bluuebunny/crossref_metadata_2025 huggingface dataset:
RNA Polymerase II-mediated transcription is required for repair of ribosomal DNA breaks in nucleolar caps, guarding against genomic instability
Authors: Checa-Rodríguez Cintia , Suárez-Quintero Beatriz , Contreras Laura , Korsholm Lea , Payne-Larsen Dorthe Helena , de la Cruz Jesús , Bartek Jiri , Gómez-Cabello Daniel
Published: October 2023

Oversized nucleoli and enhanced ribosome biogenesis are hallmarks of cancer, reflecting tumor cells’ aberrantly high demand for protein synthesis during tumorigenesis. The high-copy ribosomal DNA (rDNA) genes are highly transcribed by RNA Polimerase I (RNAPI) and inherently unstable, often subject to DNA double-strand breaks (DSBs) caused by transcription-replication conflicts. When DSBs happen, RNAPI becomes silenced by ATM signaling and rDNA DSBs are translocated to nucleolar periphery for repair mainly by homologous recombination in newly formed nucleolar caps. The molecular mechanisms underlying these processes are incompletely understood. Herein, we report that rDNA DSB translocation and nucleolar cap formation require the presence and activity of RNAPII. Nascent RNA deficiency upon RNAPII inhibition in rDNA damaged cells provoke rDNA instability and cell death. Finally, the enhanced cytotoxic effect of combined RNA transcription inhibition and rDNA damage, reported here, is consistent with addiction of cancer to nucleolar function, indicating an emerging targetable vulnerability of cancer cells that may inspire innovative treatment strategies in oncology.

Teaser

Nascent RNA synthesis by RNA PolymeraseII safeguards ribosomal DNA integrity to avoid genomic instability in human cells.

Graphical Abstract
The nitrogenase cofactor biogenesis enzyme NifB is essential for the viability of methanogens
Authors: Saini Jasleen , Dhamad Ahmed , Muniyasamy Abaranjitha , Alverson Andrew J. , Lessner Daniel J.
Published: October 2023

Dinitrogen (N2) is only bioavailable to select bacteria and archaea that possess the metalloenzyme nitrogenase, which reduces N2to NH3in a process called nitrogen fixation or diazotrophy. A long-term goal is to engineer diazotrophy into plants to decrease the use of nitrogen fertilizers, saving billions of dollars annually and greatly reducing nutrient pollution. This goal has not been realized, in part due to the inability to produce the nitrogenase metallocofactor within plants. Biogenesis of the cofactor requires NifB, a radical S-adenosy-L-methionine (SAM) enzyme that generates a precursor [8Fe-9S-C] cluster that matures into the final metallocofactor. Although maturation of nitrogenase is the only known function of NifB in bacteria, bioinformatic analyses reveal that NifB is conserved across methanogens, including those lacking nitrogenase, which suggests NifB functions outside of nitrogenase maturation. Indeed, several lines of evidence show that NifB is essential for viability of the model diazotroph,Methanosarcina acetivorans. First, CRISPRi repression was unable to abolish NifB production, whereas CRISPRi repression abolishes non-essential nitrogenase production. Second, unlike nitrogenase production, NifB production is not controlled by fixed nitrogen availability. Finally,nifBcould not be deleted fromM. acetivoransunless complementedin transwithnifBfrom other methanogens, includingMethanothrix thermoacetophila, a species that lacks nitrogenase. Notably,M. thermoacetophilaNifB supported diazotrophy inM. acetivorans, demonstrating that NifB from a non-diazotrophic methanogen produces the [8Fe-9S-C] cluster. Overall, these results link the metallocofactor biogenesis function of NifB to nitrogen fixation and methanogenesis, two processes of global importance.

SIGNIFICANCE

Methanogens directly impact life on Earth since they produce methane, a potent greenhouse gas, and are the principal archaea capable of nitrogen fixation, a process that requires nitrogenase. In this study, we demonstrate that NifB, an enzyme required to produce the metallocofactor in non-essential nitrogenase, is essential to the viability of methanogens. This identifies NifB as a new potential target in the goal of inhibiting methanogens to reduce methane emissions. The discovery that NifB functions outside of nitrogenase maturation will also aid efforts to engineer nitrogen fixation in plants, since NifB is a key factor to achieve this goal. Realization of these goals would have immense economic, environmental, and societal benefits.
ISWI chromatin remodeling complexes recruit NSD2 and H3K36me2 in pericentromeric heterochromatin
Authors: Goto Naoki , Suke Kazuma , Yonezawa Nao , Nishihara Hidenori , Sato Yuko , Kujirai Tomoya , Kurumizaka Hitoshi , Yamagata Kazuo , Kimura Hiroshi
Published: October 2023

Histone H3 lysine36 dimethylation (H3K36me2) is generally distributed in the gene body and euchromatic intergenic regions. However, we found that H3K36me2 is enriched in pericentromeric heterochromatin in some mouse cell lines. We here revealed the mechanism of heterochromatin targeting of H3K36me2. Among several H3K36 methyltransferases, NSD2 was responsible for inducing heterochromatic H3K36me2. Depletion and overexpression analyses of NSD2-associating proteins revealed that NSD2 recruitment to heterochromatin was mediated through the imitation switch (ISWI) chromatin remodeling complexes, such as BAZ1B-SMARCA5 (WICH), which directly binds to AT-rich DNA via a BAZ1B domain containing AT-hook-like motifs. The abundance and stoichiometry of NSD2, SMARCA5, and BAZ1B or BAZ2A could determine the localization of H3K36me2 in different cell types. To explore the physiological role of heterochromatic H3K36me2, we analyzed mouse tissues and embryos. As a result, H3K36me2 was found in heterochromatin at the 2- to 4-cell stages of mouse preimplantation embryos, suggesting its involvement in developmental regulation.

