Predictors of vitamin A rich food consumption among women living in households growing orange-fleshed sweetpotatoes in selected regions in Uganda

Objective

Vitamin A deficiency (VAD) has serious public health consequences including morbidity and mortality for populations in low and middle-income countries (LMICs), especially for children under 5 years and pregnant women. LMICs are at greater risk of VAD, in part due to low levels of consumption of vitamin A-rich foods most of which are plant-based, such as orange-fleshed sweet potatoes (OFSP), with lower bioavailability than animal sources of the vitamin A. Food-based approaches such as biofortification of OFSP, including promoting the consumption of vitamin A-rich biofortified staple crops, has been shown to be potentially effective in improving the status of vitamin A and other micronutrients. This study examined vitamin A-rich food consumption and its predictors among women of reproductive age from OFSP-growing households in two regions of Uganda.

Methods

A cross-sectional survey was conducted among 617 OFSP growing households, focusing on women in the reproductive age group from the northern and eastern regions of Uganda. Households were not receiving any VAD-related intervention at the time of the survey. Quantitative data included vitamin A-rich food consumption, knowledge on vitamin A, and rich food sources dietary intake, using a 7-day food frequency questionnaire. Vitamin A consumption and risk of deficiency were estimated using the Hellen Keller International guide.

Results

The majority of women in this study were either pregnant (80%) or lactating (17%). More than 70% of the study population had a weighted vitamin A rich food consumption mean score of <6 days per week, indicating a high risk of VAD. Knowledge about vitamin A [b (SE) = -0.18 (0.50), p < 0.001] was significantly and inversely associated with vitamin A rich food consumption.

Conclusion

Components of food insecurity such as availability, affordability, utilization, and changing food preferences may contribute to the unexpected inverse relationship between knowledge and consumption of vitamin A rich foods. Scaling up biofortified food initiatives, including OFSP, can improve consumption of vitamin A rich foods with effective strategies to comprehensively address consumption barriers such as lack of nutrition education, cooking skills, and storage facilities, as well as low production levels and perceived contamination of biofortified foods.

Does High-Definition 3-Dimensional Imaging Improve Orientation During Endoscopic Transsphenoidal Surgery? A Prospective Trial

BACKGROUND

Endoscopy has evolved as the standard visualization tool for endonasal transsphenoidal resection of sellar lesions. The most widely used 2-dimensional (2D) endoscopes harbor the problem of limited depth perception. Therefore, 3-dimensional (3D) endoscopes have been developed to enable depth perception through a stereoscopic view.

OBJECTIVE

To evaluate the impact of high-definition (HD) 2D vs 3D HD endoscopes on spatial orientation within the sphenoid sinus.

METHODS

In this prospective single-center study, 21 patients have been investigated (2021-2022). Eleven standardized anatomic landmarks, which were preoperatively defined on neuronavigation imaging, were intraoperatively targeted with a navigation probe using either 2D HD or 3D HD endoscopes for visualization.

RESULTS

Overall, 3D HD endoscopes provided a statistically significant higher accuracy of identification of sphenoid sinus landmarks (median deviation: 5.2 mm vs 4.2 mm, P < .001). In detail: tuberculum sellae (3.0 mm vs 4.3 mm, P = .047), most anterior point of sella (3.3 mm vs 4.8 mm, P = .049), and clivus indentation (3.8 mm vs 5.3 mm, P = .035). Anatomic variations such as a complex sphenoid sinus configuration had no influence on identifying sphenoid sinus landmarks.

CONCLUSION

According to our data, stereoscopic 3D HD endoscopy enhances intraoperative orientation by improved depth perception within the sphenoid sinus. This may add to the safety of endoscopic skull base procedures, especially in extended approaches and cases with distorted anatomy.

Comparative Analysis of Food Security Measures by Vitamin A-rich Food Consumption Among Mother-Child Dyads in Uganda

Objectives

This study examined mother-child differences in vitamin A-rich food consumption and conduct a comparative analysis of three food security indicators on household vitamin A-rich food consumption for 375 mother-child dyads from selected sweet potato growing households in Uganda.

