Large-scale phenotyping in dairy sector using milk MIR spectra: Key factors affecting the quality of predictions

Methods and technologies enabling the estimation at large scale of important traits for the dairy sector are of great interest. Those phenotypes are necessary to improve herd management, animal genetic evaluation, and milk quality control. In the recent years, the research was very active to predict new phenotypes from the mid-infrared (MIR) analysis of milk. Models were developed to predict phenotypes such as fine milk composition, milk technological properties or traits related to cow health, fertility and environmental impact. Most of models were developed within research contexts and often not designed for routine use. The implementation of models at a large scale to predict new traits of interest brings new challenges as the factors influencing the robustness of models are poorly documented. The first objective of this work is to highlight the impact on prediction accuracy of factors such as the variability of the spectral and reference data, the spectral regions used and the complexity of models. The second objective is to emphasize methods and indicators to evaluate the quality of models and the quality of predictions generated under routine conditions. The last objective is to outline the issues and the solutions linked with the use and transfer of models on large number of instruments. Based on partial least square regression and 10 datasets including milk MIR spectra and reference quantitative values for 57 traits of interest, the impact of the different factors is illustrated by evaluating the influence on the validation root mean square error of prediction (RMSEP). In the displayed examples, all factors, when well set up, increase the quality of predictions, with an improvement of the RMSEP ranging from 12% to 43%. This work also aims to underline the need for and the complementarity between different validation procedures, statistical parameters and quality assurance methods. Finally, when using and transferring models, the impact of the spectral standardization on the prediction reproducibility is highlighted with an improvement up to 86% with the tested models, and the monitoring of individual spectrometer stability over time appears essential. This list inspired from our experience is of course not exhaustive. The displayed results are only examples and not general rules and other aspects play a role in the quality of final predictions. However, this work highlights good practices, methods and indicators to increase and evaluate quality of phenotypes predicted at a large scale. The results obtained argue for the development of guidelines at international levels, as well as international collaborations in order to constitute large and robust datasets and enable the use of models in routine conditions.

Sphagnum palustre clone vs native Pseudoscleropodium purum: A first trial in the field to validate the future of the moss bag technique

Although a large body of literature exists on the use of transplanted mosses for biomonitoring of air pollution, no article has addressed so far the use and the accumulation performance of a cloned moss for this purpose. In this work, a direct comparison of metal accumulation between bags filled with a Sphagnum palustre L. clone or with native Pseudoscleropodium purum Hedw., one of the most used moss species in biomonitoring surveys, was investigated. The test was performed in sites with different atmospheric contamination levels selected in urban, industrial, agricultural and background areas of Italy and Spain. Among the eighteen elements investigated, S. palustre was significantly enriched in 10 elements (Al, Ba, Cr, Cu, Fe, Hg, Pb, Sr, V and Zn), while P. purum was enriched only in 6 elements (Al, Ba, Cu, Hg, Pb and Sr), and had a consistently lower uptake capacity than S. palustre. The clone proved to be more sensitive in terms of metal uptake and showed a better performance as a bioaccumulator, providing a higher accumulation signal and allowing a finer distinction among the different land uses and levels of pollution. The excellent uptake performance of the S. palustre clone compared to the native P. purum and its low and stable baseline elemental content, evidenced in this work, are key features for the improvement of the moss bag approach and its large scale application.

Digestibility of carbohydrates in growing pigs: a comparison between the t-cannula and the steered ileo-caecal valve cannula

We compared the determination of ileal and total tract digestibility of carbohydrates in five experimental diets using a double 5 x 5 Latin square design involving a total of 10 cannulated pigs; half of the pigs were equipped with a simple T-cannula and the other half with steered ileo-caecal valve (SICV)-cannula. The diets consisted of nitrogen-free mixture and soya bean meal, sunflower meal, peas or rape seed cake diluted to about 180 g/kg DM protein with the nitrogen-free mixture. There was no significant difference in the digestibility values using the two types of cannulas with regard to organic matter, sugars (sum of glucose, fructose and sucrose), alpha-galactosides (sum of raffinose, stachyose and verbascose), starch, cellulose, total non-cellulosic polysaccharides (NCP) and insoluble NCP constituents. The digestibility values for the NCP residues arabinose and galactose, however, were estimated higher but with a lower variability with the SICV-cannula compared with the T-cannula. The type of cannula did no influence the estimation of the total tract digestibility for any of the major dietary constituents, but the total tract digestibility was slightly more variable when the pigs were equipped with the SICV-cannula compared with the T-cannula. There was no difference in the ileal digestibility of sugars, alpha-galactosides, cellulose and the NCP arabinose and uronic acids residues among the experimental diets, while the ileal digestibility of starch and the remaining NCP sugar residues varied between diets. The total tract digestibility was complete for sugars, alpha-galactosides and starch, whereas the digestibility of the cell wall constituents varied in accordance with the polymeric composition of the cell walls. It was concluded that ileal digesta samples from SICV-cannula are more homogenous than those from the T-cannula. In cases where the precision of each determination is crucial, the SICV-cannula should be the option.

