Retrospective national cohort study of pregnancy outcomes for women with type 1 and type 2 diabetes mellitus in Republic of Ireland

AIM

Report the outcomes of pregnant women with type 1 and type 2 diabetes and to identify modifiable and non-modifiable factors associated with poor outcomes.

METHODS

Retrospective analysis of pregnancy preparedness, pregnancy care and outcomes in the Republic of Ireland from 2015 to 2020 and subsequent multivariate analysis.

RESULTS

In total 1104 pregnancies were included. Less than one third attended pre-pregnancy care (PPC), mean first trimester haemoglobin A1c was 7.2 ± 3.6% (55.5 ± 15.7 mmol/mol) and 52% received pre-conceptual folic acid. Poor preparation translated into poorer pregnancy outcomes. Livebirth rates (80%) were comparable to the background population however stillbirth rates were 8.7/1000 (four times the national rate). Congenital anomalies occurred in 42.5/1000 births (1.5 times the background rate). More than half of infants were large for gestational age and 47% were admitted to critical care. Multivariate analyses showed strong associations between non-attendance at PPC, poor glycaemic control and critical care admission (adjusted odds ratio of 1.68 (1.48-1.96) and 1.61 (1.43-1.86), p < 0.05 respectively) for women with type 1 diabetes. Smoking and teratogenic medications were also associated with critical care admission and hypertensive disorders of pregnancy.

CONCLUSION

Pregnancy outcomes in women with diabetes are suboptimal. Significant effort is needed to optimize the modifiable factors identified in this study.

Contributors to Gender Differences in Burnout and Professional Fulfillment: A Survey of Physician Faculty

BACKGROUND

This study was conducted to describe gender differences in physician burnout and professional fulfillment and to explore their potential contributors.

METHODS

This was a single-center, cross-sectional survey study of physician faculty at Brigham and Women's Hospital, an academic medical center in Boston. The population included all physician faculty who practiced clinical medicine in 2017 (n = 2,388). The study was conducted using the Stanford Physician Wellness Survey. Burnout and professional fulfillment were the main outcome measures assessed. Other variables assessed included ratings of culture of wellness, personal resilience, and efficiency of practice factors associated with physician experience.

RESULTS

The study population consisted of 1,066 faculty, of whom 46.4% were female and 59.8% were younger than 50. Female physicians reported significantly higher rates of burnout (42.4% vs. 34.4%, p = 0.01) and lower rates of professional fulfillment (35.1% vs. 50.4%, p < 0.01) than male physicians. Female physicians reported lower ratings for self-compassion and multiple culture of wellness factors. After adjusting for demographic factors and academic rank, the study team identified multiple culture of wellness factors (perceived appreciation, schedule control, work environment diversity and inclusion) and self-compassion as attenuating the significant relationship between gender and burnout. Only perceived appreciation attenuated the significant relationship between gender and professional fulfillment.

CONCLUSION

This study demonstrated higher rates of burnout and lower rates of professional fulfillment among female vs. male physician faculty. Culture of wellness factors and self-compassion may contribute to gender differences in burnout and professional fulfillment and potentially represent modifiable targets for efforts seeking to eliminate gender disparities in physicians' workplace experiences.

Delirium monitoring and management in the acute care setting

Associated with substantial morbidity and mortality, delirium is a syndrome commonly experienced by hospitalized adults. This article presents a case study highlighting how delirium may go unrecognized by the healthcare team and provides 10 suggestions for improving delirium assessment, prevention, and management in the acute care setting.

Evolution of nectar spur length in a clade of Linaria reflects changes in cell division rather than in cell expansion

BACKGROUND AND AIMS

Nectar spurs (tubular outgrowths of a floral organ which contain, or give the appearance of containing, nectar) are hypothesized to be a 'key innovation' which can lead to rapid speciation within a lineage, because they are involved in pollinator specificity. Despite the ecological importance of nectar spurs, relatively little is known about their development. We used a comparative approach to investigate variation in nectar spur length in a clade of eight Iberian toadflaxes.

