Total synthesis of (-)-callystatin A

An effective total synthesis of (-)-callystatin A (1), member of the leptomycin family of antibiotics, has been achieved. The synthesis features Evans extended aldol methodology to construct the northern polypropionate subunit and two separate Julia olefinations to assemble the conjugated dienes. The total synthesis proceeded in 2.3% overall yield with the longest linear sequence of 15 steps.

Design and synthesis of novel scaffolds for drug discovery: hybrids of beta-D-glucose with 1,2,3,4-tetrahydrobenzo[e][1,4]diazepin-5-one, the corresponding 1-oxazepine, and 2- and 4-pyridyldiazepines

[structure: see text]. We describe the syntheses of novel tricyclic scaffolds that incorporate a fusion of a substituted pyranose ring with the seven-membered rings of 1,2,3,4-tetrahydrobenzo[e][1,4]diazepin-5-one and the corresponding oxazepine and pyridyldiazepine to generate the benzodiazepines, and the related heterocycles. In each instance, the pyranose rings contain three protected hydroxyls, suitable for selective derivatization.

Self-reported quality of life of individual cancer patients: concordance of results with disease course and medical records

PURPOSE

To investigate the applicability of a standard quality of life (QL) questionnaire to individual cancer patients and to explore the potential for impact of QL information on the process of care by comparing at group level the QL results with the medical records.

PATIENTS AND METHODS

One hundred fourteen consecutive patients at the oncology clinics at St James's Hospital, Leeds, United Kingdom, completed the European Organization for the Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 on a touch-screen computer over a 6-month period. The QL results were compared with the corresponding medical records at individual and group level.

RESULTS

For individual patients, the serial measurement of QL allowed recognition of patterns over time corresponding to disease course. At group level, a higher proportion of patients reported problems on EORTC QLQ-C30 than were mentioned in the medical records (McNemar paired test, P <.01). Most often clinicians mentioned pain (22% to 39%), and at the initial visit role (66%), and social issues (77%). For the rest of the symptoms and functions, the problems were recorded in between 1% and 25% of the notes, but 20% to 76% of the patients reported QL impairment. Problems that were not recorded in the medical notes tended to be of low severity, with a significant trend observed for pain, fatigue, nausea/vomiting, dyspnea, loss of appetite, and physical function scale (chi(2) test, 11.55 to 34.42, df = 1, P <.001).

CONCLUSION

The QL data on individual patients was consistent with the clinical records, thus providing evidence for the validity of these measures in assessment of the individual. The QL profiles had more information on symptoms and particularly on functional issues, such as emotional distress and physical performance.

Large-scale heterogeneity of the fossil record: implications for Phanerozoic biodiversity studies

Patterns of origination, extinction and standing diversity through time have been inferred from tallies of taxa preserved in the fossil record. This approach assumes that sampling of the fossil record is effectively uniform over time. Although recent evidence suggests that our sampling of the available rock record has indeed been very thorough and effective, there is also overwhelming evidence that the rock record available for sampling is itself distorted by major systematic biases. Data on rock outcrop area compiled for post-Palaeozoic sediments from Western Europe at stage level are presented. These show a strongly cyclical pattern corresponding to first- and second-order sequence stratigraphical depositional cycles. Standing diversity increases over time and, at the coarsest scale, is decoupled from surface outcrop area. This increasing trend can therefore be considered a real pattern. Changes in standing diversity and origination rates over time-scales measured in tens of millions of years, however, are strongly correlated with surface outcrop area. Extinction peaks conform to a random-walk model, but larger peaks occur at just two positions with respect to second-order stratigraphical sequences, towards the culmination of stacked transgressive system tracts and close to system bases, precisely the positions where taxonomic last occurrences are predicted to cluster under a random distribution model. Many of the taxonomic patterns that have been described from the fossil record conform to a species-area effect. Whether this arises primarily from sampling bias, or from changing surface area of marine shelf seas through time and its effect on biodiversity, remains problematic.

Design and synthesis of novel 2,3-dihydro-1H-isoindoles with high affinity and selectivity for the dopamine D3 receptor

Starting from the tetrahydroisoquinoline SB-277011 1, a novel series of 5-substituted-2,3-dihydro-1H-isoindoles has been designed. Subsequent optimisation resulted in identification of 19, which has high affinity for the dopamine D3 receptor (pKi 8.3) and > or = 100-fold selectivity over other aminergic receptors. In rat studies 19 was brain penetrant with an excellent pharmacokinetic profile (oral bioavailability 77%, t1/2 5.2h).

