Detection of high-molecular-weight RNA in particles from human milk.

Particles from human milk contain a reverse transcriptase and a high-molecular-weight (60S to 70S) RNA that serves as a template. These particles have two features diagnostic of known RNA tumor viruses.

DNA content and DNA-based centromeric index of the 24 human chromosomes.

The chromosomes of two human males were identified by fluorescent banding, restained, and measured by scanning microscopy and computer analysis. The two variables, DNA content and DNA-based centromeric index, provided almost complete discrimination of chromosome types. Some chromosomes showed significant differences in DNA content between the men, and for one man two pairs of chromosomes showed significant differences between homologs.

Oxidative stress pathways highlighted in tumor cell immortalization: association with breast cancer outcome.

An improved understanding of cell immortalization and its manifestation in clinical tumors could facilitate novel therapeutic approaches. However, only rare tumor cells, which maintain telomerase expression in vitro, immortalize spontaneously. By expression-profiling analyses of limited-life primary breast tumor cultures pre- and post-hTERT transduction, and spontaneously immortalized breast cancer cell lines, we identified a common signature characteristic of tumor cell immortalization. A predominant feature of this immortalization signature (ImmSig) was the significant overexpression of oxidoreductase genes. In contrast to epithelial cells derived from low histologic grade primary tumors, which required hTERT transduction for the acquisition of ImmSig, spontaneously immortalizing high-grade tumor cultures displayed similar molecular changes independent of exogenous hTERT. Silencing the hTERT gene reversed ImmSig expression, increased cellular reactive oxygen species levels, altered mitochondrial membrane potential and induced apoptotic and proliferation changes in immortalized cells. In clinical breast cancer samples, cell-proliferation-pathway genes were significantly associated with ImmSig. In these cases, ImmSig expression itself was inversely correlated with patient survival (P=0), and was particularly relevant to the outcome of estrogen receptor-positive tumors. Our data support the notion that ImmSig assists in surmounting normal barriers related to oxidative and replicative stress response. Targeting a subset of aggressive breast cancers by reversing ImmSig components could be a practical therapeutic strategy.

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND).

BACKGROUND: Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis in most countries. Questions persist about its clinical utility because of high cost and modest efficacy. OBJECTIVES: To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Register for randomized trials in December 2004 and made enquiries of authors of trials, Aventis (manufacturer of riluzole) and other experts in the field. We searched MEDLINE (January 1966 to August 25 2006) and EMBASE (January 1980 to September 30th 2006). SELECTION CRITERIA: Types of studies: randomized trials. TYPES OF PARTICIPANTS: adults with a diagnosis of amyotrophic lateral sclerosis. Types of interventions: treatment with riluzole or placebo. Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality with riluzole 50, 100 and 200 mg; neurologic function, muscle strength and adverse events. DATA COLLECTION AND ANALYSIS: We identified four eligible randomized trials. MAIN RESULTS: The four trials examining tracheostomy-free survival included a total of 974 riluzole treated patients and 503 placebo treated patients. The methodological quality was acceptable and three trials were easily comparable, although one trial included older patients in more advanced stages of amyotrophic lateral sclerosis and one had multiple primary endpoints. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (P value = 0.042, hazard ratio 0.80, 95% confidence interval 0.64 to 0.99) and there was no evidence of heterogeneity (P value = 0.33). When the third trial (which included older and more seriously affected patients) was added, there was evidence of heterogeneity (P value < 0.0001) and the random effects model, which takes this into account, resulted in the overall treatment effect estimate falling just short of significance (P value = 0.056, hazard ratio 0.84, 95% confidence interval 0.70 to 1.01). This represented a 9% gain in the probability of surviving one year (57% in the placebo and 66% in the riluzole group). There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (weighted mean difference 2.62, 95% confidence interval 1.59 to 4.31). AUTHORS' CONCLUSIONS: Riluzole 100 mg daily is reasonably safe and probably prolongs median survival by about two to three months in patients with amyotrophic lateral sclerosis.

Outcomes associated with cesarean section versus vaginal breech delivery at a university hospital.

