Construction and properties of a family of pACYC184-derived cloning vectors compatible with pBR322 and its derivatives

A family of cloning vectors derived from plasmid pACYC184 and, therefore, compatible with pBR322 and its derivatives (especially the pUC family of vectors), is described. They all contain a multiple cloning site (MCS) and the lacZ alpha reporter gene for easy cloning. They have been grouped in three sets: (i) six of the vectors contain a chloramphenicol-resistance (CmR)-encoding gene and each a different MCS with 16 unique restriction sites overall; (ii) another six vectors contain a kanamycin-resistance (KmR)-encoding gene and the same six MCS; and (iii) two CmR vectors that contain the SP6 and T7 promoters flanking the MCS and lacZ alpha reporter gene of pUC18/19.

Reversion of metabolic abnormalities after switching from HIV-1 protease inhibitors to nevirapine

OBJECTIVES

To assess the effects of switching from HIV-1 protease inhibitors (PI) to nevirapine on metabolic abnormalities in patients with fat redistribution and on CD4 T lymphocytes and plasma HIV-1 RNA.

DESIGN

Longitudinal data analysis of 23 consecutive patients treated with two nucleoside reverse transcriptase inhibitors and at least one PI who decided to stop PI despite sustained virological suppression (< 200 copies/ml) because of psychological repercussions caused by body changes. PI were replaced by nevirapine in all patients.

METHODS

Physical examination [including measurements of body mass index (BMI) and waist: hip ratio (WHR)], fasting cholesterol, triglycerides, glucose, insulin, CD4 T lymphocytes and plasma HIV-1 RNA were performed at baseline and every 3 months.

RESULTS

Awareness of body changes occurred after a median of 12 months (range, 6-26 months) from the commencement of PI. Seventeen patients complained of increased abdominal girth (in 15 also of peripheral fat wasting) and six of peripheral fat wasting only. Hypertriglyceridemia (> or = 200 mg/dl) was present in 23 (100%), hypercholesterolemia (> or = 200 mg/dl) in 18 (78%), and impaired fasting glucose (> or = 110 mg/dl) in seven (30%) patients. Baseline CD4 T lymphocytes were 514 x 10(6)/l (range, 83-994 x 10(6)/l). HIV-1 RNA had been < 200 copies/ml a median of 9 months (range, 3-14 months) prior to withdrawal of PI. Median follow-up from the replacement of PI by nevirapine was 8 months (range, 7-11 months). Six months after PI withdrawal there was a significant improvement in cholesterol (decrease of 22%; P = 0.0005), triglycerides (decrease of 57%; P = 0.0001), glucose (decrease of 15%; P = 0.008), and fasting insulin resistance index (decrease of 45%; P = 0.0001). CD4 T-lymphocyte counts remained unchanged (401 x 10(6)/l; range, 57-941 x 10(6)/l; P = 0.13) and in only one patient did the viral load become detectable at a low count (546 copies/ml; P = 0.32). BMI did not vary (23.30 versus 23.56 kg/m2; P = 0.73), but WHR decreased significantly from 0.91 to 0.85 (P = 0.048). Twenty-one patients (91%) subjectively reported a partial improvement in their body shape (particularly in peripheral fat wasting), although none admitted to have their body shaped as prior to body changes.

CONCLUSIONS

Metabolic abnormalities associated with potent antiretroviral regimens including PI may revert at least partially, whereas the suppression achieved may be preserved at least at mid-term after replacing PI by nevirapine.

Hepatotoxicity in HIV-1-infected patients receiving nevirapine-containing antiretroviral therapy

OBJECTIVES

To assess the incidence and risk factors for hepatotoxicity associated with nevirapine.

DESIGN

A prospective cohort study in a teaching and referral hospital involving all consecutive patients who were prescribed a nevirapine-containing antiretroviral regimen between September 1997 and May 2000.

METHOD

Cutaneous and hepatic adverse reactions and clinical hepatitis were assessed. Blood analysis including plasma HIV-1 RNA CD4 cell counts, liver chemistry tests, and serology for hepatitis B and C viruses. Hepatotoxicity was defined as an increase of at least threefold in serum alanine aminotransferase or aspartate aminotransferase levels compared with baseline values.