Uptake and elimination of radiocaesium in fish and the "size effect."

A number of hypotheses have previously been developed concerning the rates of uptake and elimination of radiocaesium (137Cs) in fish. These include the influence of potassium and other water chemical parameters on both uptake and elimination, and the effect of fish size on accumulation. In order to test these hypotheses, we have assembled a data set comprising more than 1,000 measurements of radiocaesium (137Cs) in predatory fish (perch, pike and brown trout) in nine European lakes during the years after Chernobyl. These data have been analysed using simple models for uptake and excretion of 137Cs in fish, showing that: 1. Fish-water concentration factors (CF) were inversely proportional to potassium [K+] concentration of the different lakes, in agreement with previous studies. 2. The uptake rate of 137Cs in fish was negatively correlated with lake [K+], but excretion rate was independent of [K+]. 3. Lower than expected CF values were found in one lake, Iso Valkjärvi, Finland. This is attributed to inhibition of the K+ (and therefore 137Cs) high affinity transport system in aquatic plants and fish by low pH and/or low Ca2+. 4. The inclusion of fish weight as a parameter in our dynamic model significantly improves the ability of the model to fit the observed measurements of 137Cs. 5. The model developed from the above hypotheses was able to fit the data from nine different lakes to within approximately a factor of 3 of the observed values.

Susceptibility testing of pathogenic fungi with itraconazole: a process analysis of test variables

A 2(10-5) fractional factorial model was used to investigate the influence of 10 process variables in broth microdilution susceptibility tests with itraconazole against eight isolates of Candida species and six isolates of filamentous fungi in two growth media. An analysis of variance (ANOVA) indicated that glucose concentration and incubation time both significantly influenced control turbidity optical density (OD) values for most of the Candida spp. isolates, while incubation in >10% CO(2) versus ambient air, incubation temperature and inoculum size significantly influenced these OD values for about half of the yeast isolates. Control OD values for the mould isolates were most influenced by incubation time and temperature, and by occlusion of the wells with an adhesive sticker. Three statistical approaches, ANOVA, rank transformation and Mann-Whitney U-test, were used to assess the influence of the variable combinations on MIC, determined with a 50% growth reduction end-point. Incubation temperature and time, glucose concentration and inoculum size were the variables that most often affected susceptibility results to the level of statistical significance; however, the supplier of RPMI 1640 medium, the use of adhesive stickers and the atmosphere of incubation significantly influenced the MIC for some isolates. The medium used to prepare the test inoculum, the solvent used to prepare the stock solution and the shape of the microdilution plate wells significantly affected outcome, but only sporadically. A principal component analysis of the data matrix confirmed this order of relative influence of the test variables on the MIC. Since each fungal isolate responded differently to combinations of process variables in the test, we conclude that any unified method for antifungal susceptibility determination represents a compromise, rather than an idealized system.