The authors discovered histone H3K36me2, which is believed to be enriched in potentially active genomic regions, is also located in transcriptionally inactive regions called heterochromatin in some cell types. The detailed molecular mechanism of its heterochromatin targeting is now revealed.
Discontinuation of palliative brain radiotherapy in patients with brain metastases
Authors: Windisch Paul , Lütscher Jamie , Förster Robert , Zwahlen Daniel R. , Schröder Christina
Published: October 2023

Discontinuation of radiotherapy is rarely discussed in the literature. In this retrospective study of 468 consecutive patients receiving palliative radiotherapy for brain metastases, we identified 35 discontinued treatments, mainly due to clinical deterioration. Poor performance status, more advanced disease and, in turn, poor prognosis was associated with higher discontinuation rates.
Secretome of Human Umbilical cord mesenchymal stem cells exerts protective impacts on the blood-brain barrier against alpha-synuclein aggregates using anin vitromodel
Authors: Marzookian Kimia , Aliakbari Farhang , Hourfar Hamdam , sabouni farzaneh , Otzen Daniel E. , Morshedi Dina
Published: October 2023

The blood-brain barrier (BBB) is a highly developed endothelial microvessel network extended to almost all parts of the central nervous system (CNS) that tightly seals cell-to-cell contacts and plays a critical role in maintaining CNS homeostasis. It also protects neurons from factors present in systemic circulation and prevents pathogens from entering the brain. Conversely, BBB disruption can initiate multiple pathways of nerve damage. BBB injury contributes significantly to various neurodegenerative diseases, including Parkinson’s disease (PD). PD is also characterized by aggregation of the protein alpha-synuclein (αSN) to form intracellular inclusions. Recent studies have shown that due to their active secretions, mesenchymal stem cells (MSCs) can effectively relieve the severity of many neurological diseases. However, the impact of MSCs on BBB remains largely unclear. Here, we investigated the effect of Secretome extracted from MSCs on BBB when treated with toxic αSN-aggregates (αSN-AGs). For this purpose, MSCs were first isolated from Umbilical cord tissue (UC-MSC), and their secretome was collected. Then, the impact of the secretome on the cytotoxicity and inflammatory effects of αSN-AGs was examined on hCMEC/D3 cells using in vitro BBB models produced by mono- and co-culture systems. We explored the effects of αSN-AGs in the presence of UC-MSC secretome on permeability, TEER value, and cytokine/chemokine release. We found that the Secretome of UC-MSCs exerts protective effects by inhibiting the toxic effects of αSN-AGs on the BBB. These results strongly support the potential of UC-MSCs secretome for cell-free PD therapy. We also present an improved method for isolation of MSCs from umbilical cord tissue, which we hope will facilitate further studies on the use of these cells.

Graphical Abstract
Recombinase Polymerase Amplification Assay for the Field Detection of Mal Secco Disease byPlenodomus tracheiphilus
Authors: Rovetto Ermes Ivan , Garbelotto Matteo , Moricca Salvatore , Amato Marcos , Spada Federico La , Cacciola Santa Olga
Published: October 2023

In this study, we developed a new diagnostic assay based on the recombinase polymerase amplification (RPA) technology to detectPlenodomus tracheiphilus, the anamorphic fungus responsible for the destructive vascular disease of lemon named mal secco, in infected tissues of host plants. A 142 bp RPA-compatible barcode was sought within the 544 bp Internal Transcriber Spacer (ITS) fragment identified in a previous study and itsP. tracheiphilus-specificity was confirmed by BLAST in the NCBI database. This was the premise to design an RPA probe (RPA_Ptrach_Probe). The specificity and inclusivity of the RPA assay were tested on gDNA isolated from tissues ofC. limon, isolates ofP. tracheiphilusof various origins and axenic cultures of non-target organisms, including fungal and oomycete pathogens typically associated to citrus trees, such asAlternariaspp.,Colletotrichumspp.,Phyllostictaspp., Penicilliumspp.,Phytophthoraspp. With a detection threshold of 1.0 pg of gDNA the RPA assay proved to be as sensitive as the SYBR® Green I Real Time-PCR test included in the diagnostic protocol forP. tracheiphilusof the European and Mediterranean Plant Protection Organization. RPA assay was even more sensitive than Real Time-PCR in tests on DNA samples obtained through a rapid extraction method. In tests, on naturally infected lemon twigs, molecular approaches were comparable to each other and performed better than conventional isolation method. Overall, results of this study demonstrate the potential of RPA for rapid, easy to handle and cost effective in-field diagnosis of mal secco.
Addressing the dNTP bottleneck restricting prime editing activity
Authors: Ponnienselvan Karthikeyan , Liu Pengpeng , Nyalile Thomas , Oikemus Sarah , Joynt Anya T. , Kelly Karen , Guo Dongsheng , Chen Zexiang , Lee Jeong Min , Schiffer Celia A. , Emerson Charles P. , Lawson Nathan D. , Watts Jonathan K. , Sontheimer Erik J. , Luban Jeremy , Wolfe Scot A.
Published: October 2023

Prime editing efficiency is modest in cells that are quiescent or slowly proliferating where intracellular dNTP levels are tightly regulated. MMLV-reverse transcriptase - the prime editor polymerase subunit - requires high intracellular dNTPs levels for efficient polymerization. We report that prime editing efficiency in primary cells andin vivois increased by mutations that enhance the enzymatic properties of MMLV-reverse transcriptase and can be further complemented by targeting SAMHD1 for degradation.
Epidemiology and outcomes of head trauma in rural and urban populations: A systematic review and meta-analysis
Authors: Chequer de Souza Julia , Dobson Geoffrey P , Lee Celine J , Letson Hayley L
Published: October 2023

Objective

To identify and describe differences in demographics, injury characteristics, and outcomes between rural and urban head injury patients.