RESULTS

Of a total of 610 patients, 82 (13.4%) were antiretroviral naive when commencing nevirapine, and 46.2 and 8.9% were coinfected with hepatitis C and B viruses, respectively. Median duration of exposure to nevirapine was 8.7 months (interquartile range 3.4--14.3). Hepatotoxicity developed in 76 (12.5%), an incidence of 13.1/100 person-years. Kaplan--Meier estimated incidence of hepatotoxicity at 3, 6 and 12 months was 3.7, 9.7 and 20.1%, respectively. In seven (1.1%) patients, hepatotoxicity was associated with clinical hepatitis, which was reversible upon discontinuation of therapy. Multivariate analysis identified the duration of prior exposure to antiretroviral drugs, hepatitis C virus, and higher baseline levels of alanine aminotransferase as independent risk factors for hepatotoxicity.

CONCLUSIONS

Hepatotoxicity but not clinical hepatitis was common in HIV-1-infected patients receiving nevirapine-containing regimens and the incidence steadily increased over time. Prolonged exposure to any antiretroviral therapy, coinfection with hepatitis C virus and abnormal baseline levels of alanine aminotransferase identified patients at a higher risk.

Polymorphisms of the repeated sequences in the enhancer region of the thymidylate synthase gene promoter may predict downstaging after preoperative chemoradiation in rectal cancer

PURPOSE

Thymidylate synthase (TS) is an important target enzyme for the fluoropyrimidines. TS gene promoter possesses regulatory tandemly repeated (TR) sequences that are polymorphic in humans, depending on ethnic factors. These polymorphisms have been reported to influence TS expression. TS expression levels affect tumor downstaging after preoperative fluoruracil (5-FU)-based chemoradiation. Tumor downstaging correlates with improved local control and disease-free survival. The aim of this study is to correlate TR polymorphisms with downstaging and disease-free survival.

PATIENTS AND METHODS

Sixty-five patients with rectal cancer underwent tumor resection after preoperative 5-FU-based chemoradiation. Tumor downstaging was evaluated by comparing the pretreatment T stage with the pathologic stage observed in the surgical specimen. TS polymorphism genotype was determined by polymerase chain reaction amplification of the corresponding TS promoter region, and products of amplification were electrophoresed, obtaining products of 220 bp (2/2), 248 bp (3/3), or both (2/3). The TS polymorphism genotype results were subsequently compared with the downstaging observed and with disease-free survival.

RESULTS

Patients who were homozygous for triple TR (3/3) had a lower probability of downstaging than patients who were homozygous with double TR or heterozygous patients (2/2 and 2/3): 22% versus 60% (P =.036; logistic regression). Furthermore, a trend toward improved 3-year disease-free survival was detected in the 2/2 and 2/3 groups, compared with that in the 3/3 group (81% v 41%; P =.17).

CONCLUSION

This preliminary study suggests that TS repetitive-sequence polymorphisms are predictive for tumor downstaging. TR sequences in TS promoter may be useful as a novel means of predicting response to preoperative 5-FU-based chemoradiation.

Genetic determinants of hemostasis phenotypes in Spanish families

BACKGROUND

Recent studies have described genetic mutations that affect the risk of thrombosis as a result of abnormal levels of such hemostatic parameters as protein C, protein S, and the activated protein C resistance ratio. Although these mutations suggest that genes play a part in determining variability in some hemostasis-related phenotypes, the relative importance of genetic influences on these traits has not been evaluated.

METHODS AND RESULTS

The relative contributions of genetic and environmental influences to a panel of hemostasis-related phenotypes were assessed in a sample of 397 individuals in 21 extended pedigrees. The effects of measured covariates (sex, age, smoking, and exogenous sex hormones), genes, and environmental variables shared by members of a household were quantified for 27 hemostasis-related measures. All of these phenotypes showed significant genetic contributions, with the majority of heritabilities ranging between 22% and 55% of the residual phenotypic variance after correction for covariate effects. Activated protein C resistance ratio, activated partial thromboplastin time, and Factor XII showed the strongest heritabilities, with 71.3%, 83.0%, and 67.3%, respectively, of the residual phenotypic variation attributable to genetic effects.

CONCLUSIONS

These results clearly demonstrate the importance of genetic factors in determining variation in hemostasis-related phenotypes that are components of the coagulation and fibrinolysis pathways and that have been implicated in risk for thrombosis. The presence of such strong genetic effects suggests that it will be possible to localize previously unknown genes that influence quantitative variation in these hemostasis-related phenotypes that may contribute to risk for thrombosis.