Methods

This study examined baseline data collected by the International Potato Centre (IPC) for an initiative on the development and delivery of biofortified crops in Uganda. Dietary intake and livelihoods data was collected from women residing in households that grew sweet potatoes in selected regions in Uganda. Eligibility criteria included women who were pregnant or lactating and/or had children 6–24 months. The analytical dataset had 375 woman-child dyads. An adjusted Hellen Keller International (HKI) guide was used to examine data on vitamin A consumption. Scores were weighted for animal- and plant-based sources of vitamin A. Data were stratified by woman or child to allow for within- and between-person variances in vitamin A-rich food consumption. Dependent sample Student's t-tests, Pearson's correlation analysis and a repeated measure analysis of covariance (ANCOVA) tested for differences in the vitamin A-rich food consumption mother-child dyads.

Results

There was a statistically significant difference in the mean consumption of vitamin A-rich foods for women and children (F (1,370) = 6.51, p = .011). Women had a higher vitamin A consumption (M = 2.08, SD = 2.11) than children in the same household (M = 1.39, SD = 2.17). This was qualified by a significant interaction with the household wealth index (F (1,370) = 4.31, p = .039), however not with household dietary diversity (F (1,370) = 3.16, p = .07), and household food insecurity access (F (1,370) = 0.32, p = .57). HDDS and the wealth index were associated with the mother's consumption of vitamin A-rich food but not with the children's.

Conclusions

Initiatives that target mother-child dyads should be aware of factors such as intrahousehold food distribution and cultural practices that may differentially impact child consumption of vitamin A-rich and other micronutrient-rich foods. Child-friendly initiatives are recommended to maximize nutritional benefits for children under five years.

Funding Sources

International Potato Center and the University of Massachusetts Amherst.

Predictors of Vitamin A-rich Food Consumption Among Women From Selected Regions in Uganda

Objectives

Vitamin A deficiency has serious public health consequences for populations in low and middle-income countries, especially for children under five years and pregnant women. The objective of this paper was to characterize vitamin A-rich foods consumption and its predictors among women from selected regions in Uganda.

Methods

A baseline cross-sectional survey was conducted by the International Potato Centre among 617 sweet potato growing households, focusing on women in the reproductive age group from the northern and eastern regions of Uganda. Data included vitamin A-rich food consumption, dietary intake using a food frequency questionnaire, and a 24-hour recall. Vitamin A consumption was computed using the Hellen Keller International guide.

Results

The majority of women in this study were either lactating (79.6%) and/or pregnant (16.8%). More than 70% of the study population had a weighted vitamin A-rich food consumption mean score of < 6 days per week, indicating a high risk of vitamin A deficiency of the population. Knowledge about vitamin A (b(SE) = −0.18 (0.50), p < 0.001) inversely predicted vitamin A-rich food consumption. Variables including individual dietary diversity, household size, educational attainment and age were not associated with vitamin A rich food consumption.

Conclusions

The study provides evidence on the association between nutrition knowledge and consumption of Vitamin A-rich foods, suggesting that development and delivery of biofortified foods such as orange-fleshed sweet potatoes (an initiative of the International Potato Center), can further improve vitamin A status when combined with nutrition education.

Funding Sources

International Potato Center/Uganda and the University of Massachusetts Amherst.

Market Intelligence and Incentive-Based Trait Ranking for Plant Breeding: A Sweetpotato Pilot in Uganda

Crop breeding programs must accelerate crop improvement, spur widespread adoption of new varieties and increase variety turnover they are to meet the diverse needs of their clients. More comprehensive quantitative approaches are needed to better inform breeding programs about the preferred traits among farmers and other actors. However, the ability of current breeding programs to meet the demands of their clients is limited by the lack of insights about value chain actor preference for individual or packages of traits. Ranking traits based on monetary incentives, rather than subjective values, represents a more comprehensive, consistent, and quantitative approach to inform breeding programs. We conducted a large pilot in Uganda to assess the implementation of a novel approach to trait ranking, using a uniquely large sample of diverse sweetpotato value chain actors. We found meaningful differences in trait ranking and heterogeneity among different actors using this approach. We also show our approach's effectiveness at uncovering unmet demand for root quality traits and at characterizing the substantial trait demand heterogeneity among value chain players. Implementing this approach more broadly for sweetpotato and other crops would increase the effectiveness of breeding programs to improve food security in developing countries.