Solution structure of (+)-discodermolide

[structure: see text]. The solution structure of (+)-discodermolide (1) has been determined via 1- and 2-D NMR techniques in conjunction with Monte Carlo conformational analysis. Taken together, the results demonstrate that in solution (+)-discodermolide occupies a helical conformation remarkably similar to the solid state conformation.

First isolation of La Crosse virus from naturally infected Aedes albopictus

La Crosse (LAC) virus, a California serogroup bunyavirus, is the leading cause of pediatric arboviral encephalitis in the United States and an emerging disease in Tennessee, West Virginia, and North Carolina. Human cases of LAC encephalitis in Tennessee and North Carolina have increased above endemic levels during 1997 to 1999 and may represent an expansion of a new southeastern endemic focus. This report describes the isolation of LAC virus from the exotic mosquito Aedes albopictus. The discovery of LAC virus in wild populations of Ae. albopictus coupled with its expanding distribution in the southeastern United States, suggests that this mosquito may become an important accessory vector, potentially increasing the number of human cases in endemic foci or expanding the range of the disease.

Development of an efficient, regio- and stereoselective route to libraries based on the beta-D-glucose scaffold

The design and execution of an efficient synthetic route for the sequential functionalization of the five hydroxyl substituents of beta-D-glucose has been achieved. This strategy, based on the stereoselective glycosidation of thioglycosides, provides a new approach for the parallel construction of a wide variety of beta-D-glucose analogues and as such holds promise for solid-support library syntheses.

Design, synthesis, and evaluation of a pyrrolinone-based matrix metalloprotease inhibitor

[reaction: see text] A pyrrolinone-based hydroxamate matrix metalloprotease inhibitor, (-)-1, has been designed and synthesized. Enzymatic assay revealed that (-)-1 inhibited three of the ten matrix metalloprotease enzymes examined and as such represents a new, potentially important lead structure.

Intramolecular hydrogen-bond participation in phosphonylammonium salt formation

[reaction: see text] A series of phosphonochloridates and phosphonyl dichlorides were prepared, and their reactivity with triethylamine has been investigated using (31)P NMR spectroscopy. Taken together these studies provide evidence that an intramolecular hydrogen-bond is required for phosphonylammonium salt formation to render the phosphorus more electron-deficient.

Novel 2,3,4,5-tetrahydro-1H-3-benzazepines with high affinity and selectivity for the dopamine D3 receptor

Starting from the dopamine D3 receptor antagonist SB-277011 1, a series of 2,3,4,5-tetrahydro-1H-3-benzazepines has been identified with high affinity for the dopamine D3 receptor and selectivity over the D2 receptor. The 3-acetamido-2-fluorocinnamide derivative 20 gave high D3 receptor affinity (pKi 8.4) with 130-fold selectivity over the 2, receptor.

No evidence for a parent-of-origin effect detected in the pattern of inheritance of schizophrenia

BACKGROUND

Schizophrenia is a complex genetic disorder with no clear pattern of inheritance. Epigenetic modification of genes may thus play a role in its transmission.

METHODS

In our study, 439 families with at least two ill siblings with schizophrenia (208 with unilineal transmission) were examined for evidence of a parent-of-origin effect (e.g., evidence of parental imprinting on the familial transmission of schizophrenia).

RESULTS

No significant difference in the prevalence of maternal compared with paternal transmission was found. In addition, affected male subjects did not differ from affected female subjects in the proportion of their offspring diagnosed with schizophrenia.

CONCLUSIONS

Although the transmission of schizophrenia may be influenced by epigenetic events, our study fails to find evidence that one epigenetic mechanism, a parent-of-origin imprinting effect, determines whether an individual expresses the illness.