Data Sources

CINAHL, Emcare, MEDLINE, and Scopus.

Review Methods

A systematic review and meta-analysis of studies comparing epidemiology and outcomes of rural and urban head trauma was conducted in accordance with PRISMA and MOOSE guidelines.

Results

36 studies with ∼2.5-million patients were included. Incidence of head injury was higher in males, regardless of location. Rates of transport-related head injuries, particularly involving motorized vehicles other than cars, were significantly higher in rural populations (OR:3.63, 95% CI[1.58,8.35], p=0.002), whereas urban residents had more fall-induced head trauma (OR:0.73, 95% CI[0.66,0.81], p<0.00001). Rural patients were 28% more likely to suffer severe injury, indicated by Glasgow Coma Scale (GCS)≤8 (OR:1.28, 95% CI[1.04,1.58], p=0.02). There was no difference in mortality (OR:1.09, 95% CI[0.73,1.61], p=0.067), however, urban patients were twice as likely to be discharged with a good outcome (OR:0.52, 95% CI[0.41,0.67], p<0.00001).

Conclusions

Rurality is associated with greater severity and poorer outcomes of traumatic head injury. Transport accidents disproportionally affect those travelling on rural roads. Future research recommendations include addition of prehospital data, adequate follow-up, standardized measures, and sub-group analyses of high-risk groups, e.g., Indigenous populations.
Modeling cardiac fibroblast heterogeneity from human pluripotent stem cell-derived epicardial cells
Authors: Fernandes Ian , Funakoshi Shunsuke , Hamidzada Homaira , Epelman Slava , Keller Gordon
Published: October 2023

Abstract (Summary)

Cardiac fibroblasts play an essential role in the development of the heart and have been implicated in disease progression in the context of fibrosis and regeneration. Here, we established a simple organoid culture platform using human pluripotent stem cell-derived epicardial cells and ventricular cardiomyocytes to study cardiac fibroblasts’ development, maturation and heterogeneity under normal conditions and following treatment with pathological stimuli. We demonstrated that this system models the early interactions between epicardial cells and cardiomyocytes to generate a population of fibroblasts that recapitulates many aspects of fibroblast behaviourin vivoincluding changes associated with maturation and in response to pathological stimuli associated with cardiac injury. Using single cell transcriptomics, we show that the hPSC-derived organoid fibroblast population displays a high degree of heterogeneity that approximates the heterogeneity of populations in both the normal and diseased human heart. Additionally, we identified a unique subpopulation of fibroblasts possessing reparative features previously characterized in the hearts of model organisms. Taken together, our system recapitulates many aspects of human cardiac fibroblast specification, development and maturation providing a platform to investigate the role of these cells in human cardiovascular development and disease.
ROCK1 activates mitochondrial fission leading to oxidative stress and muscle atrophy
Authors: Si Meijun , Yu Rizhen , Lin Hongchun , Li Feng , Jung Sungyun , Thomas Sandhya S. , Danesh Farhard S , Wang Yanlin , Peng Hui , Hu Zhaoyong
Published: October 2023

Chronic kidney disease (CKD) is often associated with protein-energy wasting (PEW), which is characterized by a reduction in muscle mass and strength. Although mitochondrial dysfunction and oxidative stress have been implicated to play a role in the pathogenesis of muscle wasting, the underlying mechanisms remain unclear. In this study, we used transcriptomics, metabolomics analyses and mouse gene manipulating approaches to investigate the effects of mitochondrial plasticity and oxidative stress on muscle wasting in mouse CKD models. Our results showed that the expression of oxidative stress response genes was increased, and that of oxidative phosphorylation genes was decreased in the muscles of mice with CKD. This was accompanied by reduced oxygen consumption rates, decreased levels of mitochondrial electron transport chain proteins, and increased cellular oxidative damage. Excessive mitochondrial fission was also observed, and we found that the activation of ROCK1 was responsible for this process. Inducible expression of muscle-specific constitutively active ROCK1 (mROCK1ca) exacerbated mitochondrial fragmentation and muscle wasting in CKD mice. Conversely, ROCK1 depletion (ROCK1-/-) alleviated these phenomena. Mechanistically, ROCK1 activation promoted the recruitment of Drp1 to mitochondria, thereby facilitating fragmentation. Notably, the pharmacological inhibition of ROCK1 mitigated muscle wasting by suppressing mitochondrial fission and oxidative stress. Our findings demonstrate that ROCK1 participates in CKD-induced muscle wasting by promoting mitochondrial fission and oxidative stress, and pharmacological suppression of ROCK1 could be a therapeutic strategy for combating muscle wasting in CKD conditions.

