Groundwater and soil contamination by LNAPL: State of the art and future challenges.

Contamination by Light Non-Aqueous Phase Liquids (LNAPL) represents a challenge due to the difficulties encountered in its underground assessment and recovery. The major risks arising from subsoil LNAPL accumulation face human health and environment, gaining a social relevance also in the frame of a continuously changing climate. This paper reports on a literature review about the underground contamination by LNAPL, with the aims of providing a categorization of the aspects involved in this topic, analyzing the current state of the art, underlying potential lacks and future perspectives. The review was focused on papers published in the 2012-2022 time-interval, in journals indexed in Scopus and WoS databases, by querying "LNAPL" within article title, abstract and/or key words. 245 papers were collected and classified according to three "key approaches" -namely laboratory activity, field based-data studies and mathematical simulations- and subordinate "key themes", so to allow summarizing and commenting the main aspects based on the application setting, content and scope. Results show that there is a wide experience on plume dynamics and evolution, detection and monitoring through direct and indirect surveys, oil recovery and natural attenuation processes. Few cues of innovations were found regarding both the use of new materials and/or specific field configuration for remediation, and the application of new techniques for plume detection. Some limitations were found in the common oversimplification of the polluted media in laboratory or mathematical models, where the contamination is set within homogeneous porous environments, and in the low number of studies focused on rock masses, where the discontinuous hydraulic behavior complicates the address and modeling of the issue. This paper represents a reference for a quick update on the addressed topic, along with a starting point to develop new ideas and cues for the advance in one of the greatest environmental banes of the current century.

Review: Exploration of placentation from human beings to ocean-living species.

This review covers four topics. 1) Placental pathology in Himalayan mountain people. To determine morphological changes of the placenta at high altitude, pathological examination was made of 1000 Himalayan placentas obtained in Nepal and Tibet and the results compared with Japanese placentas delivered at sea level. Characteristic findings in the placental villi of the Himalayan group included high incidences of villous chorangiosis and chorangioma. These processes were clarified by ultrastructural observation. 2) Placentation in Sirenians. The giant Takikawa sea cow, which lived 5 million years ago, was discovered on Hokkaido, Japan. It was an ancestor of the dugong as well as the manatees. Sirenia, the sea cow group, shares a common ancestor with Proboscidea, the elephants, even though they now inhabit quite different environments. A comparison was made of their zonary endothelial type of placentation. 3) Placentation in sharks and rays. The remarkable placentation of hammerhead sharks and manta rays is described. 4) Placentation in the Antarctic minke whale. Placental tissue samples of this whale were obtained from the Japan Institute of Cetacean Research. In an ultrastructural study of the utero-placental junction, microfilamental processes of the allantochorionic zone and crypt formation were visualized.

Characteristics of polyarthritis in rabbits by hyperimmunization with attenuated Enterococcus faecalis.

To produce polyarthritis and rheumatoid factor like substance (RFLS), rabbits were hyperimmunized intravenously with 0.02% thimelosal (TMS)-treated Enterococcus faecalis (E. faecalis) as a persistent bacterial flora. Swelling of knee joints occurred at a rate of 41% (27/66), and of shoulder joints at a rate of 25% (17/66) while that of elbow joints occurred at a rate of 4.5% (3/66). On culturing of knee joint fluids, no colonies appeared while 2/4 fluid specimens from the shoulder joints gave positive colonies for 78 days after the first immunization; thereafter, no colonies appeared. On histological examination, in early stages, acute inflammatory reactions with degenerative changes of synovial tissue was observed. In later stages, chronic inflammatory changes, proliferation of synovial cells with pannus formation, destruction of articular cartilage and subchondral bone were observed. RFLS titer showed bi-phasic peaks at 11 days and 41 days after the first immunization. A high incidence of polyarthritis, particularly knee joints, occurred. Thus, hyperimmunization with attenuated E. faecalis as a normal intestinal flora may provide an animal model of chronic polyarthritis.

Inhibitory effects of berberine-type alkaloids on elastase.

Berberine-type alkaloids and some structurally related alkaloids were tested for inhibitory activity on porcine pancreatic elastase (PPE) and human sputum elastase (HSE). The chlorides of berberine, coptisine, and sanguinarine significantly inhibited the elastolytic activity of both the enzymes, but tetrahydroberberine had no effect on the activity. It seems that the quaternary nitrogen of the alkaloids plays an important role in the inhibition of elastolytic activity. Amidolytic activity of the elastases was not affected by any of the alkaloids tested.

[Effects of experimental Listeria monocytogenes infection on mice fed on lamprey or sardine oil prepared under high-temperature deodorization].

Fresh lamprey (F-La) or sardine (F-Sa) oil is known to contain a large amount of n-3 polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. When F-La or F-Sa was deodorized with steam at 280 degrees C under 1 mmHg for 1 h (H-La and H-Sa, respectively), the contents of EPA and DHA were reduced and unidentified peaks were newly detected by gas-liquid chromatography. To know the biological influences of these high-temperature deodorized oils, the sterilizing function of the macrophage against Listeria monocytogenes was investigated in male ddY mice fed H-La or H-Sa. One week feeding of H-La or H-Sa lowered the LD50 values of the bacteria injected intravenously. Numbers of the viable bacteria on the day 3 after intravenous injection were about 10 times higher in the liver and 5 times higher in the spleen of mice fed H-La or H-Sa as compared with those of the control group. These results suggest that the sterilizing function of fixed macrophages both in the liver and the spleen was suppressed in mice fed H-La or H-Sa.