Quality and psychosocial factors influencing purchase of orange-fleshed sweetpotato bread

This 2018 study, conducted in six Tusky's supermarkets in Nairobi, Kenya, combined the Just-About-Right, Penalty and Mean-End-Chain analyses to examine the quality and psychosocial factors influencing the purchase of a novel bread made from orange-fleshed sweet potato (OFSP), a biofortified crop, focusing on sixty-one male and eighty female urban OFSP bread buyers recruited at point of purchase. It finds that sensory and psychosocial factors drive purchasing decisions and that some of the bread's sensory characteristics are misaligned with consumers' expectations. It also finds that women and men's evaluations of the bread's characteristics are different, as are their motivations for purchase. However, good sensory attributes and the knowledge of the bread's nutritional value were key drivers. Some misaligned characteristics reveal levers for the reformulation of the bread and present opportunities for segmenting the market. Several other implications of the findings for policy and future improvement of the bread are discussed.

Comprehensive flow cytometric reference intervals of leukocyte subsets from six study centers across Europe

A group of European FOCIS Centers of Excellence adapted panels of the Human Immunophenotyping Consortium (HIPC) for whole blood analysis. Using four core panels [T/regulatory T cell/B/natural killer (T/T_reg/B/NK) and myeloid cells] the main leukocyte populations were analyzed in a clinical–diagnostic setting in a harmonized manner across different platforms. As a first step, the consortium presents here the absolute and relative frequencies of the leukocyte subpopulations in the peripheral blood of more than 300 healthy volunteers across six different European centers.

Resilient agri-food systems for nutrition amidst COVID-19: evidence and lessons from food-based approaches to overcome micronutrient deficiency and rebuild livelihoods after crises

COVID-19 has had an instant effect on food systems in developing countries. Restrictions to the movement of people and goods have impaired access to markets, services and food. Unlike other concurrent crises, rather than threatening the material hardware of food systems, COVID-19 has so far affected the 'software' of food systems, highlighting again that connectivity is at the heart of these systems. Drops in demand, the loss of markets and employment and growing concerns about international cooperation are indications of possible deeper disruptions to come. Amidst this uncertainty, strategies to safeguard food and nutrition security of the world's poor need to prioritize diversification of production and markets. Nutritious, biofortified crops such as potato, sweetpotato, but also wheat, maize and beans among others, can play a more significant role to provide key micronutrients (vitamin A, iron, zinc) at large scale. Strong local market chains, robust smallholder production systems and increasing commercial utilization make these crops powerful vehicles for securing nutrition when markets and mobility look uncertain. We posit that the evolving impacts of COVID-19 provide an opportunity to focus agricultural innovations, including the development and delivery of biofortified crops, on new and more specifically defined 'jobs to be done' throughout the food system. This will help bridge some of the current disruptions in supply and demand and will help prepare food systems for future crises.

Predictors of Intention to Integrate Biofortified Orange-fleshed Sweetpotato in Child Feeding: A Field Information Experiment in Rural Kenya

The study assesses the psychosocial predictors of intention to integrate biofortified pro-vitamin A orange-fleshed sweet potato (OFSP) in proper complementary feeding (PCF) among women who received either verbal or verbal and visual demonstrations on OFSP-based foods. A total of 764 randomly selected women grouped into four categories, namely pregnant women, women with infants, women with young children, and potential mothers, participated in this study. Using a structural equation model of predicted intentions based on an extended Theory of Planned Behavior (TPB) the study found goal-setting, perceived behavior control, subjective norms, and attitudes had a significant influence on intention to integrate OFSP in PCF. Unexpectedly, knowledge of the various health benefits of OFSP did not positively influence intention. Probabilistic recursive regression was then used to estimate the relationship between the intention to provide PCF practices and its potential antecedents. The results then showed that the model structure and explanatory power was information-specific and also revealing outcome differences by category of women. These results have implications on how interventions targeting the improvement of PCF should be organized and delivered. They underscore the need to segment the audience during nutrition education.