Causes of thrombophilia yet to be discovered: a personal view

Prediction of genetic risk factors for venous thrombosis might best be left for only wise soothsayers. Nonetheless, based on the principle that hypercoagulability, either systemic or vascular-bed-specific, predisposes to thrombosis, we venture some speculations. Hyperactivity of platelets could be caused by elevated numbers of surface glycoproteins or defective signal transduction pathways. The reported efficacy of aspirin for prevention of venous thrombosis is consistent with the prediction that certain platelet defects may increase the risk of venous thrombosis. Hyperlipidaemia is associated with hypercoagulability, and lipoproteins exhibit procoagulant (e.g. triglyceride-rich particles and oxidized low-density lipoprotein) or anticoagulant (e.g. high-density-lipoprotein's cofactor activity for activated protein C/protein S) activities. This leads to the prediction that defects in lipids and/or lipoproteins may increase the risk for venous thrombosis. Interestingly, statins were recently reported to prevent the occurrence of venous thrombosis in the HERS (Heart and Estrogen/Progestin Replacement) trial. We also predict that new defects in the protein C pathway (e.g. defective endothelial protein C receptor or novel cofactors for activated protein C/protein S) will be discovered. Risk factors affecting the majority of patients will likely involve new single nucleotide polymorphisms (SNPs) like the factor V nt G1691A or prothrombin nt G20210A SNPs. The Human Genome Project will soon accelerate discovery of new SNPs that are risk factors for venous thrombosis.

Anti-inflammatory, antithrombotic, and neuroprotective effects of activated protein C in a murine model of focal ischemic stroke

BACKGROUND

Activated protein C (APC) contributes to systemic anticoagulant and anti-inflammatory activities. APC may reduce organ damage by inhibiting thrombin generation and leukocyte activation. Neutrophils and cerebrovascular thrombosis contribute to ischemic neuronal injury, suggesting that APC may be a potential protective agent for stroke.

METHODS AND RESULTS

We examined the effects of APC in a murine model of focal ischemia. After middle cerebral artery occlusion/reperfusion, the average survival time in controls was 13.6 hours. Animals that received purified human plasma-derived APC 2 mg/kg IV either 15 minutes before or 10 minutes after stroke induction survived 24 hours and were killed for neuropathological analysis. APC 2 mg/kg given before or after onset of ischemia restored cerebral blood flow, reduced brain infarct volume (59% to 69%; P:<0.003) and brain edema (50% to 61%; P:<0.05), eliminated brain infiltration with neutrophils, and reduced the number of fibrin-positive cerebral vessels by 57% (P:<0.05) and 25% (nonsignificant), respectively. The neuroprotective effect of APC was dose-dependent and associated with significant inhibition of ICAM-1 expression on ischemic cerebral blood vessels (eg, 61% inhibition with 2 mg/kg APC). Intracerebral bleeding was not observed with APC.

CONCLUSIONS

APC exerts anti-inflammatory, antithrombotic, and neuroprotective effects in stroke. Central effects of APC are likely to be related to improved maintenance of the blood-brain barrier to neutrophils and to reduced microvascular obstructions and fibrin deposition.

A mechanistic sub-model predicting the influence of potassium on radiocesium uptake in aquatic biota

It is often argued that the quality of science is related to the possibilities of making accurate predictions. It has also long been argued that due to the complex nature of ecosystems, it will never be possible to predict important target variables, especially with more comprehensive dynamic models. New results in radioecology have, however, demonstrated that those arguments are no longer valid. The key to the predictive success lies in the structuring of the model. The accident at Chernobyl has, in fact, provided science with an intriguing opportunity to study how the pulse of 137Cs is transported through ecosystem pathways, thus revealing the basic structure of these ecosystems, i.e. which are the key and the less-important pathways. It is paradoxical to conclude that the Chernobyl accident is, perhaps, the most important factor behind the revolution in predictive ecosystem modelling which lies behind the decrease in the uncertainty factor from 10 to 0.25-0.5. The sub-model for the potassium moderator presented in this paper is an example of a mechanistically based sub-model used within the framework of a more comprehensive lake model for 137Cs. The K-moderator presented is derived from the existing knowledge on ion transport in biological membranes and takes into account ion equilibria modelled by the Nernst equation and the uptake kinetics quantified by the Michaelis-Menten model. It provides the type of structure to this overall lake model that helps to explain the excellent predictive power of this model.

Industrial emergency response training: an assessment of long-term impact of a union-based program

BACKGROUND

The long-term impact of the United Automobile Workers' (UAW) Industrial Emergency Response Training on health and safety conditions and practices in plants is described. Two strategies are combined in this 24-hour training: the use of peer (worker) trainers and a participant-centered approach, the Small Group Activity Method (SGAM).

METHODS

Impact was assessed through a telephone survey of 67 trainees conducted on average 16.8 months post-training.

RESULTS

74% of trainees reported using at least one of the provided written training materials after training. Of those reporting an accident in their facility after training, 88% said it was handled differently because of training. Trainees report that peer-trainers are more knowledgeable and communicate better than do other types of trainers. Trainees also reported that SGAM made training more applicable to their workplace. 98.5% of trainees like the methods utilized.