METHODS

Spur growth was measured at the macroscopic level over time in all eight species, and growth rate and growth duration compared. Evolution of growth rate was reconstructed across the phylogeny. Within the clade we then focused on Linaria becerrae and Linaria clementei, a pair of sister species which have extremely long and short spurs, respectively. Characterization at a micromorphological level was performed across a range of key developmental stages to determine whether the difference in spur length is due to differential cell expansion or cell division.

KEY RESULTS

We detected a significant difference in the evolved growth rates, while developmental timing of both the initiation and the end of spur growth remained similar. Cell number is three times higher in the long spurred L. becerrae compared with L. clementei, whereas cell length is only 1.3 times greater. In addition, overall anisotropy of mature cells is not significantly different between the two species.

CONCLUSIONS

We found that changes in cell number and therefore in cell division largely explain evolution of spur length. This contrasts with previous studies in Aquilegia which have found that variation in nectar spur length is due to directed cell expansion (anisotropy) over variable time frames. Our study adds to knowledge about nectar spur development in a comparative context and indicates that different systems may have evolved nectar spurs using disparate mechanisms.

Urinary Phthalate Concentrations in Mothers and Their Children in Ireland: Results of the DEMOCOPHES Human Biomonitoring Study

Background: Phthalates are chemicals which are widespread in the environment. Although the impacts on health of such exposure are unclear, there is evidence of a possible impact on the incidence of a diverse range of diseases. Monitoring of human exposure to phthalates is therefore important. This study aimed to determine the extent of phthalate exposure among mothers and their children in both rural and urban areas in Ireland, and to identify factors associated with elevated concentrations. It formed part of the ‘Demonstration of a study to Co-ordinate and Perform Human Biomonitoring on a European Scale’ (DEMOCOPHES) pilot biomonitoring study. Methods: the concentration of phthalate metabolites were determined from a convenience sample of 120 mother/child pairs. The median age of the children was 8 years. A questionnaire was used to collect information regarding lifestyle and environmental conditions of the children and mothers. Rigorous quality assurance within DEMOCOPHES guaranteed the accuracy and international comparability of results. Results: Phthalate metabolites were detected in all of the samples from both children and mothers. Concentrations were significantly higher in respondents from families with lower educational attainment and in those exposed to such items as polyvinyl chloride (PVC), fast food and personal care products (PCP). Conclusions: The study demonstrates that human biomonitoring for assessing exposure to phthalates can be undertaken in Ireland and that the exposure of the population is widespread. Further work will be necessary before the consequences of this exposure are understood.

Response of 33 UK patients with infantile-onset Pompe disease to enzyme replacement therapy

BACKGROUND

Enzyme replacement therapy (ERT) for infantile-onset Pompe disease has been commercially available for almost 10 years. We report the experience of its use in a cohort treated at three specialist lysosomal treatment centres in the UK.

METHODS

A retrospective case-note review was performed, with additional data being gathered from two national audits on all such patients treated with ERT. The impact on the outcome of various characteristics, measured just prior to the initiation of ERT (baseline), was evaluated using logistic regression.

RESULTS

Thirty-three patients were identified; 13/29 (45%) were cross-reactive immunological material (CRIM) negative, and nine were immunomodulated. At baseline assessment, 79% were in heart failure, 66% had failure to thrive and 70% had radiological signs of focal pulmonary collapse. The overall survival rate was 60%, ventilation-free survival was 40% and 30% of patients were ambulatory. Median follow-up of survivors was 4 years, 1.5 months (range 6 months to 13.5 years). As with previous studies, the CRIM status impacted on all outcome measures. However, in this cohort, baseline failure to thrive was related to death and lack of ambulation, and left ventricular dilatation was a risk factor for non-ventilator-free survival.