OBJECTIVE: To determine whether vaginal breech delivery is associated with increased morbidity in term breech singletons using strict selection criteria. This study encompasses our previous studies (in 1987 and 1995) and extends our experience to 21 years. STUDY DESIGN: Retrospective cohort study from 1980 to 2001 including term, non-anomalous singleton breech deliveries selected by strict criteria. Univariable and multivariable analyses were performed for neonatal and maternal outcomes. RESULTS: Five hundred and eleven women underwent cesarean section and 214 a trial of labor. We found greater overall maternal morbidity in the cesarean section group (odds ratio (OR) 1.89, 95% confidence interval (CI)=1.34-2.65). In the vaginal delivery group, neonates were more likely to have had >1 day of mechanical ventilation (OR 10.0, 95% CI=1.56-63.9). No maternal deaths occurred and no neonatal deaths or seizures occurred. CONCLUSION: Given our findings, offering a trial of vaginal breech delivery to well-counseled strictly selected patients remains an appropriate option.

Psychostimulants for hypersomnia (excessive daytime sleepiness) in myotonic dystrophy.

BACKGROUND: Excessive daytime sleepiness is a common symptom of myotonic dystrophy. Psychostimulants are drugs increasingly used to treat hypersomnia in myotonic dystrophy. OBJECTIVES: To search systematically for, and combine all evidence from, randomised trials relating to the effects of psychostimulants in myotonic dystrophy patients with hypersomnia. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Trials Register (January 2006), MEDLINE (from January 1966 to January 2006) and EMBASE (from January 1980 to January 2006) for randomised trials concerning psychostimulants in myotonic dystrophy, checked the bibliographies of identified papers and made enquiries of the authors of the papers. The search for relevant studies was updated in January 2006. SELECTION CRITERIA: We considered all randomised or quasi randomised trials that have evaluated any type of psychostimulants (versus a placebo or no treatment) in children or adults with proven myotonic dystrophy and hypersomnia. DATA COLLECTION AND ANALYSIS: Potentially relevant papers were scrutinised by two authors and the selection of eligible studies was agreed by them and a third author. Data were extracted by one author and checked by a second author. MAIN RESULTS: Primary outcome. One trial using a modified maintenance of wakefulness test showed an improvement by 5.70 (95% confidence intervals 0.1 to 11.3) minutes more in the modafinil than the control group. Secondary outcomes. In a double-blind crossover study of 10 participants with myotonic dystrophy, there was no difference between the selegiline and placebo periods in mean improvement in the multiple sleep latency test. Two trials, involving 60 participants in total, evaluated the efficacy and safety of modafinil in adults with myotonic dystrophy-related daytime sleepiness. The weighted mean difference on the Epworth Sleepiness Scale was -1.59 (95% confidence intervals, -2.77 to -0.42) in favour of modafinil. AUTHORS' CONCLUSIONS: There is no evidence to support the routine use of psychostimulants to treat hypersomnia in myotonic dystrophy. There is some evidence from two studies that modafinil may improve daytime sleepiness. More randomised trials are needed to evaluate the efficacy and safety of psychostimulants.

Biologic characteristics of some mouse mammary tumor viruses.

The mammary tumor virus (MuMTV) in the milks of 7 mouse strains and substrains was titrated for infectivity in 4 strains. The data indicated that: 1) Each strain shed a different MuMTV and some genetic strains carried two MuMTV's, each discernible by its mouse strain preference in infectivity tests. 2) Less than 5% of RIIIf and about 10% of Af mice shed detectable MuMTV antigen in their milks after the third parturition. After the sixth parturition, 33% of RIIIf and 50% of Af, and after the ninth parturition, 60% of RIIIf and 90% of Af mice shed viral antigen in their milks. The MuMTV's in milks of high-parity mothers were most infectious in mouse strains different from those most susceptible to MuMTV in RIII and A milks of low-parity mothers. Therefore, RIII and A mice each harbored two viruses, one that was removed by foster-nursing and the other that was not. 3) The susceptibility incidence of RIIIfC57BL mice to RIII virus changed gradually from about 10% in 1970 to about 70% in 1975. Susceptibility of C57BL mice to RIII virus did not change appreciably over this period, and the natural tumor incidence in RIIIfC57BL remained unchanged (about 10%). In addition to their susceptibility to RIII virus, C57BL mice were also susceptible to GR virus; they were relatively resistant to other strains tested. They were especially resistant to RIIIf virus, to which Af and BALB/c mice were very susceptible. 4) Approximately 90% of C3HfC57BL and C3HfBALB/c mice shed antigen in their milks after the third parturition, although the tumor incidence was less and occurred later than in C3H mice. No clear-cut differences could be detected in infectivities between low-parity C3H milk and high-parity C3Hf milks tested in several assay strains.

