Testing of Different Digestion Solutions on Tissue Samples and the Effects of Used Potassium Hydroxide Solution on Polystyrene Microspheres

Microplastic particles are ubiquitous in our environment, having entered the air, the water, the soil, and ultimately our food chain. Owing to their small size, these particles can potentially enter the bloodstream and accumulate in the organs. To detect microplastics using existing methods, they must first be isolated. The aim of this study was to develop a non-destructive method for efficiently and affordably isolating plastic particles. We investigated the digestion of kidney, lung, liver, and brain samples from pigs. Kidney samples were analyzed using light microscopy after incubation with proteinase K, pepsin/pancreatin, and 10% potassium hydroxide (KOH) solution. Various KOH:tissue ratios were employed for the digestion of lung, liver, and brain samples. Additionally, we examined the effect of 10% KOH solution on added polystyrene microplastics using scanning electron microscopy. Our findings revealed that a 10% KOH solution is the most suitable for dissolving diverse organ samples, while enzymatic methods require further refinement. Moreover, we demonstrated that commonly used 1 µm polystyrene particles remain unaffected by 10% KOH solution even after 76 h of incubation. Digestion by KOH offers a simple and cost-effective approach for processing organ samples and holds potential for isolating plastic particles from meat products.

Rapid decomposition of geological samples by ammonium bifluoride (NH4 HF2 ) for combined Hf-Nd-Sr isotope analyses

RATIONALE

Complete decomposition of silicate rock matrices is crucial in determining their isotopic compositions, but acid dissolution in a high-pressure steel-jacketed bomb, which has been the only powerful, effective technique thus far, is time-consuming and expensive. Rock dissolution using ammonium bifluoride (ABF), as described here, is a viable alternative.

METHODS

Geological reference materials (GRMs) were digested using ABF in closed Teflon beakers at temperatures of 220/230°C in a convection oven and subsequently treated with HNO₃ . Hf-Sr-Nd were separated and purified using ion-exchange chemistry columns calibrated for 50-2 mg samples. The isotopic compositions of Sr-Nd were measured by Thermal Ionization Mass Spectrometry, while that of Hf by Multi-Collector Inductively Coupled Plasma Mass Spectrometry, both with normal 10¹¹  Ω and gain calibrated 10¹³  Ω amplifiers.

RESULTS

Total procedural blanks of our protocol are 0.5 ng for Sr, 0.2 ng for Nd and <25 pg for Hf. Test runs with GRMs, ranging in composition from basic to felsic and dissolved in ABF, yield accurate ⁸⁷ Sr/⁸⁶ Sr, ¹⁴³ Nd/¹⁴⁴ Nd and ¹⁷⁶ Hf/¹⁷⁷ Hf isotope ratios as compared with those obtained with the bomb dissolution technique. Reproducibilities were comparable, on the order of 10-20 ppm. Our technique allows combined Hf-Sr-Nd isotope analyses of low-mass (50-2 mg) samples.

CONCLUSIONS

The ABF digestion is an alternative technique to high-pressure bomb dissolution in matrix decomposition for accurate and reproducible Hf-Nd-Sr isotope analyses of geological samples within a reasonable time (3-4 days), with high sample throughput and low costs in geochemistry and environmental sciences.

Organic derivatives of Mg(BH4)2 as precursors towards MgB2 and novel inorganic mixed-cation borohydrides

A series of organic derivatives of magnesium borohydride, including Mg(BH4)2·1.5DME (DME = 1,2-dimethoxyethane) and Mg(BH4)2·3THF (THF = tetrahydrofuran) solvates and three mixed-cation borohydrides, [Cat]2[Mg(BH4)4], [Cat] = [Me4N], [nBu4N], [Ph4P], have been characterized. The phosphonium derivative has been tested as a precursor for synthesis of inorganic mixed-metal borohydrides of magnesium, Mx[Mg(BH4)2+x], M = Li-Cs, via a metathetic method. The synthetic procedure has yielded two new derivatives of heavier alkali metals M3Mg(BH4)5 (M = Rb, Cs) mixed with amorphous Mg(BH4)2. Thermal decomposition has been studied for both the organic and inorganic magnesium borohydride derivatives. Amorphous MgB2 has been detected among the products of the thermal decomposition of the solvates studied, together with organic and inorganic impurities.