Development of diagnostic SNP markers for quality assurance and control in sweetpotato [Ipomoea batatas (L.) Lam.] breeding programs

Quality assurance and control (QA/QC) is an essential element of a breeding program's optimization efforts towards increased genetic gains. Due to auto-hexaploid genome complexity, a low-cost marker platform for routine QA/QC in sweetpotato breeding programs is still unavailable. We used 662 parents of the International Potato Center (CIP)'s global breeding program spanning Peru, Uganda, Mozambique and Ghana, to develop a low-density highly informative single nucleotide polymorphism (SNP) marker set to be deployed for routine QA/QC. Segregation of the selected 30 SNPs (two SNPs per base chromosome) in a recombined breeding population was evaluated using 282 progeny from some of the parents above. The progeny were replicated from in-vitro, screenhouse and field, and the selected SNP-set was confirmed to identify relatively similar mislabeling error rates as a high density SNP-set of 10,159 markers. Six additional trait-specific markers were added to the selected SNP set from previous quantitative trait loci mapping studies. The 36-SNP set will be deployed for QA/QC in breeding pipelines and in fingerprinting of advanced clones or released varieties to monitor genetic gains in famers' fields. The study also enabled evaluation of CIP's global breeding population structure and the effect of some of the most devastating stresses like sweetpotato virus disease on genetic variation management. These results will inform future deployment of genomic selection in sweetpotato.

Circulating β cell-specific CD8+ T cells restricted by high-risk HLA class I molecules show antigen experience in children with and at risk of type 1 diabetes

In type 1 diabetes (T1D), autoreactive cytotoxic CD8+ T cells are implicated in the destruction of insulin-producing β cells. The HLA-B*3906 and HLA-A*2402 class I genes confer increased risk and promote early disease onset, suggesting that CD8+ T cells that recognize peptides presented by these class I molecules on pancreatic β cells play a pivotal role in the autoimmune response. We examined the frequency and phenotype of circulating preproinsulin (PPI)-specific and insulin B (InsB)-specific CD8+ T cells in HLA-B*3906+ children newly diagnosed with T1D and in high-risk HLA-A*2402+ children before the appearance of disease-specific autoantibodies and before diagnosis of T1D. Antigen-specific CD8+ T cells were detected using human leucocyte antigen (HLA) class I tetramers and flow cytometry was used to assess memory status. In HLA-B*3906+ children with T1D, we observed an increase in PPI5-12 -specific transitional memory CD8+ T cells compared to non-diabetic, age- and HLA-matched subjects. Furthermore, PPI5-12 -specific CD8+ T cells in HLA-B*3906+ children with T1D showed a significantly more antigen-experienced phenotype compared to polyclonal CD8+ T cells. In longitudinal samples from high-risk HLA-A*2402+ children, the percentage of terminal effector cells within the InsB15-24 -specific CD8+ T cells was increased before diagnosis relative to samples taken before the appearance of autoantibodies. This is the first study, to our knowledge, to report HLA-B*3906-restricted autoreactive CD8+ T cells in T1D. Collectively, our results provide evidence that β cell-reactive CD8+ T cells restricted by disease-associated HLA class I molecules display an antigen-experienced phenotype and acquire enhanced effector function during the period leading to clinical diagnosis, implicating these cells in driving disease.

The physiochemical properties and shelf-life of orange-fleshed sweet potato puree composite bread

Value addition of orange-fleshed sweet potato (OFSP) increases diversified utilization of this crop, which is rich in provitamin A carotenoids. OFSP bread, in which 30%-45% of wheat flour is replaced with OFSP puree, has been successfully commercialized in Kenya. However, the effect of this substitution on the bread's physiochemical properties and its shelf-life are currently unknown. This study was designed to determine the physiochemical properties and shelf-life of OFSP puree-wheat flour composite bread (30% puree), compared to standard, 100% wheat flour, bread. Freshly baked bread samples were stored at 7, 20, 25, and 30°C, and monitored for moisture content, water activity, color, texture, volume, carotenoids, and microbial load. The moisture content, β-carotene content, and color of bread significantly decreased with increase in storage temperature and time (p < 0.05). Bread made with OFSP puree had a longer shelf-life, showing spoilage on day six compared with the white bread, which spoiled on the fourth day. This is attributed to the significantly higher water activity in white bread than in the OFSP bread. The substitution of wheat with OFSP puree resulted in reduced extensibility of gluten, thus, specific volume of white bread was significantly (p < 0.05) higher than that in OFSP puree bread. Refrigeration increased crumb firmness, chewiness and cohesiveness in both types of bread. In conclusion, OFSP puree increases the water binding capacity of the bread, which reduces water activity and increases its shelf-life.

