STUDIES OF GAS AND ELECTROLYTE EQUILIBRIA IN THE BLOOD : IX. THE DISTRIBUTION OF ELECTROLYTES BETWEEN TRANSUDATES AND SERUM.

1. Analyses have been made of the electrolytes and proteins of serum and transudates from human subjects. 2. The distribution ratios of HCO₃, Cl, Na, and H⁺ deviated from unity as predicted by the Gibbs-Donnan law for similar heterogeneous systems. 3. Analyses of serum, and of artificial salt solutions approximating edema fluid in composition, after equilibration across collodion membranes showed distributions similar to those between serum and edema fluid in vivo.     

Plasma proteins present in osteoarthritic synovial fluid can stimulate cytokine production via Toll-like receptor 4

Introduction

Osteoarthritis (OA) is a degenerative disease characterized by cartilage breakdown in the synovial joints. The presence of low-grade inflammation in OA joints is receiving increasing attention, with synovitis shown to be present even in the early stages of the disease. How the synovial inflammation arises is unclear, but proteins in the synovial fluid of affected joints could conceivably contribute. We therefore surveyed the proteins present in OA synovial fluid and assessed their immunostimulatory properties.

Methods

We used mass spectrometry to survey the proteins present in the synovial fluid of patients with knee OA. We used a multiplex bead-based immunoassay to measure levels of inflammatory cytokines in serum and synovial fluid from patients with knee OA and from patients with rheumatoid arthritis (RA), as well as in sera from healthy individuals. Significant differences in cytokine levels between groups were determined by significance analysis of microarrays, and relations were determined by unsupervised hierarchic clustering. To assess the immunostimulatory properties of a subset of the identified proteins, we tested the proteins' ability to induce the production of inflammatory cytokines by macrophages. For proteins found to be stimulatory, the macrophage stimulation assays were repeated by using Toll-like receptor 4 (TLR4)-deficient macrophages.

Results

We identified 108 proteins in OA synovial fluid, including plasma proteins, serine protease inhibitors, proteins indicative of cartilage turnover, and proteins involved in inflammation and immunity. Multiplex cytokine analysis revealed that levels of several inflammatory cytokines were significantly higher in OA sera than in normal sera, and levels of inflammatory cytokines in synovial fluid and serum were, as expected, higher in RA samples than in OA samples. As much as 36% of the proteins identified in OA synovial fluid were plasma proteins. Testing a subset of these plasma proteins in macrophage stimulation assays, we found that Gc-globulin, α₁-microglobulin, and α₂-macroglobulin can signal via TLR4 to induce macrophage production of inflammatory cytokines implicated in OA.

Conclusions

Our findings suggest that plasma proteins present in OA synovial fluid, whether through exudation from plasma or production by synovial tissues, could contribute to low-grade inflammation in OA by functioning as so-called damage-associated molecular patterns in the synovial joint.     

