Discovery of new tetracyclic tetrahydrofuran derivatives as potential broad-spectrum psychotropic agents

A series of novel tetracyclic tetrahydrofuran derivatives was prepared and evaluated for its potential psychotropic properties. In vitro affinities for multiple dopaminergic, serotonergic, alpha-adrenergic, and histamine receptors and for the norepinephrine transporter as well as the ED(50) values obtained in some in vivo assays for antipsychotic, anxiolytic, and antidepressant potential are reported. Compounds (-)-1, (-)-8d, and (+)-8d have been identified as potential broad-spectrum psychotropic agents.

Successful treatment of lichen planus with sulfasalazine in 20 patients

BACKGROUND

Lichen planus (LP) is a disturbing pruritic cutaneous disease that may have an spontaneous resolution or exhibit a more chronic course during some weeks or months.

OBJECTIVE

Our objective was to demonstrate that sulfasalazine is effective in the treatment of LP.

METHODS

Twenty patients were diagnosed in our department with LP of the skin and/or mucosa between 1985 and 2001 on the basis of clinical and histologic findings.

RESULTS

All patients were treated with sulfasalzine at initial doses of 1.5 g/day, increasing by 0.5 g/week to 3 g/day for 4-16 weeks. Some patients also received descendent doses for 2-12 months. Complete responses were observed in 13 patients and partial responses in seven patients. All patients reported an early resolution of the pruritus. No changes were detected in mucosal LP. Most of the patients tolerated the treatment well and only eight patients presented some minor side-effects.

CONCLUSION

Sulfasalazine is a successful therapeutic option for cutaneous LP, constituting an alternative to corticosteroids and retinoids.

Synthesis and structure–activity relationship of 2-(aminoalkyl)-3,3a,8,12b-tetrahydro-2H-dibenzocyclohepta[1,2-b]furan derivatives: a novel series of 5-HT2A/2C receptor antagonists

Following the program started at Johnson & Johnson Pharmaceutical Research & Development searching for 5-HT(2A/2C) antagonists we now report on the synthesis of a series of substituted 2-(aminomethyl)-3,3a,8,12b-tetrahydro-2H-dibenzocyclohepta[1,2-b]furan derivatives. The 5-HT2A, 5-HT2C and H1 receptor affinities of the described compounds are reported. The mCCP antagonistic activity of a set of selected molecules is also reported.

Aggressive tumors of the concha: treatment with postauricular island pedicle flap

BACKGROUND

The concha is a partially hidden anatomical area characterized by difficult access and reconstruction.

OBJECTIVE

We describe the use of the postauricular (revolving door) island pedicle flap in the treatment of aggressive tumors of the concha.

METHODS

We present two patients with aggressive cutaneous tumors localized in auricular concha. One of the patients presented with a large ulcerated basal cell carcinoma. The second patient had received a heart transplant, was receiving immunosuppressive therapy, and was affected by a squamous cell carcinoma.

RESULTS

Both defects were closed using a posterior auricular island flap that was advanced through cartilage with excellent cosmetic results.

CONCLUSION

The postauricular island pedicle flap is well suited for conchal reconstruction because of its proximity to the defect. The flap was transferred from posterior to anterior toward the concha, followed by primary closure of the retroauricular donor site.

[Antioxidant enzymes in acute cerebral infarction]

BACKGROUND AND PURPOSE

Oxidative modification of DNA, protein and lipids by reactive oxygen peroxides plays an important role in acute cerebral infarction. The biological antioxidant defence system against oxidative stress is an integrated array of enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathion peroxidase (GPx). The purpose of this work was: 1. To investigate the evolution of SOD and CAT activities as possible markers of oxidative activity in patients with acute cerebral infarction. 2. To establish the relationship between the type of stroke and the activity of these two enzymes. 3. To analyze the relationship between the degree of neurological deficits of patients with stroke and SOD and CAT activities.

PATIENTS AND METHODS

This is a prospective study comprising 45 patients with acute cerebral infarction (24 females and 21 males), aged from 48 to 96. The infarcts were classified in atherotrombotics and cardioembolics. SOD and CAT activities were measured on days 1, 3, 6 and 15.

RESULTS

Activities of SOD and CAT in patients on admission were lower than those of controls and showed a gradual increase over time. The activity mean of SOD was significantly higher in cardioembolic infarctions than in atherotrombotic infarctions (p < 0.05). SOD activity was significantly lower for Mathew score > 60, while CAT activity was higher.