Effects of Acidification and Preservatives on Microbial Growth during Storage of Orange Fleshed Sweet Potato Puree

Orange Fleshed Sweet Potato (OFSP) puree, a versatile food ingredient, is highly perishable limiting its use in resource constrained environments. It is therefore important to develop shelf-stable puree. A challenge test study was carried out to determine the effect of combinations of chemical preservatives and acidification on microbial growth in stored puree. Puree was prepared and treated as follows: control (A); 0.05% potassium sorbate+0.05% sodium benzoate+1% citric acid (B); 0.1% potassium sorbate+0.1% sodium benzoate+1% citric acid (C); 0.2% potassium sorbate+0.2% sodium benzoate+1% citric acid (D); 1% citric acid (E). Samples were inoculated with Escherichia coli and Staphylococcus aureus at levels of 5.2 x 109 cfu/100g and 1.5 x 109 cfu/100g, respectively, before being evaluated during storage for 10 weeks at prevailing ambient temperature (15-25°C) and refrigeration temperature (4°C). Total aerobic counts, yeasts, and molds were also evaluated. E. coli and S. aureus counts declined significantly (p<0.05) by 4 log cycles in all puree treatments except for control and puree with only citric acid. Total viable count, yeasts, and molds were completely inhibited except for puree with only citric acid. Combination of chemical preservatives and acidification is effective in inhibiting pathogens and spoilage microorganisms in sweet potato puree.

Resonance signatures in the body-frame valence photoionization of CF4

Photoionization of the 4t₂ orbital of CF₄ shows overlapping resonances close to threshold, leading to a striking inversion of the photoelectron angular distribution when viewed in the body-frame.

High probability of comorbidities in bronchial asthma in Germany

Clinical experience has shown that allergic and non-allergic respiratory, metabolic, mental, and cardiovascular disorders sometimes coexist with bronchial asthma. However, no study has been carried out that calculates the chance of manifestation of these disorders with bronchial asthma in Saarland and Rhineland-Palatinate, Germany. Using ICD10 diagnoses from health care institutions, the present study systematically analyzed the co-prevalence and odds ratios of comorbidities in the asthma population in Germany. The odds ratios were adjusted for age and sex for all comorbidities for patients with asthma vs. without asthma. Bronchial asthma was strongly associated with allergic and with a lesser extent to non-allergic comorbidities: OR 7.02 (95%CI:6.83-7.22) for allergic rhinitis; OR 4.98 (95%CI:4.67-5.32) allergic conjunctivitis; OR 2.41 (95%CI:2.33-2.52) atopic dermatitis; OR 2.47 (95%CI:2.16-2.82) food allergy, and OR 1.69 (95%CI:1.61-1.78) drug allergy. Interestingly, increased ORs were found for respiratory diseases: 2.06 (95%CI:1.64-2.58) vocal dysfunction; 1.83 (95%CI:1.74-1.92) pneumonia; 1.78 (95%CI:1.73-1.84) sinusitis; 1.71 (95%CI:1.65-1.78) rhinopharyngitis; 2.55 (95%CI:2.03-3.19) obstructive sleep apnea; 1.42 (95%CI:1.25-1.61) pulmonary embolism, and 3.75 (95%CI:1.64-8.53) bronchopulmonary aspergillosis. Asthmatics also suffer from psychiatric, metabolic, cardiac or other comorbidities. Myocardial infarction (OR 0.86, 95%CI:0.79-0.94) did not coexist with asthma. Based on the calculated chances of manifestation for these comorbidities, especially allergic and respiratory, to a lesser extent also metabolic, cardiovascular, and mental disorders should be taken into consideration in the diagnostic and treatment strategy of bronchial asthma.

BRONCHIAL ASTHMA

PREVALENCE OF CO-EXISTING DISEASES IN GERMANY: Patients in Germany with bronchial asthma are highly likely to suffer from co-existing diseases and their treatments should reflect this. Quoc Thai Dinh at Saarland University Hospital in Homburg, Germany, and co-workers conducted a large-scale study of patients presenting with bronchial asthma in the Saarland region between 2009 and 2012. Patients with asthma made up 5.4% of the region's total population, with a higher prevalence occurring in females. They found that bronchial asthma was strongly associated with allergic comorbidities such as rhinitis. Indeed, asthmatic patients had a seven times higher chance to suffer from allergic rhinitis than the rest of the population, and were at higher risk of respiratory diseases like pneumonia and obstructive sleep apnea syndrome. Further associations included cardiovascular, metabolic and mental disorders. Dinh's team call for asthma treatments to take such comorbidities into account.

