bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic flexibility via mitochondrial BCAA carrier SLC25A44 is required for optimal fever
Authors: Yoneshiro Takeshi , Kataoka Naoya , Walejko Jacquelyn M , Ikeda Kenji , Brown Zachary , Yoneshiro Momoko , Crown Scott B , Osawa Tsuyoshi , Sakai Juro , McGarrah Robert W , White Phillip J , Nakamura Kazuhiro , Kajimura Shingo
Published: May 2021

Importing necessary metabolites into the mitochondrial matrix is a crucial step of fuel choice during stress adaptation. Branched chain-amino acids (BCAAs) are essential amino acids needed for anabolic processes, but they are also imported into the mitochondria for catabolic reactions. What controls the distinct subcellular BCAA utilization during stress adaptation is insufficiently understood. The present study reports the role of SLC25A44, a recently identified mitochondrial BCAA carrier (MBC), in the regulation of mitochondrial BCAA catabolism and adaptive response to fever in rodents. We found that mitochondrial BCAA oxidation in brown adipose tissue (BAT) is significantly enhanced during fever in response to the pyrogenic mediator prostaglandin E2 (PGE2) and psychological stress in mice and rats. Genetic deletion of MBC in a BAT-specific manner blunts mitochondrial BCAA oxidation and non-shivering thermogenesis following intracerebroventricular PGE2 administration. At a cellular level, MBC is required for mitochondrial BCAA deamination as well as the synthesis of mitochondrial amino acids and TCA intermediates. Together, these results illuminate the role of MBC as a determinant of metabolic flexibility to mitochondrial BCAA catabolism and optimal febrile responses. This study also offers an opportunity to control fever by rewiring the subcellular BCAA fate.
Permeant fluorescent probes visualize the activation of SARM1 and uncover an anti-neurodegenerative drug candidate
Authors: Li Wan Hua , Huang Ke , Cai Yang , Wang Qian Wen , Zhu Wen Jie , Hou Yun Nan , Wang Sujing , Cao Sheng , Zhao Zhi Ying , Xie Xu Jie , Du Yang , Lee Chi-Sing , Lee Hon Cheung , Zhang Hongmin , Zhao Yong Juan
Published: May 2021

SARM1 regulates axonal degeneration through its NAD-metabolizing activity and is a drug target for neurodegenerative disorders. We designed and synthesized fluorescent conjugates of styryl derivative with pyridine to serve as substrates of SARM1, which exhibited large red shifts after conversion. With the conjugates, SARM1 activation was visualized in live cells following elevation of endogenous NMN or treatment with a cell-permeant NMN-analog. In neurons, imaging documented mouse SARM1 activation preceded vincristine-induced axonal degeneration by hours. Library screening identified a derivative of nisoldipine (NSDP) as a covalent inhibitor of SARM1 that reacted with the cysteines, especially Cys311 in its ARM domain and blocked its NMN-activation, protecting axons from degeneration. The Cryo-EM structure showed that SARM1 was locked into an inactive conformation by the inhibitor, uncovering a potential neuroprotective mechanism of dihydropyridines.
Sec17/Sec18 can support membrane fusion without help from completion of SNARE zippering
Authors: Song Hongki , Torng Thomas L , Orr Amy S , Brunger Axel T , Wickner William T
Published: May 2021

Membrane fusion requires R-, Qa-, Qb-, and Qc-family SNAREs that zipper into RQaQbQc coiled coils, driven by the sequestration of apolar amino acids. Zippering has been thought to provide all the force driving fusion. Sec17/αSNAP can form an oligomeric assembly with SNAREs with the Sec17 C-terminus bound to Sec18/NSF, the central region bound to SNAREs, and a crucial apolar loop near the N-terminus poised to insert into membranes. We now report that Sec17 and Sec18 can drive robust fusion without requiring zippering completion. Zippering-driven fusion is blocked by deleting the C-terminal quarter of any Q-SNARE domain or by replacing the apolar amino acids of the Qa-SNARE that face the center of the 4-SNARE coiled coils with polar residues. These blocks, singly or combined, are bypassed by Sec17 and Sec18, and SNARE-dependent fusion is restored without help from completing zippering.
Efficiency aware scheduling techniques in cloud computing: a descriptive literature review
Authors: Usman Sana Muhammad , Li Zhanli
Published: May 2021

In the last decade, cloud computing becomes the most demanding platform to resolve issues and manage requests across the Internet. Cloud computing takes along terrific opportunities to run cost-effective scientific workflows without the requirement of possessing any set-up for customers. It makes available virtually unlimited resources that can be attained, organized, and used as required. Resource scheduling plays a fundamental role in the well-organized allocation of resources to every task in the cloud environment. However along with these gains many challenges are required to be considered to propose an efficient scheduling algorithm. An efficient Scheduling algorithm must enhance the implementation of goals like scheduling cost, load balancing, makespan time, security awareness, energy consumption, reliability, service level agreement maintenance, etc. To achieve the aforementioned goals many state-of-the-art scheduling techniques have been proposed based upon hybrid, heuristic, and meta-heuristic approaches. This work reviewed existing algorithms from the perspective of the scheduling objective and strategies. We conduct a comparative analysis of existing strategies along with the outcomes they provide. We highlight the drawbacks for insight into further research and open challenges. The findings aid researchers by providing a roadmap to propose efficient scheduling algorithms.
Non-specific low back pain: cross-sectional study of 11,423 children and youth and the association with the perception of heaviness in carrying of schoolbags
Authors: Kędra Agnieszka , Plandowska Magdalena , Kędra Przemysław , Czaprowski Dariusz
Published: May 2021

Background

Carrying a schoolbag is a daily activity for most children and adolescents.The perception of a schoolbag’s weight depends upon the individual and is a relevant theme in schoolchildren. Describing the association between the perception of heaviness in carrying a schoolbag and NLBP can facilitate the planning of preventive programs, quite different from those based on specific weight limits for schoolbags in children and youth.

