Human TOP3: a single-copy gene encoding DNA topoisomerase III.

A human cDNA encoding a protein homologous to the Escherichia coli DNA topoisomerase I subfamily of enzymes has been identified through cloning and sequencing. Expressing the cloned human cDNA in yeast (delta)top1 cells lacking endogenous DNA topoisomerase I yielded an activity in cell extracts that specifically reduces the number of supercoils in a highly negatively supercoiled DNA. On the basis of these results, the human gene containing the cDNA sequence has been denoted TOP3, and the protein it encodes has been denoted DNA topoisomerase III. Screening of a panel of human-rodent somatic hybrids and fluorescence in situ hybridization of cloned TOP3 genomic DNA to metaphase chromosomes indicate that human TOP3 is a single-copy gene located at chromosome 17p11.2-12.

Topoisomerase IV is a target of quinolones in Escherichia coli.

We have demonstrated that, in Escherichia coli, quinolone antimicrobial agents target topoisomerase IV (topo IV). The inhibition of topo IV becomes apparent only when gyrase is mutated to quinolone resistance. In such mutants, these antibiotics caused accumulation of replication catenanes, which is diagnostic of a loss of topo IV activity. Mutant forms of topo IV provided an additional 10-fold resistance to quinolones and prevented drug-induced catenane accumulation. Drug inhibition of topo IV differs from that of gyrase. (i) Wild-type topo IV is not dominant over the resistant allele. (ii) Inhibition of topo IV leads to only a slow stop in replication. (iii) Inhibition of topo IV is primarily bacteriostatic. These differences may result from topo IV acting behind the replication fork, allowing for repair of drug-induced lesions. We suggest that this and a slightly higher intrinsic resistance of topo IV make it secondary to gyrase as a quinolone target. Our results imply that the quinolone binding pockets of gyrase and topo IV are similar and that substantial levels of drug resistance require mutations in both enzymes.

Stabilization of tetanus and diphtheria toxoids against moisture-induced aggregation.

The progress toward single-dose vaccines has been limited by the poor solid-state stability of vaccine antigens within controlled-release polymers, such as poly(lactide-co-glycolide). For example, herein we report that lyophilized tetanus toxoid aggregates during incubation at 37 degrees C and elevated humidity--i.e., conditions relevant to its release from such systems. The mechanism and extent of this aggregation are dependent on the moisture level in the solid protein, with maximum aggregation observed at intermediate moisture contents. The main aggregation pathway is consistent with formaldehyde-mediated cross-linking, where reactive electrophiles created and stored in the vaccine upon formalinization (exposure to formaldehyde during vaccine preparation) react with nucleophiles of a second vaccine molecule to form intermolecular cross-links. This process is inhibited by the following: (i) succinylating the vaccine to block reactive amino groups; (ii) treating the vaccine with sodium cyanoborohydride, which presumably reduces Schiff bases and some other electrophiles created upon formalinization; and (iii) addition of low-molecular-weight excipients, particularly sorbitol. The moisture-induced aggregation of another formalinized vaccine, diphtheria toxoid, is also retarded by succinylation, suggesting the generality of this mechanism for formalinized vaccines. Hence, mechanistic stability studies of the type described herein may be important for the development of effective single-dose vaccines.

Mixing of connexins in gap junction membrane channels.

Gap junctions are plaque-like clusters of intercellular channels that mediate intercellular communication. Each of two adjoining cells contains a connexon unit which makes up half of the whole channel. Gap junction channels are formed from a multigene family of proteins called connexins, and different connexins may be coexpressed by a single cell type and found within the same plaque. Rodent gap junctions contain two proteins, connexins 32 and 26. Use of a scanning transmission electron microscope for mass analysis of rodent gap junction plaques and split gap junctions prvided evidence consistent with a model in which the channels may be made from (i) solely connexin 26, (ii) solely connexin 32, or (iii) mixtures of connexin 26 and connexin 32 in which the two connexons are made entirely of connexin 26 and connexin 32. The different types of channels segregate into distinct domains, implying tha connexon channels self-associate to give a non-random distribution within tissues. Since each connexin confers distinct physiological properties on its membrane channels, these results imply that the physiological properties of channels can be tailored by mixing the constituent proteins within these macromolecular structures.

