Early detection of oral potentially malignant disorders using machine learning: a retrospective pilot study.

Early diagnosis of oral potentially malignant disorders (OPMDs) may be hindered by similar clinical presentations shared between benign oral lesions and OPMDs. The goal of this retrospective pilot study was to assess the use of machine learning (ML) as an adjunctive evaluation in conjunction with conventional comprehensive oral examination of OMPDs. Digital images of 80 deidentified intraoral lesions (40 benign intraoral lesions and 40 OPMDs) were collected. The images, which were previously identified independently by experienced oral pathologists, were used to create 3 datasets: raw images, grayscale images, and enhanced color images. The datasets were subsequently divided into training (n = 60), test (n = 10), and validation (n = 10) groups so that class labels (benign lesion or OMPD) were distributed equally in each group. A cross-validated grid search was used to optimize the hyperparameters of the Extreme Gradient Boosting (XGBoost) classifications model. Predictions were made on the test group and used to optimize the prediction threshold. The final results were validated by predictions based on the validation group. The XGBoost classification model was able to differentiate between benign intraoral lesions and OPMDs with a mean classification accuracy of 70%, sensitivity of 80%, and specificity of 60% when grayscale and enhanced color intraoral images were used. A mean classification accuracy of 50%, sensitivity of 40%, and specificity of 60% were observed when raw intraoral images were used. The results demonstrated that ML may be a promising tool for the diagnosis of OPMDs when used as an adjunct to conventional comprehensive oral examination.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1ß, IL-8 and Graft-Versus-Host Disease.

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low-medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1ß, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1ß and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.

Prenatal exposure to VOCs and NOx and lung function in preschoolers.

BACKGROUND: Several studies have shown that exposure to air pollutants affects lung growth and development and can result in poor respiratory health in early life. METHODS: We included a subsample of 772 Mexican preschoolers whose mothers participated in a Prenatal Omega-3 fatty acid Supplements, GRowth, And Development birth cohort study with the aim to evaluate the impact of prenatal exposure to volatile organic compounds and nitrogen oxides on lung function measured by oscillation tests. The preschoolers were followed until 5 years of age. Anthropometric measurements and forced oscillation tests were performed at 36, 48, and 60 months of age. Information on sociodemographic and health characteristics was obtained during follow up. Prenatal exposure to volatile organic compounds and nitrogen oxides was evaluated using a land use regression models and the association between them was tested using a lineal regression and longitudinal linear mixed effect models adjusting for potential confounders. RESULTS: Overall, the mean (standard deviation) of the measurements of respiratory system resistance and respiratory system reactance at 6, 8, and 10 Hz during the follow-up period was 11.3 (2.4), 11.1 (2.4), 10.3 (2.2) and -5.2 (1.6), -4.8 (1.7), and -4.6 hPa s L-1 (1.6), respectively. We found a significantly positive association between respiratory resistance (ßRrs6 = 0.011; 95%CI: 0.001, 0.023) (P < .05) and prenatal exposure to nitrogen dioxide and a marginally negatively association between respiratory reactance (ßXrs6 = -11.40 95%CI: -25.26, 1.17 and ßXrs8 = -11.91 95%CI: -26.51, 1.43) (P = .07) and prenatal exposure to xylene. CONCLUSION: Prenatal exposure to air pollutants was significantly associated with the alteration of lung function measured by oscillation tests in these preschool children.

Chrysalises as natural production units for recombinant subunit vaccines.

The baculovirus vector expression system (BEVS) combines cultured insect cells and genetically modified Autographa californica nuclear polyhedrosis virus (AcMNPV)-derived baculovirus vectors. This expression system has been widely used for the expression of hundred of proteins for more than 30 years, existing commercial products manufactured at large scale by this methodology, mainly subunit vaccines. At an industrial scale, insect cells, as any other cultured cells, require artificial media and a strict control of environmental sterile conditions in the complex and expensive bioreactors. Here we describe an efficient alternative to produce recombinant biologics using the versatile and productive baculovirus vectors. It consists in natural biocapsules (pupae from Trichoplusia ni (Hübner) Lepidoptera), containing millions of insect cells in perfect physiological conditions, ready to be programmed by a genetically modified AcMNPV-derived baculovirus vector to produce large quantities of any recombinant protein. This technology, denominated CrisBio, has been tested to produce dozens of proteins, reaching productivities on the range of milligrams per infected pupa, that can be translated into dozens of vaccine doses, for example. The biologics production by CrisBio was industrialized with the design of both insect rearing and pupae storage single-use plastic devices, compatible with machines specifically designed for the automation of pupae manipulation and inoculation. These devices and machines reduce manual operations, increase batches consistency and facilitate the scaled production of any recombinant protein. As a mode of examples, the productivity in CrisBio technology platform of two virus-like particle (VLP) vaccine antigens is described in this work.