Objective

To determine the prevalence of non-specific low back pain (NLBP) and to analyse the association between the perception of heaviness in carrying of schoolbags and NLBP in Polish children and youth aged 10–19.

Methods

This study included 11,423 children and youth (6,252 girls and 5,171 boys) from Poland. An original questionnaire was used to assess NLBP prevalence.

Results

Among 11,423 of the respondents, 41.5% of the respondents admitted that they had experienced NLBP in the period of the last 12 months. The percentage of individuals reporting NLBP increased with age of participants, p < 0.001. Girls reported NLBP more often than boys (p < 0.001). Students with NLBP declared that their school backpack was heavy more often than students without LBP. Students who thought that their backpacks weighed too much manifested a 1.44 (95% Cl [1.33–1.55]) times higher probability to experience NLBP.

Conclusion

In the examined group of schoolchildren a frequent occurrence of NLBP (41.5%) was noted. Its occurrence was related to female sex and age. Students who thought that their backpacks weighed too much manifested higher probability to develop NLBP.
Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada
Authors: Holland Brayden , Bell Phil R. , Fanti Federico , Hamilton Samantha M. , Larson Derek W. , Sissons Robin , Sullivan Corwin , Vavrek Matthew J. , Wang Yanyin , Campione Nicolás E.
Published: May 2021

Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian–Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but are less frequently documented from more northern regions. The Wapiti Formation (Campanian–Maastrichtian) of northwestern Alberta is a largely untapped resource of terrestrial palaeontological information missing from southern Alberta due to the deposition of the marine Bearpaw Formation. In 2018, the Boreal Alberta Dinosaur Project rediscovered the Spring Creek Bonebed, which had been lost since 2002, along the northern bank of the Wapiti River, southwest of Grande Prairie. Earlier excavations and observations of the Spring Creek Bonebed suggested that the site yielded young hadrosaurines. Continued work in 2018 and 2019 recovered ~300 specimens that included a minimum of eight individuals, based on the number of right humeri. The morphology of several recovered cranial elements unequivocally supports lambeosaurine affinities, making the Spring Creek sample the first documented occurrence of lambeosaurines in the Wapiti Formation. The overall size range and histology of the bones found at the site indicate that these animals were uniformly late juveniles, suggesting that age segregation was a life history strategy among hadrosaurids. Given the considerable size attained by the Spring Creek lambeosaurines, they were probably segregated from the breeding population during nesting or caring for young, rather than due to different diet and locomotory requirements. Dynamic aspects of life history, such as age segregation, may well have contributed to the highly diverse and cosmopolitan nature of Late Cretaceous hadrosaurids.
The chemical composition of free-range and conventionally-farmed eggs available to Canadians in rural Nova Scotia
Authors: English Marcia M.
Published: May 2021

In rural Nova Scotia (NS), many small family farms raise free-range hens that consume a varied diet that is different from that of conventionally-farmed hens in caged housing systems. However, it is not known how this varied diet impacts the quality of these eggs. The objective of the present study was to compare the chemical composition of free-range eggs obtained from a small family farm in rural NS to that of conventionally-farmed eggs purchased from a local grocery store. The values obtained from the present study were also compared to published values in the Canadian Nutrient File (CNF) and the U.S. Department of Agriculture FoodData Central database. The egg components and the amino acid compositions were evaluated, and protein concentrations were determined using the Kjeldahl method whereas the fatty acid profiles of the egg yolks were determined using gas chromatography. No difference (P = 0.3) in protein content was observed in free-range eggs (10.6 ± 1.1%) compared to conventionally-farmed eggs (9.7 ± 0.6%). Similar values were also observed for the physical properties of the two types of eggs measured except for the weights of the egg shells. Conversely, the amino acid cysteine, was in higher amounts (P = 0.05) 0.26 g/100 g in the CNF compared to the measured values of ~0.16 g/100 g. Notably, the polyunsaturated linoleic acid (C18:2n-6) was higher (P = 0.001) in the free-range eggs (45.6%) compared to (40.8%) the conventionally-farmed eggs. The cholesterol content of egg yolks was lower in free-range eggs (253.4 ± 0.01 mg/extra-large yolk or 14 mg cholesterol/g of yolk) vs. for conventionally-farmed eggs (263 ± 0.7 mg/extra-large yolk or 15.4 mg cholesterol/g of yolk), respectively. In terms of protein nutrition, free-range eggs may be a suitable alternative to conventionally-farmed eggs, moreover, the lower cholesterol content may be a favourable attribute for Canadian consumers who wish to purchase local free-range eggs.
Taxonomic Characteristics and Phytochemical Constituents of Asystasiagangetica (L.) T. Anderson, a Member of Acanthaceae
Authors: Wahua C. , Odogwu B. A.
Published: May 2021