In vitro susceptibility of mink lung cells to the mouse mammary tumor virus.

Lung cells from mink embryos were infected in vitro with a purified mammary tumor virus isolated from RIII mouse milk. Specific virus antigen at the cell surface was detected by membrane immunofluorescence; B-type virions budding from the cell membrane were seen by electron microscopy. Nucleic acid hybridization confirmed replication and specificity of the virus produced.

Chromosomal alterations in ductal carcinomas in situ and their in situ recurrences.

BACKGROUND: Ductal carcinoma in situ (DCIS) recurs in the same breast following breast-conserving surgery in 5%-25% of patients, with the rate influenced by the presence or absence of involved surgical margins, tumor size and nuclear grade, and whether or not radiation therapy was performed. A recurrent lesion arising soon after excision of an initial DCIS may reflect residual disease, whereas in situ tumors arising after longer periods are sometimes considered to be second independent events. The purpose of this study was to determine the clonal relationship between initial DCIS lesions and their recurrences. METHODS: Comparative genomic hybridization (CGH) was used to compare chromosomal alterations in 18 initial DCIS lesions (presenting in the absence of invasive disease) and in their subsequent ipsilateral DCIS recurrences (detected from 16 months to 9.3 years later). RESULTS: Of the 18 tumor pairs, 17 showed a high concordance in their chromosomal alterations (median = 81%; range = 65%-100%), while one case showed no agreement between the paired samples (having two and 20 alterations, respectively). Morphologic characterization of the DCIS pairs showed clear similarities. The mean number of CGH changes was greater in the recurrent tumors than in the initial lesions (10.7 versus 8.8; P =.019). The most common changes in both the initial and the recurrent in situ lesions were gains involving chromosome 17q and losses involving chromosomes 8p and 17p. The degree of concordance was independent of the time interval before recurrence and of the presence of positive surgical margins. CONCLUSIONS: In this study, DCIS recurrences were clonally related to their primary lesions in most cases. This finding is consistent with treatment paradigms requiring wide surgical margins and/or postoperative radiation therapy.

Inability to predict mammary tumorigenesis in strain A mice from presence of mammary tumor virus or antigen in the milk.

Strain A females were milked and their milk was tested for mammary tumor virus (MTV) by the hyperplastic alveolar nodule test and for MTV antigen by microimmunodiffusion. An attempt was made to correlate these results with later occurrence of mammary tumors in the females. There was not full agreement between the results of the test for the presence of the MTV and those of the test for MTV antigen, and from these results it was impossible to predict accurately whether a specific female would later develop a tumor. It is concluded that, in this strain, factors other than the MTV can be the determinant in whether the individual female will develop a tumor.

Tumor angiogenesis as a prognostic assay for invasive ductal breast carcinoma.

