Pollen as food and medicine—A review

Pollen, the male gametophyte of flowering plants, is a high energy material, which is collected by insects and stored as food reserve. Pollen has been used traditionally by humans for religious purposes and as supplementary food. Pollen is a concentrated, energy and vitamin rich food that in contemporary times is not only consumed as a dietary component, but also is used in alternative medical treatments. Pollen has potential imporiance as a supplementary and survival food, and for conditioning of athletes. Pollen has been used medically in prostatitis, bleeding stomach ulcers and some infectious diseases, although such use has been questioned by the medical profession. Pollen may also be used for treatment and prevention of the high-altitude-sickness syndrome. Because some individuals are allergic to pollen, and various pollen species contain specific allergens, individual sensitivities must be tested before pollen is used as a treatment or as a supplementary food.     

Molecular genetics of preeclampsia and HELLP syndrome — A review

Preeclampsia is characterised by new onset hypertension and proteinuria and is a major obstetrical problem for both mother and foetus. Haemolysis elevated liver enzymes and low platelets (HELLP) syndrome is an obstetrical emergency and most cases occur in the presence of preeclampsia. Preeclampsia and HELLP are complicated syndromes with a wide variety in severity of clinical symptoms and gestational age at onset. The pathophysiology depends not only on periconceptional conditions and the foetal and placental genotype, but also on the capability of the maternal system to deal with pregnancy. Genetically, preeclampsia is a complex disorder and despite numerous efforts no clear mode of inheritance has been established. A minor fraction of HELLP cases is caused by foetal homozygous LCHAD deficiency, but for most cases the genetic background has not been elucidated yet. At least 178 genes have been described in relation to preeclampsia or HELLP syndrome. Confined placental mosaicism (CPM) is documented to cause early onset preeclampsia in some cases; the overall contribution of CPM to the occurrence of preeclampsia has not been adequately investigated yet. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.     

Bryophyte-cyanobacteria symbioses and their nitrogen fixation capacity—A review

苔藓-蓝藻共生体(BCS)能固氮, 是养分贫瘠地区森林氮输入的不可忽视的来源。BCS关系与固氮能力研究为科学认识生态系统氮输入与氮循环过程和机理提供了新的视角和有效途径, 具有重要的理论价值。然而, BCS关系、固氮作用与机理的研究迄今未受到足够关注, 报道较少, 认识仍然是零星而片段化的。基于系统查阅的相关文献, 该文综述了BCS的种类组成与共生关系类型、固氮能力及所固定氮的去向及其影响因素和作用机理, 指出了存在的问题及需要深入关注和亟待突破的4个研究方向。     

Cyanobacterial bioactive metabolites—A review of their chemistry and biology

Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1–3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds.Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.     

Collagen formation — observations on its intracellular packaging and transport

Summary Odontoblasts, osteoblasts and fibroblasts of young rats were examined in the electron microscope after staining thin sections either with lead citrate alone or with uranyl acetate prior to lead citrate.With lead citrate alone, collagen fibrils in the extracellular matrix stand out as lucent structures against a moderately electron dense background. Within the cells, lucency is restricted to certain dilated portions of the Golgi saccules as well as to the secretory granules located nearby and in the secretory pole of the cells. The lucency present in these compartments may be attributed to fibrils that are similar to the lucent collagen fibrils in the extracellular matrix. Other cellular compartments, e.g. the rough ER, do not display lucency.When preparations are stained with uranyl acetate prior to lead citrate, lucency is observed neither in the matrix nor in the cells. In the matrix, collagen fibrils are easily identifiable by their cross banded pattern. In the odontoblasts, dilated portions of Golgi saccules between the outer and inner face contain filaments aligned in parallel that are approximately 3 000 Å in length. In saccules on the inner face filament aggregates are present, some of them exhibiting a cross banding pattern. In secretory granules, however, the contents appear rather homogeneous.It is suggested that filament aggregates of collagen can assemble in the Golgi apparatus from filamentous units. These are transported through the cell by way of secretion granules and are discharged to the extracellular matrix by exocytosis.This investigation was supported by grants of the Medical Research Council of Canada. The author wishes to express appreciation to Dr. C. P. Leblond for his guidance in the course of this work.     