The branched-chain amino acid transaminase 1 sustains growth of antiestrogen-resistant and ERα-negative breast cancer

Antiestrogen-resistant and triple-negative breast tumors pose a serious clinical challenge because of limited treatment options. We assessed global gene expression changes in antiestrogen-sensitive compared with antiestrogen-resistant (two tamoxifen resistant and two fulvestrant resistant) MCF-7 breast cancer cell lines. The branched-chain amino acid transaminase 1 (BCAT1), which catalyzes the first step in the breakdown of branched-chain amino acids, was among the most upregulated transcripts in antiestrogen-resistant cells. Elevated BCAT1 expression was confirmed in relapsed tamoxifen-resistant breast tumor specimens. High intratumoral BCAT1 levels were associated with a reduced relapse-free survival in adjuvant tamoxifen-treated patients and overall survival in unselected patients. On a tissue microarray (n=1421), BCAT1 expression was detectable in 58% of unselected primary breast carcinomas and linked to a higher Ki-67 proliferation index, as well as histological grade. Interestingly, BCAT1 was predominantly expressed in estrogen receptor-α-negative/human epidermal growth factor receptor-2-positive (ERα-negative/HER-2-positive) and triple-negative breast cancers in independent patient cohorts. The inverse relationship between BCAT1 and ERα was corroborated in various breast cancer cell lines and pharmacological long-term depletion of ERα induced BCAT1 expression in vitro. Mechanistically, BCAT1 indirectly controlled expression of the cell cycle inhibitor p27^Kip1 thereby affecting pRB. Correspondingly, phenotypic analyses using a lentiviral-mediated BCAT1 short hairpin RNA knockdown revealed that BCAT1 sustains proliferation in addition to migration and invasion and that its overexpression enhanced the capacity of antiestrogen-sensitive cells to grow in the presence of antiestrogens. Importantly, silencing of BCAT1 in an orthotopic triple-negative xenograft model resulted in a massive reduction of tumor volume in vivo, supporting our findings that BCAT1 is necessary for the growth of hormone-independent breast tumors.

[Treatment of proximal humerus fractures: relative position of different locking plates to the axillary nerve]

OBJECTIVES

Placement of a proximal humerus locking plate through a percutaneous transdeltoid approach bears the advantages of a minimally invasive approach but may compromise the anterior branches of the axillary nerve. This anatomic study aimed to develop a risk profile for 6 types of modern proximal humerus locking plates as to their interference with the axillary nerve.

MATERIALS AND METHODS

In this study six different implants (Arthrex®, DePuy®, Königsee®, Smith & Nephew®, Stryker® and Synthes®) were placed on the intact proximal humerus of 33 embalmed cadaveric upper extremities and the relative positioning between the axillary nerve and the screw holes was determined.

RESULTS

All locking plates displayed an area of risk which concerned 3 out of 7 (Arthrex®), 4 out of 10 (DePuy®), 2 out of 9 (Königsee®), 3 out of 11 (Smith & Nephew®), 3 out of 11 (Stryker®) and 6 out of 12 (Synthes®) screw holes of the plate.

CONCLUSIONS

Using the anterolateral percutaneous deltoid splitting approach the relative position of the axillary nerve to the holes of a specific implant is of relevance for avoidance of iatrogenic lesions to the nerve.

[External fixation with motion capacity and radius fractures. Methods and results]

Both the radiocarpal and distal radioulnar joints are often affected in"distal radius fractures". The incidence of this injury increases markedly among women over the age of 40. Bearing in mind the wide variety of distal radius fractures, a fixation system should be used which permits trans- and extra-articular application and subsequent reduction by means of distraction, as well as wrist mobilization. It is important that both reduction and position of the carpal bones can be checked. The possibility of extra-articular (radioradial) fixation should always be considered. AO group A2 and A3 fractures with sufficiently large fragments are suitable for this procedure. In other cases, transarticular application is advised. Complementary measures are justified in the case where two or more cortices in AP and lateral X-rays are destroyed. Adequate implants are also used to stabilize the articular surface. Large bone defects should be filled with corticocancellous material.