Salts of highly fluorinated weakly coordinating anions as versatile precursors towards hydrogen storage materials

We report the most recent results related to application of a metathetic pathway towards mixed-metal borohydrides. The synthetic protocol utilizes highly-fluorinated weakly coordinating anion salts as precursors. We discuss the technicalities related to the use of fluorine-rich anions as well as the improvements which are still needed to deliver high-purity materials with potential applications for hydrogen storage. The applicability of the method is expanded beyond the previously described complex borohydrides of alkali metal Zn or Y, towards the systems containing Mg(II), Sc(III), Mn(II), or Eu(III). We have prepared for the first time [Ph4P]2[Mn(BH4)4] and [Me4N]2[Mg(BH4)4], solved their crystal structures from powder x-ray diffraction, and used selected organic metal borohydride derivatives as precursors towards mixed-metal borohydrides (K2Mn(BH4)4, Rb3Mg(BH4)5, etc.). We have also prepared [Ph4P][Eu(BH4)4], which is the first derivative of Eu(III) in the homoleptic environment of borohydride anions.

Rb/Sr isotopic and compositional retentivity of muscovite during deformation

Permian metapegmatite muscovite from the Upper-Austroalpine Matsch Unit in Southern Tyrol (Italy) was investigated regarding its Rb/Sr and compositional retentivity during Cretaceous Upper-greenschist facies deformation. The data imply that microstructurally relic Permian magmatic muscovite largely maintained its major and trace element compositions during deformation, whereas the Rb/Sr geochronometer is strongly affected by a net loss of Sr. Lower Sr concentrations of muscovite correlate with higher ⁸⁷Rb/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios. In most samples, the muscovite grain size- and magnetic-fractions with the lowest ⁸⁷Rb/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios preserve a Permo-Triassic muscovite-whole rock Rb/Sr apparent age interpreted as to reflect formation during or cooling after pegmatite emplacement. Contrastingly, muscovite fractions with higher ⁸⁷Rb/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios are arranged along a roughly linear array with a positive correlation of the ⁸⁷Rb/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios in the ⁸⁷Rb/⁸⁶Sr vs ⁸⁷Sr/⁸⁶Sr space. They yield successively lower muscovite-whole rock Rb/Sr apparent ages. We explain the variations in the Rb/Sr isotopic character of microstructurally relic muscovite by a, presumably deformation-related, loss of Sr during the Cretaceous event. Contemporaneously, only very limited amounts of isotopically different Sr from the matrix reservoir might possibly have entered the muscovite. Consequently, the Rb/Sr of the relic muscovite is affected by a net loss of Sr. The results imply that at temperatures of < 500 °C, deformation is supposed to be the predominant factor in controlling the Rb/Sr geochronometer of relic muscovite, by significantly reducing the characteristic length scale for volume diffusion. However, variations of the major and trace element compositions within Permian relic muscovite are interpreted to rather reflect primary compositional instead of deformation-related variations.

Expression of a mutated form of the p85alpha regulatory subunit of phosphatidylinositol 3-kinase in a Hodgkin's lymphoma-derived cell line (CO)

Phosphatidylinositol (PI) 3-kinase plays an important role in a variety of biological processes, including proliferation and apoptosis. PI3-kinase is a heterodimer consisting of an 85 kDa adapter protein (p85) containing one SH3 domain and two SH2 domains and a 110 kDa catalytic subunit (p110). Recently an oncogenic form of p85 named p65-PI3K lacking the C-terminal SH2 domain has been cloned from an irradiation-induced murine thymic lymphoma and transgenic mice expressing p65-PI3K in T lymphocytes develop a lymphoproliferative disorder. Here we describe the cloning of a C-terminal truncated form of p85 expressed in a human lymphoma cell line (CO) with a T cell phenotype derived from a patient with Hodgkin's disease. As a result of a frame-shift mutation at amino acid 636, p76 is lacking most of the C-terminal SH2 domain, but contains the inter-SH2 domain and is associated with an active form of PI3-kinase. A PI3-kinase-dependent constitutive activation of Akt was detected in CO cells which was only partially reduced after serum starvation. Treatment of CO cells with the PI3-kinase inhibitor wortmannin resulted in a concentration-dependent inhibition of cell proliferation associated with an increased number of apoptotic cells. This is the first detection of a mutated form of the p85 subunit of PI3-kinase in human hematopoietic cells further underlining a potential role of PI3-kinase/Akt signaling in human leukemogenesis.