BACKGROUND: Tumor angiogenesis, as assayed by microvessel density, has been proposed as an independent prognostic marker for clinical outcome in breast cancer patients. PURPOSE: The present study evaluated the microvessel density assay and assessed its utility, alone and together with the evaluation of other tumor characteristics, in predicting outcome in patients with invasive ductal carcinomas. METHODS: In a blinded design, cases of invasive ductal carcinoma were selected from a registry containing the records of and tumor specimens from 386 breast cancer patients treated at the Massachusetts General Hospital from 1977 through 1982. After the exclusion of ineligible patients and inadequate specimens, 220 patients were included in the study; their median time of follow-up was 11.5 years. Half of these patients (n = 110) were positive for axillary lymph node metastases. Histologic sections of the tumors were stained immunocytochemically for factor VIII, a coagulation protein expressed by blood vessel endothelium, and for p53 protein. Independently, two analysts counted microvessels in three microscope fields selected from separate vascular regions of the tumor. Variability in microvessel scores between analysts and among different fields of the same tumor was summarized by the coefficient of variation. The kappa statistic tested for agreement between the analysts while correcting for chance agreement. The effects of tumor characteristics on metastasis-free survival and overall survival were tested univariately by the Harrington-Fleming rank test procedure. The effect of multiple factors on survival was tested under a Cox multivariate proportional hazards model. RESULTS: Microvessel count showed considerable variability between the two analysts and among regions within each tumor, with an overall concordance for tumor classification of 73%. Univariate analysis revealed no association between microvessel count and any other tumor or patient characteristic. Multivariate analysis indicated, for these patients, that nodal status and p53 staining predicted metastasis-free survival and that nodal status, estrogen receptor (ER) status and tumor grade predicted overall survival. CONCLUSIONS: Microvessel count showed much variation among different regions of each tumor. It did not predict metastasis-free survival or overall survival. Nodal status was the most powerful criterion to stratify these patients with invasive ductal carcinoma of the breast into different survival groups. Only ER status, tumor grade, and p53 staining had additional prognostic utility for these patients after they had been stratified by nodal status.

Tumor angiogenesis: a new significant and independent prognostic indicator in early-stage breast carcinoma.

BACKGROUND: Axillary lymph node status has been the most important prognostic factor in operable breast carcinoma, but it does not fully account for the varied disease outcome. More accurate prognostic indicators would help in selection of patients at high risk for disease recurrence and death who are candidates for systemic adjuvant therapy. Our recent findings indicated that microvessel density (count or grade) in invasive breast carcinoma (a measure of tumor angiogenesis) is associated with metastasis and thus may be a prognostic indicator. PURPOSE: This study was designed to further define the relationship of microvessel density with overall and relapse-free survival and with other reported prognostic indicators in breast carcinoma. METHODS: In a prospective, blinded study of 165 consecutive patients, the microvessels within primary invasive breast carcinoma were highlighted by immunocytochemical staining to detect factor VIII-related antigen. Using light microscopy, we counted microvessels per 200x field in the most active areas of neovascularization and graded microvessel density. These findings were correlated, by univariate and multivariate analyses, with overall and relapse-free survival, axillary node status, and other prognostic indicators (median follow-up, 51 months). RESULTS: There was a highly significant (P < or = .001) association of microvessel density with overall survival and relapse-free survival in all patients, including node-negative and node-positive subsets. All patients with breast carcinomas having more than 100 microvessels per 200x field experienced tumor recurrence within 33 months of diagnosis, compared with less than 5% of the patients with breast carcinoma having 33 or fewer microvessels per 200x field. Moreover, microvessel density was the only statistically significant predictor of overall survival among node-negative women (P < .001). Only microvessel density (P < .001) and histologic grade (P = .04) showed statistically significant correlations with relapse-free survival in the node-negative subset. CONCLUSIONS: Microvessel density in the area of the most intense neovascularization in invasive breast carcinoma is an independent and highly significant prognostic indicator for overall and relapse-free survival in patients with early-stage breast carcinoma (I or II by International Union Against Cancer criteria). IMPLICATIONS: Such an indicator would be useful in selection of those node-negative patients with breast carcinoma who are at high risk for having occult metastasis at presentation. These patients could then be given systemic adjuvant therapy.

Immunization of mice against murine mammary tumor virus infection and mammary tumor development.