Translational Statement

Protein-energy wasting (PEW) is a prevalent issue among patients with chronic kidney disease (CKD) and is characterized by the loss of muscle mass. Our research uncovers a critical role that ROCK1 activation plays in muscle wasting induced by CKD. We found that ROCK1 is instrumental in causing mitochondrial fission, which leads to increased oxidative stress in muscle cells. By employing a pharmacological inhibitor, hydroxyfasudil, we were able to effectively curb ROCK1 activity, which in turn mitigated muscle wasting by reducing both mitochondrial fission and oxidative stress. These findings suggest that pharmacological inhibition of ROCK1 presents a promising therapeutic strategy for combating the muscle wasting associated with CKD.
Epigenetic deregulation of IFN and WNT pathways in AT2 cells impairs alveolar regeneration (in COPD)
Authors: Prada Maria Llamazares , Schwartz Uwe , Pease Darius F. , Pohl Stephanie T. , Ackesson Deborah , Li Renjiao , Behrendt Annika , Tamas Raluca , Richter Mandy , Muley Thomas , Hey Joschka , Espinet Elisa , Heußel Claus P. , Warth Arne , Schneider Mark , Winter Hauke , Herth Felix , Imbusch Charles D , Brors Benedikt , Benes Vladimir , Wyatt David , Jurkowski Tomasz P. , Stahl Heiko F. , Plass Christoph , Jurkowska Renata Z.
Published: October 2023

Chronic lung diseases, including chronic obstructive pulmonary disease (COPD), affect over 500 million people and are a leading cause of death worldwide. A common feature of both chronic and acute lung diseases is altered respiratory barrier integrity and impaired lung regeneration. We hypothesized that alveolar type 2 (AT2) cells, as alveolar epithelial progenitors, will carry molecular alterations that compromise alveolar regeneration in COPD. Sorted AT2 cells from ex-smokers with and without COPD at different disease stages were subjected to RNA sequencing and whole-genome bisulfite sequencing to generate unbiased transcriptome and DNA methylation maps of alveolar progenitors in the lung. Our analysis revealed genome-wide epigenetic changes in AT2 cells during COPD that were associated with global gene expression changes. Integrative data analysis uncovered a strong anti-correlation between gene expression and promoter methylation, suggesting that dysregulation of COPD-associated pathways in AT2 cells may be regulated by DNA methylation. Interferon (IFN) signaling was the top-upregulated pathway associated with the concomitant loss of promoter DNA methylation. Epigenetic regulation of the IFN pathway was validated in both global and targeted DNA demethylation assays in A549 cells. Notably, targeted DNA demethylation of IRF9 triggered upregulation of IFN signaling, mimicking the effects observed in COPD AT2 cells in the profiling data. Our findings suggest that COPD-triggered epigenetic alterations in AT2 cells may impair internal regeneration programs in human lung parenchyma.
Deepening the divide: Does globalization increase the polarization between winners and losers of globalization?
Authors: Ollroge Rasmus
Published: October 2023

Does globalization increase polarization in attitudes toward international trade, immigration, and international organizations? Research from a variety of fields and disciplines assumes this relationship, but empirical studies are few. In this study, I examine whether globalization increases the attitudinal divide between education groups, with education being one of the main characteristics of social stratification distinguishing winners from losers of globalization. I use data from three waves of the National Identity Module of the International Social Survey Programme (ISSP) from 1995 to 2013 covering 29 countries (n = 79,101) to analyze between‐ and within‐country interactions between the level of globalization and education in explaining attitudes toward globalization. The results show that while the attitudinal divide between educational groups is larger in countries with higher levels of globalization (between effect), polarization decreases as the level of globalization increases within countries (within effect), as persons with lower and medium levels of education become more positive toward globalization under increasing levels of globalization. The results are consistent across a wide range of robustness checks, including controlling for occupational class as a further distinction between winners and losers of globalization. The findings suggest that the expectations about a widening attitudinal divide between winners and losers of globalization should be treated with more caution.
Delinquency, unstructured socializing, and social change: The rise and fall of a teen culture of independence
Authors: Osgood D. Wayne
Published: October 2023

This article delves into the connections between time trends in unstructured socializing and other dramatic changes in adolescence since the 1950s. Osgood et al.’s (1996) individual‐level application of routine activity theory proposed that unstructured socializing contributes to crime by exposing people to situations conducive to deviance, and a large body of research supports this idea. Unstructured socializing has proven useful as an explanatory bridge that links crime and deviance to key social factors like age, class, and gender. The present article expands on two recent studies (Baumer et al., 2021; Svensson & Oberwittler, 2021), which showed that changing rates of unstructured socializing help explain time trends in delinquency as well. Based on time trends across many domains of adolescent life, I argue that changes in unstructured socializing were a manifestation of the rise and fall of a teen culture of independence from the 1950s to the 2020s. The effectiveness of unstructured socializing as an explanatory bridge demonstrates the value of focusing on ordinary, everyday activities for tapping into features of life that are consequential and that vary across social conditions.
Spatial and temporal patterns of sarcoptic mange in wombats using the citizen science tool, WomSAT
Authors: MAYADUNNAGE Sujatha , STANNARD Hayley Jade , WEST Peter , OLD Julie M.
Published: October 2023

There is currently limited information regarding the levels of infection and distribution of sarcoptic mange in the wombat population throughout Australia. We analyzed cases of sarcoptic mange in bare‐nosed wombats reported into WomSAT, a website and mobile phone application where citizen scientists can upload sightings of wombats, burrows, and sarcoptic mange status. We used Maxent software to predict locations and the environmental factors associated with sarcoptic mange occurrence in bare‐nosed wombats. A total of 1379 sarcoptic mange‐infected and 3043 non‐sarcoptic mange‐infected wombats were reported by 674 and 841 citizen scientists, respectively. Of all the wombats reported to WomSAT from 2015 to 2019, 31.2% were infected with sarcoptic mange. Sarcoptic mange in bare‐nosed wombats was reported in 502 suburbs across four states. New South Wales had the highest number of sarcoptic mange cases reported to WomSAT. There was no statistically significant seasonal variation of sarcoptic mange levels in bare‐nosed wombats. The model showed that Euclidean distance to urban areas was the highest contributing factor for sarcoptic mange occurrence. As distance to urban areas decreased, the suitability for sarcoptic mange increased. Annual precipitation was the next contributing factor in the model, with higher rainfall of 400–700 mm correlating to an increase in sarcoptic mange occurrence. As the data collected to date have provided the largest‐scale contemporary distribution of sarcoptic mange in wombats, data should continue to be collected by citizen scientists as it is an easy and low‐cost method of collecting data over large areas. We suggest targeting the identified hotspot areas and more site‐specific studies for studying and mitigating sarcoptic mange in bare‐nosed wombats.
Evolutionary plant–pollinator responses to anthropogenic land‐use change: impacts on ecosystem services
Authors: Pontarp Mikael , Runemark Anna , Friberg Magne , Opedal Øystein H. , Persson Anna S. , Wang Lingzi , Smith Henrik G.
Published: October 2023