Phototrophic transformation of phenol to 4-hydroxyphenylacetate by Rhodopseudomonas palustris

Newly isolated and culture collection strains of Rhodopseudomonas palustris were able to transform phenol to 4-hydroxyphenylacetate under phototrophic conditions in the presence of acetate, malate, benzoate, or cinnamate as growth substrates. The reaction was examined with uniformly (14)C-labelled phenol and the product was identified by HPLC retention time, UV-scans, and (1)H- and (13)C-NMR analysis. The transformation reaction was detectable in cell-free extracts in the presence of NAD(+) and acetyl-CoA. For further degradation of 4-hydroxyphenylacetate by R. palustris, low partial pressures of oxygen were essential, presumably for aerobic aromatic ring fission reactions by mono- and di-oxygenases.

Estrogen induces a rapid secretion of amyloid beta precursor protein via the mitogen-activated protein kinase pathway

The female sex hormone estrogen (17beta-estradiol; E2) may function as a neurohormone and has multiple neuromodulatory functions in the brain. Its potent neuroprotective activities can be dependent and independent of estrogen receptors (ERs). In addition, E2 influences the processing of the amyloid beta precursor protein (APP), one central step in the pathogenesis of Alzheimer's disease. Here, we show: (a) that physiological concentrations of E2 very rapidly cause an increased release of secreted nonamyloidogenic APP (sAPPalpha) in mouse hippocampal HT22 and human neuroblastoma SK-N-MC cells; and (b) that this effect is mediated through E2 via the phosphorylation of extracellular-regulated kinase 1 and 2 (ERK1/2), prominent members of the mitogen-activated protein kinase (MAPK) pathway. Furthermore, we show that the activation of MAPK-signaling pathway and the enhancement of the sAPP release is independent of ERs and could be induced by E2 to a similar extent in neuronal cells either lacking or overexpressing a functional ER.

The female sex hormone oestrogen as neuroprotectant: activities at various levels

The female sex hormone oestradiol (oestrogen) is a steroidal compound that binds to specific intracellular receptors which act as transcription factors. Oestrogen displays many of its effects by the classical mode of action through receptor binding, transactivation and binding to consensus oestrogen response elements on DNA. Although the primary role of oestrogen as an ovarian steroid was thought to be the regulation of sex differentiation and maturation, since oestrogen receptors are expressed in a variety of other tissues besides sex organs, oestrogen is believed to exert multiple activities in several target sites throughout the body, including the nervous system. In the brain oestrogens have multiple activities. Potential neuroprotective functions of oestrogens are being intensively studied and it is becoming increasingly clear that oestrogens are (1) neuroprotective hormones acting via oestrogen receptor-dependent pathways at the genomic level and (2) neuroprotective steroidal structures acting independently of the activation of specific oestrogen receptors. One striking activity of the molecule oestradiol is its intrinsic antioxidant activity which makes it a potential chemical shield for neurons. Nerve cells frequently encounter oxidative challenges during the normal physiology, but also under pathophysiological conditions. Oxidative stress has been implicated in a variety of neurodegenerative disorders including amyotrophic lateral sclerosis, Parkinson's disease and Alzheimer's disease. It is important to stress that the antioxidant neuroprotective activity of oestrogens is independent of oestrogen receptor activation, since oestrogen derivatives and aromatic alcohols that do not bind to oestrogen receptors share the same antioxidant neuroprotective activity. Although this effect of oestrogens can clearly be separated from oestrogen receptor binding, oestrogens may interact with intracellular signalling pathways, such as the mitogen activated protein kinase, cyclic AMP pathways, and with the activity of the redox-sensitive transcription factor NF-kappa B.