羊水栓塞妊娠大鼠血清中PLA2和PAF的水平变化研究

摘要 目的：探讨羊水栓塞妊娠大鼠血清中PLA2和PAF的水平变化。方法：30只健康妊娠大鼠均分为生理盐水组（A组）、羊水组（B组）及羊水胎粪混合组（C组）。将健康妊娠大鼠麻醉,麻醉效果生成后,全部切除大鼠子宫后关腹,分离出左颈总动脉,并将二通道生理记录仪与其连接,连续监测血液动力学指标,随后将生理盐水、羊水和羊水胎粪混合液腹腔静脉注射于大鼠,1小时后取大鼠肺组织,用HE、APK染色结合CK16免疫组织化学法来检测模型是否制作成功。实验前后1小时两个取血点时,在制备好的羊水栓塞模型大鼠左颈动脉插管处各取1 mL血。采取酶联免疫检测法,测定血清、羊水及羊水胎粪混合液中 PLA2、PAF 的含量。获得的数据用SPSS 20.0软件进行处理,采用配对 t 检验、协方差分析及相关回归分析对血清PLA2、PAF 的浓度进行分析。结果：B组和C组的3个血液动力学指标（动脉收缩压、舒张压及平均动脉压）均显著低于A组（P<0.05）,而B组与C组的4个血液动力学指标均无显著性差异（P>0.05）。同时,A组、B组与C组之间在心率改变方面无显著性差异（P>0.05）。HE染色中,B组与C组大鼠的肺间质显著变宽,且有充血、水肿及炎性细胞浸润,而A组无此现象。AMP染色中,B组和C组大鼠的肺小管中可见被染成蓝色的不定形物质和桃红色的角化鳞状上皮,而A组无此现象。CK16染色中,B组和C组大鼠的肺小管中,可以看到被染成黄色的颗粒和鳞状上皮,而A组无此现象。实验1小时后所取血液中,B组和C组的PLA2与PAF的含量显著高于A组（P<0.05）,且C组中升高程度更大。妊娠大鼠羊水与羊水胎粪混合液中均检测到PLA2和PAF,且羊水胎粪混合液中二者的含量均高。实验1小时前所取的血液中,PLA2和PAF浓度无相关性（P=0.762,R=0.012）,而实验1小时后所取血液中,PLA2和PAF浓度呈正相关关系（P=0.002,R=0.437）。结论：羊水栓塞妊娠模型大鼠羊水和胎粪中均有PLA2和PAF,且实验1小时后所取血液中,PLA2和PAF含量在B组和C组中显著高于A组,说明羊水和胎粪中含有使PLA2、PAF水平增高的刺激因子。     

Metabolite and ionic composition of follicular fluid from different-sized follicles and their relationship to serum concentrations in dairy cows

Metabolic changes in blood serum may be reflected in the biochemical composition of follicular fluid and could indirectly influence oocyte quality. The purpose of this study was to examine the biochemical composition of follicular fluid harvested from different-sized follicles and its relationship with that of blood serum in dairy cattle. Following slaughter, blood samples were collected from dairy cows (n=30) and follicular fluid aspirated from three size classes of non-atretic follicles (<4 mm, 6–8 mm and >10 mm diameter). Samples remained independent between cows and between size classes within cows. Serum and follicular fluid samples were assayed using commercial clinical and photometric chemistry assays for ions (sodium, potassium and chloride) and metabolites (glucose, β-hydroxybutyrate (β-OHB), lactate, urea, total protein, triglycerides, non-esterified fatty acids (NEFA) and total cholesterol). Results showed that follicular fluid concentrations of glucose, β-OHB and total cholesterol increased from small to large follicles and decreased for potassium, chloride, lactate, urea and triglycerides. There was a significant concentration gradient for all variables between their levels in serum and follicular fluid (P<0.05). Significant correlations were observed for chloride (r=0.40), glucose (r=0.56), β-OHB (r=0.85), urea (r=0.95) and total protein (r=0.60) for all three follicle size classes and for triglycerides (r=0.43), NEFA (r=0.50) and total cholesterol (r=0.42) for large follicles (P<0.05). The results from the present study suggest that the oocyte and the granulosa cells of dairy cows grow and mature in a biochemical environment that changes from small to large follicles. Furthermore, the significant correlation between the composition of serum and follicular fluid for the above-mentioned metabolites suggests that metabolic changes in serum levels will be reflected in the follicular fluid and, therefore, may affect the quality of both the oocyte and the granulosa cells.     