Rapid urinary antigen test for diagnosis of pneumococcal community-acquired pneumonia in adults

Streptococcus pneumoniae is suspected to cause an important proportion of community-acquired pneumonia (CAP) whose aetiology cannot be detected with conventional tests. In this study, the authors evaluated the diagnostic yield of a new immunochromatographic membrane test (ICT) for the detection of the S. pneumoniae antigen in the urine of patients admitted with diagnosed CAP. ICT was performed in unconcentrated and concentrated urine from all the patients. ICT was repeated 1 month after discharge in a group initially testing positive. The authors also studied the ICT in clinically stable human immunodeficiency virus type 1 (HIV1)-infected patients. S. pneumoniae antigen was detected in all of the 68 (100%) patients tested with definitive pneumococcal pneumonia. In five of these cases ICT was only positive when it had been performed on the patients. The S. pneumoniae antigen was also detected in 36 (69.2%) of 52 patients with probable pneumococcal pneumonia and in 50 of 277 (18%) patients without pneumococcal pneumonia. ICT remained positive in 16 (69.5%) of 23 patients, 1 month after hospital discharge. Nasopharyngeal colonisation with S. pneumoniae was detected in 8 (12%) of 68 clinically stable HIV1 infected patients, but none tested ICT positive. The Binax NOW it immunochromatographic membrane test is a rapid, sensitive and specific test for detecting pneumococcal community-acquired pneumonia in adults. The test may remain positive for several weeks after pneumococcal pneumonia.

A randomized trial of the discontinuation of primary and secondary prophylaxis against Pneumocystis carinii pneumonia after highly active antiretroviral therapy in patients with HIV infection. Grupo de Estudio del SIDA 04/98

BACKGROUND

Prophylaxis against Pneumocystis carinii pneumonia is indicated in patients with human immunodeficiency virus (HIV) infection who have less than 200 CD4 cells per cubic millimeter and in those with a history of P. carinii pneumonia. However, it is not clear whether prophylaxis can be safely discontinued after CD4 cell counts increase in response to highly active antiretroviral therapy.

METHODS

We conducted a randomized trial of the discontinuation of primary or secondary prophylaxis against P. carinii pneumonia in HIV-infected patients with a sustained response to antiviral therapy, defined by a CD4 cell count of 200 or more per cubic millimeter and plasma HIV type 1 (HIV-1) RNA level of less than 5000 copies per milliliter for at least three months. Prophylactic treatment was restarted if the CD4 cell count declined to less than 200 per cubic millimeter.

RESULTS

The 474 patients receiving primary prophylaxis had a median CD4 cell count at entry of 342 per cubic millimeter, and 38 percent had detectable HIV-1 RNA. After a median follow-up period of 20 months (758 person-years), there had been no episodes of P. carinii pneumonia in the 240 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 0.85 episode per 100 person-years). For the 113 patients receiving secondary prophylaxis, the median CD4 cell count at entry was 355 per cubic millimeter, and 24 percent had detectable HIV-1 RNA. After a median follow-up period of 12 months (123 person-years), there had been no episodes of P. carinii pneumonia in the 60 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 4.5 episodes per 100 person-years).

CONCLUSIONS

In HIV-infected patients receiving highly active antiretroviral therapy, primary and secondary prophylaxis against P. carinii pneumonia can be safely discontinued after the CD4 cell count has increased to 200 or more per cubic millimeter for more than three months.

Prothrombotic state and signs of endothelial lesion in plasma of patients with inflammatory bowel disease

Recent investigations suggest that microthrombi formation in bowel capillaries could be a determinant factor in inflammatory bowel disease (IBD) pathogenesis. To evaluate the implication of the hemostatic system during these thrombotic events, we analyzed plasmatic values of prothrombotic state markers, physiologic inhibitors of coagulation, and endothelial lesion markers in 112 IBD patients. We found an increase in thrombin-antithrombin complexes and a decrease in antithrombin III, probably due to consumption, demonstrating an increase in thrombin generation. High levels of D-dimer reflect increased fibrin formation, but there is no correlation between thrombin generation markers and D-dimer, possibly suggesting the presence of inadequate fibrinolysis. Levels of tissue factor pathway inhibitor were higher in patients than in controls. Nine patients with Crohn's disease (35% of our sample) had levels of this marker under 70% (range 37-69%). Von Willebrand factor values were increased and those of thrombomodulin only in active patients. Most of the changes were detected in patients with inflammatory activity, and there were no differences between ulcerative colitis and Crohn's disease. In conclusion, these results support the hypothesis that there is an endothelial lesion with sustained coagulation activation in IBD patients.