This study examined the taxonomic characteristics of Asystasiagangetica; a perennial herb characterized by its trailing to erect habit and as a result, roots from the nodes. It is glabrous and grows up to 80±20 cm. There are simple leaves with petioles which are ovate in shape with opposite phyllotaxy and margins are even to slightly serrated, measuring up to 7±2 cm in length and 3±1 cm in width. The inflorescence is one-sided raceme with purplish-blue tubular flowers which is pentamerous. The fruits are dry dehiscent capsule up to 2±0.5 cm in length. The epidermal studies revealed presence of simple elongated to conical shaped multicellular trichomes and cyclocytic stomata which are amphistomatic in nature, though very scanty in adaxial foliar region. Anatomical study showcased a single layer in the epidermis. The hypodermis consists of 2 to 3 layers of collenchyma, the general cortex and pith is made of parenchyma and cuts across mid-ribs, petioles, stems, nodes and roots, occurring in similar locations except that the number of layers of cells are not the same and vascular bundle is open type. The phytochemical study revealed that the following secondary metabolites are present: alkaloids, saponins and cardiac glycosides while steroidal aglycones, not observed. This information here would assist for further delimitation of the species.
Image Compression Based on Deep Learning: A Review
Authors: Yasin Hajar Maseeh , Abdulazeez Adnan Mohsin
Published: May 2021

Image compression is an essential technology for encoding and improving various forms of images in the digital era. The inventors have extended the principle of deep learning to the different states of neural networks as one of the most exciting machine learning methods to show that it is the most versatile way to analyze, classify, and compress images. Many neural networks are required for image compressions, such as deep neural networks, artificial neural networks, recurrent neural networks, and convolution neural networks. Therefore, this review paper discussed how to apply the rule of deep learning to various neural networks to obtain better compression in the image with high accuracy and minimize loss and superior visibility of the image. Therefore, deep learning and its application to different types of images in a justified manner with distinct analysis to obtain these things need deep learning.
Occurrence of an Abdominal Leiomyosarcoma in the Cyprinus carpio: Optical and Immunohistochemical Study
Authors: Romano Luis Alberto , Pedrosa Virgínia Fonseca
Published: May 2021

A capsulated nodular neoplasm measuring 9 cm in diameter, located between the swim bladder and the kidney sample of Cyprinuscarpio, was in laboratory. The neoplasm had a solid consistency in one sector and very adherent to the capsule. Histopathological examination of the neoplasm revealed a monotonous proliferation of spindle cells, and pleomorphic, sometimes in a vortex pattern and interspersed with collagen fibers. Cells had numerous well-oriented myofibrils giving them a deep red. The cytoplasm is eosinophilic and the nuclei are hyperchromatic located in the center with blunt or "cigar-shaped" ends. In the immunohistochemical examination, the tumor cells were positive for desmin, smooth muscle actin and K-47, the latter antibody showing significant cell proliferation. Due to histopathological and immunohistochemical findings, diagnosis was made with leiomyosarcoma.
Glomus intraradices and Funneliformis mosseae am Strains Influence on Soil Physical, Biological and Chemical Characteristics in Tea Plantations in Kenya
Authors: Chelangat Awa , Gweyi-Onyango Joseph P , K Korir Nicholas , Mwangi Maina
Published: May 2021

Arbuscular mycorrhizal (AM) fungi occur over a wide range of agro climatic conditions and are geographically ubiquitous. Arbuscular mycorrhizal fungi are the medium of soil structure, they determine the flow of water, nutrients, and air, directs the pathways of root growth, and opens channels for the movement of soil animals. As the moderator of the microbial community, they also determine the metabolic processes of the soil. In other words, the mycorrhizal network is practically synonymous with ecosystem function. The tremendous advances in research on mycorrhizal physiology and ecology over the past 40 years have led to a greater understanding of the multiple roles of AMF in the ecosystem. The current study was informed due to the depletion of nutrients and poor soil microbiology in tea production whose production has declined in the recent years. The trial was conducted in the research and development greenhouse at the James Finlays Farm in Kericho County, Kenya. The experiment was laid out in a Randomized Complete Block Design (RCBD) with factorial arrangements of tea clones and mycorrhizae levels. The phosphorus treatments consisted of a standard rate of 107.66kg ha -1, two clones of the tea (S15/10 and SC 12/28) and two mycorrhizal strains (Funneliformis mosseae and Glomus intraradices) at two rates (50 kg ha-1 and 70 kg ha-1) and an untreated control without mycorrhizae. The soil pH was positively influenced by reducing the acidity content significantly where mycorrhizae strains were introduced with the highest unit change (1.3) was recorded on clone SC 12/28 at the 50 kg Mycorrhizae ha-1 rate. The same treatment also significantly increased the soil total phosphorus level (2.3 g/kg) compared to all other treatments with the least change observed on the control. Application of AMF strains Glomus intraradices and Funneliformis mosseae is recommended in tea production at the rate of 50 kg ha-1 which improves and enhances the general positive characteristics of soil health.
Genetics Analysis of Rf Gene in Chilli Pepper (Capsicum annuum L.)
Authors: N. Manoj Kumar , Sharma Vinod K. , Sharma V. R. , Pandav Ajay K
Published: May 2021

The inability to develop functional pollen is caused by cytoplasmic male sterility (CMS), a maternally inherited trait. Restorer-of-fertility (Rf), a nuclear gene, could cause normal pollen production in CMS plants, resulting in fertility in the plant. This paper aimed to study the inheritance of restoration of fertility traits in both Sweet pepper and Hot pepper. The study was conducted in the Indian agricultural research institute, Katrain regional station, India. Genetic analysis of fertility restoration was performed on the progeny of chilli and sweet pepper. KTCA 5 (cytoplasmic-genetic male sterile line-Sweet pepper), KTCA 10 (cytoplasmic-genetic male sterile line-Sweet pepper. F2 segregation population and back cross BC1 population obtained from an F1 hybrid between KTCR 15 (a fertility restorer line).  The fertility of the test-crossed lines was assessed under open field conditions using pollen related criteria.  The fertility restoration trait segregated in 3:1 and 1:1 F2 segregation populations and backcrossed BC1 populations respectively in both Sweet Pepper and Hot pepper backgrounds. This indicates single dominant gene inheritance of the Rfgene. There is no effect of CMS background on the restoration trait inheritance.
Interactive Effect of Elevated CO2 and Moisture Stress on Anatomical Configuration in Brassica Species
Authors: Das Ranjan
Published: May 2021