CONCLUSIONS

Our findings suggest that there is a progressive increase in SOD and CAT activity during ictus evolution, a different activity of SOD and CAT in cardioembolic and atherotrombotic infarctions, and that there is a relationship between activity of antioxidant enzymes and Mathew's score.

Significance of protein p53 overexpression in the clinical course of high-risk superficial bladder cancer

OBJECTIVES

This is a retrospective study in which the long-term biological behavior of 67 "high-risk" superficial bladder tumors and the prognostic relevance (prediction of disease recurrence and progression) of the determination of the p53 phenotype in these cases were studied.

MATERIAL AND METHODS

67 tumors with a "high-risk" of progression were selected from the 1,103 transurethral resections for bladder cancer carried out in 640 patients in this center between 1987 and 1992. These included 39 T1G3, 14 Tis (isolated or associated with Ta-T1, non-G3 tumors), and 14 Ta-T1, non-G3 tumors with submucosal lymphatic affection (L+). The median follow-up of these cases was 69.7 months. An immunohistochemical technique with monoclonal antibodies (DO-7) was used to detect the p53 phenotype in paraffin-fixed material.

RESULTS

Tumor recurrence occurred in 31 patients (46.3%) and local or distant progression in 14 (20.9%). Radical cystectomy was carried out in 16 (23.9%) cases. p53 overexpression of > or =20% ("p53+") was detected in 40 tumors (59.7%). The rate of recurrence and progression, the disease and progression-free intervals, cancer-specific survival, disease-free survival and progression-free survival were similar in the 3 tumor groups (in all cases, p > 0.05). There were no significant differences in the overexpression of protein p53, using the standard cutoff point of 20% stained nuclei, on comparing the same variables in the whole group of 67 patients (in all cases, p > 0.05).

CONCLUSION

The detection of protein p53 was not found to be of use in the retrospective prediction of disease progression or survival in "high-risk" superficial bladder cancer.

Synthesis and structure-activity relationship of 2-(aminoalkyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives: a novel series of 5-HT(2A/2C) receptor antagonists. Part 1

The synthesis of a series of novel 2-(aminoalkyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives as well as their 5-HT(2A/2C) and H(1) receptor binding affinities are described. The in vivo activity as potential anxiolytics of the synthesised compounds was measured in a mCPP challenge test. One of the compounds, 2a, proved to be a potent 5-HT(2A/2C) receptor antagonist showing as well oral activity and therefore could be considered as a potential anxiolytic/antidepressant agent.

Synthesis and structure-activity relationship of 2-(aminoalkyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives: a novel series of 5-HT(2A/2C) receptor antagonists. Part 2

Following the programme started at Janssen Research Foundation searching for 5-HT(2A/2C) antagonists, we now report on the synthesis of a series of substituted 2-(Dimethylaminomethyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives. The 5-HT(2A), 5-HT(2C) and H(1) receptor affinities as well as the mCPP antagonistic activity of the compounds synthesised is described.

The use of neural networks and logistic regression analysis for predicting pathological stage in men undergoing radical prostatectomy: a population based study

PURPOSE

Clinical under staging occurs in 40% to 60% of patients who undergo radical prostatectomy for prostate cancer. To decrease under staging several methods of predicting pathological stage preoperatively have been developed based on statistical logistic regression analysis and neural networks. To our knowledge none has been validated in our homogeneous regional patient population to date. We created logistic regression and neural network models, and implemented and adapted them into our practice. We also compared the 2 methods to determine their value and practicality in daily clinical practice. We present the results of our novel approach for predicting pathological staging of prostate adenocarcinoma.

MATERIALS AND METHODS

Between 1986 and 1999, 600 white men from the Aragon region of Spain underwent surgery for prostate cancer; of whom 468 were selected for study. Predictive study variables included patient age, clinical stage, biopsy Gleason score and preoperative prostate specific antigen (PSA). The predicted result included in analysis was organ confined or nonorgan confined disease. Data were analyzed by multivariate logistic regression and a supervised neural network (multilayer perceptron and radial basis function). Results were compared by comparing the areas under the receiver operating characteristics curves.