High incidence of herpes zoster in patients with AIDS soon after therapy with protease inhibitors

A high incidence of herpes zoster was noticed among patients with AIDS, shortly after addition of a protease inhibitor to their baseline treatment with nucleoside analogue reverse-transcriptase inhibitors. Within a median follow-up of 64 weeks (range, 34-103 weeks), 14 patients (7%) had a first episode or a recurrence of herpes zoster (6.2 episodes per 100 patient-years). No episodes of zoster were diagnosed before week 4. Twelve episodes (86%) occurred between weeks 4 and 16. The risk of zoster was independent of age, sex, type of protease inhibitor, and CD4+ lymphocyte count and viral load at baseline and month 1. A CD8+ lymphocyte proportion at baseline of > 66% (hazard ratio [HR], 10.6; 95% confidence interval [CI], 3.4-33.1) and an increase in CD8+ lymphocyte proportion at month 1 of > 5% (HR, 32; 95% CI, 8.1-126.4) were independently associated with the risk of herpes zoster. These data might be clinically useful for determining transient prophylaxis for those patients at high risk.

Impact of switching from human immunodeficiency virus type 1 protease inhibitors to efavirenz in successfully treated adults with lipodystrophy

We prospectively followed 20 consecutive patients with human immunodeficiency virus type 1 (HIV-1) with viral loads of <200 RNA copies/mL. These patients had been treated with 2 nucleoside reverse transcriptase inhibitors and > or =1 HIV-1 protease inhibitor for > or =3 months; they developed body changes consistent with lipodystrophy and requested they be switched from protease inhibitor to efavirenz. At baseline and every 3 months, we assessed the following: body mass index, waist-to-hip ratio, regional fat thickness (assessed by sonography), fasting total and high-density lipoprotein cholesterol, triglycerides, glucose, insulin, CD4(+) cells, and viral load. At baseline, hypertriglyceridemia (> or =200 mg/dL) was present in 17 (85%) patients, hypercholesterolemia (> or =200 mg/dL) in 14 (70%), and impaired fasting glucose (> or =110 mg/dL) in 8 (40%); CD4(+) T cells were 280x10(6) cells/L (range, 64-942x10(6) cells/L). HIV-1 RNA had been at <200 copies/mL for a median of 14 months (range, 3-24 months). Six months after switching to efavirenz, there was a reduction in triglyceride levels (a decrease of 31%; P=.03) and fasting insulin resistance index (a decrease of 28%; P=.03), but total and high-density lipoprotein cholesterol and glucose did not change. Waist-to-hip ratio decreased from 0.92 to 0.87 (P=.06). Subcutaneous fat thickness did not change. CD4(+) cells remained stable (363x10(6) cells/L; range, 102-741x10(6) cells/L; P=.65). Nineteen patients (95%) had HIV-1 RNA levels that remained at <200 copies/mL. Although CD4(+) response and viral suppression remained preserved after 6 months of switching from protease inhibitor to efavirenz, the benefits of this approach on the evolution of lipodystrophy were limited, and our findings do not support its routine recommendation to treat lipodystrophy.

Postsynaptic antagonistic interaction between adenosine A1 and dopamine D1 receptors

Behavioural and biochemical evidence for the existence of a powerful specific postsynaptic interaction between adenosine A1 and dopamine D1 receptors in the mammalian brain was found. Behavioural data showed that A1 receptor stimulation induced a decrease in the D1-induced motor activation in reserpinized mice and a decrease in the D1-dependent oral dyskinesia in rabbits. Biochemical data suggested that A1 receptor stimulation could produce a GTP-independent uncoupling of the rat striatal D1 receptor to the G protein. The A1-D1 receptor-receptor interaction might represent an important additional mechanism of action responsible for the motor depressant effects of adenosine agonists and for the motor stimulant effects of adenosine antagonists, like the methylxanthines caffeine and theophylline.