[Problematic aspects of breeding dwarf rabbits]

Some aspects of relevance for animal protection in breeding dwarf (pet) rabbits are enumerated and discussed. The predisposition of these standard dwarfs (Dw/dw) for certain defects and diseases underlines the partial dominance of Dw; mating of these heterozygous dwarfs is an open neglect of the German animal protection law (section 11b). For feasibility of control breeders (and especially so in commercial pet rabbitries) should be obliged to guarantee unambiguous identification of breeding animals and their progeny.

Pathophysiological and functional aspects of the megacolon-syndrome of homozygous spotted rabbits

The Megacolon-Syndrome is a hereditary disease of homozygous spotted rabbits (En En). Investigations have been performed on some special traits related to functional aspects of the gut in comparison to vital heterozygous spotted rabbits (En en). It was found that En En rabbits showed significantly reduced sodium absorption rates across the wall of the cecum. Consequently, the dry matter content of the ingesta was reduced at this location, whereas the content of the ashes was increased. These results indicate that a further important pathogenetic aspect of this hereditary disease is an undue liquification of ingesta in proximal parts of the large intestine. Severe clinical problems, however, resulted from obstipation. This is concluded to be a late complication due to and modified by different stressors of endogenic and exogenic origin. Thus, there are some indications that an early site of spot-gene related effects might be the small intestine. This segment of the bowel was shorter and had an increased dry matter proportion of its wall when compared with heterozygous spotted rabbits. But a decreased proportion of dry matter within the wall of the large intestine was found. The latter could be an effect of the hypothyreotic state of metabolism in En En rabbits.

[The problems of spotted breeds of rabbits. 4. Morpho- and histometric findings in the CNS and thyroid glands and the hormone content in blood at slaughter of hybrid rabbits, and estimation of the heterosis effect]

Morpho- und histometric investigations of brains, pituitary and thyroid glands as well as thyroid-related functional parameters in the blood of purebred and hybrid rabbits revealed a predisposition to hypothyreotic conditions in homozygous, megacolon-prone genotypes. In addition to this also a hypoganglionotic state in different gut wall localizations was confirmed; pituitary traits however did not indicate a primary contribution of this gland to the syndrome, though some alterations were found, which are interpreted as secondary sv. symptomatic. Gender influences varied hormonal characteristics and disease manifestations too: A dramatic fall in severely diseased does with respect to T3-concentration as well as a seemingly more inactive thyroid gland compared to bucks underline hormonal influences. As a consequence of these results it is concluded, that hybridisation within spotted rabbits does not amend the inclination to megacolon in animals homozygous for the K (En) gene, though it may influence its manifestation.

[Reflections on 100 years of animal breeding as mirrored in the Deutsche Tierärztliche Wochenschrift]

In 1893 a major component of veterinary practice derived from 4 million horses and from farm animals, whereas thousands of dogs were even slaughtered every year, especially in Saxony and Silesia. Nowadays companion animals figure as an element of ever growing importance for the practitioner. Teaching and research adapted themselves to this altered situation, research funding and professional politics not yet so completely. In former days veterinarians even presided the licensing committees for breeder animals--today the animal breeding act merely mentions them in connection with institutions of AI and ET. Misdevelopments during the Nazi period are discussed as possible causes. In analogy to refugee problems after World War II, in this decade crowding effects again challenge the profession, resulting from increasing numbers of students and European migrations.

[The problems of breeding spotted rabbits. 3. Variability of the pigmentation grade, ganglionic intestinal wall supply, relationship to pathogenesis--animal breeding and animal welfare aspects]

In a total of 128 animals of the German Giant Spot und the English Spot Breed grade of pigmentation and spotting pattern were investigated by photography and planimetry. A clear cut binary distribution, representing homozygous (KK) or heterozygous spot rabbits (Kk), and a strong bilateral concordance was found as well as a broad variance within both genotypical groups. Thus only a small percentage of animals bred can be compatible with mandatory fancy breed standards. Measurements of intestinal layers and neural components in well pigmented and depigmented individuals revealed an enhancement of these histological structures but a relative hypoganglionosis in distal parts of the gut in animals with predisposition to megacolon (KK, so-called chaplins). It is not yet clear whether this is symptomatic or of primary pathogenetic relevance. There were no pleiotropic deleterious effects of the K-allele in heterozygous rabbits and no correlations between the degree of depigmentation and the severity of symptoms in homozygous spotted ones, thus indicating a mode of inheritance by an incompletely dominant gene K, acting as or being linked to a recessive semilethal when homozygous. A change in breeders' attitude and breeding practices is mandatory because neither the permanent elimination of animals not "fitting" a fancy standard nor the continuous production of defective genotypes is legal.