RESULTS

We generated 5 logistic regression models. The model created with clinical staging, Gleason biopsy score and PSA distributed in 5 categories (p <0.001) with an area under the receiver operating characteristics curve of 0.840 proved to be most predictive of pathological stage. Similarly of the 6 neural network models evaluated the radial basis function model, which included age, clinical stage, Gleason biopsy score and preoperative PSA distributed in 5 categories with an area under the curve of 0.882, proved the most predictive but not superior to the logistic regression model. The difference in the area under the curves in the 2 chosen models was 0.042 (p = 0.1).

CONCLUSIONS

It is possible to generate useful predictive models of organ confined disease using logistic regression or neural networks with high indexes of clinical and statistical validity. However, using these variables neural networks did not prove to be better than logistic regression analysis. Therefore, better predictive variables must be identified, preferably nonlinear characteristics with respect to the probability of organ confined tumor, to generate better predictive models using neural networks.

Sonography in acute appendicitis: diagnostic utility and influence upon management and outcome

A study is made of the diagnostic utility of echography in clinically suspected appendicitis, and its influence upon patient management and outcome. A total of 374 consecutive patients with possible appendicitis were prospectively evaluated by ultrasound. Two groups were established: group A (high clinical probability, > or =0.70) and group B (moderate clinical probability, 0.20-0.60). In group-A patients (n = 105, 28%), prevalence of appendicitis = 0.90) underwent surgery regardless of the echographic findings. In group B (n = 269, 72%), prevalence of appendicitis = 0.28) surgery was performed in the event of positive echography, whereas negative echographic findings did not definitively discard appendicitis. The diagnostic utility of echography was evaluated by applying the Pauker-Kasirer threshold approach to clinical decision making. The influence of ultrasound upon outcome was in turn evaluated by contrasting the total appendectomized patients (190 of 374) with a series of 181 individuals subjected to appendectomy prior to the introduction of echography. The probability of appendicitis in the presence of positive echography was 0.95 in group A (sensitivity = 0.92) and 0.89 in group B (sensitivity = 0.91). The probability of appendicitis in the event of negative ultrasound was 0.58 in group A (specificity = 0.55) and 0.03 in group B (specificity = 0.95) . In 46% of cases the echographic findings led to a change in therapeutic regimen. In addition, the incidence of negative appendectomies was significantly reduced (19.3 vs 11.6% with echography; p = 0.03), as was the delay in establishing a diagnosis (under 6 h in 68.5 vs 84.2% with echography; p = 0.002) and the number of medical acts required (three in 71.3 vs 84.1% with echography; p = 0.001). There was no significant reduction in the incidence of perforated appendicitis (17.1 vs 17.9% with echography), in the number of postoperative complications (13.8 vs 7.6% with echography), or in the days of hospital stay (4.44 vs 4.80 with echography). Echography proved useful in group B, and was generally of little utility in group A. The technique had a positive influence on treatment, with management reorientation in a considerable number of patients, and on outcome, since ultrasound contributed to establishing an earlier diagnosis, with a reduction of unnecessary appendectomies.

BIG: a calossin-like protein required for polar auxin transport in Arabidopsis

Polar auxin transport is crucial for the regulation of auxin action and required for some light-regulated responses during plant development. We have found that two mutants of Arabidopsis-doc1, which displays altered expression of light-regulated genes, and tir3, known for its reduced auxin transport-have similar defects and define mutations in a single gene that we have renamed BIG. BIG is very similar to the Drosophila gene Calossin/Pushover, a member of a gene family also present in Caenorhabditis elegans and human genomes. The protein encoded by BIG is extraordinary in size, 560 kD, and contains several putative Zn-finger domains. Expression-profiling experiments indicate that altered expression of multiple light-regulated genes in doc1 mutants can be suppressed by elevated levels of auxin caused by overexpression of an auxin biosynthetic gene, suggesting that normal auxin distribution is required to maintain low-level expression of these genes in the dark. Double mutants of tir3 with the auxin mutants pin1, pid, and axr1 display severe defects in auxin-dependent growth of the inflorescence. Chemical inhibitors of auxin transport change the intracellular localization of the auxin efflux carrier PIN1 in doc1/tir3 mutants, supporting the idea that BIG is required for normal auxin efflux.

Gastrointestinal bezoars: sonographic and CT characteristics

OBJECTIVE

The purpose of this study was to assess the value of imaging studies--conventional abdominal radiographs, sonography, and CT--in the diagnosis of gastrointestinal bezoars.