Large-scale production of recombinant hepatitis B surface antigen from Pichia pastoris

The ability of the Pichia pastoris-based technology for large-scale production of recombinant hepatitis B virus surface antigen (HBsAg) and both reproducibly purify HBsAg and remove most of the relevant contaminants was ascertained by evaluating ten industrial production batches, five in 1993 and five in 1998. At an early stage, the clarification of mechanically disrupted yeast cells by acid precipitation renders HBsAg with a purity as low as 3.8 +/- 0.6%. However, by adsorption/desorption from diatomaceous earth matrix, the purity of HBsAg rapidly increases to 18.8 +/- 5%, which is suitable for chromatographic processing. This step also eliminates non-particulated forms of HBsAg, significantly lowers the amount of carbohydrates and lipids, and concentrates the HBsAg 4.8-fold. Finally, a sequential purification procedure that includes large-scale immunoaffinity, ion-exchange, and size-exclusion chromatographies further purifies the preparation, resulting in a product (HBsAg at a concentration of 1.3 +/- 0.2 g l-1) with a purity of 95% or more. Furthermore, each of the other contaminants measured reaches the following low levels per 20 micrograms HBsAg: host deoxyribonucleic acid (< 10 pg), carbohydrates (1.2 +/- 0.02 micrograms), lipids (14 +/- 0.28 micrograms), immunopurification-released immunoglobulin G (less than 100 ppm), and endotoxins (106.7 +/- 19.3 pg). These values are below those specified for recombinant DNA hepatitis B vaccines according to World Health Organization (WHO) guidelines.

The EORTC QLQ-C30 (version 3.0) Quality of Life questionnaire: validation study for Spain with head and neck cancer patients

The EORTC Quality of Life Study Group has developed a questionnaire for evaluating Quality of Life in international clinical trials: QLQ-C30. The purpose of the present work is to validate the third version of this questionnaire (3.0) for use in Spain. Two hundred and one head and neck cancer patients completed the QLQ-C30 at one or two time points during the treatment and follow-up periods, and a subsample completed the questionnaire on three occasions. Psychometric evaluation of the structure, reliability and validity of the questionnaire was undertaken. The data support the structure and the reliability of the scales. Validity was confirmed in three ways: the interscale correlations are statistically significant and moderate, several scales and items discriminate among groups of patients with different scores on the clinical variables, and some scales reflect significant changes during treatment and the follow-up period. The EORTC QLQ-C30 (version 3.0) is a reliable and valid questionnaire when applied to a sample of Spanish head and neck cancer patients. These results are in line with previous studies.

Nitrogen-fixing nodules induced by Agrobacterium tumefaciens harboring Rhizobium phaseoli plasmids

Rhizobium phaseoli CFN299 forms nitrogen-fixing nodules in Phaseolus vulgaris (bean) and in Leucaena esculenta. It has three plasmids of 185, 225, and 410 kilobases. The 410-kilobase plasmid contains the nitrogenase structural genes. We have transferred these plasmids to the plasmid-free strain Agrobacterium tumefaciens GMI9023. Transconjugants containing different combinations of the R. phaseoli plasmids were obtained, and they were exhaustively purified before nodulation was assayed. Only transconjugants harboring the 410-kilobase plasmid nodulate P. vulgaris and L. esculenta. Nodules formed by all such transconjugants are able to reduce acetylene. Transconjugants containing the whole set of plasmids from CFN299 nodulate better and fix more nitrogen than the transconjugants carrying only the Sym plasmid. Microscopic analysis of nodules induced by A. tumefaciens transconjugants reveals infected cells and vascular bundles. None of the A. tumefaciens transconjugants, not even the one with the whole set of plasmids from CFN299, behaves in symbiosis like the original R. phaseoli strain; the transconjugants produce fewer nodules and have lower acetylene reduction (25% as compared to the original R. phaseoli strain) and more amyloplasts per nodule. More than 2,000 bacterial isolates from nodules of P. vulgaris and L. esculenta formed by the transconjugants were analyzed by different criteria. Not a single rhizobium could be detected. Our results show that R. phaseoli plasmids may be expressed in the A. tumefaciens background and direct the formation of effective, differentiated nodules.

Incidence and causes of death in HIV-infected persons receiving highly active antiretroviral therapy compared with estimates for the general population of similar age and from the same geographical area

BACKGROUND

Since the introduction of highly active antiretroviral therapy (HAART), the incidence of death in HIV-infected patients has dramatically decreased, and causes of death other than those related to HIV infection have increased, although it is unclear how these parameters compare with those in the age-matched general population living in the same geographical region.

METHODS

Consecutive HIV-infected adults who were prescribed HAART in our hospital were prospectively followed from January 1997 to December 2004 or until death, loss to follow-up or discontinuation of HAART. Estimations of the annual incidence and causes of death in the general population of similar age in Catalonia per calendar year in the study period were obtained and compared with those in the HIV-infected cohort.