Separation and assay of lysins and lysin-inhibitor complexes in blood and tissues

1. A process of extraction and assay, which combines the features of several existing methods, is described for the lytic materials which can be obtained from blood, plasma, serum, and tissues. At least two alcohol-soluble substances, one ether-soluble ("soap-like") and the other insoluble in ether in the cold ("lysolecithin-like"), can be obtained from preincubated blood, plasma, or serum. The hemolytic activity (or concentration) of the soap-like lysin obtained from blood is greater than that of the lysolecithin-like substance, but for plasma and serum the reverse is true, i.e. the red cells are involved in the production of the soap-like lysin, and probably supply some of it when acted upon by enzymes contained in plasma and serum. Preincubation of the blood or plasma increases the yield of lysin two- or threefold, and small quantities of both soap-like and lysolecithin-like lysins can be obtained from unpreincubated blood or plasma. 2. The soap-like lysins obtained from preincubated mouse liver are some 5 to 15 times as active as, or occur in some 5 to 15 times the concentration of, those obtained from blood or plasma. The lysolecithin-like lysins of preincubated liver are about twice as active as, or occur in about twice as great concentration of, those obtained from blood. Because of the shape of the time-dilution curve for these lysins, the relations between their activities, or concentrations, are often quite different from those which one would anticipate if one were to consider only the times required for the production of hemolysis. 3. Paper chromatography can be used to separate the soap-like and the lysolecithin-like lysins obtainable from small quantities of preincubated mouse liver homogenates or preincubated mouse blood. The presence of lysins is detected by their effect on the red cells of a suspension as it wets the paper. Various technical procedures for separating lytic components and for demonstrating that they move on the paper along with protein components are described. 4. Paper strip electrophoresis can be used to show that the supernatant fluid of a preincubated mouse liver homogenate contains at least two protein components and at least two lytic components, not very closely associated in their electrophoretic behavior. 5. Observations on the physical nature of the alcohol- and ether-soluble lysin point to its having a soap-like character. Its activity, as well as that of the lysolecithin-like lysin, is inhibited by cholesterol, by lecithin, and by various fractions of serum. Some of these effects have been studied quantitatively. The most inhibitory of the protein fractions are those which contain lipoproteins; i.e., II + III and IV + V.     

Determination of causes of death via spectrochemical analysis of forensic autopsies‐based pulmonary edema fluid samples with deep learning algorithm

This study investigated whether infrared spectroscopy combined with a deep learning algorithm could be a useful tool for determining causes of death by analyzing pulmonary edema fluid from forensic autopsies. A newly designed convolutional neural network‐based deep learning framework, named DeepIR and eight popular machine learning algorithms, were used to construct classifiers. The prediction performances of these classifiers demonstrated that DeepIR outperformed the machine learning algorithms in establishing classifiers to determine the causes of death. Moreover, DeepIR was generally less dependent on preprocessing procedures than were the machine learning algorithms; it provided the validation accuracy with a narrow range from 0.9661 to 0.9856 and the test accuracy ranging from 0.8774 to 0.9167 on the raw pulmonary edema fluid spectral dataset and the nine preprocessing protocol‐based datasets in our study. In conclusion, this study demonstrates that the deep learning‐equipped Fourier transform infrared spectroscopy technique has the potential to be an effective aid for determining causes of death.     

The dual role of the cystathionine γ-lyase/hydrogen sulfide pathway in CVB3-induced myocarditis in mice

The present study found that serum H₂S level, H₂S production rate, CSE mRNA and CSE protein levels were increased in CVB3-induced myocarditis. dl-proparglygylcine (PAG), an irreversible CSE inhibitor, decreased the infected myocardium titers on postinfection day 4, while NaHS, a H₂S donor, alleviated myocardial injury and necrosis, inflammatory cell infiltration and interstitial edema on postinfection day 10. These data reveal that the CSE/H₂S pathway is upregulated in the heart in a murine model of CVB3-induced myocarditis and that inhibition of endogenous H₂S is beneficial to treatment early in the disease while administration of exogenous H₂S is protective to infected myocardium during the later stage.     