Free-Air CO2 Enrichment (FACE) was developed as a means to study the crops response to elevated level of CO2 under the fully open-air field conditions. In this study, results of FACE experiments are summarized by disusing the root and shoot anatomy. Result indicated that elevated Co2 significantly altered the root and shoot xylem and phloem characters such as both proto and meta xylem and phloem; vessels, character of root and shoots which are vital for the transpiration regulation, along with leaves photosynthesis as a whole. The coexistence of two ontogenetically different phloem sieve element in Brassica plant under elevated CO2 might have possibility of two different transport functions at the same time. One may be involved in supplying for the structural development (leaf size, stem girth and root volume) and other may cater the need of increased new sinks. Though these parameters were found to decrease under moisture stress condition but these impacts of stress were reduced at higher level of atmospheric CO2.
Protective Effects of Alcoholic and Aqueous Extracts of Lyophilized Kiwifruit on Acute Kidney Injury (AKI) Induced by Glycerol in Male Albino Rat
Authors: Hakami Rawiyah M. , Khalifa Fares K. , Alharbi Asmaa A.
Published: May 2021

Objectives: The study aimed to evaluate and compare the protective effects of alcoholic and aqueous extracts of lyophilized kiwifruit on acute kidney injury (AKI) induced by glycerol in male albino rats.

Methods: Rats were divided into four groups: negative control healthy group, acute kidney injury group (administered glycerol), AKI rats treated with ethanolic kiwifruit extract group, and AKI rats treated with aqueous kiwifruit extract group. Kidney biomarkers, oxidative stress, and inflammatory markers were measured and histological examination was performed.

Results: We observed that glycerol induced acute renal injury and as a result there was an increase in the levels of blood urea nitrogen, creatinine, Na+, K+, Cl-, uric acid, cystatin-C, neutrophil gelatinase-associated lipocalin, C-reactive protein, tumour necrosis factor-α, interleukin-6, and malondialdehyde as well as a decrease in the levels of reduced glutathione and superoxide dismutase compared to that in the negative control group. Ethanolic and aqueous kiwifruit extracts improved all the kidney biomarkers in AKI rats. Histological examination showed acute tubular necrosis in the AKI group.  However, there was an improvement in the renal tissue, represented by epithelial cell regeneration, in rats that were administered both the extracts.

Conclusion: Kiwifruit extracts have a positive effect on serum biochemical parameters and renal tissue, which can be beneficial in the treatment of AKI. The treatment with the ethanolic extract is more potent than with the aqueous extract.
To Evaluate the Frequency of Diabetes Mellitus Patients with Hepatitis C at Tertiary Hospital of Sindh, Pakistan
Authors: Mewaram Kuldeep Kumar , Rajper Faraz Qurban , Unar Khalida , Baig Mirza Tasawar , Baig Mirza Tasawar , Unar Ayaz Ali
Published: May 2021

Objective: The major theme of the research was to evaluate the frequency of diabetes mellitus patients with hepatitis C infection at tertiary care hospital of Sindh, Pakistan.

Methodology: Descriptive cross sectional study was conducted at tertiary care hospital of Sindh, Pakistan for the period of 08 months; total 374 sample size was calculated by using Rao soft sample size calculator at the prevalence rate of 58.3% and confidence level 95% and margin of error 5%. Data was collected from patients of sero-positive HCV-RNA (Hepatitis C Virus-Ribose Nucleic Acid) visiting outpatient department or admitted at tertiary care hospital of Sindh, Pakistan and Informed consent form was also filled from all included subjects and data was analyzed by using SPSS software version 24.00.

Results: From the 374 patients 209 were males and 165 females and all participants were divided in to various age groups as 15 patients were in the age group of 20-25 years, 67 patients were in 26-30 years, 48 patients included in 31-35 years and 109 patients were included in to age group of 36-40 years. Only 12 patients were included in the age group of 50 years and above. Total 164 (43.85%) were diabetic and 229 (61.22%) were diagnosed with Hepatitis C RNA (Ribose Nucleic Acid) positive. Patients had various range of HbA1c as 93 patients had range between 6-7mmol/dl. 107(28.60%) included in 7-9mmol/dl, 145(38.77%) included in 9-11mmol/dl and only 29 patients were having HbA1c (Glycated Hemoglobin) level above 11mmol/dl.

Conclusion: It was concluded that there were increased number of diabetic patients with hepatitis C in worsening condition, so the proper programs should be conducted in order to reduce the complication of co-morbid disease.
Evaluation of Drug Resistance and Treatment Outcomes among TB Patients with Diabetes Mellitus at Tertiary Care Hospital of Sindh, Pakistan
Authors: Khan Kahaf , Unar Ayaz Ali , Unar Khalida , Rajper Faraz Qurban , Baig Mirza Tasawar
Published: May 2021

The objective of the study is to evaluate of drug resistance and treatment outcomes among tuberculosis patients with diabetes mellitus at tertiary care hospital of Sindh, Pakistan.  Tuberculosis (TB) is considered as very dangerous infectious disease caused by Mycobacterium tuberculosis orother tubercle bacilli pathogen affects the lungs and it can be spread from person to person through very minute droplet released by infected person via coughing or sneezing.