Federal plant introduction—A review

In 1898 the U. S. Department of Agriculture be?an importation of economically important plants for possible cultivation and utilization in the United States. Since then nearly a quarter million introductions have been made, including the hard winter wheats which today are ?rown annually on some 27 million acres, and soybeans which now support a billion-dollar industry.     

Equilibrative nucleoside transporters—A review

Equilibrative nucleoside transporters (ENTs) are polytopic integral membrane proteins that mediate the transport of nucleosides, nucleobases, and therapeutic analogs. The best-characterized ENTs are the human transporters hENT1 and hENT2. However, non-mammalian eukaryotic ENTs have also been studied (e.g., yeast, parasitic protozoa). ENTs are major pharmaceutical targets responsible for modulating the efficacy of more than 30 approved drugs. However, the molecular mechanisms and chemical determinants of ENT-mediated substrate recognition, binding, inhibition, and transport are poorly understood. This review highlights findings on the characterization of ENTs by surveying studies on genetics, permeant and inhibitor interactions, mutagenesis, and structural models of ENT function.     

Canine behavioral genetics — A review

A chronological review of the history of research in canine behavioral genetics is presented. Prior to the work of Scott and Fuller, many studies attempted to describe observed results in simple Mendelian terms. More recently, a quantitative mode of inheritance has been ascribed to many behavioral traits, and heritabilities have been calculated in different populations. Studies of behavioral traits are complicated by the effects of learning, which may well explain the reports of low heritability of behavioral traits measured on adults. Both genotype and environment have been shown to play major roles in the expression of behavioral traits. Maternal effects and the sex of an individual have important effects on behavior scores. Breeders usually select for both physical and behavioral traits in the same individuals, and this review includes a summary of reported research on the relationships between physical and mental traits.     

A review of a potential and promising probiotic candidate—Akkermansia muciniphila

Akkermansia muciniphila, a common colonizer in the intestinal mucus layer of humans, has gradually been considered as promising candidate for the next-generation probiotic, given its physiological benefits from animal and human studies. This article comprehensively reviewed A. muciniphila from the published peer-reviewed articles in the aspects of its role in the host physiology and commonly consumed food that can boost its abundance, which should provide useful and fundamental information for scientists and engineers and even ordinary consumers. Akkermansia muciniphila is not only a crucial biomarker that indicates the physiology of human beings but also has huge potential to become a probiotic given its physiological benefits in various clinical scenarios. Current barriers in terms of regulations, necessity for large-scale clinical experiments and production feasibility need to be resolved before A. muciniphila can be widely applied as the next-generation probiotic.     

Stimulation and inhibition of anaerobic processes by heavy metals—A review

Stimulatory, inhibitory and antagonistic roles of heavy metals in anaerobic digestion are reviewed. Partitioning and speciation, variety of biotic and abiotic detoxifying mechanisms as well as acclimation are shown to hinder an accurate prediction of response based on a given total metal concentration.     

Biodeterioration problems of North Sea oil and gas production—A review

The North Sea is both a highly corrosive and highly biologically productive environment. Oil and gas production structures in this environment not only suffer from the physical effects, corrosion, wave and storm action, of being immersed in this environment, but also the effects of biological activity. Such biodeterioration problems occur both on the external and internal surfaces of the structure and the internal surfaces of any plant or pipework which contains, or has contained, water. The platform jacket may experience biological problems due to external macro- and microfouling or to internal microfouling. Pipelines, risers and topside systems have usually all been hydrostatically tested leaving residual water and possible sites for bacterial activity. Waterflooding with seawater and the separation of produced water from oil also provide sites suitable for biological activity and associated corrosion, slime and blockade problems. This paper reviews these areas in the light of recent advances in investigation and uderstanding of the problems.     