Medication error reporting: a survey of nursing staff

The objective of this article is to describe findings from a medication error (ME) survey, to estimate the extent of ME underreporting by comparison of survey results with written incident reports (IRs), and to determine factors associated with IR reporting of MEs. Participants were registered nurses from the 38-bed infant unit of a pediatric hospital. Most recent ME in each of four stages of the medication process was classified as to: timing, nature, whether the error was prevented from the patient, patient injury, and completed IR. Surveys were administered to nurses during mandatory skills session and were compared with IRs for MEs for the previous 6 months. The survey response rate was 93.5 percent; 72 nurses described 177 errors, 40.3 percent observed an ME in the previous week, 62.1 percent were prevented from reaching the patient and the likelihood of prevention was reduced in the later stages of the medication process. About 30 percent of MEs resulted in IRs. Administration errors were more likely to result in IRs compared with ordering errors, especially when the error was not prevented from the patient. There were 51 IRs for MEs. A multivariate logistic regression with completed IRs as the dependent variable showed a decreased likelihood of IRs for ordering than administration errors. IRs were more likely for wrong medication or dose errors and IRs were less likely for errors prevented from reaching the patient. The study found that by augmenting IR reporting of MEs and classifying errors by stage, anonymous ME surveys can be used for monitoring and guiding improvements to hospital medication systems.

An algorithm for source checking continuous air monitors using radon progeny

Department of Energy requirements contained within 10CFR835 require that continuous air monitors be periodically checked for operability. The DOE air monitoring implementation guide for 10CFR835 allows the use of radon progeny to perform the recommended weekly source check. The Defense Waste Processing Facility located at the Savannah River Site has demonstrated that, through the use of the Hypotheses Concerning Two Means, diurnal change in the radon progeny detected by the monitors meets the requirements for weekly source checks. The use of the diurnal change in radon progeny has replaced the person-hours expended performing direct weekly source checking with an automated system requiring minimal person-hour expenditure.

Synthesis of polypyrrolinones on solid support

[reaction: see text] An efficient, three-step iterative synthesis of polypyrrolinones has been achieved on solid support, setting the stage for the construction of a wide variety of libraries based on the pyrrolinone scaffold. Central to the approach is an effective end-game sequence featuring pyrrolinone ring construction with traceless release from the solid support.

A second-generation synthesis of polypyrrolinone nonpeptidomimetics: prelude to the synthesis of polypyrrolinones on solid support

[reaction: see text] A second-generation asymmetric synthesis of polypyrrolinones (3) has been achieved exploiting scalemic alpha-aminolactones (1) as building blocks. Imine formation between an appropriate lactone (1) and aldehyde (2), followed in turn by pyrrolinone ring construction promoted by KHMDS in the presence of 18-crown-6 and modified Swern oxidation furnished pyrrolinone aldehyde 3. This iterative, efficient three-step protocol paves the way for the synthesis of polypyrrolinones on solid support.

Total synthesis of the ansamycin antibiotic (+)-thiazinotrienomycin E

The first total synthesis of (+)-thiazinotrienomycin E (1), member of a novel class of cytotoxic ansamycin antibiotics, has been achieved. Key features of the synthetic strategy include (a) the efficient construction of sulfone 7 incorporating TBS protection of the aniline, (b) an improved synthesis of allyl chloride (-)-6, the advanced intermediate employed in our trienomycins A and F total syntheses, (c) application of the Kocienski modified Julia protocol to elaborate the E,E,E-triene subunit in a stereo-controlled fashion, (d) an efficient union of sulfone 7 with advanced iodide 62, and (e) Mukaiyama macrolactamization to access the thiazinotrienomycin macrocyclic ring.

Failure to establish linkage on the X chromosome in 301 families with schizophrenia or schizoaffective disorder

The hypothesis that a gene for susceptibility to psychosis (specifically in the X-Y homologous class) is located on the sex chromosomes has been proposed. Such a gene would account for the excess of sex chromosome anomalous males and females in populations of patients with psychosis, a tendency towards concordance by sex within families, and sex differences associated with psychosis and its underlying brain pathology. In earlier studies we observed small positive LOD scores in Xp11, and in a more recent and larger cohort of 178 sibling pairs, a peak multipoint nonparametric LOD score of 1. 55 at the locus DXS8032 in Xq21. The present study with a new set of markers extended the cohort to 301 ill sibling pairs and their parents. Despite the increase in sample size, the LOD score did not increase. A peak NPL of 1.55 was observed at the locus DXS1068 in proximal Xp, a region remote from the previous report. Separating families into those who were more likely to have X chromosome inheritance (maternal with no male to male transmission) did not yield stronger findings. In spite of the evidence that psychosis is related to a sex-dependent dimension of cerebral asymmetry, it is concluded that no consistent linkage of schizophrenia to the X chromosome can be demonstrated. In the context of the general failure of replication of linkage in psychosis, the possibility that the genetic predisposition to psychosis is contributed to by epigenetic modification rather than variations in the nucleotide sequence has to be considered.