Immunomodulatory activity of different blood products on the mitogen-induced human lymphocyte transformation

Blood transfusions have an immunosuppressive effect on the recipient and induce changes in several immunological parameters. We studied the effect of homologous and autologous fresh plasma (FP), fresh frozen plasma (FFP), heparinized plasma, as well as the influence of red blood cells (RBC), CPDA-1, CPD, heparin, PAGGS-mannitol, SAG-mannitol and ADSOL on mitogen-induced lymphocyte transformation. Both homologous and autologous FP and FFP decreased the PHA and ConA response of human lymphocytes (P < 0.05). The PWM response was reduced by FP (P < 0.05). The mean t1/2 of plasma-induced suppression was approximately 38 h. Dose-dependent suppression rates were observed with pure CPDA-1 and CPD solutions. In contrast, heparinized plasma showed an elevated PHA- and ConA-induced transformation rate (P < 0.025), whereas PWM induction was unaffected. In addition, washed RBC, pure PAGGS-M, SAG-M and ADSOL solutions revealed no effect on the PHA response. Freezing, heating or recalcification of plasma resulted in an increase in the PHA response. Adenine was not immunosuppressive in vitro. We conclude that, in addition to unspecific mechanisms by CPDA-1 or CPD, an unknown plasma factor, which is susceptible to changes in temperature or storage conditions, suppresses the PHA-, PWM- or ConA-induced T-cell immune response. Further clinical studies are needed to correlate these observations with clinical phenomena.

[The problem of breeding for spots in rabbits. 2. Further results on the variation of characteristics in fattening and breeding animals]

The mode of inheritance of spotting in both breeds (ES and DRS) is compatible with incompletely dominant resp. intermediate segregation, though a broad variability of spotted areas exists, indicating the influence of minor genes or other ontogenetic factors. Additional findings support the conclusion, that there is a very distinct predisposition of homozygous KK animals to develop megacolon with growing age. This also has consequences for the relative organ weight of the heart and of the adrenals in this genotype. Sporadically encountered accessory adrenal cortical tissue however did not exhibit genotypic preferences.

[The problems of spotted breeds of rabbits. 1. Fattening and body condition at slaughter, organ parameters]

Rabbits of the Giant German Spot Breed and of the English Spot Breed were bred, reared, fattened and evaluated under standardized conditions. A total of 50 animals (31 German spot = DRS; 19 English spot = ES; both derived from mating of heterozygotes) was tested, belonging to the three possible genotypes: Homozygous black (kk), heterozygous spotted (Kk, "standard animals") and homozygous spotted (KK, so-called "Chaplins"). As expected, breed differences consisted of better daily gains and higher carcass weights in DRS, but higher dressing percentages in ES. With respect to colour genotypes, only in DRS-KK depressions of daily gains and carcass weight were observed; food conversion efficiency however was even better in these animals (of both breeds), primarily because of lower feed uptake. Very distinct differences in some important organ traits could be demonstrated for those genotypes: A significantly augmented intestine (abs. and rel.) in KK-animals, specially with reference to the gross intestine--indicating a tendency to motility disturbances and/or chronic obstipation. This predisposition was underlined by the premature loss of three KK-rabbits suffering from severe corresponding symptoms. Seemingly analogous syndromes (Megacolon) in man and other species are cited, though further investigations are needed to clarify the etiology in spot rabbits. Significance of lower heart weights was stated in DRS-KK-animals, probably induced by minor activities observed in this genotype. Thus the K-gene can be classified as a subvital one when homozygous though manifestations of the symptoms obviously vary with the genetic background (breed, line) and perhaps with the environment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Raising fighting dogs]

Some experience is reported, referring to court trials of accidents involving members of the so-called "fighting dog" breeds. Analysis of the situation makes obvious that many breeders and owners of these or similar dogs demonstrate an irresponsible attitude, thereby fostering breed standards which should be corrected. A future solution of this problem and of others could only be brought about by a law, which would regulate companion animal breeding and ownership. A ban on special breeds or their integration into a "Dangerous animals act" seems for now to be feasible for breeds only which are explicitly standard-bred for aggressiveness against man. Responsible dog breeding and ownership is postulated in order to avoid a growing aversion against dogs in society, which certainly contributed to the stagnation of the dog population in the FRG during the last years.