Agricultural intensification at field and landscape scales, including increased use of agrochemicals and loss of semi‐natural habitats, is a major driver of insect declines and other community changes. Efforts to understand and mitigate these effects have traditionally focused on ecological responses. At the same time, adaptations to pesticide use and habitat fragmentation in both insects and flowering plants show the potential for rapid evolution. Yet we lack an understanding of how such evolutionary responses may propagate within and between trophic levels with ensuing consequences for conservation of species and ecological functions in agroecosystems. Here, we review the literature on the consequences of agricultural intensification on plant and animal evolutionary responses and interactions. We present a novel conceptualization of evolutionary change induced by agricultural intensification at field and landscape scales and emphasize direct and indirect effects of rapid evolution on ecosystem services. We exemplify by focusing on economically and ecologically important interactions between plants and pollinators. We showcase available eco‐evolutionary theory and plant–pollinator modelling that can improve predictions of how agricultural intensification affects interaction networks, and highlight available genetic and trait‐focused methodological approaches. Specifically, we focus on how spatial genetic structure affects the probability of propagated responses, and how the structure of interaction networks modulates effects of evolutionary change in individual species. Thereby, we highlight how combined trait‐based eco‐evolutionary modelling, functionally explicit quantitative genetics, and genomic analyses may shed light on conditions where evolutionary responses impact important ecosystem services.
History of Veterinary Immunology in New Zealand
Authors: Buddle Bryce M
Published: October 2023

Knowledge gained from veterinary immunology has played an important role in the control of microbial and parasitic diseases in New Zealand through the development and use of vaccines and diagnostic tests. In this article celebrating the 100th anniversary of the Journal, I follow the development of important discoveries in veterinary immunology which have led to major advances in the control of animal diseases.
A comparison of the cardiovascular effects of phenylpropanolamine and phenylephrine containing proprietary cold remedies.
Authors: Thomas SH , Clark KL , Allen R , Smith SE
Published: October 2023

1. The cardiovascular effects of the proprietary cold remedies, Mu‐cron and Boots Cold Relief tablets were compared with ‘placebo’ Boots Pain Relief tablets in a double‐blind study involving 16 healthy volunteers. Measurements (impedance cardiography, forearm plethysmography) were made over 4 h after oral drug administration. 2. Two Mu‐cron tablets (containing phenylpropanolamine [(1R,2S)‐ plus (1S,2R)‐norephedrine] 50 mg) increased blood pressure (maximal effect 18 +/‐ 1/8 +/‐ 1 mm Hg (mean +/‐ s.e. mean), P less than 0.001), stroke volume (4.9 +/‐ 0.8 ml m‐2, P less than 0.05), total peripheral resistance (243 +/‐ 27 dyn s cm‐5 m2, P less than 0.001) and forearm vascular resistance (1.3 +/‐ 0.3 mm Hg ml‐1 min, P less than 0.01) and reduced the ratio of pre‐ ejection period to ventricular ejection time (‐0.031 +/‐ 0.003, P less than 0.05) and forearm blood flow (‐2.6 +/‐ 0.5 ml min‐1, P less than 0.05) but did not affect heart rate or cardiac index. 3. Two Boots Cold Relief tablets (containing phenylephrine 10 mg and caffeine 60 mg) caused a small and short‐lived increase in total peripheral resistance but did not have consistent effects on other measurements. Two Boots Pain Relief tablets (containing caffeine 60 mg) did not have important cardiovascular effects. 4. The cardiovascular effects of phenylpropanolamine, including vasoconstriction and an increase in cardiac performance, are consistent with its alpha‐ and beta 1‐ adrenoceptor agonist action. While it may help the symptoms of rhinitis, its use in patients with heart disease or hypertension is hazardous.(ABSTRACT TRUNCATED AT 250 WORDS)
Effect of enalapril on allergen‐induced cutaneous hypersensitivity reaction.
Authors: Snyman JR , Sommers DK
Published: October 2023

1. To test the hypothesis that the in vivo inhibition of angiotensin converting enzyme in a patient who presents atopy, results in a significant increase in cutaneous bradykinin and prostaglandin production, the effect of enalapril on the cutaneous hypersensitivity reaction was examined in 10 atopic volunteers. 2. A crossover study design was used and volunteers were randomly allocated to treatment with either enalapril (10 mg) alone, or in combination with indomethacin (75 mg), with and without ketotifen (1 mg). Drugs were administered twice daily for 2 days. 3. Allergen (Southern Grass Mix) was administered intradermally 2 h after last drug dosage and the surface areas of the immediate wheal‐and‐flare‐reactions were measured 15 min later. The late phase of the cutaneous response was evaluated 6 h later by determining skinfold thickness and surface area. 4. Enalapril alone had no effect on any of the parameters measured. 5. The cutaneous hypersensitivity reaction was significantly reduced with regard to both immediate and late cutaneous responses when the indomethacin and ketotifen combination was added to enalapril therapy. 6. When only indomethacin was added to enalapril pretreatment the flare reaction was significantly reduced, but whealing was unaffected. 7. This study presents further evidence that mast cell mediators other than prostaglandins are involved in the cutaneous hypersensitivity reaction. Furthermore, that endogenous bradykinin production after enalapril pretreatment either never reaches the supraphysiological concentrations used in previous experiments, or that bradykinin is rapidly and effectively broken down to inactive peptides by other carboxypeptidase enzymes.
Exercise performance during captopril and atenolol treatment in hypertensive patients.
Authors: van Baak MA , Koene FM , Verstappen FT , Tan ES
Published: October 2023