Descriptive cross-sectional study was carried out at different Tuberculosis setting located at tertiary care hospital of Sindh, Pakistan for the period of 10 months. Tuberculosis OPD is considered as major health care facility for the TB, MDR-TB and XDR-TB patients for the local population and peripheries. Total 389 samples were collected through purposive sampling techniques. From the given data, there were 209 Males and 180 females, all participants belong to different areas, so 216 patients belong to rural areas, 121 study participants were house wives, 134 were employed and 41 were have their own business. From the clinical data, 229 participants shown positive response with TB smear test, whereas; 156 participants had positive results with TB culture test. 247 patients had previous history of Tuberculosis, 120 had developed drug resistance and 24 had developed multi-drug resistance (MDR). 312 patients were recently diagnosed with Diabetes mellitus and they had one year of duration of diabetes. Complication of tuberculosis developed among 113 patients and complication of diabetes developed among 194 participants. 39 people were using oral therapy for the management of diabetes and 341 participants had successfully completed their therapy and cured whereas 2 patients were died due to complication

It was concluded from the current research that there were many chances for developing drug resistance and multi-drug resistance among the patients suffering from co-morbid including tuberculosis along with Diabetes mellitus. Proper counseling should be conducted, in order to reduce the complication of either type of disease.
Formulation Evaluation and In- Vitro Antioxidant activity of Microparticles of Syzygium Cumini Plant Extract
Authors: Koka Sweta Srivastava , Sharma Pravin Kumar , Sharma Vaishali , Verma Jaya , Darwhekar G. N.
Published: May 2021

Sygygium cumini, commonly known as Malabar plum, Java plum, black plum, jamun or jambolan, is an evergreen tropical tree in the flowering plant family Myrtaceae. The present study the antioxidant effects of microparticles of S. cumini plant extract were evaluated using in vitro, 2, 2-diphenylpicrylhydrazine photometric assay, total antioxidant activity and super oxide free radical scavenging activity. The microparticles showed different levels of radicals scavenging activity in a dose-dependent manner over the range of 50–150 µg/mL concentration, indicating the high antioxidative capacity of the extract. In all the experimental screening models microparticles of aqueous extract show the maximum inhibition of free radicals comparison of other experimental model at different concentrations. These findings suggest that the seed of Syginium cumini has potent antioxidant activity which may be responsible for some of its reported pharmacological activities and can be used as antioxidant supplement.
The electron paramagnetic resonance spectra of partially purified cytochrome b6f complex from spinach
Authors: Salerno J.C. , McGill J.W. , Gerstle G.C.
Published: July 2002

In addition to the signals exhibited by cytochrome f and a Rieske‐type iron‐sulfur cluster, cytochrome b
6
f preparations exhibit a broad asymmetric peak near g ∼ 3.7 due to cytochrome‐b‐563 components and a free radical signal which may be a bound semiquinone. Signals near g ∼ 6 and g ∼ 2.9 correspond at least in part to denatured cytochrome b‐563; this suggests the possibility of strained bis‐histine ligation in the native cytochrome. UHDBT but not antimycin A has a strong specific effect on the spectra of the complex.
Proinsulin‐like material in mouse foetal brain cell cultures
Authors: Birch Nigel P. , Christie David L. , Renwick Alistair G.C.
Published: July 2002

Two main forms of immunoreactive insulin have been identified in cultures of foetal mouse brain using HPLC and gel filtration. The major component which resembled proinsulin was converted by trypsin to the minor form which was similar to authentic pancreatic insulin in chromatographic behaviour. Both components showed immunological properties comparable to insulin and proinsulin including sensitivity of the former to reduction and alkylation.
Competitive solid‐phase immunoassay of testosterone using time‐resolved fluorescence
Authors: Bertoft E. , Eskola J.U. , Näntö V. , Lövgren T.
Published: July 2002

A competitive solid‐phase immunoassay for the determination of testosterone in serum samples using time‐resolved fluorescence is described. The solid phase is a testosterone‐3‐(O‐carboxymethyl)‐oxime‐ovalbumin conjugate coated to polystyrene microtiter strips. Europium‐labelled polyclonal and monoclonal antibodies against testosterone‐3‐(O‐carboxymethyl)‐oxime‐bovine serum albumin were compared. Their behavior was quite similar although the polyclonal antibody was more sensitive, giving a detection limit of 15 fmol testosterone per assay. Correlation with RIA was very good (r = 0.982 and y = −0.150 + 0.969x).
Interaction of plasmid DNA with yeast protoplasts and a mechanism of genetic transformation
Authors: Brzobohatý Břetislav , Kováč Ladislav
Published: July 2002

DNA of plasmid pBB 29 is bound to protoplasts of Saccharomyces cerevisiae by a time‐dependent, energy‐independent process requiring Ca2+. It is not degraded during binding but most of the bound DNA can be degraded by exogenously added DNase. Foreign DNA competes for the binding. Genetic transformation of protoplasts depends on the same conditions as does the binding of DNA but, in addition, it also requires conditions allowing fusion of the protoplasts. Transformation may consist of firm adsorption of plasmid DNA to the protoplast surface, mediated by Ca2+, and of internalization of the DNA entrapped between two aggregated protoplasts as a suit of their fusion.
Indole ring binds to 7‐methylguanine base by π‐π stacking interaction
Authors: Kamiichi Katsuhisa , Danshita Masaya , Minamino Naoko , Doi Mitsunobu , Ishida Toshimasa , Inoue Masatoshi
Published: July 2002

Strong π‐π stacking interaction between the indole ring and 7‐methylguanine base was shown by X‐ray crystal analysis of the 7‐methylguanosine 5'‐monophosphate‐tryptamine complex. This interaction appears to be strengthened by the attachment of ribose and phosphate groups to the base.
fixA, B and C genes are essential for symbiotic and free‐living, microaerobic nitrogen fixation
Authors: Gubler Marcel , Hennecke Hauke
Published: July 2002