Formalin-inactivated whole murine mammary tumor virus (MuMTV), VuMTV membranes, the acid-soluble component of MuMTV, and purified MuMTV glycoprotein with a molecular weight of 55,000 (gp55; also designated as gp52) were used as vaccines in an attempt to identify the MuMTV antigen(s) that can protect mice from exogenous MuMTV infection and subsequent tumor development. Formalin-inactivated whole MuMTV, MuMTV membranes, and purified MuMTV gp55 were effective immunogens, whereas the acid-soluble component of MuMTV (which consists mainly of MuMTV gp55) failed to protect mice from challenge with live virus. These results suggest that (a) MuMTV gp55 is the major immunizing antigen and (b) its native conformation must be maintained for it to be an effective vaccine.

Observations on the question of horizontal transmission of mouse mammary tumor virus.

Antigen and tumor incidences in BALB/c and C57BL mice after living as weanlings for 5 weeks in cages with mouse mammary tumor virus-infected females were compared with control BALB/c and C57BL mice living in the same laboratory. All mice were bred continuously, and third-lactation milks were tested for mouse mammary tumor virus antigen by Ouchterlony microimmunodiffusion test. Mammary tumor incidences in the cagemates were not significantly different from those in the controls, although the antigen incidences were significantly greater. However, phosphate-buffered salt solution (0.02 M phosphate, pH 7.4; 0.15 M NaCl; and 0.1% bovine serum albumin) and sham-inoculated mice also had elevated antigen incidences. Repeat tests of milks at the fourth or fifth lactations indicated that more than 50% of those positive at the third became negative at later lactations.

Further immunization studies with mammary tumor virus.

A single i.m. dose of formalin-inactivated murine mammary tumor virus greatly reduces viral expression and mammary tumorigenesis in Af (tumor incidence, 39%) and RIIIf (tumor incidence, 11%) mice, which carry only endogenous, gamete-transmitted virus. In C57BL mice, 1 mug of vaccine in Freund's complete adjuvant protects against later challenge with RIII virus.

Quantification by DNA-based cytophotometry of the 9q+/22q-chromosomal translocation associated with chronic myelogenous leukemia.

DNA-based cytophotometry was used to analyze metaphase chromosomes in four patients with chronic myelogenous leukemia. In three of these patients, both Philadelphia chromosome (Ph1)-positive and Ph1-negative cells were measured. On the basis of these three patients, the characteristic 9q+/22q- translocation of chronic myelogenous leukemia involves the net transfer of 0.325% of the autosomal genome; there is no evidence of net gain or loss of DNA (apart from duplication of the Ph1 chromosome in one patient), and no significant difference is found in the amount of DNA transferred in different patients. Significant differences are found among patients in the derived Chromosomes 9 and the Ph1 chromosomes and are ascribed to preexisting variations in the Ph1-negative cells of these patients. There is no evidence in these patients of any further cytogenetic lesion associated with chronic myelogenous leukemia.

Partial enzymatic degradation of stroma allows enrichment and expansion of primary breast tumor cells.

The goal of this study was to isolate and expand tumor cells in culture that closely resemble invasive cells in primary breast carcinoma tissue. Based on the hypothesis that invasive tumor cells are released more readily upon digestion with connective tissue-degrading enzymes because they are not confined within a basement membrane, we have designed a novel procedure for their isolation. Using this method, we have successfully expanded in culture aneusomic tumor cells from several primary breast tumors. Twenty nine of 44 (66%) specimens processed yielded proliferative and passageable cultures of up to 2 x 10(7) cells. The original tumor tissue and cultures derived therefrom were compared for aneusomy and the abnormal expression of the erb-B2, p53, and bcl-2 gene products. Remarkable similarities were observed. However, some intratumor heterogeneity in chromosome content was found between touch preparations and cultured cells. Overexpression of erb-B2 was observed in the vast majority of cases (16 of 20), suggesting that this phenotype may be important for dysregulated proliferation in vitro. The simple and rapid method described in this report could enable routine expansion of primary breast tumors and provide adequate numbers of viable cells for studying and manipulating their functional characteristics.

Experimental infection of a cat kidney cell line with the mouse mammary tumor virus.