Paleoecology of the cenozoic reefal foraminifers and algae — A brief review

The paleoecology of reefal foraminifers and algae assumes a considerable importance in determining and delineating sub-environments of ancient reefs, especially those of non-coral origin.A review of the ecologic distribution of the Cenozoic larger foraminifers in different biofacies of the reef-complex environment has revealed the following: (1) a prolific growth of “Alveolina” was possible in the back-reef region near the reef core; (2) Orbitolites and Marginopora preferred sheltered waters on the reef-flat and in the back-reef zones; (3) nummulitids and Discocyclina thrived in both fore- and back-reef shoal areas, but the species living in the former are much stouter than those living in the latter; (4) Heterostegina is and, in the geologic past, was a form, preferring quieter waters of the back-reef lagoons and reef-flat pools; (5) Pellatispira was a typical fore-reef form.Smaller foraminifers, as a whole, are dominant in back-reef lagoons. An abundance of miliolids indicates a sheltered environment prevailing in the reef-flat pools and back-reef zones, whereas reef flats, in general, are characterized by a paucity of smaller foraminifers. An increase in the number of nodosariids and globigerinids points to a fore-reef environment, the depth of which is indicated by the relative abundance of the latter group. Encrusting foraminifers are characteristic of the reef core and are important constituents of for-algal (foraminiferal + algal) reef complexes.Of the algae, the calcarous chlorophyte Halimeda is relatively more abundant in the sheltered parts of a reef-complex, especially the lagoons, where water is moderately agitated and clear; its sudden abundance in the geologic record indicates the advent of a reefal environment. An abundance of the calcareous chlorophyte Dasycladaceae indicates the shallow back-reef areas adjacent to the reef core. Articulated coralline algae are associated with reef-complexes but are varied in their adaptability and, hence, are widely distributed in different parts of the complex. Abundant crustose coralline algae almost certainly indicate a reef-core sub-environment; their skeletons are among the chief constructional units of the core. They increase in abundance towards the outer edge of the reef core and decrease away from it.     

Molecular biology of Ri-plasmid—A review

Agrobacterium rhizogenes transfers a segment of its plasmid to the plant genome. The transferred DNA contains genes which are involved in the synthesis of plant hormones. These genes express in the plant cell and give rise to rooty-tumors at the infection site. Transgenic plants can be readily regenerated from the rooty-tumors and the transferred DNA is transmitted to progeny plants. High regeneration potential and sustained maintenance of transferred DNA makes the bacterium a suitable vector for plant genetic engineering. DNA sequences homologous to the transferred DNA ofAgrobacterium rhizogenes were detected in some untransformed plant species suggesting a past infection byAgrobacterium rhizogenes during evolution of some genera, notably Nicotiana.     

Nonspecific X-linked mental retardation—A review

Summary Mental retardation, in particular the X-linked type, has interested geneticists for many years. An increasing number of affected families have been to genetic counselling centres, and an effort is being made to find clinical and cytogenetic methods so a reliable diagnosis can be made. This would enable the detection of carriers and the opportunity to offer prenatal diagnosis. Many questions remain regarding X-linked mental retardation, its causes, diagnosis, and prevention. In this article we try to give an overview about the status of our present knowledge and the questions to be answered in the future.     

Analytical techniques for vancomycin—A review

Vancomycin belongs to the vancomycin-ristocetin family of glycopeptides, and is a subclass of linear sugar containing peptides composed of seven amino acids. Its stereochemical configuration forms the basis of a particular mode of action, though its complexation with the D-alanyl-D-alanine terminus of peptidoglycon monomer. The glycosylated hexapeptide chain consists of chloro-β-hydroxytyrosines, p-hydroxyphenylglycines, N-methylleucine and aspartic acid forms a rigid molecular frame work and gives the difficulty in the analysis. Vancomycin in the serum samples is usually estimated by liquid chromatography and the bacterial sensitivity was genereally tested by the microbiological assay. The present review deals with the qualitative, quantitative, microbiological and immunological assays and the comparison of the quantitative methods. Clinical implications of vancomycin have also been cited in the review.     