NDR1, a locus of Arabidopsis thaliana that is required for disease resistance to both a bacterial and a fungal pathogen.

We have employed Arabidopsis thaliana as a model host plant to genetically dissect the molecular pathways leading to disease resistance. A. thaliana accession Col-0 is susceptible to the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000 but resistant in a race-specific manner to DC3000 carrying any one of the cloned avirulence genes avrB, avrRpm1, avrRpt2, and avrPph3. Fast-neutron-mutagenized Col-0 M2 seed was screened to identify mutants susceptible to DC3000(avrB). Disease assays and analysis of in planta bacterial growth identified one mutant, ndr1-1 (nonrace-specific disease resistance), that was susceptible to DC3000 expressing any one of the four avirulence genes tested. Interestingly, a hypersensitive-like response was still induced by several of the strains. The ndr1-1 mutation also rendered the plant susceptible to several avirulent isolates of the fungal pathogen Peronospora parasitica. Genetic analysis of ndr1-1 demonstrated that the mutation segregated as a single recessive locus, located on chromosome III. Characterization of the ndr1-1 mutation suggests that a common step exists in pathways of resistance to two unrelated pathogens.

Priming of tumor-specific T cells in the draining lymph nodes after immunization with interleukin 2-secreting tumor cells: three consecutive stages may be required for successful tumor vaccination.

Although both CD4+ and CD8+ T cells are clearly required to generate long-lasting anti-tumor immunity induced by s.c. vaccination with interleukin 2 (IL-2)-transfected, irradiated M-3 clone murine melanoma cells, some controversy continues about the site and mode of T-cell activation in this system. Macrophages, granulocytes, and natural killer cells infiltrate the vaccination site early after injection into either syngeneic euthymic DBA/2 mice or athymic nude mice and eliminate the inoculum within 48 hr. We could not find T cells at the vaccination site, which argues against the concept that T-cell priming by the IL-2-secreting cancer cells occurs directly at that location. However, reverse transcription-PCR revealed transcripts indicative of T-cell activation and expansion in the draining lymph nodes of mice immunized with the IL-2-secreting vaccine but not in mice vaccinated with untransfected, irradiated M-3 cells. We therefore propose that the antigen-presenting cells, which invade the vaccination site, process tumor-derived antigens and, subsequently, initiate priming of tumor-specific T lymphocytes in lymphoid organs. These findings suggest a three-stage process for the generation of effector T cells after vaccination with IL-2-secreting tumor cells: (i) tumor-antigen uptake and processing at the site of injection by antigen-presenting cells, (ii) migration of antigen-presenting cells into the regional draining lymph nodes, where T-cell priming occurs, and (iii) circulation of activated T cells that either perform or initiate effector mechanisms leading to tumor cell destruction.

Professionals’ Perceptions of Support Resources for Battered Immigrant Women Chronicle of an Anticipated Failure

The aim of this study was to explore the experience of service providers in Spain regarding their daily professional encounters with battered immigrant women and their perception of this group’s help-seeking process and the eventual abandonment of the same. Twenty-nine in-depth interviews and four focus group discussions were conducted with a total of 43 professionals involved in providing support to battered immigrant women. We interviewed social workers, psychologists, intercultural mediators, judges, lawyers, and public health professionals from Spain. Through qualitative content analysis, four categories emerged: (a) frustration with the victim’s decision to abandon the help-seeking process, (b) ambivalent positions regarding differences between immigrant and Spanish women, (c) difficulties in the migratory process that may hinder the help-seeking process, and (d) criticisms regarding the inefficiency of existing resources. The four categories were cross-cut by an overarching theme: helping immigrant women not to abandon the help-seeking process as a chronicle of anticipated failure. The main reasons that emerged for abandoning the help-seeking process involved structural factors such as economic dependence, loss of social support after leaving their country of origin, and limited knowledge about available resources. The professionals perceived their encounters with battered immigrant women to be frustrating and unproductive because they felt that they had few resources to back them up. They felt that despite the existence of public policies targeting intimate partner violence (IPV) and immigration in Spain, the resources dedicated to tackling gender-based violence were insufficient to meet battered immigrant women’s needs. Professionals should be trained both in the problem of IPV and in providing support to the immigrant population.