Simultaneous detection of cerebral blood perfusion and cerebral edema using swept‐source optical coherence tomography

The progression of ischemic cerebral edema (CE) is closely related to the level of cerebral blood perfusion (CBP) and affects each other. Simultaneous detection of CBP and CE is helpful in understanding the mechanisms of ischemic CE development. In this article, a wide field of view swept‐source optical coherence tomography system was used to detect CE status and CBP levels simultaneously in middle cerebral artery occlusion rats. Images reflecting these two physiological states can be reconstructed with only one C‐scan. We quantify these two physiological states into four parameters, which contain two vascular parameters (vascular displacement distance and vascular perfusion density) and two edema parameters (optical attenuation coefficient and edema area). The association between the two vascular parameters and the two edema parameters was analyzed. The results show that there is a strong linear relationship between blood flow parameters and edema parameters. This work provides a new option for CE in vivo detection, and is very likely to play an important role in the development of relevant drugs or in selection of treatment options.      

Trends in speciation analysis of some heavy metals in serum of patients with chronic hepatitis C and chronic hepatitis B using differential pulse adsorptive stripping voltammetric measurement and atomic absorption spectrophotometry

The relationships between chronic liver diseases and trace heavy metal contents in blood are debatable and have not been understood clearly. The present study is undertaken to determine Co, Fe, and Ni concentrations in sera from viral hepatitis patients. In all eighty patients with chronic hepatitis (B, C) and 29 healthy individuals were chosen for this study. Donors were selected from different environmental areas, including Aswan, Kom Ombo, and Edfu as polluted areas, and Daraw as an unpolluted area. Co, Fe, and Ni concentrations in patient and healthy blood serum were measured by two different analytical techniques: differential pulse adsorptive stripping voltammetry (DPA_dSV) and atomic absorption spectrophotometer (AAS). The results reveal that Fe is present in higher level in the blood serum of hepatitis patients than in the healthy control, whereas Co and Ni showed the opposite trend. Hepatitis patients from Edfu area exhibited higher Fe level in their serum than those from the other areas, while hepatitis patients and healthy control from Daraw area (free from pollution) exhibited the lowest metal values. Patients with hepatitis C show lower levels of Co, Ni, and Fe in their serum than those with hepatitis B. A comparative study was carried out between the results using DPA_dSV and AAS techniques, which are in very good agreements.     

Changes in the mechanical properties of the respiratory system during the development of interstitial lung edema

Background

Pulmonary edema induces changes in airway and lung tissues mechanical properties that can be measured by low-frequency forced oscillation technique (FOT). It is preceded by interstitial edema which is characterized by the accumulation of extravascular fluid in the interstitial space of the air-blood barrier. Our aim was to investigate the impact of the early stages of the development of interstitial edema on the mechanical properties of the respiratory system.

Methods

We studied 17 paralysed and mechanically ventilated closed-chest rats (325–375 g). Total input respiratory system impedance (Zrs) was derived from tracheal flow and pressure signals by applying forced oscillations with frequency components from 0.16 to 18.44 Hz distributed in two forcing signals. In 8 animals interstitial lung edema was induced by intravenous infusion of saline solution (0.75 ml/kg/min) for 4 hours; 9 control animals were studied with the same protocol but without infusion. Zrs was measured at the beginning and every 15 min until the end of the experiment.

Results

In the treated group the lung wet-to-dry weight ratio increased from 4.3 ± 0.72 to 5.23 ± 0.59, with no histological signs of alveolar flooding. Resistance (Rrs) increased in both groups over time, but to a greater extent in the treated group. Reactance (Xrs) did not change in the control group, while it decreased significantly at all frequencies but one in the treated. Significant changes in Rrs and Xrs were observed starting after ~135 min from the beginning of the infusion. By applying a constant phase model to partition airways and tissue mechanical properties, we observed a mild increase in airways resistance in both groups. A greater and significant increase in tissue damping (from 603.5 ± 100.3 to 714.5 ± 81.9 cmH₂O/L) and elastance (from 4160.2 ± 462.6 to 5018.2 ± 622.5 cmH₂O/L) was found only in the treated group.

Conclusion

These results suggest that interstitial edema has a small but significant impact on the mechanical features of lung tissues and that these changes begin at very early stages, before the beginning of accumulation of extravascular fluid into the alveoli.     