1. Maximal aerobic exercise capacity, submaximal endurance exercise performance, and exercise haemodynamics have been studied in sixteen patients with mild to moderate essential hypertension during treatment with captopril and atenolol. 2. Administration of atenolol (1 x 100 mg day‐1) or captopril (1 x 100 mg day‐1) for 6 weeks resulted in similar supine and erect systolic and diastolic blood pressures. Heart rate was significantly lower during atenolol treatment. 3. Exercise heart rate and systolic blood pressure were significantly lower during atenolol than during captopril treatment, exercise diastolic blood pressure (at 100W) did not differ significantly. With atenolol exercise cardiac output was significantly lower and exercise stroke volume significantly higher than with captopril. 4. Maximal work rate, maximal oxygen consumption and maximal heart rate were significantly lower during atenolol than during captopril treatment (respectively 6%, 8% and 25%). Maximal respiratory exchange ratio and lactate concentration did not differ. 5. No statistically significant difference in submaximal endurance time between atenolol and captopril was found. Endurance time was reduced by 19% during atenolol and by 13% during captopril as compared with placebo. No difference in rating of perceived exertion between atenolol and captopril was present. 6. The results indicate that atenolol will reduce blood pressure during exercise more effectively than captopril in patients with hypertension. The limitation of submaximal endurance exercise performance by both agents is of similar magnitude. This may be regarded as an unwanted side effect in certain physically active patients with hypertension.
Carbamazepine‐hypersensitivity: assessment of clinical and in vitro chemical cross‐reactivity with phenytoin and oxcarbazepine.
Authors: Pirmohamed M , Graham A , Roberts P , Smith D , Chadwick D , Breckenridge AM , Park BK
Published: October 2023

1. Seven patients clinically diagnosed as being hypersensitive to carbamazepine and one patient hypersensitive to both carbamazepine and oxcarbazepine have been identified. They have been compared with a control group (hereafter referred to as ‘control subjects’) comprising five patients on chronic carbamazepine therapy without adverse effects and 12 healthy volunteers who have never been exposed to anticonvulsants. 2. An in vitro cytotoxicity assay employing mononuclear leucocytes as target cells has been used first, to determine the ability of 10 different human livers to bioactivate carbamazepine to a cytotoxic metabolite, and secondly, to compare the cell defences of carbamazepine‐hypersensitive patients and control subjects to oxidative drug metabolites generated by a murine microsomal system, using a blinded protocol. 3. With human liver microsomes, the metabolism‐dependent cytotoxicity of carbamazepine increased with increasing microsomal protein concentration. At a protein concentration of 2 mg per incubation, the cytotoxicity of carbamazepine with human liver microsomes (n = 10 livers) increased from 7.2 +/‐ 0.8% (baseline) to 16.4 +/‐ 2.1% (with NADPH; P = 0.002). 4. In the presence of phenobarbitone‐induced mouse microsomes and NADPH, the mean increase in cytotoxicity above the baseline with carbamazepine was significantly greater (P less than 0.001) for the cells from the carbamazepine‐ hypersensitive patients (7.9 +/‐ 0.8%) than from control subjects (2.6 +/‐ 0.3%). 5. In the presence of phenobarbitone‐induced mouse microsomes and NADPH, there was no significant difference in cytotoxicity between the cells from carbamazepine hypersensitive patients and from control subjects in the presence of either phenytoin or oxcarbazepine.(ABSTRACT TRUNCATED AT 250 WORDS)
Excretion of indomethacin in breast milk.
Authors: Lebedevs TH , Wojnar‐Horton RE , Yapp P , Roberts MJ , Dusci LJ , Hackett LP , Ilett KF
Published: October 2023

1. The excretion of indomethacin into breast milk and subsequent exposure of infants was studied in 16 women and seven of their infants. The median milk:plasma ratio in seven patients where there were measurable drug concentrations in both milk and plasma was 0.37. 2. Total infant dose, assuming a daily milk intake of 150 ml kg‐1 and 100% absorption, ranged from 0.07% to 0.98% (median = 0.18%) of the weight adjusted maternal dose. 3. Plasma samples were obtained in seven infants. In six of these, indomethacin concentrations were below the sensitivity of the assay (less than 20 micrograms l‐1), while one infant had a plasma indomethacin concentration of 47 micrograms l‐1. 4. No adverse effects due to indomethacin were reported in the infants.
Bopindolol in chronic stable angina pectoris: duration and extent of antianginal action.
Authors: Carboni GP , Scardovi AB , D'Ermo M , Prati PL
Published: October 2023