African swine fever virus serodiagnosis: a general review with a focus on the analyses of African serum samples.

African swine fever (ASF) is an infectious disease that causes heavy mortality in domestic pigs. At present there is no vaccine against ASF, and eradication in countries where the disease is endemic is based only on competent diagnosis programs and the sacrifice of infected animals. Due to the presence of natural attenuated strains, certain infection conditions may result in reduced mortality. In these situations, the disease can be diagnosed by detection of specific antibodies. The use of classical and validated diagnosis assays, such as ELISA and Indirect Immunofluorescence or Immunoblotting, allowed the eradication of ASF in the Iberian Peninsula in the 1990s. However, given that conventional tests include the use of antigens obtained from ASF virus (ASFV)-infected cells, they have several disadvantages, such as difficulties to achieve standardization and also the risks associated with the manipulation of live virus. Such drawbacks have led to the development of alternative and more robust systems for the production of ASFV antigens for use in anti-ASFV antibody detection systems. In the present review, we provide an update on current knowledge about antigen targets for ASFV serodiagnosis, the significant progress made in recombinant antigen production, and the refinement of ASF serological diagnostic assays. Moreover, we describe the accuracy of an ELISA developed for the serodiagnosis of ASFV in Africa. This assay is based on a novel p30 recombinant protein (p30r) obtained from an Eastern African viral isolate (Morara strain), which shares 100% amino acid sequence identity with the Georgia virus isolate. That study included the analyses of 587 field sera collected from domestic pigs and warthogs in Senegal (West Africa), the Democratic Republic of Congo (Central Africa), Mozambique (South-East Africa), and South Africa. The results revealed that the novel p30r-based ELISA allows the accurate detection of antibodies against ASFV, independently of the geographical origin of the sera.

Rotavirus A-specific single-domain antibodies produced in baculovirus-infected insect larvae are protective in vivo.

BACKGROUND: Single-domain antibodies (sdAbs), also known as nanobodies or VHHs, are characterized by high stability and solubility, thus maintaining the affinity and therapeutic value provided by conventional antibodies. Given these properties, VHHs offer a novel alternative to classical antibody approaches. To date, VHHs have been produced mainly in E. coli, yeast, plants and mammalian cells. To apply the single-domain antibodies as a preventive or therapeutic strategy to control rotavirus infections in developing countries (444,000 deaths in children under 5 years of age) has to be minimized their production costs. RESULTS: Here we describe the highly efficient expression of functional VHHs by the Improved Baculovirus Expression System (IBES® technology), which uses a baculovirus expression vector in combination with Trichoplusia ni larvae as living biofactories. Two VHHs, named 3B2 and 2KD1, specific for the inner capsid protein VP6 of Group A rotavirus, were expressed in insect larvae. The IBES® technology achieved very high expression of 3B2 and 2KD1, reaching 2.62% and 3.63% of the total soluble protein obtained from larvae, respectively. These expression levels represent up to 257 mg/L of protein extract after insect processing (1 L extract represents about 125 g of insect biomass or about 375 insect larvae). Larva-derived antibodies were fully functional when tested in vitro and in vivo, neutralizing Group A rotaviruses and protecting offspring mice against rotavirus-induced diarrhea. CONCLUSIONS: Our results open up the possibility of using insects as living biofactories (IBES® technology) for the cost-efficient production of these and other fully functional VHHs to be used for diagnostic or therapeutic purposes, thereby eliminating concerns regarding the use of bacterial or mammalian cells. To the best of our knowledge, this is the first time that insects have been used as living biofactories to produce a VHH molecule.

The association between body shape silhouette and dietary pattern among Mexican women.