Distribution of Dengue Virus Types 1 and 4 in Blood Components from Infected Blood Donors from Puerto Rico

Background

Dengue is a mosquito-borne viral disease caused by the four dengue viruses (DENV-1 to 4) that can also be transmitted by blood transfusion and organ transplantation. The distribution of DENV in the components of blood from infected donors is poorly understood.

Methods

We used an in-house TaqMan qRT-PCR assay to test residual samples of plasma, cellular components of whole blood (CCWB), serum and clot specimens from the same collection from blood donors who were DENV-RNA-reactive in a parallel blood safety study. To assess whether DENV RNA detected by TaqMan was associated with infectious virus, DENV infectivity in available samples was determined by culture in mosquito cells.

Results

DENV RNA was detected by TaqMan in all tested blood components, albeit more consistently in the cellular components; 78.8% of CCWB, 73.3% of clots, 86.7% of sera and 41.8% of plasma samples. DENV-1 was detected in 48 plasma and 97 CCWB samples while DENV-4 was detected in 21 plasma and 31 CCWB samples. In mosquito cell cultures, 29/111 (26.1%) plasma and 32/97 (32.7%) CCWB samples were infectious. A subset of samples from 29 donors was separately analyzed to compare DENV viral loads in the available blood components. DENV viral loads did not differ significantly between components and ranged from 3–8 log₁₀ PCR-detectable units/ml.

Conclusions

DENV was present in all tested components from most donors, and viral RNA was not preferentially distributed in any of the tested components. Infectious DENV was also present in similar proportions in cultured plasma, clot and CCWB samples, indicating that these components may serve as a resource when sample sizes are limited. However, these results suggest that the sensitivity of the nucleic acid tests (NAT) for these viruses would not be improved by testing whole blood or components other than plasma.     

Dose response relation of the renal effects of PGA1, PGE2, and PGF2α in dogs

The effects of the three prostaglandins A₁, E₂, and F_2α on renal blood flow, glomerular filtration rate (GFR), fluid excretion, and urinary output of Na, K, Ca, Cl, and solutes were evaluated at a dose range of 0.01 – 10 μg/min. The prostaglandins were infused into the renal artery of dogs. GFR was not significantly altered by the PGs. PGA₁ increased renal blood flow by approximately of the control at 0.01 μg/min without dose dependence at higher infusion rates. It had only little effects which were not dose dependent on fluid and electrolyte output. The effects of PGE₂ on renal blood flow, fluid, sodium, and chloride excretion were dose dependent with a steep slope of the dose response curve between 0.1 and 1.0 μg/min. Blood flow was increased maximally by 80 %, urine volume by more than 400 %. PGF_2α had no effect on renal blood flow, whereas urinary output was increased to approximately the same maximal level as by E₂ although ten times higher doses were needed. Potassium excretion was less influenced than the excretion of Na and Cl and osmolar clearance was less increased than urine volume by all three prostaglandins.It is concluded that if a PG is involved in the regulation of the renal fluid or electrolyte excretion it is likely to be of the PGE-type. A PGA could only be involved in regulation of renal hemodynamics, whereas PGF although effective in the kidney exerts its effects at doses too high to have physiological significance.     