METHODS AND METHODS

A review was made of the radiologic findings of 17 consecutive patients with surgically verified gastrointestinal bezoars over a period of 51 months.

RESULTS

Twelve patients had a history of previous gastric surgery. In no patient was a bezoar clinically suspected. Phytobezoars were recorded in 16 patients and a trichobezoar in only one. A total of 33 bezoars were identified at surgery. Two patients had isolated gastric bezoars, whereas 15 patients had bezoars located in the small bowel. Among the latter group, associated gastric bezoars were found in eight patients, and five patients had multiple intestinal bezoars. Abdominal radiographs revealed bezoars in three patients, sonography revealed bezoars in 15, and CT revealed bezoars in all 17. Seven patients had associated gastric bezoars revealed at CT versus only two patients with gastric bezoars revealed at sonography. CT revealed multiple intestinal bezoars in five patients whereas sonography revealed them in only two patients.

CONCLUSION

Both sonography and CT are reliable methods for diagnosing gastrointestinal bezoars. CT is more accurate, however, and exhibits a quite characteristic bezoar image; in addition, this imaging technique is able to reveal the presence of additional gastrointestinal bezoars.

Photocontrol of subcellular partitioning of phytochrome-B:GFP fusion protein in tobacco seedlings

Photomorphogenesis of higher plants is regulated by photoreceptors including the red/far-red light-absorbing phytochromes, blue-UV/A sensing cryptochromes and as yet uncharacterized UV/B receptors. Specific phototransduction pathways that are controlled by either individual or interacting photoreceptors mediate regulation. Phytochrome B (phyB) is the major red light-sensing photoreceptor. Phototransduction mediated by this light sensor has been shown to include light-dependent nuclear import and interaction of phyB with transcription factor-like proteins in the nucleus. Here we report that nuclear import of phyB and physiological responses regulated by this photoreceptor exhibit very similar wavelength- and fluence rate-dependence. Nuclear import of phyB is insensitive to single red, blue and far-red light pulses. It is induced by continuous red light and to a lesser extent by continuous blue light, whereas far-red light is completely ineffective. The data presented indicate that light-dependent partitioning of phyB exhibits features characteristic of blue light responsiveness amplification, a phenomenon that is thought to be mediated by interaction of phyB with CRY1.

Wells' syndrome (eosinophilic cellulitis): correlation between clinical activity, eosinophil levels, eosinophil cation protein and interleukin-5

Wells' syndrome (WS) (eosinophilic cellulitis) is characterized by the presence of oedematous skin lesions associated with eosinophilia of the tissues. It has recently been observed that in patients with this disease, increased eosinophil cation protein (ECP) and interleukin (IL) -5 can be detected in peripheral blood, with T lymphocytes that have mRNA for this lymphokine. We present a patient with WS in whom we found a close correlation between clinical activity, eosinophils in blood and bone marrow, and ECP and IL-5 levels in peripheral blood and tissues. We underline the major part played by IL-5 in this disease.

[Usefulness of bronchoalveolar lavage in the renal transplant patient with suspected respiratory infection]

In this retrospective study we aimed to assess the diagnostic yield of bronchoalveolar lavage (BAL) in kidney transplant patients who were suspected of having severe respiratory infection or in whom empirical antibiotic treatment had failed. All BAL procedures performed on kidney transplanted patients suspected of having respiratory infections between January 1, 1988 and July 31, 1996 were analyzed. BAL was carried out in the standard way and samples were sent for cytologic and bacteriologic study. Thirty-three patients with a mean age of 48.5 years were enrolled. All had been receiving immunosuppressive treatment and the mean time following transplantation was 320 days. Thirty-one had received antibiotic treatment before BAL. BAL was positive for 21 of the 33 patients (64%). Twenty-two pathogens were identified: 6 Pneumocystis carinii, 4 Cytomegalovirus, 3 Mycobacterium tuberculosis, 2 Aspergillus fumigatus, 2 Herpes simplex type I, 1 Streptococcus pneumoniae, 1 Staphylococcus aureus, 1 Streptococcus mitis, 1 Legionella pneumophila, 1 Legionella longbeachae. BAL was negative for 12 patients, of whom 8 were tentatively diagnosed of bacterial infection, 3 of acute pulmonary edema and one of pulmonary infarction. Based on the results, therapy was changed for 20 patients (61%), 19 (58%) because an unsuspected pathogen was identified and 1 because treatment could be simplified. The diagnostic yield of BAL is high (64%) in kidney transplant patients suspected of respiratory infection and is useful for managing such cases, as evidenced by the fact that a high proportion (19/33) of our patients were infected by pathogens not covered by empirical treatment.