OBJECTIVE: To investigate the relationship between dietary patterns and self-perceived body shape silhouette and BMI in a sample of Mexican women. DESIGN: A cross-sectional analysis of dietary habits from baseline data of a large cohort study (EsMaestra) conducted in 2006-2008. SETTING: The state of Veracruz, Mexico. SUBJECTS: Mexican teachers (n 20 330) provided information on body shape silhouette at baseline, changes in body shape silhouette and BMI, as well as information on sociodemographic variables and lifestyle. RESULTS: The median BMI was 26·8 kg/m2; 43 % of women were overweight and 24 % were obese. The carbohydrates, sweet drinks and refined foods pattern was associated with a greater risk of having a large silhouette and a large BMI (BMI ≥ 30·0 kg/m2 v. BMI < 25·0 kg/m2; ORT1-3 = 1·86, 95 % CI 1·56, 2·22 and 1·47, 95 % CI 1·28, 1·69, respectively) with a significant trend when comparing the first and third tertiles of intake. The fruit and vegetable pattern was associated with a lower risk of having a large silhouette and a large BMI (ORT1-3 = 0·68, 95 % CI 0·57, 0·82 and ORT1-3 = 0·77, 95 % CI 0·67, 0·88, respectively) with a significant decreasing trend. Similar results were observed when change in silhouette (from 18 years of age to current silhouette) was considered. CONCLUSIONS: High intakes of carbohydrates, sweet drinks and refined foods are related to larger silhouettes. Public health intervention improving access to healthy dietary guidelines, healthy food choice in the work place, promotion of physical activity and regulation of beverages with a high sugar content and of refined foods should be considered.

Homochiral drugs: a demanding tendency of the pharmaceutical industry.

The issue of drug chirality is now a major theme in the design and development of new drugs, underpinned by a new understanding of the role of molecular recognition in many pharmacologically relevant events. In general, three methods are utilized for the production of a chiral drug: the chiral pool, separation of racemates, and asymmetric synthesis. Although the use of chiral drugs predates modern medicine, only since the 1980's has there been a significant increase in the development of chiral pharmaceutical drugs. An important commercial reason is that as patents on racemic drugs expire, pharmaceutical companies have the opportunity to extend patent coverage through development of the chiral switch enantiomers with desired bioactivity. Stimulated by the new policy statements issued by the regulatory agencies, the pharmaceutical industry has systematically begun to develop chiral drugs in enantiometrically enriched pure forms. This new trend has caused a tremendous change in the industrial small- and large-scale production to enantiomerically pure drugs, leading to the revisiting and updating of old technologies, and to the development of new methodologies of their large-scale preparation (as the use of stereoselective syntheses and biocatalyzed reactions). The final decision whether a given chiral drug will be marketed in an enantiomerically pure form, or as a racemic mixture of both enantiomers, will be made weighing all the medical, financial and social proficiencies of one or other form. The kinetic, pharmacological and toxicological properties of individual enantiomers need to be characterized, independently of a final decision.

Acyclonucleosides, modified seco-nucleosides, and salicyl- or catechol-derived acyclic 5-fluorouracil O,N-acetals: antiproliferative activities, cellular differentiation and apoptosis.

The goal of cancer chemotherapy with classical drugs - the destruction of the tumor cells - is often complicated by significant toxicity. As an alternative, induced differentiation modulates the cell programme by transforming malignant cells into mature cells with no proliferative potential. Our data demonstrate that (+/-)-1-{[3-(2-hydroxyethoxy)-1-isopropoxy]propyl}-5-fluorouracil inhibits proliferation, induces myogenic differentiation, increases the expression of proteins specifically present in normally differentiated skeletal muscle cells, and modifies the adhesion capacity of these cells against the rhabdomyosarcoma cell line RD. From a designing point of view, a benzene ring was fused to the side chain in order to increase the lipophilicity and anticancer activity of our molecules. Herein we report the preparation and biological activity of three compounds having the general formula (+/-)-1-[2-(5-substituted-2-hydroxybenzyloxy)-1-methoxyethyl]-5-fluorouracils. A catechol-derived compound such as (+/-)-1-[3-(2-hydroxyphenoxy)-1-methoxypropyl]-5-fluorouracil and two salicyl-derived compounds such as (+/-)-(Z)-1-[4-(2-hydroxyphenyl)-1-methoxy-but-3-enyl]-5-fluorouracil [(Z)-43] and its dihydrogenated derivative (+/-)-1-[4-(2-hydroxyphenyl)-1-methoxybutyl]-5-fluorouracil were prepared to complete the set of six O,N-acetals. The most active compound against the MCF-7 breast cancer cell line was (+/-)-(Z)-43 with an IC(50) = 9.40 +/- 0.64 microM. Differentiated breast cancer cells generate fat deposits within the cytoplasm. The MCF-7 cells trea-ed with (+/-)-(Z)-43 caused an increase in the lipid content over control cells after 3 days of treatment. Our results suggest that there may be significant potential advantages in the use of this new differentiating agent for the treatment of breast cancer.