[Eye changes in the merle syndrome in the dog (author's transl)]

In 44 dachshunds of both sexes, reared and held under identical conditions in order to investigate the effects of the merle gene, ophthalmologic examinations were performed. Eleven extreme dapples with a cutaneous depigmentation beyond 50% (homozygous merle animals, MM) exhibited severe defects in variable forms: Microphthalmia and microcornea, microcoria and corectopia, cataracts and colobomas, rudimentary lenses and ectasia of episcleral vessels. In heterozygous merles with a white percentage of coat color beneath 50% (Mm), lacking tapetum lucidum, depigmented retina, papillary anomaly and ectasia of episcleral vessels were stated, as well as in MM-animals, though not in all. These findings are interpreted as obvious gene dosis effects of the incompletely dominant merle gene which is used to produce a characteric harlequin dappling in many breeds of dogs. With the exception of ectasia of episcleral vessels in a few animals, the homozygous well pigmented controls (mm) displayed none of the anomalies mentioned. The meaning of these results for comparactive medicine and animal protection is discussed.

Bone scanning and diagnosis of reflex sympathetic dystrophy secondary to herniated lumbar disks

In two cases, reflex sympathetic dystrophy (RSD) was due to herniated intervertebral disk at L4-5. In both cases, bone scanning with technetium 99m pyrophosphate was of value and its use is recommended in diagnosing mild or early cases of RSD. RSD may be the cause of persisting pain after disk surgery.

[Some mechanical properties of the pig aorta (author's transl)]

In a machine for tensile tests the ultimate strength, stress and strain of the aorta ascendens of 47 female pigs (German landrace) at three different regions of the vessel wall were determined. The animals were fattened under identical conditions in a progeny testing station and slaughtered at the same living weight (102 +/- 2 kg). Weak regressions of body weight and age on parameters measured were nevertheless accounted for. The average elastin content of the aorta ascendens diminished with advancing age but was not significantly correlated to biomechanical properties of the three single samples. Maximum load, stress and modulus of vessel wall segment I (stamped out nearer to the heart) was greater than in sample II. These circumferential segments however exhibited highly stronger biomechanical resistance than sample III, which was stamped longitudinally. In samples I and II there was a negative correlation between thickness of the wall and ultimate tensile stress (N/mm2). Freezing of the material prior to test at -18degrees C for one week resulted in a significant rise in ultimate tensile strength and stress. The meaning of these findings for comparative angiology is discussed.

[The exogenous and genetic components of some vessel wall characteristics in the pig (author's transl)]

Insufficiencies of the circulatory system and increasing transport losses in pigs as well as analogies with respect to atherosclerosis of men and swine were the motives for a broad statistical investigation of important characteristics of the circulatory system in a big population of female German landrace pigs, fattened as progeny groups under identical conditions in a testing station and slaughtered at 100 kg weight. As the most essential results, highly significant seasonal and genetical influences on several traits are to be mentioned, and some meaningful correlations between them: Plasma cholesterol, ceruloplasmin and hematocrit showed markedly lower levels in the summer and increased values in the cold season; the thickness of the intima (aorta and arteria pulmonalis) was quite distinctly greatest in the spring, this phenomenon being almost exactly paralleled by augmented amounts of copper and iron in the aortic wall. Increased heart weights were again found in the cold, decreased ones in the warm seasons. On average, bigger hearts and vessels were accompanied by higher elastin contents of the aorta, but these contents stood in very significant negative correlation to the ash content and the amounts of certain mineral components (Ca, Mg and P) of the vessel wall, especially to the ash percentage of the elastic fibers. This indicates that calcifying and mineralizing processes in the wall obviously take place at the cost of the elastic components. The estimation of heritabilities in half and full sibs revealed with h2 = 60% high henetic influences on the elastin content of the aorta and equally so on the ash percentage of elastic fibers. Future investigations must correlate these findings with direct measurements of biomechanical and rheological properties of the vessels.