[The main etiopathogenic mechanisms of neurocutaneous diseases]

Neurocutaneous syndromes constitute a large and complex group of diseases in which recent medical advances, particularly in the field of molecular biology and genetics, have afforded a deeper understanding of the way in which these diseases originate. In this article, we review the advances concerning pathogenic mechanisms. First, we discuss the malformations disorders of the central nervous system associated with skin disorders, which range from spinal and/or cranial dysraphism with skin lesions to fustrated forms of malformations of the neural tube, such us membranous aplasia cutis. Neurocutaneous vascular disorders can be due to malformational disease, such as in Sturge-Weber syndrome, as well as to autoimmune diseases. The analysis of mutations affecting the capacity for migration and differentiation of melanocyte precursors enables us to gain a better understanding of disorders of the cells of the neural crest, such as piebaldism and Waardenburg's syndrome. Mutations in tumor suppressor genes play an important part in the development of hamartomatous and neoplastic lesions in neurofibromatosis and tuberous sclerosis. Genetic mosaicism, both of the functional and the genomic kind, accounts for the great diversity of phenotypes and the distribution of neurocutaneous diseases. Lastly, neurocutaneous syndromes such as the paracrinopathies form an attractive hypothesis, which is as yet to be confirmed.

[Neuropsychological deficits, obstetric complications and premorbid adjustment in patients with the first psychotic episode]

In spite of the great number of studies that have proved the existence of cognitive disturbances in schizophrenic subjects, conflicting results have not allowed to glimpse a typical pattern of neuropsychological deficits in schizophrenia. On the contrary, these results have raised important controversies regarding the nature of such cognitive impairment. Thus, questions concerning the existence of generalized versus focal cognitive impairment or in relation lo the static versus progressive nature of these deficits remain unresolved. In the middle of these debates, the need for prospective research, which focuses on the neuropsychological deficits of schizophrenia and other psychotic disorders from the beginning of the illness, has been pointed out. In these lines we present the results obtained in our study in which 59 subjects, who were admitted in our hospital for presenting a first psychotic episode, were assessed. Measures of premorbid adjustment, obstetric complications and clinical symptoms were taken and correlated to measures of cognitive performance obtained by using a minibattery of neuropsychological tests at time of dismissal. Results showed, as in previous research, that neuropsychological deficits are already present in psychotic patients at the beginning of the illness. These deficits in our sample were related lo obstetric complications especially in males, and disturbances of premorbid adjustment occurred in early stages of development. These results support the neurodevelopmental hypothesis of schizophrenia.

Streptogramin B biosynthesis in Streptomyces pristinaespiralis and Streptomyces virginiae: molecular characterization of the last structural peptide synthetase gene

Streptomyces pristinaespiralis and S. virginiae both produce closely related hexadepsipeptide antibiotics of the streptogramin B family. Pristinamycins I and virginiamycins S differ only in the fifth incorporated precursor, di(mono)methylated amine and phenylalanine, respectively. By using degenerate oligonucleotide probes derived from internal sequences of the purified S. pristinaespiralis SnbD and SnbE proteins, the genes from two streptogramin B producers, S. pristinaespiralis and S. virginiae, encoding the peptide synthetase involved in the activation and incorporation of the last four precursors (proline, 4-dimethylparaaminophenylalanine [for pristinamycin I(A)] or phenylalanine [for virginiamycin S], pipecolic acid, and phenylglycine) were cloned. Analysis of the sequence revealed that SnbD and SnbE are encoded by a unique snbDE gene. SnbDE (4,849 amino acids [aa]) contains four amino acid activation domains, four condensation domains, an N-methylation domain, and a C-terminal thioesterase domain. Comparison of the sequences of 55 amino acid-activating modules from different origins confirmed that these sequences contain enough information for the performance of legitimate predictions of their substrate specificity. Partial sequencing (1,993 aa) of the SnbDE protein of S. virginiae allowed comparison of the proline and aromatic acid activation domains of the two species and the identification of coupled frameshift mutations.