Design, synthesis and anticancer activity against the MCF-7 cell line of benzo-fused 1,4-dihetero seven- and six-membered tethered pyrimidines and purines.

Having previously reported the synthesis and anticancer activities of cyclic 5-fluorouracil (5-FU) O,N-acetalic compounds, the decision was made to change 5-FU for uracil (U), with the prospect of finding an antiproliferative agent endowed with a new mechanism of action. The use of a reverse transcription-PCR-based assay decreased cyclin D1 mRNA, suggesting that this cyclic U O,N-acetalic compound exerts its regulatory action on cyclin D1 at the level of transcription. Following the ongoing Anticancer Drug Programme we planned the synthesis of compounds bearing a natural pyrimidine base and also, the oxygen atom at position 1 of the seven-membered cycle was replaced by its isosteric sulfur atom, and its oxidized states. Next, the pyrimidine base was substituted for the purine one, with the objective of increasing both the lipophilicity and the structural diversity of the target molecules. If the previously described compounds were not prodrugs, it would not be necessary to maintain the O,N-acetalic characteristic. Therefore, molecules were designed in which both structural entities (such as the benzoheterocyclic ring and the purine base) were linked by a heteroatom-C-C-N bond. A series of (RS)-9-(2,3-dihydro-1,4-benzoxathiin-3-ylmethyl)-9H-purine derivatives was obtained and the anticancer activity for the most active compounds was correlated with their capability to induce apoptosis. Finally, completing a SAR study, a series of (RS)-6-substituted-7- or 9-(1,2,3,5-tetrahydro-4,1-benzoxazepine-3-yl)-7H- or 9H-purines was prepared. The studies by microarray technology showed that the main molecular targets of some of these compounds are pro-apoptotic genes with protein kinase activity such as GP132, ERN1 or RAC1, which prevent the metastatic progression.

Benign paroxysmal positional vertigo and clinical test of sensory interaction and balance in systemic sclerosis.

OBJECTIVE: To assess the frequency and characteristics of benign paroxysmal positional vertigo (BPPV) and clinical test of sensory interaction and balance (CTSIB) abnormalities in patients with systemic sclerosis (SSc). STUDY DESIGN: A series of consecutive patients diagnosed with SSc according to well-established classification criteria and matched controls were studied. SETTING: The study was performed at the otolaryngology division of a tertiary reference center. PATIENTS: Forty-two patients (35 with limited SSc [lSSc] and 7 with diffuse SSc [dSSc]) and 74 controls were studied between January and May 2007. INTERVENTION: Dix-Hallpike and cephalic rotational tests and CTSIB were performed in SSc patients and age-, sex-, and ethnically frequency-matched controls. MAIN OUTCOME MEASURE: Type and frequency of BPPV and CTSIB conditions were assessed. RESULTS: Seven patients (17%) fulfilled the diagnostic criteria for BPPV compared with none of the controls (p < 0.001). It was related to the involvement of the posterior semicircular canal in two lSSc patients and the horizontal semicircular canal in another three patients with lSSc and two with dSSc. A significantly increased frequency of abnormal CTSIB was also observed in SSc patients (20 [48%]) compared to controls (7 [10%]; p < 0.0001; odds ratio, 8.70; 95% confidence interval, 2.97-27.2). It was caused by a vestibular pattern in most patients (p < 0.0001). CONCLUSION: The present study shows an increased frequency of BPPV and a vestibular pattern in CTSIB in SSc patients.

Systemic sclerosis in northwestern Spain: a 19-year epidemiologic study.