RESULTS

There were 235 deaths among the 4471 patients on HAART (5%). The incidence of mortality decreased over time in HIV-infected patients (P<0.001; chi(2) test for trend), although it has remained approximately five times higher than that for the age-matched general population. AIDS-related events were the most common cause of death (n=95; 40%), although they significantly decreased over time (P<0.001; chi(2) test for trend), whereas liver diseases (P<0.001; chi(2) test for trend) and non-AIDS-defining infections (P=0.008; chi(2) test for trend) significantly increased over time. Infections in general (33 times higher), liver diseases (11 times higher) and non-Hodgkin lymphoma (5 times higher) were overrepresented as causes of death in the HIV-infected cohort compared with the age-matched general population.

CONCLUSIONS

Non-AIDS-defining infectious diseases, liver diseases, and non-Hodgkin lymphoma represent specific targets for efforts to further decrease mortality in HIV-infected patients receiving HAART.

Genomic instability in Rhizobium phaseoli

Experience from different laboratories indicates that Rhizobium strains can generate variability in regard to some phenotypic characteristics such as colony morphology or symbiotic properties. On the other hand, several reports suggest that under certain stress conditions or genetic manipulations Rhizobium cells can present genomic rearrangements. In search of frequent genomic rearrangements, we analyzed three Rhizobium strains under laboratory conditions that are not considered to cause stress in bacterial populations. DNAs from direct descendants of a single cell were analyzed in regard to the hybridization patterns obtained, using as probes different recombinant plasmids or cosmids; while most of the probes utilized did not show differences in the hybridization patterns, some of them revealed the occurrence of frequent genomic rearrangements. The implications and possible biological significance of these observations are discussed.

Hypersensitivity reactions to rifampin. Pathogenetic mechanisms, clinical manifestations, management strategies, and review of the anaphylactic-like reactions

Many of the adverse events induced by rifampin have been considered allergic in origin. The flu-like syndrome and other hypersensitivity reactions seem to be caused by immune complexes, although their pathogenetic mechanisms are not fully elucidated. Many cases have been reported of the flu-like syndrome, thrombocytopenia, hemolytic anemia, and renal failure caused by rifampin. In almost all of the patients in whom they were sought, nonreaginic antirifampin antibodies were detected. On the other hand, anaphylactic reactions seem to be IgE-mediated. We have analyzed the 18 reported cases of anaphylactic reactions severe enough to cause marked hypotension. The interval between the onset of treatment and the anaphylactic reaction was highly variable. Most patients presented with prodromes, mainly rash, before the development of anaphylactic symptoms, and, in most cases, the reaction occurred after reexposure to rifampin. Clinical findings include a variety of symptoms, such as fever, exanthem, dyspnea, abdominal pain, and vomiting. Seven of the 9 patients in whom HIV status was known were seropositive, including the only 2 patients who died. We believe that, in case of a non-life-threatening adverse reaction caused by immune complexes, rifampin could be readministered, if necessary, at a more frequent and reduced dose, perhaps with the addition of corticosteroids. In case of anaphylactic reactions the drug should be avoided, although desensitization procedures may be useful. Certain laboratory findings may serve as a clue to predict anaphylactic reactions in patients who have experienced minor adverse events to rifampin. However, the diagnostic value of such findings is not well established and, therefore, patients with previous adverse reactions should be carefully monitored if reexposure to rifampin is essential.

A predictive model of pathologic response based on tumor cellularity and tumor-infiltrating lymphocytes (CelTIL) in HER2-positive breast cancer treated with chemo-free dual HER2 blockade

Background

The presence of stromal tumor-infiltrating lymphocytes (TILs) is associated with increased pathologic complete response (pCR) and improved outcomes in HER2-positive early-breast cancer (BC) treated with anti-HER2-based chemotherapy. In the absence of chemotherapy, the association of TILs with pCR following anti-HER2 therapy-only is largely unknown.

Patients and methods

The PAMELA neoadjuvant trial treated 151 women with HER2-positive BC with lapatinib and trastuzumab [and hormonal therapy if hormone receptor (HR)-positive] for 18 weeks. Percentage of TILs and tumor cellularity were determined at baseline (N = 148) and at day 15 (D15) of treatment (N = 134). Associations of TILs and tumor cellularity with pCR in the breast were evaluated. A combined score based on tumor cellularity and TILs (CelTIL) measured at D15 was derived in PAMELA, and validated in D15 samples from 65 patients with HER2-positive disease recruited in the LPT109096 neoadjuvant trial, where anti-HER2 therapy-only was administer for 2 weeks, then standard chemotherapy was added for 24 weeks.