CONCLUSION

The outcome of treated patients remains heterogeneous despite attempts at immunomodulation. Failure to thrive at baseline and left ventricular dilation appear to be associated with poorer outcomes.

Understanding deliberate practice in preschool-aged children

Deliberate practice is essential for skill acquisition and expertise and may be a direct consequence of episodic foresight. However, little is known about how deliberate practice develops in children. We present two experiments testing children's ability to selectively practise a behaviour that was going to be useful in future and to reason about the role of practice in skill formation. Five-year-olds demonstrated an explicit understanding of deliberate practice both in selectively choosing to practise a future-relevant skill and in predicting skill change in others based on their practice. Four-year-olds showed some capacities, but failed to demonstrate consistent understanding of the relationship between practice and skill improvement. Children's understanding of this relationship was significantly related to their understanding of how information leads to knowledge, suggesting that both may draw on similar cognitive developmental changes.

Communication in a Human biomonitoring study: Focus group work, public engagement and lessons learnt in 17 European countries

A communication strategy was developed by The Consortium to Perform Human Biomonitoring on a European Scale (COPHES), as part of its objectives to develop a framework and protocols to enable the collection of comparable human biomonitoring data throughout Europe. The framework and protocols were tested in the pilot study DEMOCOPHES (Demonstration of a study to Coordinate and Perform Human biomonitoring on a European Scale). The aims of the communication strategy were to raise awareness of human biomonitoring, encourage participation in the study and to communicate the study results and their public health significance. It identified the audiences and key messages, documented the procedure for dissemination of results and was updated as the project progressed. A communication plan listed the tools and materials such as press releases, flyers, recruitment letters and information leaflets required for each audience with a time frame for releasing them. Public insight research was used to evaluate the recruitment material, and the feedback was used to improve the documents. Dissemination of results was coordinated in a step by step approach by the participating countries within DEMOCOPHES, taking into account specific national messages according to the needs of each country. Participants received individual results, unless they refused to be informed, along with guidance on what the results meant. The aggregate results and policy recommendations were then communicated to the general public and stakeholders, followed by dissemination at European level. Several lessons were learnt that may assist other future human biomonitoring studies. Recruitment took longer than anticipated and so social scientists, to help with community engagement, should be part of the research team from the start. As a European study, involving multiple countries, additional considerations were needed for the numerous organisations, different languages, cultures, policies and priorities. Therefore, communication documents should be seen as templates with essential information clearly indicated and the option for each country to tailor the material to reflect these differences. Future studies should consider setting up multidisciplinary networks of medical professionals and communication experts, and holding training workshops to discuss the interpretation of results and risk communication. Publicity and wide dissemination of the results helped to raise awareness of human biomonitoring to the general public, policy makers and other key stakeholders. Effective and timely communication, at all stages of a study, is essential if the potential of human biomonitoring research to improve public health is to be realised.

Fish consumption patterns and hair mercury levels in children and their mothers in 17 EU countries