Regulatory activity exerted by the SAUR-AC1 promoter region in transgenic plants

SAUR-AC1 is a small-auxin-up-RNA (SAUR) gene of Arabidopsis. Here we demonstrate that the SAUR-AC1 promoter region induces accumulation of a reporter transcript upon treatment with auxin and is preferentially active in elongating hypocotyls and certain other organs and tissues of transgenic Arabidopsis and tobacco plants. This study extends the utility of the SAUR-AC1 gene by providing a foundation for comparative analyses of SAUR promoter activity in auxin-responsive mutants of Arabidopsis.

[Skin tumor as presentation form of lung actinomycosis]

We report three cases of thoracic actinomycosis whose symptoms were cutaneous tumors on the thorax. Clinical signs and images are described, along with diagnostic procedures. The excellent outcome after antibiotic treatment, which must last at least 6 months, is emphasized as well as the need to keep this disease in mind when certain symptoms and images coincide.

Clinical tolerance, parasitological efficacy and environmental effects of dehumidifiers in stable asthmatics sensitized to house dust mites

Dehumidifiers (DH) are potentially effective appliances as coadjuvant therapy in the treatment of bronchial asthma caused by sensitization to house dust mites. The aims of this study were to analyze DH tolerance in asthmatic patients, to assess the parasitological effects and to analyze the environmental effects produced by the use of these appliances in the bedrooms of asthmatic patients sensitized to house dust mites. 10 stable asthmatic patients sensitized to house dust mites were studied. DH appliances (CD-300) were installed in their bedrooms. Each patient was given symptom scoring tables and a portable peak expiratory flow (P.E.F.) during a period of 5 months, 1 month before installing the DH and 4 months afterwards. To study the parasitological efficacy of the DHs, we analyzed dust samples from the bedrooms and determined the Der p I, Der f I and Der II allergens by means of a modified ELISA based on monoclonal antibodies. Dust samples were collected before installing the DHs and after they had been working for 2 and 4 months. Dry temperature and relative humidity measurements at three time intervals (7-9, 15-17 and 22-24 h) were carried out. The 1st measurement was done prior to installation of the DHs in the patients' bedrooms and the 2nd and 3rd were achieved 2 and 4 months respectively after the installation. Statistical analysis was done by comparison of paired means. No significant differences were detected in the patients' symptoms nor in the P.E.F. measurements in the course of the study. Decreases in the house dust mite allergens were observed in 4 bedrooms. A significant decrease in relative humidity in the bedrooms of mite asthma patients after use of dehumidifier appliances was observed (p < 0.01). Significant differences between the measurements of the bedrooms with and without DH were detected (p < 0.01). In summary, DHs were well tolerated by stable asthmatic patients, produced a significant decrease in the relative humidity level and showed some parasitological efficacy.

Pristinamycin I biosynthesis in Streptomyces pristinaespiralis: molecular characterization of the first two structural peptide synthetase genes

Two genes involved in the biosynthesis of the depsipeptide antibiotics pristinamycins I (PI) produced by Streptomyces pristinaespiralis were cloned and sequenced. The 1.7-kb snbA gene encodes a 3-hydroxypicolinic acid:AMP ligase, and the 7.7-kb snbC gene encodes PI synthetase 2, responsible for incorporating L-threonine and L-aminobutyric acid in the PI macrocycle. snbA and snbC, which encode the two first structural enzymes of PI synthesis, are not contiguous. Both genes are located in PI-specific transcriptional units, as disruption of one gene or the other led to PI-deficient strains producing normal levels of the polyunsaturated macrolactone antibiotic pristinamycin II, also produced by S. pristinaespiralis. Analysis of the deduced amino acid sequences showed that the SnbA protein is a member of the adenylate-forming enzyme superfamily and that the SnbC protein contains two amino acid-incorporating modules and a C-terminal epimerization domain. A model for the initiation of PI synthesis analogous to the established model of initiation of fatty acid synthesis is proposed.