To investigate the epidemiology of systemic sclerosis (SSc) in southern Europe, we assessed the incidence, prevalence, clinical spectrum, and survival of patients diagnosed with SSc in the Lugo region of northwestern Spain. Between January 1988 and December 2006, SSc was diagnosed in 78 Lugo residents according to the criteria proposed by LeRoy and Medsger and/or the 1980 American College of Rheumatology (ACR) preliminary criteria for the classification of SSc. However, only 44 (56.4%) of the 78 patients fulfilled the 1980 ACR criteria for the classification of SSc. The mean age at the time of disease diagnosis was 59.8 +/- 13.3 years. Twenty-three (29.5%) met definitions for diffuse SSc (dSSc), and 55 (70.5%) for limited SSc (lSSc). Patients with lSSc had a longer disease duration before the diagnosis (10.2 +/- 12.0 yr) than those with dSSc (3.7 +/- 3.2yr) (p < 0.001). Based on the criteria proposed by LeRoy and Medsger and/or the 1980 ACR criteria for the classification of SSc, the overall age- and sex-adjusted annual incidence rate over the 19-year study period was 2.3 (95% confidence interval [CI], 1.6-2.5) per 100,000 population aged 15 yr and older (women: 3.5 [95% CI, 2.3-3.9]; men: 1.0 [95% CI, 0.5-1.4]; p < 0.001). Using only the 1980 ACR criteria for SSc, the total annual-adjusted incidence rate was 1.2 (95% CI, 0.9-1.6) per 100,000 population aged 15 years and older (women: 1.8 [95% CI, 1.2-2.5]; men: 0.7 [95% CI, 0.3-1.2]; p < 0.001). The incidence increased significantly in individuals aged 45 years or older. The overall incidence rates of SSc increased over the length of the study (p for trend in the total incidence < 0.001). This was mainly due to a progressive increase of SSc in women between 1993 and 2002. By December 31, 2006, the overall age-adjusted SSc prevalence in the Lugo region of patients who met the criteria proposed by LeRoy and Medsger and/or the 1980 ACR criteria was 27.7 (95% CI, 21.1-35.84) per 100,000 population aged 15 years and older. Cardiopulmonary complications were the leading cause of death (13 of 20 cases). Compared with that in the general population, the probability of survival in patients with SSc was significantly reduced (p < 0.001).The current study establishes a baseline estimate of the incidence and clinical spectrum of SSc in northwestern Spain. According to our results, the incidence and prevalence of SSc in northwestern Spain are similar to those found in Greece and some regions of the United States. Our data confirm a reduced probability of survival in patients with SSc.

Audiovestibular manifestations in patients with limited systemic sclerosis and centromere protein-B (CENP-B) antibodies.

Audiovestibular dysfunction has been reported in patients with connective tissue disease. Systemic sclerosis (SSc; scleroderma) is a rare connective tissue disease of unknown etiology. In the current study we assess whether audiovestibular involvement is present in patients with limited scleroderma (lSSc). To answer this question we studied a series of 35 consecutive patients who fulfilled well-established classification criteria for lSSc and had antibodies against the major centromere protein-B (CENP-B), and 59 matched controls. Individuals with a history of cerebrovascular complications, syphilis, Ménière and other vestibular syndromes, infections involving the inner ear, barotrauma, or in treatment with ototoxic drugs were excluded. The majority of patients with lSSc were women (94%). The mean age at time of study was 64.5 years, and the mean age at time of disease diagnosis was 56.9 years. Besides Raynaud phenomenon, most patients with lSSc had other typical features of CREST (calcinosis, Raynaud phenomenon, esophageal hypomotility, sclerodactyly, and telangiectasia) syndrome. Twenty-seven (77%) patients showed abnormal hearing loss in the audiogram compared with only 15 (26%) of the controls (p < 0.001). Values of audiometric tests (pure-tone average and speech reception threshold) yielded significant differences between patients and controls (p < 0.001). The typical pattern of hearing impairment in our series of lSSc patients was a bilateral and symmetrical sensorineural hearing loss with a flat pattern in the audiogram. Abnormal tympanogram and abnormal stapedial reflex were more commonly observed in patients than controls (p < or = 0.001). Similarly, a significantly increased frequency of abnormal oculocephalic response (10 patients, 29%) and head-shaking nystagmus (9 patients, 26%) was observed in patients compared with controls (p < 0.001 for both comparisons). Finally, a significantly increased frequency of abnormal caloric test and clinical test of sensory integration and balance was observed in lSSc patients (31% and 46% of patients, respectively) compared with controls (0% and 12%, respectively) (p < 0.001 for both comparisons). The current study demonstrates strong evidence for inner ear compromise in patients with lSSc.