CONCLUSIONS

Worker-trainers and SGAM are effective training methods enhancing the long-term impact of union-based workplace health and safety training programs.

Prognostic value of protein C concentrations in neutropenic patients at high risk of severe septic complications

OBJECTIVE

To assess the prognostic value of protein C, endogenous activated protein C, and D-dimer concentrations in patients at high risk of developing severe septic complications secondary to cytostatic chemotherapy.

DESIGN

Prospective, comparative, single-center study.

SETTING

Specialized ward for treating patients with acute leukemia and associated intensive care unit at a university hospital.

SUBJECTS

Twenty-six consecutive patients who developed either severe sepsis (n = 13) or septic shock (n = 13) during chemotherapy-induced neutropenia (leukocytes <1,000/microL).

INTERVENTION

None, other than standard care.

MEASUREMENTS AND MAIN RESULTS

Baseline blood samples were obtained from 97 adult patients treated with intensive cytostatic chemotherapy. Serial blood sampling was performed in 62 of 97 patients who developed fever (>38.3 degrees C). Thirteen patients progressed to severe sepsis and 13 patients to septic shock. Protein C, endogenous activated protein C, and D-dimer were measured in these 26 patients. At fever onset, protein C concentrations decreased from normal baseline concentrations and were significantly lower in the group of patients who progressed to septic shock compared with those who developed severe sepsis (medians for protein C activity: 23.1% vs. 69.5%; p = .0003). The median elapsed time between detection of fever and the diagnosis of severe sepsis or septic shock was 16 hrs and 12 hrs, respectively. All septic shock patients died, whereas patients who progressed only to severe sepsis survived.

CONCLUSIONS

Septic shock in neutropenic patients is associated with increased protein C consumption. The data demonstrate that the coagulation cascade is activated and produces a hypercoagulable state before the onset of clinical symptoms of severe sepsis and septic shock. Low protein C concentrations at the onset of fever and before the onset of clinical symptoms of severe sepsis or septic shock may have prognostic value in predicting an unfavorable outcome. Protein C measurements may help identify patients at risk in an early phase of neutropenic sepsis. It is also attractive to speculate that because low protein C concentrations were seen in these patients, protein C replacement may be beneficial in sepsis.

Effects of long-term treatment of colon adenocarcinoma with crocin, a carotenoid from saffron (Crocus sativus L.): an experimental study in the rat

We used an experimental model in the rat to examine the effects of long-term treatment with crocin, a glycosylated carotenoid from the stigmas of the saffron crocus, on colon cancer. BD-IX rats were divided into four groups: Groups G1 and G2, designated "cancer groups," were used to study the effects of crocin on the progression of colon cancer, and Groups G3 and G4, designated "toxicity groups," were used to study the effects of the treatment on metabolic processes and the parenchyma. DHD/K12-PROb cells were injected subcutaneously into the chest of Group G1 and G2 animals. From 1 to 13 weeks after inoculation, animals in Groups G2 and G4 received a weekly injection of crocin (400 mg/kg body wt s.c.). Animals in Groups G1 and G3 received no treatment. In addition, lines of animal and human colon adenocarcinoma cells (DHD/K12-PROb and HT-29) were used to perform assays in vitro to examine the cytotoxicity of crocin. Life span was extended and tumor growth was slower in crocin-treated female rats, but no significant antitumor effect was found in male rats. Acute tubular necrosis was found in all kidney samples from crocin-treated animals, but slight signs of nephrotoxicity were found by biochemical analysis of the serum. In assays in vitro, crocin had a potent cytotoxic effect on human and animal adenocarcinoma cells (HT-29 and DHD/K12-PROb cells, 50% lethal dose = 0.4 and 1.0 mM, respectively). Treated cells exhibited a remarkable loss of cytoplasm and wide cytoplasmic vacuole-like areas. In conclusion, long-term treatment with crocin enhances survival selectively in female rats with colon cancer without major toxic effects. The effects of crocin might be related to its strong cytotoxic effect on cultured tumor cells.