The toxicity of methylmercury (MeHg) in humans is well established and the main source of exposure is via the consumption of large marine fish and mammals. Of particular concern are the potential neurodevelopmental effects of early life exposure to low-levels of MeHg. Therefore, it is important that pregnant women, children and women of childbearing age are, as far as possible, protected from MeHg exposure. Within the European project DEMOCOPHES, we have analyzed mercury (Hg) in hair in 1799 mother-child pairs from 17 European countries using a strictly harmonized protocol for mercury analysis. Parallel, harmonized questionnaires on dietary habits provided information on consumption patterns of fish and marine products. After hierarchical cluster analysis of consumption habits of the mother-child pairs, the DEMOCOPHES cohort can be classified into two branches of approximately similar size: one with high fish consumption (H) and another with low consumption (L). All countries have representatives in both branches, but Belgium, Denmark, Spain, Portugal and Sweden have twice as many or more mother-child pairs in H than in L. For Switzerland, Czech Republic, Hungary, Poland, Romania, Slovenia and Slovakia the situation is the opposite, with more representatives in L than H. There is a strong correlation (r=0.72) in hair mercury concentration between the mother and child in the same family, which indicates that they have a similar exposure situation. The clustering of mother-child pairs on basis of their fish consumption revealed some interesting patterns. One is that for the same sea fish consumption, other food items of marine origin, like seafood products or shellfish, contribute significantly to the mercury levels in hair. We conclude that additional studies are needed to assess and quantify exposure to mercury from seafood products, in particular. The cluster analysis also showed that 95% of mothers who consume once per week fish only, and no other marine products, have mercury levels 0.55 μg/g. Thus, the 95th percentile of the distribution in this group is only around half the US-EPA recommended threshold of 1 μg/g mercury in hair. Consumption of freshwater fish played a minor role in contributing to mercury exposure in the studied cohort. The DEMOCOPHES data shows that there are significant differences in MeHg exposure across the EU and that exposure is highly correlated with consumption of fish and marine products. Fish and marine products are key components of a healthy human diet and are important both traditionally and culturally in many parts of Europe. Therefore, the communication of the potential risks of mercury exposure needs to be carefully balanced to take into account traditional and cultural values as well as the potential health benefits from fish consumption. European harmonized human biomonitoring programs provide an additional dimension to national HMB programs and can assist national authorities to tailor mitigation and adaptation strategies (dietary advice, risk communication, etc.) to their country's specific requirements.

A pharmacologic investigation of the 'transport response' in the white rat

In a series of six experiments, the ability of specific neurotransmitter antagonists to alter the 'transport response' was investigated in 19-day-old rat pups. The serotonergic blocker, methysergide, and the cholinergic blocker, scopolamine, did not produce any consistent changes in the intensity of the response. Likewise, the opiate receptor blocker, naloxone, was without effect. Large, dose-dependent decreases in transport response intensity were seen with administration of the beta-noradrenergic receptor blocker, propranolol, and with administration of the dopaminergic blocker, haloperidol. The alphanoradrenergic receptor blocker, phentolamine, produced inconsistent changes in the response. These results indicate a central catecholaminergic involvement in the transport response.

Femoral fractures in children, is early interventional treatment beneficial?

A protocol of early intervention (flexible intramedullary nails, early hip spica, and external fixation) was started in 1999 and during a 3-year period there were 25 children who sustained a femoral shaft fracture (early intervention group). These were prospectively reviewed with a minimum follow up of 24 months (Range 24-35 months). A historical control group of 41 children was used. These children were injured between February 1996 and February 1999 and were retrospectively reviewed. They had traditional in patient treatments with either Gallows or Thomas splint traction (traditional treatment group). Over the 6-year period from 1996 to 2002 there were a total of 66 femoral shaft fractures in the study that presented to our hospital. The mean length of hospital stay was 29 nights in the traditional group and 10 nights in the early intervention group. This difference is significant (p<0.001). The malunion rate was slightly higher in the early active group at radiological union but most of these remodelled over the 2 years of follow up. The protocol of early intervention used in our institution, of flexible nails, early hip spica or external fixation depended on the age of the child, and has resulted in a shorter hospital stay for the children. This has benefits for the child, the family and the hospital.