A cat kidney cell line, CRFK-F2, was successfully inoculated in suspension and in monolayer culture with a purified mouse mammary tumor virus derived from RIII milk. The virus produced by the infected cells was identified by immunogluorescence, electron microscopy, and RNA-directed DNA polymerase assays; it was a B-type virion that did not cross-react with mouse or feline leukemia-sarcoma viruses, had spikes on its envelope, and had a RNA-directed DNA polymerase reaction that was typical of mouse mammary tumor virus. The producing cells were identified as cat cells by chromosome number, cytotoxic assays, and isoenzyme migratory patterns. A standardized method for the in vitro inoculation of cat cells is described that presently permits highly reproducible results. For the first time, the mouse mammary tumor virus is seen replicating in cells from another species, thus offering an opportunity to study the kinetics of infection of that virus.

Identification of the virions in the in vitro L1210(V) leukemia cell lines by morphological, virological, and immunological techniques.

In vitro L1210 (V) cell lines contained abundant intracytoplasmic A-particles, numerous C-type particles, a small number of B-type particles, and occasional intracisternal A-particles. The intracytoplasmic A-particles were incorporated into both spiked (B-type) and smooth-surfaced (C-type) particles formed at the budding site. Both B-and C-type particles also developed by gradual accululation of neucleooid material. The particles, particularly the C-type, exhibited a wide range of densities. The cells showed strong surface immunofluoresence for both murine mammary tumor virus and Gross murine leukemia virus antigens and variable degrees of cytoplasmic immunoflurescence for the protein antigens (p1 to p6) of Rauscher leukemia virus. The cells, the culture supernatant, and the purified virus each gave positive reactions with murine mammary tumor virus and murine leukemia virus antisera by immunodiffusion. The viral particles failed to infect C57BL, C57BL/6 X DBA/2F1 (hereafter called BD2F1), BALB/c, Af,and RIIIf mice. Howver, the cells were highly tumorigenic in BD1F-1 mice, moderately tumorigenic in BALB/c mice, but not tumorigenic in C57BL, Af, and RIIIf mice.

Genetic alterations in untreated metastases and androgen-independent prostate cancer detected by comparative genomic hybridization and allelotyping.

A newly developed method of comparative genomic hybridization (CGH) employing quantitative statistical comparisons was applied to DNA from two different types of advanced prostate cancer tissue. Multiple CGH analyses were obtained for each chromosome in each tumor, and the results of point-by-point comparison of the mean tumor:normal color ratio to a control normal:normal color ratio in each of 1247 evenly distributed data channels constituting the entire human genome were interpreted as loss, gain, or no change in copy number in the tumor genome. Group I tissue was obtained from prostate cancer metastases from 20 patients, 19 of whom had received no prior prostate cancer treatment. This DNA also was analyzed by Southern and microsatellite allelotyping at 53 different loci on 20 different chromosome arms. CGH results agreed with allelotyping results at 92% of the informative loci studied. These samples, which contained highly enriched tumor DNA, showed the highest rates of alteration yet reported in several chromosomal regions known to be altered frequently in prostate cancer: 8q gain (85%), 8p loss (80%), 13q loss (75%), 16q loss (55%), 17p loss (50%), and 10q loss (50%). Group II tissue was obtained predominately from primary or recurrent tumor from 11 patients who had been treated with long-term androgen-deprivation therapy and developed androgen-independent metastatic disease. Quantitative CGH analysis on DNA from these tissues showed chromosomal alterations that were very similar to those found in group I, suggesting that untreated metastatic tumors contain the bulk of chromosomal alterations necessary for recurrence to occur during androgen deprivation. In the entire data set, a number of previously undetected regions of frequent loss or gain were identified, including losses of chromosomes 2q (42%), 5q (39%), 6q (39%), and 15q (39%) and gains of chromosomes 11p (52%), 1q (52%), 3q (52%), and 2p (45%). Chi-squared analysis showed a significantly higher frequency of gain of the 4q25-q28 region in tumors from African-American patients, indicating a possible oncogene whose activation may play a role in the higher rate of progression seen in this ethnic group. Additional study of these frequently altered regions may provide insight into the mechanism of prostate cancer progression and lead to important tools for tumor-specific prognosis and therapy.