Barriers and facilitators to effective coverage of Intimate Partner Violence services for immigrant women in Spain

Objective: To explore service providers’ perceptions in order to identify barriers and facilitators to effective coverage of Intimate Partner Violence (IPV) services for immigrant women in Spain, according to the different categories proposed in Tanahashi's model of effective coverage. Methods: A qualitative study based on 29 in-depth personal interviews and four group interviews with a total of 43 professionals working in public services (social and health-care services, women's refuges, the police force, the judiciary) and NGOs in Barcelona, Madrid, Valencia and Alicante (Spain) in 2011. Findings: Current IPV services in Spain partially fail in their coverage of abused immigrant women due to barriers of (i) availability, such as the inexistence of culturally appropriate services; (ii) accessibility, as having a residence permit is a prerequisite for women's access to different services and rights; (iii) acceptability, such as women's lack of confidence in the effectiveness of services; and (iv) effectiveness, for example, lack of specific training among professionals on the issues of IPV and immigration. However, interviewees also identified facilitators, such as the enabling environment promoted by the Spanish Law on Gender-Based Violence (1/2004), and the impetus it has provided for the development of other specific legislative tools to address IPV in immigrant populations in Spain (availability, accessibility and effectiveness). Conclusion: Whilst not dismissing cultural barriers, aspects related to service structure are identified by providers as the main barriers and facilitators to immigrant women use of IPV services. Despite noteworthy achievements, improvements are still required in terms of mainstreaming assistance tailored to immigrant women's needs in IPV policies and services.

Factors Associated with the Cessation of Intimate Partner Violence in Women Attending Primary Care in Spain

This study aimed to identify factors associated with the likelihood of IPV cessation among women attending Spanish primary healthcare. Of the 2465 women who reported lifetime IPV, 36.1 % stated that violence had ceased. Those women not currently abused had higher levels of education and social support, were workers or students, and had no dependent children. When IPV duration was less than 5 years, the likelihood of cessation was two times higher than when IPV continued beyond 5 years. For women who have experienced physical IPV, the probability of ending the violent relationship was 10 times higher than for those suffering from psychological IPV. The implications of the findings regarding clinical significance and future research are discussed.

A Mourning Ditty: On the Conflagration of Harvard Hall in Cambridge New England. On the 24th Day of January 1764, [1764]

One-page handwritten copy of "A Mourning Ditty" signed "Philomusus Or A lover of the Muses"describing in a classical style the burning of Harvard Hall. The transcription is signed "Correctly Translated from the Printed Copy, by Peter Thacher." Thacher's translation is of the Latin poem "Threnodia" that appeared on the front page of the Massachusetts Gazette on February 2, 1764.

[Form of Admission of Ephraim Morton (Harvard AB 1787)], 1784 March 15

Printed certificate of admission for undergraduate Ephraim Morton signed by President Joseph Willard. Includes a handwritten emendation to the text made by President Willard on February 17, 1784.

[Form of Admission of Ichabod Tucker (Harvard AB 1791)], 1787 August 16-17

Printed certificate of admission for undergraduate Ichabod Tucker certified by Steward Caleb Gannett on August 16, 1787 and signed by President Joseph Willard on August 17, 1787.

[Form of Admission of Francis Oliver (Harvard AB 1795)], 1791 August 19-20

Printed certificate of admission for undergraduate Francis J. Oliver certified by Steward Caleb Gannett on August 19, 1791 and signed by President Joseph Willard on August 20, 1791.

An oration, Thaddeus M Harris A.M. now minister of Dorchester, 1790

This small paper notebook contains a twenty-one-page handwritten oration on learned societies delivered by Phi Beta Kappa member Thaddeus Mason Harris on September 1, 1790. The oration is followed by five pages of "notes and illustrations" on the text. Title transcribed from title page. Item bound in blue-and-white floral wallpaper covers.

An oration delivered at the request of the PBK society, at Cambridge. By Thomas W. Hooper, 1790

This small paper notebook contains a sixteen-page handwritten copy of an oration on "amiable and useful virtues" delivered by Phi Beta Kappa member Thomas W. Hooper on September 1, 1790. Title transcribed from the first page of text. Item bound in blue-and-white floral wallpaper covers.