Engineering and public health at CDC

Engineering is the application of scientific and technical knowledge to solve human problems. Using imagination, judgment, and reasoning to apply science, technology, mathematics, and practical experience, engineers develop the design, production, and operation of useful objects or processes. During the 1940s, engineers dominated the ranks of CDC scientists. In fact, the first CDC director, Assistant Surgeon General Mark Hollis, was an engineer. CDC engineers were involved in malaria control through the elimination of standing water. Eventually the CDC mission expanded to include prevention and control of dengue, typhus, and other communicable diseases. The development of chlorination, water filtration, and sewage treatment were crucial to preventing waterborne illness. Beginning in the 1950s, CDC engineers began their work to improve public health while developing the fields of environmental health, industrial hygiene, and control of air pollution. Engineering disciplines represented at CDC today include biomedical, civil, chemical, electrical, industrial, mechanical, mining, and safety engineering. Most CDC engineers are located in the National Institute for Occupational Safety and Health (NIOSH) and the Agency for Toxic Substances and Disease Registry (ATSDR). Engineering research at CDC has a broad stakeholder base. With the cooperation of industry, labor, trade associations, and other stakeholders and partners, current work includes studies of air contaminants, mining, safety, physical agents, ergonomics, and environmental hazards. Engineering solutions remain a cornerstone of the traditional "hierarchy of controls" approach to reducing public health hazards.

Sex attractant pheromone of the red-shouldered stink bug Thyanta pallidovirens: a pheromone blend with multiple redundant components

The male-produced sex pheromone of the red-shouldered stink bug, Thyanta pallidovirens (Stål) (Hemiptera: Pentatomidae) consists of a blend of methyl (E2,Z4,Z6)-decatrienoate (E2,Z4,Z6-10:COOMe), and the sesquiterpenes (+)-alpha-curcumene, (-)-zingiberene, and (-)-beta-sesquiphellandrene. In laboratory bioassays, sexually mature males attracted sexually mature females but not males, and females did not attract either sex. Extracts of volatiles collected from sexually mature males contained compounds not present in extracts from females or sexually immature males, and male-produced extract was attractive to females. Biological activity was lost when the extract was fractionated, indicating that the pheromone consisted of at least two components having different chemical properties. Individually, pheromone components were not attractive to females, but E2,Z4,Z6-10:COOMe in combination with at least one of the three male-produced sesquiterpenes was attractive. The presence of more than one sesquiterpene in the blend did not increase attraction, indicating redundancy in the pheromone signal. Male extract was as attractive as a blend reconstructed from synthesized compounds, indicating all biologically active components had been identified. In bioassays conducted at dusk in a 1- x 1- x 1-m screen field cage, females were attracted to synthetic pheromone lures. In field trials, adult female T pallidovirens were attracted to pheromone-baited traps in relatively low numbers. The profile of volatiles released by sexually mature males of a congeneric species, Thyanta accerra custator McAtee, was remarkably similar to that of male T. pallidovirens, with the exception that the former species produced (E)-2-decenal, a compound that was not found in T. pallidovirens extracts.

A Phase I study of raltitrexed, an antifolate thymidylate synthase inhibitor, in adult patients with advanced solid tumors

The purpose of this study was to perform a Phase I trial of raltitrexed, a selective inhibitor of thymidylate synthase, and to determine the pharmacokinetic and toxicity profiles as a function of raltitrexed dose. Fifty patients with advanced solid tumors and good performance status were treated with raltitrexed as a 15-min i.v. infusion every 3 weeks, at doses escalating from 0.6 to 4.5 mg/m2. Asthenia, neutropenia, and hepatic toxicity were the most common dose-limiting toxicities in this largely pretreated patient population, but they occurred during the initial cycle in only one of nine patients treated with 4.0 mg/m2 and in two of nine patients treated with 4.5 mg/m2. Only 2 of 13 patients treated with 3.5 mg/m2 ultimately experienced unacceptable toxicity after three and seven cycles, compared with 42 and 56% of patients receiving 4.0 and 4.5 mg/m2 after medians of three and two cycles, respectively. The maximum raltitrexed plasma concentration and the area under the plasma concentration-time curve increased in proportion to dose. Raltitrexed clearance was independent of dose and was associated with the estimated creatinine clearance. Asthenia, neutropenia, and hepatic transaminitis were dose-related and tended to occur more frequently when patients received three or more cycles of therapy. A 3-week treatment interval was feasible in the majority of patients at all doses. Although 4.0 mg/m2 appeared to be a safe starting dose in this pretreated patient population, about half who received two or more courses ultimately experienced dose-limiting toxicity. A dose of 3.5 mg/m2 was well tolerated in most patients.