Regiospecific microwave-assisted synthesis and cytotoxic activity against human breast cancer cells of (RS)-6-substituted-7- or 9-(2,3-dihydro-5H-1,4-benzodioxepin-3-yl)-7H- or -9H-purines.

Extended studies on the synthesis and pharmacological evaluation of (RS)-6-substituted-7 or 9-(2,3-dihydro-5H-1,4-benzodioxepin-3-yl)-7H- or -9H-purines are presented. The microwave-assisted organic synthesis has provided faster access to the target compounds with the advantage of selective obtaining the N-7' or N-9' regioisomers simplifying their isolation. To test the behaviour of the products (including the purine bases) on cellular systems, cytotoxic activity against the MCF-7 human breast cancer cell line was determined, and the three most active compounds were used to study the cell cycle distribution and apoptosis in the MCF-7 cell line.

Synthesis and anticancer activity of (R,S)-9-(2,3-dihydro-1,4-benzoxathiin-3-ylmethyl)-9H-purines.

A series of eleven 2- and 6-substituted (R,S)-9-(2,3-dihydro-1,4-benzoxathiin-3-ylmethyl)-9H-purine derivatives was obtained by applying a standard Mitsunobu protocol that led to a six-membered ring contraction from (R,S)-3,4-dihydro-2H-1,5-benzoxathiepin-3-ol via an episulfonium intermediate. The signal approximately delta=151 ppm, which corresponds to the C4' carbon atom, is unequivocal proof of the N9' regioisomer. The potential of the target molecules as anticancer agents is reflected in their activity against the MCF-7 cancer cell line. The most active compounds have IC(50) values of (6.18+/-1.70) and (8.97+/-0.83) microM. The results indicate that the anticancer activity for the most active compounds is correlated with their capacity to induce apoptosis.

A synthetic uracil derivative with antitumor activity through decreasing cyclin D1 and Cdk1, and increasing p21 and p27 in MCF-7 cells.

The anticarcinogenic potential of (RS)-1-(2,3-dihydro-5H-1,4-benzodioxepin-3-yl)uracil (DBDU), with the naturally occurring pyrimidine base uracil, is reported against the MCF-7 cancer cell line. The arrest in the G0/G1 and G2/M cell cycle phases was accounted for by decrease in the expression of the cyclin D1 and Cdk1 proteins, and increase in p21 and p27 proteins. Using a reverse transcription-polymerase chain reaction-based assay at a dose of 5 muM of DBDU cyclin D1 mRNA was decreased, suggesting that DBDU exerts its regulatory action on cyclin D1 at the level of transcription. DNA fragmentation was performed and demonstrated that apoptosis occurred in the tumor cell line treated with DBDU. The G0/G1 arrest is an irreversible process and the cells undergo apoptosis in a p53-independent manner. DBDU administered intravenously twice a week (50 mg/kg dose each time) induced neither toxicity nor death in mice for 5 weeks.

Quantitative structure-activity relationships for a series of symmetrical bisquaternary anticancer compounds.

56 biscationic dibromides with distinct polar heads [bis(4-substituted)pyridinium, bis(4-aminoquinolinium), bisquinolinium, and bisisoquinolinium moieties] and several spacers between the two charged nitrogen atoms were synthesised. This oriented synthesis produced 45 inhibitors of choline kinase with antitumour activity against the HT-29 cell line. In an attempt to understand the antiproliferative activity, a quantitative structure-activity relationship was developed. The unknown sigma(R) and sigma(R)(+) descriptors for the diallylamino, pyrrolidino, piperidino and perhydroazepino groups and sigma(R) for the N-methylanilino moiety, were estimated by (13)C NMR spectroscopy in a simple, fast and reproducible manner. The electron characteristic of the substituent at position 4 of the heterocycle and the theoretical lipophilic character of the whole molecule were found to significantly affect the antitumour activity. 1,1'-[Ethylenebis(benzene-1,4-diylmethylene)]bis[4-(N-methylanilino)pyridinium] dibromide is the most active compound of the series so far described and shows a reasonable agreement between predicted and observed antiproliferative data (predicted pIC(50)=6.50, experimental pIC(50)=6.46).