Site‐specific mutations were contructed within Bradyrhizobium japonicum fixA, B and C regions that had previously been identified by interspecies hybridization [(1985) Mol.Gen.Genet. 199, 315‐322]. The corresponding mutants were not only Fix− in otherwise fully developed soybean root nodules but also Nif− in free‐living microaerobic culture. Specific fixA, B and C probes hybridized to DNA of the aerobic diazotroph, Azotobacter vinelandii. We hypothesize, therefore, that fixA, B and C genes are of general importance for aerobic/microaerobic nitrogen fixation.
The 240‐kDa subunit of human erythrocyte spectrin binds calmodulin at micromolar calcium concentrations
Authors: Berglund Åsa , Backman Lars , Shanbhag Vithaldas P.
Published: July 2002

Calmodulin
(Human)
Spectrin
Erythrocyte cytoskeleton
Aqueous two‐phase partitioning
The amino acid sequence of an atypical single‐chain lectin from seeds of Lathyrus sphaericus (Retz)
Authors: Richardson Michael , Yarwood Alan , Rougé Pierre
Published: July 2002

The major lectin from seeds of Lathyrus spaericus (Retz) was purified by fractional precipitation with (NH4)2SO4, affinity chromatography on Sephadex G‐100, chromatofocusing on PBE 94 and gel filtration on Biogel P‐100 in the presence of 6 M guanidine HCl. The protein was found to be atypical of the lectins found in the Vicieae in that it was a dimer of two identical single polypeptide chains whose monomer molecular mass was estimated to be 27–28 kDa by SDS‐PAGE. The complete amino acid sequence of the monomer was determined by analysis of peptides derived from the protein by digestion with trypsin, chymotrypsin, pepsin, the S.aureus V8 protease and a lysine‐specific protease from Lysobacter enzymogenes, as well as fragments produced by cleavage with iodosobenzoic acid. The polypeptide chain contained 244 amino acids and exhibited overlapping homology with the β (heavy) and α (light) chains of the two‐chain lectins found in other Lathyrus species and in genera belonging to the tribe Vicieae, but was unusual in containing additional amino acids at the N‐terminus and in two other regions (insertions), some deletions, and alterations in 44 previously conserved amino acid positions.
Primary structure of duck amyloid protein A The form deposited in tissues may be identical to its serum precursor
Authors: Ericsson Lowell H. , Eriksen Nils , Walsh Kenneth A. , Benditt Earl P.
Published: July 2002

The amino acid sequence has been determined for the major protein that accumulates in amyloid fibrils in tissues of the Pekin duck. With the exception of 16 residues at the amino terminus, this 106‐residue protein is homologous with human serum amyloid protein A (104‐residue apoSAA), which is the putative precursor of the 76‐residue protein that accumulates in human patients with amyloidosis. Duck serum is shown to contain a protein that is immunologically related and approximately equal in size (12 kDa) to the deposited form in ducks. These results indicate that proteolytic processing of the precursor is not a necessary step in the deposition of amyloid fibrils, at least in the duck.
Botulinum C2 toxin potentiates activation of the neutrophil oxidase Further evidence of a role for actin polymerization
Authors: Al-Mohanna F.A. , Ohishi I. , Hallett M.B.
Published: July 2002

Botulinum C2 toxin was employed as a specific inhibitor of actin polymerization in rat neutrophils to determine its role in oxidase activation. This toxin was shown to inhibit actin polymerization and the microfilament‐dependent function, phagocytosis. Oxidase activation in response to the chemotactic peptide, f‐Met‐Leu‐Phe (FMLP) was enhanced approx. 3‐fold. The enhancement by C2 toxin did not occur in cells pretreated with cytochalasin B. C2 toxin had no significant effect on the FMLP‐induced intracellular Ca2+ rise. These data are consistent with an inhibitory role for actin polymerization in oxidase activation.
Regulation of the choline, ethanolamine and serine base exchange enzyme activities of rat brain microsomes by phosphorylation and dephosphorylation
Authors: Kanfer J.N. , McCartney D. , Hattori H.
Published: July 2002

The base exchange enzyme activities of rat brain microsomes were estimated subsequent to preincubations under conditions for either protein phosphorylation or dephosphorylation. Quantitatively the choline base exchange activity was most affected by these treatments. Exposure of the microsomes to alkaline phosphatase resulted in a decrease of all three base exchange activities. Pretreatment with a cAMP‐dependent protein kinase resulted in increases of all 3 enzyme activities. Conditions favoring protein kinase C phosphorylation resulted in stimulation of the choline base exchange activity.
Kinetic properties of polyphenoloxidase in organic solvents A study in Brij 96‐cyclohexane reverse micelles
Authors: Sa´nchez-Ferrer Alvaro , Bru Roque , Garci´a-Carmona Francisco
Published: July 2002

Polyphenoloxidase entrapped in Brij 96‐cyclohexame reverse micelles showed both cresolase activity towards monophenols and catecholase activity towards diphenols. The kinetic parameters, such as apparent K
m, temperature effect and pH profile, were determined for catecholase activity, the findings being very close to those found in aqueous systems. The enzyme activity was dependent on the molecular ratio of water to surfactant (ωo), obtaining a maximum activity at ωo=10. The stability of the system with time increased with the water content until ωo=10, and then decreased. An inverse relation was found between activity and water volume fraction (θ) when ωo was held constant. In this situation V
max was constant while K m varied proportionally with θ.
Complementary DNA and deduced amino acid sequences of porcine α1‐microglobulin and bikunin
Authors: Gebhard Wolfgang , Schreitmüller Thomas , Vetr Helga , Wachter E. , Hochstrasser Karl
Published: July 2002