The utility of monitoring carcinoembyronic antigen during systemic therapy for advanced colorectal cancer

To determine if pre-treatment serum carcinoembryonic antigen (CEA) levels or changes in CEA values during treatment have prognostic value, we reviewed five prior fluorouracil/leucovorin-based trials and identified 125 colorectal cancer patients with no prior chemotherapy for metastatic disease in whom CEA values were available. Although pre-treatment serum CEA values did not predict for clinical response or time to progression, serial monitoring of CEA appeared to be useful in patients with an elevated pre-treatment CEA, particularly when a decrease in CEA occurred in concert with radiographic evidence of disease response. The CEA nadir was a strong prognostic variable with respect to time to disease progression. A consistent rise in CEA values over the minimum value signals the need for radiographic re-assessment of the patient's disease status to rule out disease progression.

Transmembrane-truncated alphavbeta3 integrin retains high affinity for ligand binding: evidence for an 'inside-out' suppressor?

The molecular mechanisms of alphavbeta3 integrin affinity regulation have important biological implications in tumour development, wound repair and angiogenesis. We expressed, purified and characterized recombinant forms of human alphavbeta3 (r-alphavbeta3) and compared the activation state of these with alphavbeta3 in its cellular environment. The ligand specificity and selectivity of recombinant full-length and double transmembrane truncations of r-alphavbeta3 cloned in BacPAK6 vectors and expressed in Sf9 and High Five insect cells were compared with those of native placental alphavbeta3 and the receptor in situ on the cell surface. r-alphavbeta3 integrins were purified by affinity chromatography from detergent extracts of cells (full-length), and from the culture medium of cells expressing double-truncated r-alphavbeta3. r-alphavbeta3 had the same epitopes, ligand-binding specificities, bivalent cation requirements and susceptibility to RGD-containing peptides as native alphavbeta3. On M21-L4 melanoma cells, alphavbeta3 mediated binding to vitronectin, but not to fibrinogen unless activated with Mn2+. Non-activated alphaIIbbeta3 integrin as control in M21-L-IIb cells had the opposite profile, mediating binding to fibrinogen, but not to vitronectin unless activated with Mn2+. Thus these receptors had moderate to low ligand affinity. In marked contrast, purified alphavbeta3 receptors, with or without transmembrane and cytoplasmic domains, were constitutively of high affinity and able to bind strongly to vitronectin, fibronectin and fibrinogen under physiological conditions. Our data suggest that, in contrast with the positive regulation of alphaIIbbeta3 in situ, intracellular controls lower the affinity of alphavbeta3, and the cytoplasmic domains may act as a target for negative regulators of alphavbeta3 activity.

A pilot study of gamma-1b-interferon in combination with fluorouracil, leucovorin, and alpha-2a-interferon