Results

In PAMELA, baseline and D15 TILs were significantly associated with pCR in univariate analysis. In multivariable analysis, D15 TILs, but not baseline TILs, were significantly associated with pCR. At D15, TILs and tumor cellularity were found independently associated with pCR. A combined score (CelTIL) taking into account both variables was derived. CelTIL at D15 as a continuous variable was significantly associated with pCR, and patients with CelTIL-low and CelTIL-high scores had a pCR rate of 0% and 33%, respectively. In LPT109096, CelTIL at D15 was found associated with pCR both as a continuous variable and as group categories using a pre-defined cut-off (75.0% versus 33.3%).

Conclusions

On-treatment TILs, but not baseline TILs, are independently associated with response following anti-HER2 therapy-only. A combined score of TILs and tumor cellularity measured at D15 provides independent predictive information upon completion of neoadjuvant anti-HER2-based therapy.

Clinical trial number

NCT01973660.

Randomized phase II trial of carboplatin versus paclitaxel and carboplatin in platinum-sensitive recurrent advanced ovarian carcinoma: a GEICO (Grupo Espanol de Investigacion en Cancer de Ovario) study

BACKGROUND

The aim of this study was to determine whether the response rate for the paclitaxel-carboplatin combination is superior to carboplatin alone in the treatment of patients with platinum-sensitive recurrent ovarian carcinoma.

PATIENTS AND METHODS

Patients with recurrent ovarian carcinoma, 6 months after treatment with a platinum-based regimen and with no more than two previous chemotherapy lines, were randomized to receive carboplatin area under the curve (AUC) 5 (arm A) or paclitaxel 175 mg/m(2) + carboplatin AUC 5 (arm B). The primary end point was objective response, following a 'pick up the winner' design. Secondary end points included time to progression (TTP), overall survival, tolerability and quality of life (QoL).

RESULTS

Eighty-one patients were randomized and included in the intention-to-treat analysis. The response rate in arm B was 75.6% [26.8% complete response (CR) + 48.8% partial response (PR)] [95% confidence interval (CI) 59.7% to 87.6%] and 50% in arm A (20% CR + 30% PR) (95% CI 33.8% to 66.2%). No significant differences were observed in grade 3-4 hematological toxicity. Conversely, mucositis, myalgia/arthralgia and peripheral neurophaty were more frequent in arm B. Median TTP was 49.1 weeks in arm B (95% CI 36.9-61.3) and 33.7 weeks in arm A (95% CI 25.8-41.5). No significant differences were found in the QoL analysis.

CONCLUSIONS

Paclitaxel-carboplatin combination is a tolerable regimen with a higher response rate than carboplatin monotherapy in platinum-sensitive recurrent ovarian carcinoma.

Stem cell differentiation by functionalized micro- and nanostructured surfaces

New fabrication technologies and, in particular, new nanotechnologies have provided biomaterial and biomedical scientists with enormous possibilities when designing customized supports and scaffolds with controlled nanoscale topography and chemistry. The main issue now is how to effectively design these components and choose the appropriate combination of structure and chemistry to tailor towards applications as challenging and complex as stem cell differentiation. Occasionally, an incomplete knowledge of the fundamentals of biological differentiation processes has hampered this issue. However, the recent technological advances in creating controlled cellular microenvironments can be seen as a powerful tool for furthering fundamental biology studies. This article reviews the main strategies followed to achieve solutions to this challenge, particularly emphasizing the working hypothesis followed by the authors to elucidate the mechanisms behind the observed effects of structured surfaces on cell behavior.

Reiterated DNA sequences in Rhizobium and Agrobacterium spp

Repeated DNA sequences are a general characteristic of eucaryotic genomes. Although several examples of DNA reiteration have been found in procaryotic organisms, only in the case of the archaebacteria Halobacterium halobium and Halobacterium volcanii [C. Sapienza and W. F. Doolittle, Nature (London) 295:384-389, 1982], has DNA reiteration been reported as a common genomic feature. The genomes of two Rhizobium phaseoli strains, one Rhizobium meliloti strain, and one Agrobacterium tumefaciens strain were analyzed for the presence of repetitive DNA. Rhizobium and Agrobacterium spp. are closely related soil bacteria that interact with plants and that belong to the taxonomical family Rhizobiaceae. Rhizobium species establish a nitrogen-fixing symbiosis in the roots of legumes, whereas Agrobacterium species is a pathogen in different plants. The four strains revealed a large number of repeated DNA sequences. The family size was usually small, from 2 to 5 elements, but some presented more than 10 elements. Rhizobium and Agrobacterium spp. contain large plasmids in addition to the chromosomes. Analysis of the two Rhizobium strains indicated that DNA reiteration is not confined to the chromosome or to some plasmids but is a property of the whole genome.