Analysis of complementary DNA for porcine α1‐microglobulin and bikunin indicates that both proteins result from proteolytic processing of a common precursor similar to that found in man. Complete primary structures of these proteins are deduced from the nucleic acid sequence and partially confirmed by peptide sequencing.
Construction and properties of a triprotein containing the high‐affinity nickel transporter of Alcaligenes eutrophus
Authors: Wolfram Lutz , Eitinger Thomas , Friedrich Bärbel
Published: July 2002

The high‐affinity nickel transporter of Alcaligenes eutrophus H16 is encoded by gene hoxN, which maps within the hydrogenase gene cluster of megaplasmid pHG1. A tripartite gene fusion was constructed, consisting of (i) the Escherichia coli lacZ gene for β‐galactoxidase, (ii) a segment encoding an endoproteolytically cleavable peptide, and (iii) the A. eutrophus gene hoxN. An E. coli strain harboring this construct (plasmid pCH307) efficiently produced the corresponding triprotein upon induction. A broad‐host‐range derivative of pCH307 was shown to complement an A. eutrophus HoxN− mutant.
Cellular HSP90 (HSP86) mRNA level and in vitro differentiation of mouse embryonal carcinoma (F9) cells
Authors: Kohda Takashi , Kondo Kazuhiro , Oishi Michio
Published: July 2002

Treatment of mouse embryonal carcinoma (F9) cells with retinoic acid, an inducer of F9 cell differentiation, greatly increased the level of mRNA specific to one of the heat‐shock proteins (HSP86). Experiments including the one employing differentiation‐resistant mutant F9 cells suggested that the increase represents early molecular events associated with the embryonal differentiation. The increased HSP86 mRNA declined to the original level during further incubation. The presence of cyclic AMP, which stimulates conversion of the retinoic acid‐induced primitive endoderm cells to parietal endoderm cells, prevented the decline. These results suggest that not only the elevation of HSP86 mRNA level represents early molecular events in F9 cell differentiation but also that sustaining the elevated level (by cyclic AMP) is associated with further differentiation of the embryonal cells.
Dissection of Calbindin D9k into two Ca2+‐binding subdomains by a combination of mutagenesis and chemical cleavage
Authors: Finn Bryan E. , Kördel Johan , Thulin Eva , Sellers Peter , Forsén Sture
Published: July 2002

Calbindin D9k is a 75‐residue globular protein made up of two Ca2+‐binding subdomains of the EF‐hand type. In order to examine the subdomains independently, a method was devised to selectively cleave the loop between them. Using site‐directed mutagenesis, a unique methionine was substituted for Pro43 in the loop, thus allowing cleavage using cyanogen bromide. Agarose gel electrophoresis shows that the fragments have a high affinity for one another, although less so in the absence of calcium.1H‐NMR spectra of the fragments indicate that the structures of the heterodimers are changed little from that of the intact protein. However, the Ca2+ binding constants of the individual subdomains are several orders of magnitude lower than for the corresponding sites in the uncleaved protein.
The Euglena gracilis rbcS gene contains introns with unusual borders
Authors: Tessier Luc-Henri , Chan Raquel L. , Keller Mario , Weil Jacques-Henry , Imbault Patrice
Published: July 2002

We have recently shown that, in Euglena gracilis, leader sequences are transferred by trans‐splicing to the vast majority of cytoplasmic mRNAs. Trans‐splicing is involved in the maturation of the rbcS transcript, which encodes eight small subunits of the ribulose 1,5 bisphosphate carboxylase/oxygenase. In this report, we show that the Euglena rbcS gene introns are different from introns found in plant rbcS genes. In addition these introns do not have the conserved 5′ and 3′ border sequences found in introns of eucaryotic nuclear‐encoded pre‐mRNAs, and they do not present any homology with self‐splicing introns of groups I and II. Secondary structure analyses show that the 5′ and 3′ ends of Euglena introns can base‐pair, suggesting that an unusual splicing mechanism exists in Euglena.
Generation of substance P carbamate in neutral aqueous solution
Authors: Davis Adrian J. , Hawkes Geoffrey E. , Haycock Peter R. , O'Brien Paul , Kidd Bruce L. , Mapp Paul I. , Naughton Declan , Grootveld Martin
Published: July 2002

High‐field proton (1H) nuclear magnetic resonance (NMR) spectroscopy has been employed to evaluate the formation of substance P carbamate in aqueous solution. Equilibration of substance P with physiologically relevant concentrations of bicarbonate (2.50 × 10−2 mol·dm−3) at pH 7.00 generated a new multiplet signal centred at 4.13 ppm in its NMR spectrum, characteristic of the α‐proton of peptide carbamate species. High‐field 1H NMR spectroscopy also demonstrated that the model dipeptide, Arg‐Gly, formed a carbamate in neutral aqueous solutions containing 2.50 × 10−2 mol·dm−3 HCO3. The physiological significance of these results is discussed in view of the central roles of vasoactive neuropeptides in human joint diseases and the hypercapnic environment of the inflamed rheumatoid joint.
Nitric oxide synthase activity from a hematophagous insect salivary gland
Authors: Ribeiro José M.C. , Nussenzveig Roberta H.
Published: July 2002