THE NATURE AND ORIGIN OF THE SOLUBLE PROTEIN IN HUMAN AMNIOTIC FLUID

1. Amniotic fluid surrounds the human fetus and is separated from the uterus by the amnion, chorion and placenta. The ability to obtain samples of amniotic fluid from women by a simple procedure has encouraged studies on the nature and origin of the fluid, and on its use for the diagnosis of a variety of clinical conditions. The fluid contains cells, which are of fetal origin, and can be grown in a tissue culture. Cyto-genetic and biochemical analyses can therefore be used to detect chromosomal aberrations and inborn errors of metabolism in the fetus. 2. The supernatant of amniotic fluid contains many of the solutes typical of extracellular fluid. In particular, it contains a wide range of proteins and those which are of fetal origin are likely to be of use in the prenatal diagnosis of fetal disease. This review examines the nature and origin of the soluble protein in amniotic fluid, and discusses the diagnostic uses of the proteins which are of fetal origin. 3. In other mammals, the arrangement of the fetal membranes is different from that in man, and these differences are reflected by changes in the nature of the amniotic fluid. Thus data from other animals have little applicability to man. 4. Electrophoresis and immunoelectrophoresis have established that the major proteins in amniotic fluid are also present in maternal and fetal sera. Their concentrations in the fluid are influenced by their molecular weight and proteins larger than about 2.5 times 10⁶ may be excluded. Towards term, phenotyping studies show that a number of serum proteins in amniotic fluid are of maternal origin. In the case of group-specific component (Gc) this has been shown to be so throughout pregnancy. Such proteins must enter the fluid by diffusing across either the chorion or the chorionic plate and then the amnion. 5. It has been previously claimed that various serum proteins in amniotic fluid are of fetal origin. For albumin and IgG there are data that strongly support a maternal origin. The evidence on the origin of insulin is inconclusive. The concentration of β₂-microglobulin in amniotic fluid exceeds that in maternal serum and is probably too high also for fetal serum to be its major source. It has a wide tissue distribution and probably enters the fluid from surrounding structures. 6. Alpha-fetoprotein in amniotic fluid is of fetal origin as it is present in maternal serum at far lower concentrations. It is found in fetal serum, urine and yolk sac, but it is not clear how it enters the amniotic fluid of normal fetuses. The concentrations of Gc and alpha-fetoprotein have been measured in amniotic fluid and in their sera of origin. The relative concentration of Gc in amniotic fluid was found to be much greater than that of alpha-fetoprotein and the concentration gradients of these marker proteins can be compared with data for other proteins. In this way further evidence has been obtained that the albumin, α₁,-antitrypsin and transferrin in amniotic fluid are mainly of maternal origin throughout pregnancy. 7. Immunological studies have shown that at least three proteins of non-serum origin are present in amniotic fluid and they have also been located in the amnion and uterine decidua. 8. The enzymes present in amniotic fluid are summarized. Many lysosomal enzymes are clearly of fetal origin since they show altered specific activities in the appropriate cases where the fetus is affected with an inborn error of metabolism. For other enzymes, analysis of specific activity gradients can help to decide the extent to which an enzyme is of serum origin, although this will not exclude the possibility of a maternal (uterine) contribution. The results of such analyses suggest that, relative to the serum protein in amniotic fluid, the greatest concentrations of the minor non-serum proteins in the fluid occurs between thirteen and eighteen weeks of pregnancy and also towards term. 9. Some inborn errors of metabolism may be diagnosed prenatally by measuring the specific activity of the respective enzyme in amniotic fluid. However, the presence of different enzymes with similar substrate specificities has prevented this in Pompe's disease. 10. In cases where the fetus is affected with anencephaly or spina bifida there is an increase in the concentration of alpha-fetoprotein in the amniotic fluid. This has provided a way of detecting these diseases early enough to allow termination of pregnancy. 11. The discovery of new proteins in fetal serum and in the tissues surrounding the amniotic cavity would seem to provide the best chance of extending the uses of amniotic fluid into the other areas of prenatal medicine.     

Neovascularization with blood-brain barrier breakdown in delayed neuronal death

Various kinds of acute pathological events in the central nervous system, such as ischemia, hemorrhage, and trauma, often cause brain edema. The edema may advance for days or weeks while inducing extensive damage in neural function, regardless of the extent of the original damage, and often results in death. Delayed edema is thought to be vasogenic; however, the mechanism underlying edema induction remains unknown. We found delayed vascular cell proliferation with a blood-brain barrier breakdown in and around the gerbil CA1 hippocampus, a region known to be involved in delayed apoptotic neuronal death 2-6 days after transient ischemia. Vascular cell proliferation, assessed by (3)H-thymidine incorporation, was most prominent 4-6 days after ischemia, and extravasation of exogenously applied dye or endogenous serum albumin from blood vessels was observed concomitantly. We propose neovascularization in delayed neuronal death as a cause of brain edema advancing days after neurological events.     