Identification and analysis of genes from Streptomyces pristinaespiralis encoding enzymes involved in the biosynthesis of the 4-dimethylamino-L-phenylalanine precursor of pristinamycin I

Four pap genes (papA, papB, papC, papM) were found by sequencing near to snbA, a Streptomyces pristinaespiralis gene which was previously shown to encode one of the pristinamycin I (PI) synthetases. Analysis of the homologies observed from the deduced amino acid sequences suggested that these four genes could be involved in the biosynthesis of the PI precursor 4-dimethylamino-L-phenylalanine (DMPAPA). This was first verified when disruption of papA in S. pristinaespiralis led to a PI- phenotype, which was reversed by the addition of DMPAPA into the culture medium. Further confirmation was obtained when papM was overexpressed in Escherichia coli and the corresponding protein purified to homogeneity. It catalysed the two successive N-methylation steps of 4-amino-L-phenylalanine leading to DMPAPA via 4-methylamino-L-phenylalanine. These results allowed us to assign a function to each of the four pap genes and to propose a biosynthetic pathway for DMPAPA.

Determination of malonaldehyde in Alzheimer's disease: a comparative study of high-performance liquid chromatography and thiobarbituric acid test

The concentration of malonaldehyde (MDA) was measured in human erythrocytes obtained from subjects suffering from senile dementia of the Alzheimer type (SDAT), non-demented elderly subjects, and from young controls by two methods: high-performance liquid chromatography (HPLC) and the thiobarbituric acid (TBA) test. The MDA concentration measured by HPLC showed significant differences between SDAT and young control groups (p < 0.01) and between SDAT and non-demented elderly groups (p < 0.01), respectively. Nevertheless, significant differences were not exhibited between young control and non-demented elderly. Moreover, the rate of accumulation of TBA-reactive substances was not significantly different among the three groups. Our results indicate that the HPLC method is highly specific and accurate and distinguishes between true MDA and other aldehydes that may react with TBA. Significant increases in the concentration of MDA of SDAT subjects were found in comparison with the two other groups, indicating that the measurement of MDA in erythrocytes could be used as a marker of oxidative damage in Alzheimer's disease.

[Tracheobronchial amyloidosis: apropos of 3 cases]

We report 3 cases of tracheobronchial amyloidosis starting with post-obstructive pneumonitis, suggesting underlying neoplasm. The diagnosis was by fiberoptic bronchoscopy. We also describe radiological findings and their usefulness, therapeutic options, and course of disease.

Multiple regions of the Arabidopsis SAUR-AC1 gene control transcript abundance: the 3' untranslated region functions as an mRNA instability determinant

The small-auxin-up-RNA (SAUR) transcripts are rapidly induced by auxin and are among the most short-lived mRNAs in higher plants. In this study, we investigate the regulation of SAUR-AC1, a well characterized SAUR gene of Arabidopsis. Be examining the expression of chimeric genes in transgenic tobacco, we demonstrate that the promoter region of SAUR-AC1 mediates auxin induction. Sequences downstream of the promoter region were found to limit mRNA accumulation in a manner that was independent of auxin treatment. Both the coding region and the 3' untranslated region (UTR) of SAUR-AC1 independently contribute to this limitation. Effects on mRNA stability were assayed using chimeric genes under the control of the tetracycline-repressible Top10 promoter. mRNA half-life analysis following tetracycline treatment showed that the SAUR-AC1 coding region does not contain elements that decrease mRNA stability. In contrast, the 3' UTR was found to act as a potent mRNA instability determinant. This finding and the general utility of the Top10 system should provide the means to elucidate mRNA decay pathways that are potentially novel and specific for certain unstable transcripts.

Identification of a transcription factor that binds to the S box of the I-A beta gene of the major histocompatibility complex

Class II genes of the MHC show a striking homology upstream of the transcription start site that is composed of three conserved sequences (S, X and Y boxes, each separated by 15-20 bp). The presence of the S-box sequence in the mouse MHC class II gene I-A Beta was examined for its influence on the expression of this gene. Deletion or mutation of the S box decreased the induction of chloramphenicol acetyltransferase (CAT) activity in B lymphocytes by 32%. In macrophages, deletion or mutation of the S box abolished interferon-gamma (IFN-gamma) inducibility of CAT activity. Using a gel-retardation assay, we have identified a nuclear factor whose binding site overlaps the 7-mer conserved sequence of the S box. This factor is present in lymphocytes, macrophages, mastocytes and fibroblasts. Surprisingly, binding of this nuclear factor to DNA was induced by IFN-gamma in bone-marrow-derived macrophages, but not in macrophage-like cell lines. The binding site for this factor was defined by DNase I footprinting and partially purified by using an affinity column containing double-stranded oligonucleotides containing a sequence of the S box. A prominent protein of 43 kDa was found that bound specifically to the S-box sequence.