The combination of IFN-alpha-2a (IFN-alpha) and IFN-gamma-1b (IFN-gamma) has been found to produce more than additive cytotoxicity with fluorouracil (5-FU) in HT 29 colon cancer cells due to enhanced DNA-directed effects. We therefore studied the combination of IFN-gamma with IFN-alpha, 5-FU, and leucovorin (LV) in a clinical trial. Fifty-three patients received an initial cycle of 5 million units (MU)/m2 IFN-alpha s.c. on days 1-7 with 500 mg/m2 LV and 370 mg/m2 5-FU i.v. on days 2-6. IFN-gamma was then added once tolerable doses of 5-FU and IFN-alpha were established for each patient. IFN-gamma was administered at one of six dose levels between 0.3-4.8 MU/m2 s.c. on days 1-7. This design permitted comparison of the clinical toxicity and pharmacokinetics of 5-FU in two consecutive cycles in an individual treated with the same doses of 5-FU/LV/IFN-alpha in the absence and presence of IFN-gamma. In 43 matched patient cycles, the addition of IFN-gamma did not seem to worsen gastrointestinal toxicity, and skin toxicity tended to be milder. 5-FU clearance was higher in 14 cycles with IFN-gamma compared to the patient's prior cycle with the same doses of 5-FU/LV/IFN-alpha: 798 +/- 309 versus 601 +/- 250 ml/min/m2 (mean +/- SD; P = 0.04). In these 28 cycles, the median 5-FU clearance was significantly lower in 11 cycles that were complicated by more severe diarrhea: 524 versus 798 ml/min/m2 (grade 2 versus 0-1; P = 0. 0032). Overall, 38% and 26% of patients had grade 3-4 diarrhea and mucositis. Dose reductions of IFN-gamma for chronic fatigue, malaise, or anorexia were ultimately required more frequently with >/=2.4 MU/m2 (P = 0.018), and the maximum tolerated dose of IFN-gamma was considered to be 1.2 MU/m2/ day. Objective responses were seen in 41% of 29 measurable colorectal cancer patients. Compared to our previous experience with 5-FU/LV/IFN-alpha, IFN-gamma and IFN-alpha appeared to have opposite effects on 5-FU clearance. These results suggest that any potential benefit of adding IFN-alpha to 5-FU/LV on this schedule may not depend solely on alterations in 5-FU clearance.

Novel non-nucleoside inhibitors of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. 4. 2-Substituted dipyridodiazepinones as potent inhibitors of both wild-type and cysteine-181 HIV-1 reverse transcriptase enzymes

The major cause of viral resistance to the potent human immunodeficiency virus type 1 reverse transcriptase (RT) inhibitor nevirapine is the mutation substituting cysteine for tyrosine-181 in RT (Y181C RT). An evaluation, against Y181C RT, of previously described analogs of nevirapine revealed that the 2-chlorodipyridodiazepinone 16 is an effective inhibitor of this mutant enzyme. The detailed examination of the structure-activity relationship of 2-substituted dipyridodiazepinones presented below shows that combined activity against the wild-type and Y181C enzymes is achieved with aryl substituents at the 2-position of the tricyclic ring system. In addition, the substitution pattern at C-4, N-5, and N-11 of the dipyridodiazepinone ring system optimum for inhibition of both wild-type and Y181C RT is no longer the 4-methyl-11-cyclopropyl substitution preferred against the wild-type enzyme but rather the 5-methyl-11-ethyl (or 11-cyclopropyl) pattern. The more potent 2-substituted dipyridodiazepinones were evaluated against mutant RT enzymes (L100I RT, K103N RT, P236L RT, and E138K RT) that confer resistance to other non-nucleoside RT inhibitors, and compounds 42, 62, and 67, with pyrrolyl, aminophenyl, and aminopyridyl substituents, respectively, at the 2-position, were found to be effective inhibitors of these mutant enzymes also.

3T3 cell surface galactosyltransferase is a calcium-dependent adhesion molecule for collagen type IV

Cell surface galactosyltransferase (GalTase) has been previously shown to mediate cell spreading or migration on laminin matrices. This work demonstrates that 3T3 cell surface GalTase also mediates cell attachment to collagen type IV. Attachment to collagen type IV was blocked by perturbations of GalTase or substrate pregalactosylation on cells possessing only calcium-dependent mechanisms of adhesion. Cells with both calcium-dependent and calcium-independent systems were not affected by GalTase perturbation. Collagen type IV was shown to possess GalTase substrates since matrices could be galactosylated by both soluble enzyme and 3T3 cells.