Composition and digestibility of untreated and chemically treated animal excreta for ruminants—A review

The paper reports on the crude nutrient content and the mineral profile, as well as the apparent digestibility by ruminants, of faeces of poultry, pigs and cattle, poultry litter and solid matter of poultry, pig and cattle slurries. The second part of the paper deals with chemical treatment of pig and cattle slurry solids with NaOH, KOH and urea.Nutrient and mineral content as well as digestibility of animal excreta are greatly influenced by species, age and type of feeding, the bedding material used and the method of solid-liquid separation of slurries.The digestibility of poultry excreta is higher than that of pig waste. Cattle faeces are unsuitable as feeds even after chemical treatment.In sacco degradability, apparent digestibility, energy content and intake of pig slurry solids were increased by treatment with urea, NaOH and KOH. Level of chemicals used and temperature influenced the effect of treatment. Wet pig-slurry solids may be preserved with urea.     

Toilet hygiene—review and research needs

The goal of good toilet hygiene is minimizing the potential for pathogen transmission. Control of odours is also socially important and believed to be a societal measure of cleanliness. Understanding the need for good cleaning and disinfecting is even more important today considering the potential spread of emerging pathogens such as SARS-CoV-2 virus. While the flush toilet was a major advancement in achieving these objectives, exposure to pathogens can occur from failure to clean and disinfect areas within a restroom, as well as poor hand hygiene. The build-up of biofilm within a toilet bowl/urinal including sink can result in the persistence of pathogens and odours. During flushing, pathogens can be ejected from the toilet bowl/urinal/sink and be transmitted by inhalation and contaminated fomites. Use of automatic toilet bowl cleaners can reduce the number of microorganisms ejected during a flush. Salmonella bacteria can colonize the underside of the rim of toilets and persist up to 50 days. Pathogenic enteric bacteria appear in greater numbers in the biofilm found in toilets than in the water. Source tracking of bacteria in homes has demonstrated that during cleaning enteric bacteria are transferred from the toilet to the bathroom sinks and that these same bacteria colonize cleaning tools used in the restroom. Quantitative microbial risk assessment has shown that significant risks exist from both aerosols and fomites in restrooms. Cleaning with soaps and detergents without the use of disinfectants in public restrooms may spread bacteria and viruses throughout the restroom. Odours in restrooms are largely controlled by ventilation and flushing volume in toilet/urinals. However, this results in increased energy and water usage. Contamination of both the air and surfaces in restrooms is well documented. Better quantification of the risks of infection are needed as this will help determine what interventions will minimize these risks.     

O2 sensitivity and H2 production activity of hydrogenases—A review

Hydrogenases are metalloproteins capable of catalyzing the interconversion between molecular hydrogen and protons and electrons. The iron–sulfur clusters within the enzyme enable rapid relay of electrons which are either consumed or generated at the active site. Their unparalleled catalytic efficiency has attracted attention, especially for potential use in H₂ production and/or fuel cell technologies. However, there are limitations to using hydrogenases, especially due to their high O₂ sensitivity. The subclass, called [FeFe] hydrogenases, are particularly more vulnerable to O₂ but proficient in H₂ production. In this review, we provide an overview of mechanistic and protein engineering studies focused on understanding and enhancing O₂ tolerance of the enzyme. The emphasis is on ongoing studies that attempt to overcome O₂ sensitivity of the enzyme while it catalyzes H₂ production in an aerobic environment. We also discuss pioneering attempts to utilize the enzyme in biological H₂ production and other industrial processes, as well as our own perspective on future applications.