Serotonin in body fluids: characterization of human plasmatic and cerebrospinal fluid pools by means of a new HPLC method

A new HPLC technique for the analysis of picomolar amounts of serotonin (5HT) in plasma and cerebrospinal fluid (CSF) is described. Bufotenin is used as internal standard. Detection is achieved electrochemically or fluorimetrically. The detection limit can be estimated as 50 pg 5HT/mL of either fluid (0.3 picomolar). The method is used to characterize a non-particulate pool of 5HT which is clearly distinct of the platelet pool. Administration of parachlorophenylalanine (PCPA) 300 mg/kg to rats leads to a 90% reduction in the plasmatic pool whereas platelet 5HT is only slightly decreased (3rd day after PCPA) or even increased (7th day after PCPA). Human concentration (n = 15) of 5HT in plasma is 2.6 +/- 0.9 ng/mL (X +/- S.D.). The application of the method to CSF of neurological patients reveals 5HT concentrations ranging from 93 to 962 pg/mL.

Risk of ischemic stroke and lifetime estrogen exposure

BACKGROUND

Estrogen loss has been related to higher incidence of stroke in postmenopausal women, but randomized trials have demonstrated an increased risk of stroke in women receiving hormone replacement therapy (HRT).

OBJECTIVE

To assess the relationship between exposure to endogenous ovarian hormones and the risk of noncardioembolic ischemic stroke.

METHODS

We conducted a multicenter, age-matched, case-control study in postmenopausal women (case: nonembolic ischemic stroke; control: no stroke) comparing duration of ovarian activity or lifetime estrogen exposure, which was defined as age at menarche to age at menopause. Embolic cardiopathy and unreliable gynecologic data were exclusion criteria. Cardiovascular disease risk factors were recorded. The relationships of the principal variables to the risk of stroke were assessed using a conditional logistic regression analysis.

RESULTS

There were 430 cases and 905 controls in the study. In the multivariate analysis, hypertension (odds ratio [OR]: 2.73; 95% CI: 2.09 to 3.58; p < 0.0001), diabetes (OR: 3.38; 95% CI: 2.53 to 4.52; p < 0.0001), hyperlipidemia (OR: 1.31; 95% CI: 1.01 to 1.7; p = 0.045), lifespan of ovarian activity <34 years (OR: 1.51; 95% CI: 1.13 to 2.03; p = 0.005), and menarche at <13 years of age (OR 1.49; 95% CI: 1.15 to 1.92; p = 0.002) were independently related to an increased risk of stroke. Obesity (OR: 0.73; 95% CI: 0.56 to 0.95; p = 0.021) was related to a lower risk of stroke.

CONCLUSIONS

Longer lifetime exposure to ovarian estrogens may protect against noncardioembolic ischemic stroke. However, a very early age of exposure onset could be disadvantageous.

Biodistribution and pharmacokinetics of uniform magnetite nanoparticles chemically modified with polyethylene glycol

The influence of polyethylene glycol (PEG) grafting on the pharmacokinetics, biodistribution and elimination of iron oxide nanoparticles is studied in this work. Magnetite nanoparticles (12 nm) were obtained via thermal decomposition of an iron coordination complex as a precursor. Particles were coated with meso-2,3-dimercaptosuccinic acid (DMSA) and conjugated to PEG-derived molecules by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC) chemistry. Using a rat model, we explored the nanoparticle biodistribution pattern in blood and in different organs (liver, spleen and lungs) after intravenous administration of the product. The time of residence in blood was measured from the evolution of water proton relaxivities with time and Fe analysis in blood samples. The results showed that the residence time was doubled for PEG coated nanoparticles and consequently particle accumulation in liver and spleen was reduced. Post-mortem histological analyses showed no alterations in the liver and confirm heterogeneous distribution of NPs in the organ, in agreement with magnetic measurements and iron analysis. Finally, by successive magnetic resonance images we studied the evolution of contrast in the liver and measured the absorption, time of residence and excretion of nanoparticles in the liver during a one month period. On the basis of these results we propose different metabolic routes that determine the fate of magnetic nanoparticles.