Effect of aluminum chloride on mitogenesis,mitosis, and cell cycle in human short-term whole blood cultures: Lower concentrations enhance mitosis

Aluminum, the third most common element in the earth's crust (second to oxygen and silicon) and recently suspected by some investigators to be implicated in Alzheimer disease etiology, has been studied in relation to its effect on mitogenesis, mitosis, and cell cycle. We have observed that 2–4 mM concentrations of AlCl₃ have decreased the number of cells that undergo mitogenesis (PHA-induced blast transformation) and mitosis in human short term whole blood cultures. We have also shown that the rate of the cell cycle was slowed down, i.e., cell cycle time was increased in the presence of AlCl₃. Also, we have demonstrated a reversible effect on aluminum-induced reduced mitotic index in long-term EBV-transformed lymphoblastoid cultures. Although safeguards such as limiting aluminum serum concentrations have been recommended to protect individuals undergoing dialysis, it should be realized that concentration accumulations of aluminum may increase over chronic exposures. Accordingly, if the number of cells stimulated by PHA is reduced in the presence of AlCl₃, there may be a reduction of immune competence, since the degree of PHA stimulation has been used as an indicator of immune response. Similar reductions in mitotic index could affect every tissue involved with cell division. Although it may not be the same for higher concentrations, from our results, we have also shown that decreased mitotic rates were reversible in long-term EBV-transformed lymphoblastoid cultures. Increased numbers of mitoses were observed in human short-term whole blood cultures that were exposed to 2 μM concentrations of aluminum chloride. The concentration is close to those found in normal human serum and within the “safeguard” range recommended for dialysis patients. A similar trend for aluminum sulfate was also observed, while preliminary results for three other aluminum species, lactate, citrate, and maltol, were also reported. Although previous reports have indicated a positive effect of aluminum on mitosis in vitro or in vivo, this is the first such report involving human material. It is clear that higher concentrations of aluminum chloride at 2.0–4.0 mM reversibly inhibit mitosis while more dilute concentrations of 1–2 μM, closer to those found in normal serum, enhance mitosis. The present results, as well as those in the literature, suggest that aluminum may be an essential element in cellular processes for optimal growth, development, and health maintenance. Future research will further test this hypothesis.     

Hematologic and semen quality changes in bulls with experimental eperythrozoon infection

Eperythrozoon organisms were isolated from the blood of a young beef bull with scrotal and hindlimb edema. Young beef bulls, managed under conditions closely mimicking those used in organized bull testing programs, were experimentally administered eperythrozoon organisms. Scant to few organisms were identified on blood smears from bulls (5 of 6) for 2 to 4 days starting 12 days after administration. After a second challenge with intravenously administered viable eperythrozoon organisms, the bulls demonstrated immunity by either failing to become parasitemic (4 of 6) or rapidly clearing the organisms from the blood (2 of 6). No bull became anemic, icteric, or hypoglycemic. Increased serum lactate and decreased blood bicarbonate concentrations probably reflected increased glycolytic activity of infected erythrocytes. A cause for azotemia observed late in the study was not determined. The bulls did not develop scrotal or hindlimb edema. Scrotal circumference and texture remained constant throughout the study. Semen quality was minimally altered while the bulls had organisms identified on blood smears. Harsh lung sounds were asculted in bulls during and immediately after organisms were present in the blood. Although the bulls reliably had organisms in the blood, none showed anemia, scrotal or hindlimb edema, or decreased semen quality; therefore, an additional factor or factors, or greater parasite load may be required for the expression of disease.     

