

A phase I clinical and pharmacokinetic study of the angiogenesis inhibitor, tecogalan sodium

BACKGROUND

Tecogalan sodium is an angiogenesis inhibitor isolated from a sulfated polysaccharide produced by the bacterium Arthrobacter. The antiangiogenic effect of tecogalan sodium is thought to be mediated by the inhibition of binding of basic fibroblast growth factor to cellular receptors.

PATIENTS AND METHODS

A phase I study was conducted in thirty-three patients with refractory malignancies, including AIDS-associated Kaposi's sarcoma. Patients received a single i.v. infusion every three weeks with the infusion duration ranging from one to twenty-four hours. Seven different dosage levels were studied (125, 185, 240, 300, 390, 445, and 500 mg/m2).

RESULTS

The primary dose-limiting toxicity was prolongation of the activated partial thromboplastin time with peak times being between 1.0-4.0 times the upper limit of normal. This toxicity was ameliorated at a given dose level by prolonging the infusion time. Other common toxicities included fever (40%) and rigors (31%) which were well controlled with acetominophen and meperidine. The serum half-life of tecogalan sodium was between 1-1.5 hours and < 25% of unchanged drug was excreted in the urine.

CONCLUSIONS

The recommended phase II dose of tecogalan sodium on this schedule is 390 mg/m2 over 24 hours. Other schedules including continuous administration should be investigated to maximize the efficacy of this novel angiogenesis inhibitor.

Renal cell carcinoma metastatic to the ovary. Ultrasound and CT appearance

Three years following nephrectomy for renal cell carcinoma, a 54-year-old woman presented with symptoms secondary to ascites, and a large left adnexal mass. A large predominantly cystic, partially solid, septated mass with thick irregular margins was found on ultrasound and computed tomography scans. Pathological examination revealed renal cell carcinoma identical to the original tumor. The etiology and appearance of metastatic disease to the ovary are discussed.

A protein linkage map of Escherichia coli bacteriophage T7

Genome sequencing projects are predicting large numbers of novel proteins, whose interactions with other proteins must mediate the function of cellular processes. To analyse these networks, we used the yeast two-hybrid system on a genome-wide scale to identify 25 interactions among the proteins of Escherichia coli bacteriophage T7. Among these is a set of six interactions connecting proteins that function in DNA replication and DNA packaging. Remarkably, two genes, arranged such that one entirely overlaps the other and uses a different reading frame, encode interacting proteins. Several of the interactions reflect intramolecular associations of different domains of the same polypeptide, suggesting that the two-hybrid assay may be useful in the analysis of protein folding. This global approach to protein-protein interactions may be applicable to the analysis of more complex genomes whose sequences are becoming available.

Retrocrural splanchnic nerve alcohol neurolysis with a CT-guided anterior transaortic approach

Retrocrural splanchnic nerve alcohol neurolysis with a CT-guided anterior transortic approach, a new method for splanchnic block alleviation of chronic abdominal pain, is described. Ten patients with chronic abdominal pain requiring narcotic treatment, six with pancreatic carcinoma, one with gastric carcinoma, two with chronic pancreatitis, and one with pain of unknown etiology, were referred for splanchnic nerve neurolysis. With CT guidance, a 20 gauge needle was placed through the aorta into the retrocrural space at T11-T12, and 5-15 ml 96% alcohol was injected into the retrocrural space. Following the procedure, 6 of 10 patients were pain free, 2 patients had temporary pain relief, and 2 patients were without response. There were no significant complications. CT-guided anterior transaortic retrocrural splanchnic nerve alcohol neurolysis is technically feasible, easier to perform than the classic posterolateral approach, and may have less risk of complications. The success rate in this initial trial was reasonable and, therefore, this technique provides an additional method for the treatment of abdominal pain.

Docetaxel (Taxotere) in combination: a step forward

Docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) is a hemisynthetic derivative from European yew that inhibits tubulin depolymerization and enhances the formation of microtubule bundle aggregates, causing cell death. Activity against a variety of tumor types has been reported. Single-agent chemotherapy is rarely curative; hence, combination regimens are the logical next step in the attempt to improve tumor reduction and prolong survival. In preclinical studies, docetaxel has shown synergism with vinorelbine (Navelbine; Burroughs Wellcome Company, Research Triangle Park, NC), etoposide, cyclophosphamide, 5-fluorouracil, and methotrexate against a variety of murine tumors; in each case, at least 60% of the maximum tolerated dose could be administered without additional toxicity. Similar studies indicated an overlap in dose-limiting toxicity for docetaxel with cisplatin or doxorubicin, whereas with vincristine at least 80% of the maximum tolerated dose could be administered without additional toxicity. A number of docetaxel combinations are currently undergoing clinical evaluation and preliminary results appear to be encouraging. In a phase I trial, the docetaxel/5-fluorouracil combination exhibited activity against refractory solid tumors; grade IV neutropenia was observed, but there was no increase in gastrointestinal toxicity. The docetaxel/doxorubicin combination demonstrated impressive antitumor activity as front-line therapy for metastatic breast cancer (response rate, 70%), with little evidence of mucositis and dose-limiting toxicity experienced by only a minority of patients. Among 12 heavily pretreated phase I patients, the docetaxel/cyclophosphamide combination produced two partial responses in patients with breast cancer; three patients had febrile neutropenia and two had grade II mucositis. The docetaxel/vinorelbine combination produced responses at all dose levels as front-line therapy for metastatic breast cancer; dose-limiting toxicity was experienced by two patients, but only when the vinorelbine dose was raised to 22.5 mg/m2. In phase II studies in non-small cell lung cancer, preliminary results have shown the docetaxel/cisplatin combination to have a promising level of activity and an acceptable toxicity profile. Future trials will continue to evaluate the role of docetaxel in combination and in sequential regimens, most particularly in metastatic breast cancer and non-small cell lung cancer.