Cardiolipin is a normal component of human plasma lipoproteins

Anticardiolipin (anti-CL) antibodies, diagnostic for antiphospholipid antibody syndrome, are associated with increased risks of venous and arterial thrombosis. Because CL selectively enhances activated protein C/protein S-dependent anticoagulant activities in purified systems and because CL is not known to be a normal plasma component, we searched for CL in plasma. Plasma lipid extracts [chloroform/methanol (2:1, vol/vol)] were subjected to analyses by using TLC, analytical HPLC, and MS. A plasma lipid component was purified that was indistinguishable from reference CL (M:1448). When CL in 40 fasting plasma lipid extracts (20 males, 20 females) was quantitated by using HPLC, CL (mean +/- SD) was 14.9 +/- 3.7 microgram/ml (range 9.1 to 24.2) and CL was not correlated with phosphatidylserine (3.8 +/- 1.7 microgram/ml), phosphatidylethanolamine (64 +/- 20 microgram/ml), or choline-containing phospholipid (1,580 +/- 280 microgram/ml). Based on studies of fasting blood donors, CL (>/=94%) was recovered in very low density, low density, and high density lipoproteins (11 +/- 5.3%, 67 +/- 11.0%, and 17 +/- 10%, respectively), showing that the majority of plasma CL (67%) is in low density lipoprotein. Analysis of relative phospholipid contents of lipoproteins indicated that high density lipoprotein is selectively enriched in CL and phosphatidylethanolamine. These results shows that CL is a normal plasma component and suggest that the epitopes of antiphospholipid antibodies could include CL or oxidized CL in lipoproteins or in complexes with plasma proteins (e. g., beta(2)-glycoprotein I, prothrombin, protein C, or protein S) or with platelet or endothelial surface proteins.

Multifactorial protective mechanisms to limit viral replication in the lung of mice during primary murine cytomegalovirus infection

In this article, we investigated the protective host immune mechanisms against acute murine cytomegalovirus (MCMV) infection. For this purpose, we used various knockout mice lacking molecules, which include interferon-gamma (IFN-gamma), interferon-gamma receptor (IFN-gamma-R), interferon regulatory factor-1 (IRF-1), inducible nitric oxide synthase (iNOS), and perforin. We also used mutant mice lacking Fas molecule. When we infected these mice with MCMV and determined the viral titers in their lungs at different time points, we found that IFN-gamma, IFN-gamma-R, IRF-1, iNOS, and perforin-deficient mice developed significantly higher titers of infectious MCMV in the lung, compared to those observed in their respective wild-type controls. In the lungs of Fas-mutant mice, viral titers were similar to those obtained in wild-type mice.

Extensive venous and arterial thrombosis associated with an inhibitor to activated protein C

Activated protein C resistance (APCR) in the absence of alterations in the factor V gene has been observed during pregnancy, in patients on oral contraceptives, in the presence of antiphospholipid antibodies, and in patients with ischemic stroke. We report a 49-year-old woman with recurrent major venous and arterial thromboses who displayed pronounced APCR, yet no changes in the activated protein C (APC) cleavage sites of factor V. The APCR values determined by four different assays were similar to those obtained in plasma from a homozygote for factor V Q506. Addition of IgG isolated from the patient's serum to normal plasma lowered the APCR ratio from 2.4 to 1.6. Incubation of patient's IgG with normal APC resulted in a profound change in the mobility of APC in crossed immunoelectrophoresis. APC was also shown to bind to patient's IgG immobilized on a protein A agarose column. Factor Va inactivation by APC was inhibited by patient's IgG, but not by control IgG in the presence or absence of either phospholipids or protein S. These results provide evidence for the existence of an acquired antibody against APC in the patient's plasma, which gave rise to the APCR phenotype and was probably responsible for the major thrombotic events. We suggest that acquired APCR due to anti-APC antibodies be considered a potential cause for severe venous and arterial thromboses.