Physiological quiescence in plasma-derived serum: Influence of platelet-derived growth factor on cell growth in culture

A platelet-derived growth factor can be shown to be the principal stimulant of DNA synthesis in whole blood serum for those cells that require serum for maintenance and growth in culture. Cell free plasma-derived serum lacks such platelet-derived material. 3T3 cells and primate arterial smooth muscle cells can be maintained in a quiescent state in culture for as long as six weeks in plasma-derived serum. Such cells can grow logarithmically after exposure to 5% whole blood serum or as little as 100 ng/ml of partially purified platelet factor. The cell cycle of smooth muscle cells has been studied in the quiescent (5% plasma-derived serum) and growing state (5% whole blood serum or 5% plasma-derived serum plus platelet factor). The generation time of smooth muscle cells is 16 to 18 hours as shown by autoradiographic frequency of labelled mitoses. The generation time is the same for cells in the growth fraction in either 5% whole blood serum or 5% plasma-derived serum. Thus, platelet factor acts by recruiting cells into the growth fraction rather than effecting a change in the duration of the cell cycle. Flow microfluorimetry studies on cells growing logarithmically in 5% whole blood serum give the following phase durations: G₁ = 5.6 hours; S = 7.6 hours; and G₂ + M = 3.8 hours. Based on these studies the argument is presented that cells cultured in 5% plasma-derived serum provide a more physiological base for the study of quiescence than do cells in low concentrations of whole blood serum or confluent, density inhibited cells at high (5% or greater) concentrations of whole blood serum. Furthermore, 5% plasma-derived serum represents an appropriate state to examine the perturbation of quiescent cells.     

Accidental methyl methacrylate inhalation toxicity in a rhesus monkey (Macaca mulatta).

A rhesus monkey (Macaca mulatta), accidentally exposed to vapors of methyl methacrylate for 22 hours was found in a comatose condition. Attempts to revive the animal were unsuccessful. Necropsy revealed a diffusely mottled liver, pulmonary edema, and atelectasis. The thoracic cavities each contained 30 ml of clear yellow fluid. Histopathologic review of the tissues showed central lobular liver necrosis, pulmonary edema, pulmonary emphysema, and atelectasis. Analysis of a blood sample obtained from the monkey 1.5 hours prior to death showed a normal hemogram, but elevated values for serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactate dehydrogenase, phosphohexose isomerase, blood urea nitrogen, and serum sodium. The pathologic findings, laboratory results, and clinical history suggested a diagnosis of methyl methacrylate poisoning.     

Role of Third Serum Vitamin B12 Binding Protein in Vitamin B12 Transport

A third vitamin B₁₂ binding protein present in normal serum has been shown to participate in transport of labelled vitamin B₁₂ absorbed from the gut. All three vitamin B₁₂ binding proteins in serum were labelled at the same time after oral administration of vitamin B₁₂, implying that “free” vitamin B₁₂ reached the portal blood from the gut mucosa.     

KINETICS OF THROMBIN INACTIVATION AS INFLUENCED BY PHYSICAL CONDITIONS,TRYPSIN, AND SERUM

1. A new technique for studying the progressive inactivation of thrombin is described. 2. Thrombin inactivation follows the kinetics of a first order reaction. 3. The rate constant of the inactivation reaction increases with temperature and pH (5.0 → 10.0), and also with the presence of crystalline trypsin, or serum. The rate varies for different thrombin preparations, even under the same experimental conditions. 4. The temperature characteristics of the reaction indicate that thrombin is associated with protein. 5. Thrombin preparations are most stable at pH 4 to 5, even when trypsin or serum is added. 6. The progressive inactivation is believed to be due to two mechanisms: (1) a major effect, thought to be the action of a "serum-tryptase," which is usually present in the thrombin preparations, and (2) a minor effect, probably attributable to denaturation of thrombin-protein. 7. Sources of the thrombinolytic factor (serum-tryptase) and its implications in the general theory and practical problems of blood coagulation and antithrombic action are briefly discussed.