The effects of bopindolol, a new beta‐adrenoceptor blocker, on the exercise tolerance of 12 in‐patients, mean age 57 (5 years), with stable angina pectoris and documented coronary artery disease were evaluated. All patients received on 4 different days a single oral dose of bopindolol 0.5 mg, bopindolol 1.0 mg, bopindolol 2.0 mg and placebo according to a double‐blind latin square design. Treadmill symptoms‐ limited exercise tests were performed using a Bruce protocol, 3, 12 and 24 h after dosing. Bipindolol improved (P less than 0.05) exercise tolerance in comparison with placebo (by a maximum of 33%, 52% and 26% after the 2.0 mg dose) with no adverse effect on ischaemia. The primary action of bopindolol appeared to be to reduce myocardial oxygen consumption (mainly by its negative chronotropic effect) for up to the 24th hour after oral administration. Eight (66%) patients were angina free at the 3rd, 12th and 24th h exercise test. The effects of bopindolol were not dose‐related. A short period of inactivity due to hospitalization may have influenced the exercise performance and led us to underestimate the presence of a dose‐response. The results of this report suggest that bopindolol has a long lasting effect in the treatment of patients with chronic stable angina pectoris.
Single and multiple dose pharmacokinetics of ticlopidine in young and elderly subjects.
Authors: Shah J , Teitelbaum P , Molony B , Gabuzda T , Massey I
Published: October 2023

The pharmacokinetics of orally administered ticlopidine hydrochloride, a novel inhibitor of platelet aggregation, were determined both after a single dose and after 21 days of twice daily dosing in 12 young (mean 28.6 years) and 13 elderly (mean 69.5 years) subjects. Concentrations of unchanged ticlopidine in plasma were measured by g.l.c. After a single 250 mg dose of ticlopidine, the mean area under the curve, AUC (0‐12 h) was 1.11 micrograms ml‐1 h in young subjects and 2.04 micrograms ml‐1 h in old subjects (P = 0.002). Mean values of t1/2,z in young and elderly subjects were 7.9 h and 12.6 h, respectively (P = 0.01). Steady state plasma drug concentrations were attained after 14 days of dosing with ticlopidine. After the final dose on day 21, AUC values in elderly subjects were 2‐3 times those in young subjects (P less than 0.001). The plasma t1/2,z averaged 4.0 days for young subjects and 3.8 days for elderly subjects (P = 0.7). The longer t1/2,z and higher AUC values after multiple dosing probably reflect an increase in bioavailability of ticlopidine after repeated dosing, saturation of metabolism or insufficient analytical sensitivity to characterize the terminal elimination phase after single dose.
Interethnic differences in drug glucuronidation: a comparison of paracetamol metabolism in Caucasians and Chinese.
Authors: Osborne NJ , Tonkin AL , Miners JO
Published: October 2023

Paracetamol disposition following a single oral 1 g dose of the drug was compared in groups (n = 12) of healthy young adult male Caucasians and Chinese. There was no difference between the groups in terms of paracetamol oral clearance, elimination half‐life, or partial metabolic (glucuronidation, sulphation, oxidation) and renal clearances. The results demonstrate that drug glucuronidation is not universally impaired in Chinese and, together with previously published data, that paracetamol glucuronidation is minimally affected by race.
The effect of age on glucuronidation and sulphation of paracetamol by human liver fractions.
Authors: Herd B , Wynne H , Wright P , James O , Woodhouse K
Published: October 2023

Glucuronidation and sulphation were studied in vitro in human liver samples from 22 subjects aged 40‐89 years using paracetamol as substrate. There was no significant correlation with age for the activity of either enzyme pathway. These results provide further evidence that age per se does not have a major effect on the activities of hepatic metabolising enzymes.
Oral amino acids and gastric emptying: an investigation of the mechanism of levodopa‐induced gastric stasis.
Authors: Waller DG , Usman F , Renwick AG , Macklin B , George CF
Published: October 2023

To investigate possible mechanisms of levodopa‐induced gastric stasis, we have studied the effect of other amino acids on gastric emptying. The large neutral amino acid tryptophan delays gastric emptying in the dog at molar concentrations below those required to stimulate duodenal osmoreceptors. In healthy volunteers, we have shown that neither tryptophan nor the small neutral amino acid glycine delayed gastric emptying when given in concentrations similar to those of levodopa which produce gastric stasis. The study suggests that levodopa does not inhibit gastric emptying by an effect on duodenal amino acid receptors or via osmoreceptors.
Preparation of Heteroenzyme Conjugates: Trypsin‐Chymotrypsin and Trypsin‐Alkaline Phosphatase
Authors: Rajput YS , Gupta MN
Published: October 2023

Hybrid enzymes which have two different enzyme activities linked together covalently may be useful reagents for various applications, such as the determination of complex biological structures. The present paper describes the preparation and purification of two such enzyme‐enzyme conjugates, namely, trypsin‐chymotrypsin and trypsin‐alkaline phosphatase. Whereas the former has been prepared by using the well‐known bifunctional reagent glutaraldehyde, the latter exploited the Schiff base formation between the oxidized carbohydrate moiety of alkaline phosphatase and the free amino groups of trypsin.
Characterization of Anti‐Prostatic Acid Phosphatase Monoclonal Antibody and its Medical Significance
Authors: Kuciel R. , Mazurkiewicz A. , Ostrowski WS , Stachura J. , Steuden I. , Szkudlarek J. , Radzikowski C.
Published: October 2023