[Studies on collagenase inhibitors. IV. Inhibitors of bacterial collagenase in Coptidis rhizoma].

A hot aqueous extract of Coptidis Rhizoma had an inhibitory effect on the bacterial collagenase from Clostridium histolyticum. Active principles were isolated by silica gel column chromatography from the CHCl3 extract. Consequently, two inhibitors obtained were identified with the chloride of berberine and coptisine. The concentrations of the berberine and coptisine in the assay mixture to give 50% inhibition (IC50) were 0.73 mM and 0.16 mM, respectively. The type of inhibition by coptisine chloride was shown to be a mixture type from Lineweaver-Burk plots. Tetrahydroberberine, a reduction product of berberine chloride, had no inhibitory effect. This result suggests that the quaternary nitrogen of the alkaloids plays an important role in inhibitory activity.

[Studies on collagenase inhibitors. III. Inhibitory effects of anthracyclines on bacterial collagenase].

Inhibitory effects of anthracyclines on bacterial collagenase were examined. Daunomycin, doxorubicin, and aclarubicin potently inhibited the collagenase, but mitomycin C and 5-fluorouracil did not inhibit. Inhibitory activities of anthracyclines were constant regardless of the concentrations of Ca2+, activator of collagenase, or of Zn2+, active center of collagenase. These results suggest that the inhibitory mechanisms of anthracyclines were independent of a chelate effect on Ca2+ or Zn2+.

[Studies on collagenase inhibitors. II. Inhibitory effects of anthraquinones on bacterial collagenase].

The inhibitory activities of 44 anthraquinones against bacterial collagenase were assayed in vitro. Emodin (1,6,8-trihydroxy-3-methylanthraquinone, 41) was the most potent active inhibitor among them (IC50; 4.0 X 10(-5) M). The type of inhibition by 41 was found to be a mixture type by use of Lineweaver-Burk plots. Since the inhibitory activities of anthraquinones were not affected by the concentration of Ca2+ in the assay medium, it is considered that the inhibitory mechanism is not a chelate effect on Ca2+. In mono-substituted anthraquinones, the compounds which have a substituent (OH or SO3Na) at 2-position show more potent inhibitory activity than the corresponding 1-substituted compound.

[Effects of lamprey oil prepared under different deodorization conditions on serum lipids, reticuloendothelial system and antibody production in mice].

Fresh lamprey oil (F-La) is known to contain a large amount of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. When F-La was deodorized with steam at 280 degrees C and 1 mmHg for 1 h, the contents of EPA and DHA were reduced and unidentified peaks were detected by gas-liquid chromatography. In male ddY mice, one week feeding of the lamprey oil deodorized at 280 degrees C (H-La) remarkably decreased the serum triglyceride level and increased the liver weight 2.0-fold. H-La also lowered the corrected phagocytic index (alpha), which is an indicator of activities of reticuloendothelial system, but suppressed relatively little the antibody production against sheep red blood cells. It is suggested that H-La contains biologically active substances, which have potent hepatotoxic and serum triglyceride-reducing effects. This biologically active substances appear to be derived from long-chain polyunsaturated fatty acids under thermal deodorization conditions.

Protection of the rat myocardium from ischemic injury by dietary lamprey oil.

The lamprey (Entosphenus japonicus Martens) has been recommended in Japan as an efficacious diet for curing some of chronic inflammatory disorders. Fresh lamprey is rich in n-3 unsaturated fatty acids (e.g., eicosapentaenoic and docosahexaenoic acids) with minimal seasonal variation. The dietary effect of lamprey oil on acute myocardial ischemia was therefore investigated. Rats were fed a control diet or a diet supplemented with 5% safflower oil (SO) or 5% lamprey oil (LO) for 4 weeks. After coronary artery ligation, rats fed the LO diet demonstrated a higher 24-h survival rate and a reduced loss of creatine kinase activity from ischemic myocardium when compared with rats fed the control or SO diet. Moreover, the intracellular redistribution of lysosomal enzyme activity in the ischemic myocardium was significantly suppressed in the LO diet group. Analysis of the fatty acid composition of myocardial phospholipids in rats fed LO showed marked elevation of n-3 fatty acids, whereas arachidonic acid (n-6) content was significantly reduced. Hence, the n-3/n-6 ratio of myocardial phospholipids was markedly increased in the LO diet group. In addition, there was more than a 77% reduction in TXB2 synthetic capacity in whole blood in rats fed the LO diet when compared with rats fed either the control or SO diet. In conclusion, dietary supplementation with LO prevents sudden cardiac death and limits the extension of cellular damage from acute myocardial ischemia in rats. Both changes in thromboxane generation and altered membrane fatty acid composition may be involved in the observed reduction of ischemic damage in the heart.