Novel non-nucleoside inhibitors of HIV-1 reverse transcriptase. 2. Tricyclic pyridobenzoxazepinones and dibenzoxazepinones

Dibenz[b,f][1,4]oxazepin-11(10H)-ones (III), pyrido[2,3-b][1,4]benzoxazepin-6(5H)-ones (IV), and pyrido[2,3-b]- [1,5]benzoxazepin-5(6H)-ones (V) were found to inhibit human immunodeficiency virus type 1 reverse transcriptase with IC50 values as low as 19 nM. A-ring substitution has a profound effect on activity, with appropriate substituents at the positions ortho and para to the lactam nitrogen providing dramatically enhanced potency. Substitution in the C-ring is generally neutral or detrimental to activity. Although a C-ring amino substituent at the position meta to the lactam carbonyl is generally beneficial to activity, it has essentially no effect when the A-ring is optimally substituted. Like the dipyridodiazepinone nevirapine, compounds III-V are specific for HIV-1 RT, exhibiting no inhibitory activity against HIV-2 RT or other virial reverse transcriptase enzymes.

Bis basic substituted diaminobenzobisthiazoles as potential antiarthritic agents

A series of benzobisthiazoles were screened for antiinflammatory activity in the carrageenan paw edema and adjuvant arthritis tests. Compound 26, 2,6-bis(N,N-diethylamino)benzo[1,2-d:5,4-d']bisthiazole, was found to inhibit the swelling of the uninjected paw in the prophylactic adjuvant arthritis model with an ED50 of 2.3 mg/kg orally. As with most compounds of this series, 26 was inactive in acute model of inflammation, such as paw edema; like steroids, it showed activity in the granuloma pouch assay but did not inhibit cyclooxygenase, indicating a mode of action different from the classical nonsteroidal antiinflammatory drugs (NSAID's). At doses higher than those producing antiinflammatory activity, 26 had some immunoregulating properties.

Novel non-nucleoside inhibitors of HIV-1 reverse transcriptase. 1. Tricyclic pyridobenzo- and dipyridodiazepinones

Novel pyrido[2,3-b][1,4]benzodiazepinones (I), pyrido[2,3-b][1,5]benzodiazepinones (II), and dipyrido[3,2-b:2',3'-e][1,4]diazepinones (III) were found to inhibit human immunodeficiency virus type 1 (HIV-1) reverse transcriptase in vitro at concentrations as low as 35 nM. In all three series, small substituents (e.g., methyl, ethyl, acetyl) are preferred at the lactam nitrogen, whereas slightly larger alkyl moieties (e.g., ethyl, cyclopropyl) are favored at the other (N-11) diazepinone nitrogen. In general, lipophilic substituents are preferred on the A ring, whereas substitution on the C ring generally reduces potency relative to the corresponding compounds with no substituents on the aromatic rings. Maximum potency is achieved with methyl substitution at the position ortho to the lactam nitrogen atom; however, in this case an unsubstituted lactam nitrogen is preferred. Additional substituents on the A ring can be readily tolerated. The dipyridodiazepinone derivative 11-cyclopropyl-5,11-dihydro-4-methyl-6H-dipyrido[3,2-b:2',3'-e] [1,4]diazepin-6-one (96, nevirapine) is a potent (IC50 = 84 nM) and and selective non-nucleoside inhibitor of HIV-1 reverse transcriptase, and has been chosen for clinical evaluation.

CONTRIBUTION À L'ÉTUDE DE LA RÉACTION DE VON RICHTER: IV. COMMENTAIRES CONCERNANT LA RÉACTION

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CONTRIBUTION À L'ÉTUDE DE LA RÉACTION DE VON RICHTER: III. SUR LA RÉACTION AVEC DIVERS NITRONAPHTALÈNES

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CONTRIBUTION À L'ÉTUDE DE LA RÉACTION DE VON RICHTER: II. SUR L'IDENTIFICATION DE PRODUITS NEUTRES

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CONTRIBUTION À L'ÉTUDE DE A RÉACTION DE VON RICHTER: I. SUR L'IDENTIFICATION DE QUELQUES PRODUITS ACIDES

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