Investigation of a candidate gene for schizophrenia on Xq13 previously associated with mental retardation and hypothyroidism

Weak support for linkage of schizophrenia to proximal Xq has previously been reported. In addition, an increased prevalence of thyroid disorder has been noted in families of individuals with schizophrenia. Recently, a gene mapped to Xq13 termed HOPA has been found to be associated with mental retardation, hypothyroidism, and depression and to function as a coactivator for the thyroid receptor. We therefore examined the HOPA gene in a group of 111 probands from a larger cohort of multiplex families with schizophrenia, several of whom (n = 53) also had a family history of hypothyroidism. Four males and two females were found with an alteration in exon 42 of the HOPA gene compared with 8/492 males and 18/471 females (942 X chromosomes) compared with consecutively screened newborns (chi(2) = 3.92, P < 0.05). However, when available family members of each of the probands with an exon 42 variation were subsequently screened, the mutation did not segregate with schizophrenia in three of five families, although all 6 probands with an exon 42 variation did have hypothyroidism in either themselves (n = 3) or their mothers (n = 3) (P < 0.008). These findings replicate prior findings demonstrating an association between HOPA polymorphisms and hypothyroidism. In addition, the increased frequency of HOPA variants in this population may also provide a genetic basis for the familial association of thyroid disease and schizophrenia.

Chiral action at a distance: remote substituent effects on the optical activity of calyculins A and B

[structure--see text] Calyculins A and B differ only by the (E)- vs (Z)-configuration at C(2). Yet, they show a large difference in optical rotations. We demonstrate a new strategy that provides a physical analysis of this long-range chiro-optical effect by Boltzmann-averaged atomic contribution mapping. The polarizability characteristics of the CN substituent rather than the perturbation of the stereogenic centers or the introduction of asymmetry into the polyene chain give rise to the remarkable difference in rotation angles.

Taxol and discodermolide represent a synergistic drug combination in human carcinoma cell lines

Recently, three natural products have been identified, the epothilones, eleutherobin, and discodermolide, whose mechanism of action is similar to that of Taxol in that they stabilize microtubules and block cells in the mitotic phase of the cell cycle. In this report, we have compared and contrasted the effects of these new agents in Taxol-sensitive and -resistant cell lines. We also have taken advantage of a human lung carcinoma cell line, A549-T12, that was isolated as a Taxol-resistant cell line and found to require low concentrations of Taxol (2-6 nM) for normal cell division. This study then examined the ability of these new compounds to substitute for Taxol in sustaining the growth of A549-T12 cells. Immunofluorescence and flow cytometry have both indicated that the epothilones and eleutherobin, but not discodermolide, can substitute for Taxol in this Taxol-dependent cell line. In A549-T12 cells, the presence of Taxol significantly amplified the cytotoxicity of discodermolide, and this phenomenon was not observed in combinations of Taxol with either the epothilones or eleutherobin. Median effect analysis using the combination index method revealed a schedule-independent synergistic interaction between Taxol and discodermolide in four human carcinoma cell lines, an effect that was not observed between Taxol and epothilone B. Flow cytometry revealed that concurrent exposure of A549 cells to Taxol and discodermolide at doses that do not induce mitotic arrest caused an increase in the hypodiploid population, thereby indicating that a possible mechanism for the observed synergy is the potentiation of apoptosis. Our results suggest that Taxol and discodermolide may constitute a promising chemotherapeutic combination.

Lack of evidence for linkage to chromosomes 13 and 8 for schizophrenia and schizoaffective disorder

A previous report [Blouin et al., 1998: Nat Genet 20:70-73] suggesting linkage to chromosomes 13q32 and 8p21 in families with schizophrenia led us to investigate these regions in a large set of 301 multiplex families with schizophrenia. Multipoint analyses failed to reveal evidence for linkage to any portion of chromosome 13, while only a weakly positive score was present on 8p using the identical marker reported in the earlier report. Failure to confirm the Blouin et al claims in a substantially larger cohort adds emphasis to the inconsistency of the findings concerning linkage in schizophrenia. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:235-239, 2000.