The salivary glands of the hematophagous insect, Rhodnius prolixus, contain a nitrosylhemeprotein that dissociates its ligand, NO, to the host tissues while the insect is searching for a blood meal. We now report a salivary nitric oxide synthase activity in this insect. The activity is dependent on NADPH, FAD, tetrahydrobiopterin, calmodulin, Ca2+, and converts arginine to citrulline while producing vasorelaxing activity. Molecular sieving indicates a molecular weight of 185 kDa, coeluting with a diaphorase activity. Results indicate similarity of this insect activity to the vertebrate constitutive NO synthase, suggesting NO synthesis is an evolutionary old biological pathway.
Molecular cloning of a cDNA encoding a novel small GTP‐binding protein
Authors: Koda Toshiaki , Kakinuma Mitsuaki
Published: July 2002

A cDNA encoding a small GTP‐binding protein, S10, was cloned from Jurkat cells. The deduced amino acid sequence of S10 had the structural features characteristic to this family of proteins with highest homology to rab subfamily. Northern blot analysis revealed that this gene is expressed only in lymphoid cell lines and a histiocytic leukemia, U937. Hence, it should have a specialized function in cells derived from the hematopoietic stem cell.
Phospholipase C activation and Ca2+ mobilization by cloned human somatostatin receptor subtypes 1–5, in transfected COS‐7 cells
Authors: Akbar Mohammed , Okajima Fumikazu , Tomura Hideaki , Majid Mohammed Abdul , Yamada Yuichiro , Seino Susumu , Kondo Yoichi
Published: July 2002

We transfected the COS‐7 cells with cDNAs encoding different human somatostatin receptor (hSSTR) subtypes, and found that hSSTR subtypes mediate not only the inhibition of forskolin‐induced cAMP accumulation but also the stimulation of phospholipase C (PLC) and Ca2+ mobilization. Activation of PLC by 1 μM somatostatin (SRIF) was in the order of: hSSTR5 ⪢ hSSTR2 ⪢ hSSTR3 ⪢ hSSTR4 ⪢ hSSTR1. Pertussis toxin (PTX) treatment completely or partially reversed the PLC activation. 1 nM SRIF was equally effective for adenylate cyclase (AC) inhibition in a PTX‐sensitive manner, in all the cells expressing different hSSTRs, except for hSSTR1. Nevertheless, SRIF stimulated AC even in the presence of forskolin at higher doses of SRIF in PTX‐treated hSSTR5‐expressing cells. We conclude that the cloned hSSTRs differentially couple to PTX‐sensitive and ‐insensitive G‐proteins to modulate PLC, Ca2+ mobilization and AC.
Contribution of salt bridge in the protease inhibitor SSI (Streptomyces subtilisin inhibitor) to its inhibitory action
Authors: Kojima Shuichi , Fujimura Konomi , Kumagai Izumi , Miura Kin-ichiro
Published: July 2002

The tertiary structure of proteinaceous protease inhibitors is considered to be maintained by various interactions in the molecule that prevent degradation by protease. In this study, the Arg29 of Streptomyces subtilisin inhibitor (SSI) forming a salt bridge with the carboxyl group of carboxyl‐tenninal Phe113 was replaced with Ala, Met or Lys by cassette mutagenesis to clarify the role of Arg29 in the function of SSI. The inhibitory activity of each mutated SSI decreased with increasing incubation time after mixing with subtilisin, indicating that the SSI was changed into a temporary inhibitor upon mutation. This decrease was shown by SDS polyacrylamide gel electrophoresis to be due to cooperative degradation of the mutated SSI by subtilisin. In addition, the denaturation temperature of the Ala or Met mutant was decreased by ten degrees and that of the Lys mutant by 1.5 degrees, suggesting that the destabilization of SSI may be related to its temporary inhibition. Thus, interaction in the protease inhibitor molecule for maintaining the tertiary structure, such as that of Arg29 in SSI, was shown to be required for the inhibitory action.
RGD induces conformational transition in purified platelet integrin GPIIb/IIIa‐SDS system yielding multiple binding states for fibrinogen γ‐chain C‐terminal peptide
Authors: Mayo Kevin H. , Fan Francis , Beavers Mary Pat , Eckardt Annette , Keane Patricia , Hoekstra William J. , Andrade-Gordon Patricia
Published: July 2002

Fibrinogen γ‐chain C‐terminal peptide HHLGGAKQAGDV (γ12) and α‐chain peptide GRGDSP are known to inhibit fibrinogen‐mediated platelet cell aggregation via competitive interactions with platelet integrin receptor GPIlb/IIIa. NMR studies of γ12 in the presence of purified GPIIb/IIIa in SDS/water solution have demonstrated the presence of two γ12 binding states, one of which is eliminated by GRGDSP (RGD) up to a RGD: γ12 ratio of 2:1. RGD: γl2 ratios greater than 2:1 produce multiple sets of γ12 NMR signals in TOCSY spectra. At a ratio of 4:1, two to four such resonance sets can be resolved for A405, Q407, A408, G409, D410 and V411 spin systems. The number of multiple resonances remains unchanged at ratios of 6:1 and 8:1. Addition of γ12 to reverse the ratio to 8:8 (1::1) has no apparent effect on the RGD‐induced distribution. Results suggest that RGD irreversibly induces a conformational transition(s) in GPIIb/IIIa to produce multiple γ12 binding sites on the receptor.
Genital burns and vaginal delivery
Authors: Pant R. , Manandhar V. , Wittgenstein F. , Fortney J.A. , Fukushima C.
Published: July 2002

Obstetric complications may result from burn scarring in the genital area. Women in developing countries typically squat around cooking fires, and burns are common. This recent case in Nepal describes obstructed labor in a young woman whose genital area had extensive scarring from a cooking fire injury. Proper antenatal assessment by health care providers can reduce the risk to mothers and infants of the consequences of a birth canal damaged or obstructed by burn scarring.