Monoclonal antibody to purified prostatic acid phosphatase from seminal plasma was produced by fusion of spleen cells from immunized mice with the Sp2/O‐Ag 14 cell line. This hybridoma‐derived antibody, designated MAb‐14, was classified as IgG1 immunoglobulin. The apparent affinity constant of phosphatase. MAb‐14 complex formation calculated by using the Langmuir isotherm is 2.4 times 10(‐8) M. The molecular weight of the complex formed under the condition of antibody excess was found to be 350K, which suggests that 2 molecules of prostatic phosphatase bind to 1 molecule of the antibody. The MAb‐14 antibody bound to phosphatase had a negligible effect on the catalytic activity of the enzyme. All isoenzymatic forms of catalytically active prostatic phosphatase, resolved by isoelectric focusing or by chromatofocusing in different pH gradients, reacted with the monoclonal antibody. Several peptides of Mr 25K to 76K and of 13K to 76K were adsorbed from the prostatic tissue extract and from seminal fluid, respectively, on an MAb‐14‐Sepharose column. The MAb‐14 monoclonal antibody was applied to the immunohistochemical investigation of prostatic phosphatase distribution in normal human prostate gland, in nodular hyperplasia, and in adenocarcinoma of the prostate. Immunostaining was observed in prostatic secretory epithelium, within the luminal content of prostatic glands, and in the neighborhood of prostatic cancer cells. Metastatic prostatic carcinoma was also strongly immunoreactive with the antibody. There was no cross‐reactivity with leukocytes, kidney, liver, pancreas, spleen, breast, stomach mucosal, and colon tissues.
Biochemical and Immunochemical Analysis of Gangliosides of Human Small Cell Lung Carcinoma: Production of Monoclonal Antibodies Against a Unique Marker of Small Cell Lung Carcinoma, Ganglioside Fuc GM1
Authors: Fuchs BB , Avrova NF , Starosvetskaya NA , Boltovskaya MN , Zaraisky EI , Karpova OB , Reznikova EV , Soldatova LN , Stepanov AA
Published: October 2023

Immunization of mice with a pure preparation of the ganglioside adsorbed on Salmonella typhimurium and hybridization of splenocytes with myeloma P3‐X63‐Ag 8.653 have resulted in hybridomas producing monoclonal antibodies against ganglioside Fuc GM1, a marker of human small cell lung carcinoma. Characterization of four hybridomal clones and data on the antigenic specificity of the monoclonal antibodies are given. All four monoclonal antibodies reacted only with Fuc GM1 in an enzyme‐linked immunosorbent assay. In radioimmunodetection of the antigen on thin‐layer plates, two of the four monoclonal antibodies gave cross‐reactions with Fuc GD1b. The obtained monoclonal antibodies have revealed the presence of Fuc GM1 in all seven cases of small cell lung carcinoma we have studied and the absence of Fuc GM1 in the normal human lung tissue and in lung adenocarcinomas.
Characterization of free and immobilized amine oxidases
Authors: Stevanato R. , Porchia M. , Befani O. , Mondovi B. , Rigo A.
Published: October 2023

Bovine plasma amine oxidase was covalently bound to CH‐Sepharose 4B by 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide hydrochloride. The immobilized enzyme showed no significant change in specific activity when spermidine was the substrate, while the enzyme affinity toward benzylamine and propylamine increased significantly. Similarly, the pig kidney diamine oxidase physically adsorbed to Con A‐Sepharose showed large changes in affinity toward substrates such as p‐dimethylaminoethylbenzylamine with respect to the native enzyme. These changes are discussed in terms of active site modification as a consequence of the enzyme immobilization.
Strategy for selection of internal, low redundancy probes for identification of specific cDNA
Authors: Shimomura K. , Schuler LA , Bremel RD
Published: October 2023

Internal peptide fragments containing tryptophan residues are useful predictors of coding sequence for selection of restriction enzyme fragments or synthetic oligonucleotides to use in isolation of a cDNA or genomic clone. We describe a strategy to identify such fragments which uses an on‐line photodiode array spectrophotometric analysis of tryptic fragment elution from an HPLC system to select peptides for amino acid sequence analysis. We applied this information to the identification and subsequent isolation of a cDNA corresponding to bovine placental lactogen from a bovine placental cDNA library which contains numerous closely related gene products.
Overproduction of thermostable leucine dehydrogenase of Bacillus stearothermophilus and its one‐step purification from recombinant cells of Escherichia coli
Authors: Oka M. , Yang YS , Nagata S. , Esaki N. , Tanaka H. , Soda K.
Published: October 2023

We have cloned the leucine dehydrogenase (EC 1.4.1.9) gene from a thermophile, Bacillus stearothermophilus, into Escherichia coli MV1184 with a vector plasmid, pUC119. The cloned cells produced a large amount of the thermostable enzyme, which corresponds to about 60% of the total soluble protein. The enzyme was purified to more than 95% homogeneity by only one step, heat treatment of the cell‐extracts, with an average yield of 75 mg/g of wet cells (obtained from 100 ml of the culture).
Enzymatic production of L‐tryptophan from DL‐serine and indole by a coupled reaction of tryptophan synthase and amino acid racemase
Authors: Ishiwata K. , Fukuhara N. , Shimada M. , Makiguchi N. , Soda K.
Published: October 2023

Enzymatic production of L‐tryptophan from DL‐serine and indole by a coupled reaction of tryptophan synthase and amino acid racemase was studied. The tryptophan synthase (EC 4.2.1.20) of Escherichia coli catalyzed beta‐substitution reaction of L‐serine into L‐tryptophan and the amino acid racemase (EC 5.1.1.10) of Pseudomonas putida catalyzed the racemization of D‐serine simultaneously in one reactor. Under optimal conditions established for L‐tryptophan production, a large‐scale production of L‐tryptophan was carried out in a 200‐liter reactor using intact cells of E. coli and P. putida. After 24 h of incubation with intermittent indole feeding, 110 g liter‐1 of L‐tryptophan was formed in molar yields of 91 and 100% for added DL‐serine and indole, respectively. Continuous production of L‐tryptophan was also carried out using immobilized cells of E. coli and P. putida. The maximum concentration of L‐tryptophan formed was 5.2 g liter‐1 (99% molar yield for indole), and the concentration decreased to 4.2 g liter‐1 after continuous operation for 20 days.