Cloning and analysis of structural genes from Streptomyces pristinaespiralis encoding enzymes involved in the conversion of pristinamycin IIB to pristinamycin IIA (PIIA): PIIA synthase and NADH:riboflavin 5'-phosphate oxidoreductase

In Streptomyces pristinaespiralis, two enzymes are necessary for conversion of pristinamycin IIB (PIIB) to pristinamycin IIA (PIIA), the major component of pristinamycin (D. Thibaut, N. Ratet, D. Bisch, D. Faucher, L. Debussche, and F. Blanche, J. Bacteriol. 177:5199-5205, 1995); these enzymes are PIIA synthase, a heterodimer composed of the SnaA and SnaB proteins, which catalyzes the oxidation of PIIB to PIIA, and the NADH:riboflavin 5'-phosphate oxidoreductase (hereafter called FMN reductase), the SnaC protein, which provides the reduced form of flavin mononucleotide for the reaction. By using oligonucleotide probes designed from limited peptide sequence information of the purified proteins, the corresponding genes were cloned from a genomic library of S. pristinaespiralis. SnaA and SnaB showed no significant similarity with proteins from databases, but SnaA and SnaB had similar protein domains. Disruption of the snaA gene in S. pristinaespiralis led to accumulation of PIIB. Complementation of a S. pristinaespiralis PIIA-PIIB+ mutant with the snaA and snaB genes, cloned in a low-copy-number plasmid, partially restored production of PIIA. The deduced amino acid sequence of the snaC gene showed no similarity to the sequences of other FMN reductases but was 39% identical with the product of the actVB gene of the actinorhodin cluster of Streptomyces coelicolor A(3)2, likely to be involved in the dimerization step of actinorhodin biosynthesis. Furthermore, an S. coelicolor A(3)2 mutant blocked in this step was successfully complemented by the snaC gene, restoring the production of actinorhodin.

Characterization of the auxin-inducible SAUR-AC1 gene for use as a molecular genetic tool in Arabidopsis

The small auxin up RNA (SAUR) genes were originally characterized in soybean, where they encode a set of unstable transcripts that are rapidly induced by auxin. In this report, the isolation of a SAUR gene, designated SAUR-AC1, from Arabidopsis thaliana (L.) Heynh. ecotype Columbia is described. The promoter of the SAUR-AC1 gene contains putative regulatory motifs conserved among soybean SAUR promoters, as well as sequences implicated in the regulation of other genes in response to auxin. The transcribed region is approximately 500 bp in length and contains no introns. Highly conserved sequences located within the SAUR-AC1 transcript include the central portion of the coding region and a putative mRNA instability sequence (DST) located in the 3' untranslated region. Accumulation of SAUR-AC1 mRNA is readily induced by natural and synthetic auxins and by the translational inhibitor cycloheximide. Moreover, several auxin- and gravity-response mutants of Arabidopsis exhibit decreased accumulation of the SAUR-AC1 mRNA in elongating etiolated seedlings. In particular, in the axr2-1 mutant the SAUR-AC1 transcript accumulates to less than 5% of wild-type levels. These studies indicate that SAUR-AC1 will be a useful probe of auxin-induced gene expression in Arabidopsis and will facilitate the functional analysis of both transcriptional and posttranscriptional regulatory elements.

Two-Hz wide EEG bands in Alzheimer's disease

Twenty Alzheimer's Disease (AD) patients in a mild to moderate stage of the disease and 20 control subjects were compared in 17 2-Hz wide bands from the electrodes 01, 02, P3, P4, T5, T6, F3, F4, F7, F8, Fp1, and Fp2. Differences reached statistical significance for 0-2 and 4-6 Hz bands, where AD patients presented highest power values. The AD group was divided into two groups according to the stage of disease. Both groups of patients presented 0-2 Hz increase in frontal, right parieto-temporal, and occipital areas. The increase in 4-6 Hz band was mainly over frontal areas in both groups and over left parietal region in moderate AD patients. These results and those relative to dominant frequency and crossover frequency between groups are discussed according to previous results with conventional and 2-Hz wide bands in AD patients in a severe stage of the disease.