The multicomponent reactions and their libraries for natural and preparative chemistry

It was recently recognized that three different types of multi-component reactions (MCRs) exist. In preparative chemistry, the MCRs of type II form their products particularly efficiently. These reactions correspond to equilibria of educts and intermediate products, whose final products are formed practically irreversibly. In recent years, the four component reaction of the isocyanides (U-4CR) of type II and their unions with various reactions and MCRs have become an important industrial process for preparing products and their libraries. It has been demonstrated that all conceivable collections of U-4CR educts can be converted into the corresponding products. In the usual chemical reactions, only the substituents of the products can be varied, whereas the U-4CR and related reactions can also produce skeletally different types of products with diverse substituents. The preparative advantages of forming products by the one-pot MCRs and the great variety of the possible products are illustrated in this review.

A new screen for protein interactions reveals that the Saccharomyces cerevisiae high mobility group proteins Nhp6A/B are involved in the regulation of the GAL1 promoter

The split-ubiquitin assay detects protein interactions in vivo. To identify proteins interacting with Gal4p and Tup1p, two transcriptional regulators, we converted the split-ubiquitin assay into a generally applicable screen for binding partners of specific proteins in vivo. A library of genomic Saccharomyces cerevisiae DNA fragments fused to the N-terminal half of ubiquitin was constructed and transformed into yeast strains carrying either Gal4p or Tup1p as a bait. Both proteins were C-terminally extended by the C-terminal half of ubiquitin followed by a modified Ura3p with an arginine in position 1, a destabilizing residue in the N-end rule pathway. The bait fusion protein alone is stable and enzymatically active. However, upon interaction with its prey, a native-like ubiquitin is reconstituted. RUra3p is then cleaved off by the ubiquitin-specific proteases and rapidly degraded by the N-end rule pathway. In both screens, Nhp6B was identified as a protein in close proximity to Gal4p as well as to Tup1p. Direct interaction between either protein and Nhp6B was confirmed by coprecipitation assays. Genetic analysis revealed that Nhp6B, a member of the HMG1 family of DNA-binding proteins, can influence transcriptional activation as well as repression at a specific locus in the chromosome of the yeast S. cerevisiae.

Insertion of enhanced green fluorescent protein into the lysozyme gene creates mice with green fluorescent granulocytes and macrophages

Pluripotent hematopoietic stem cells have been studied extensively, but the events that occur during their differentiation remain largely uncharted. To develop a system that allows the differentiation of cultured multipotent progenitors by time-lapse fluorescence microscopy, myelomonocytic cells were labeled with green fluorescent protein (GFP) in vivo. This was achieved by knocking the enhanced GFP (EGFP) gene into the murine lysozyme M (lys) locus and using a targeting vector, which contains a neomycin resistant (neo) gene flanked by LoxP sites and "splinked" ends, to increase the frequency of homologous recombination. Analysis of the blood and bone marrow of the lys-EGFP mice revealed that most myelomonocytic cells, especially mature neutrophil granulocytes, were fluorescence-positive, while cells from other lineages were not. Removal of the neo gene through breeding of the mice with the Cre-deleter strain led to an increased fluorescence intensity. Mice with an inactivation of both copies of the lys gene developed normally and were fertile. (Blood. 2000;96:719-726)

A new method for the selection of protein interactions in mammalian cells

In the present study we present a new method that allows for the selection of protein interactions in mammalian cells. We have used this system to verify two interactions previously characterized in vitro. (1) The interaction between human TATA-binding protein 1 and nuclear factor kappaB and (2) the association of Homo sapiens nuclear autoantigen SP100B with human heterochromatin protein 1alpha, a protein implicated in chromatin remodelling. We observe for the first time that these interactions also occur in vivo. One protein was fused to the N-terminal half of ubiquitin, while the interacting partner was fused to the C-terminal half of ubiquitin, that was itself linked to guanine phosphoryltransferase 2 (gpt2) modified to begin with an arginine residue. Upon interaction of both proteins, ubiquitin is reconstituted, and its association with the Rgpt2 reporter is subsequently cleaved off by ubiquitin-processing enzymes. The presence of arginine in the Rgpt2 gene product leads to the degradation of the product by the N-end rule pathway. In the human fibroblast cell line HT1080HPRT(-) (that is deficient in the enzyme for hypoxanthine-guanine phosphoribosyltransferase) cells in which interaction between both proteins of interest occurs can then be selected for by hypoxanthine/aminopterin/thymine medium and counterselected against by 6-thioguanine medium. This method provides a suitable alternative to the yeast two-hybrid system and is generally applicable.