Direct observation of the self-association of dilute proteins in the presence of inert macromolecules at high concentration via tracer sedimentation equilibrium: theory, experiment, and biological significance

The technique of tracer sedimentation equilibrium [Rivas, G., et al. (1994) Biochemistry, 2341-2348 (1); Rivas, G., et al. (1996) J. Mol. Recognit. 9, 31-38 (2)] is utilized, together with an extension of the theory of sedimentation equilibrium of highly nonideal solutions [Chatelier and Minton, (1987) Biopolymers 26, 1097-1113 (3)], to characterize the thermodynamic activity and/or the state of association of a dilute, labeled macromolecular solute in the presence of an arbitary concentration of a second, unlabeled macromolecular solute. Experiments are performed on solutions of labeled fibrinogen (0.25-1 g/L) in bovine serum albumin (0-100 g/L) in the presence and absence of divalent cations (Ca(2+), Mg(2+)), and on solutions of labeled tubulin (0.2-0.6 g/L) in dextran (0-100 g/L). It is found that in the absence of the divalent cations, the large dependence of the thermodynamic activity of fibrinogen on BSA concentration is well accounted for by a simple model for steric repulsion. In the presence of the cations and sufficiently large concentrations of BSA (>30 g/L), fibrinogen appears to self-associate to a weight-average molar mass approximately twice that of monomeric fibrinogen. Tubulin appears to self-associate to an extent that increases monotonically with increasing dextran concentration, reaching a weight-average molar mass almost 3 times that of the alphabeta dimer in the presence of 100 g/L dextran. Possible biological ramifications are discussed.

Phenotypic and functional characterization of CD8(+) T cell clones specific for a mouse cytomegalovirus epitope

A series of CD8(+) T cell clones, specific for the IE1 epitope YPHFMPTNL, of the immediate-early protein 1 of the murine cytomegalovirus (MCMV) were generated in order to determine their protective activity against this infection and correlate their phenotypic markers with antiviral activity. We found that the adoptive transfer of three of these anti-MCMV CD8(+) T cell clones into irradiated naive mice resulted in protection against challenge, while another CD8(+) T cell clone, of the same specificity, failed to confer protection. The clones that conferred protection against lethal challenge reduced greatly viral replication in the lung and other organs of the mice. Using one of the protective anti-MCMV CD8(+) T cell clones we found that in order to be fully protective the cells had to be transferred to recipient mice no later than 1 day after MCMV challenge. The adoptive transfer of these CD8(+) T cell clones also protected CD4(+) T-cell-depleted mice. Phenotypic characterization of the anti-MCMV clones revealed that the nonprotective clone expressed very low levels of CD8 molecules and produced only small amounts of TNF-alpha upon antigenic stimulation. Most importantly, our current study demonstrates that this MHC class I-restricted IE1 epitope of MCMV is efficiently presented to CD8(+) T cell clones in vivo and further strengthens the possibility of the potential use of CD8(+) T cell clones as immunotherapeutic tools against cytomegalovirus-induced disease.

Phosphorylation- and activation-independent association of the tyrosine kinase Syk and the tyrosine kinase substrates Cbl and Vav with tubulin in B-cells

Aggregation of the B-cell antigen receptor leads to the activation of the 72-kDa Syk protein-tyrosine kinase and the phosphorylation of tubulin on tyrosine. To explore the requirement of Syk catalytic activity for tubulin phosphorylation, tubulin was isolated from cytosolic fractions from anti-IgM-activated B-cells (DT40) that lacked endogenous Syk and immunoblotted with anti-phosphotyrosine antibodies. Tubulin was not tyrosine-phosphorylated in Syk- B-cells. Phosphorylation could be restored by the expression of wild-type, but not catalytically inactive, Syk. However, both catalytically inactive and wild-type Syk were capable of constitutive association with tubulin, indicating that tubulin phosphorylation is not required for this interaction. Anti-phosphotyrosine antibody immunoblotting of proteins adsorbed to colchicine-agarose revealed the presence of three major tubulin-associated phosphoproteins of 110, 90, and 74 kDa, the phosphorylation of which was dependent on Syk expression. The proteins of 110 and 90 kDa were identified as Cbl and Vav, two proto-oncogene products known to become prominently phosphorylated following receptor engagement. Both proteins were shown to be constitutively associated with tubulin.

Identification of the HSV-1 genome by "Dot Blot hybridization" in the geniculate ganglion of rabbits

Herpes simplex Virus type 1 (HSV-1) was inoculated into 48 rabbits by 3 different routes: 10 rabbits were dosed by mouth, 18 rabbits injected in the tongue and 14 injected in the perineurium of the facial nerve at its entrance into the stylomastoid foramen. Some of the animals were killed after a week and others after three weeks. Facial palsy was produced in none of the cases. Seroconversion was demonstrated in the peripheral blood of 100% of the inoculated animals. Cultures of macerate of the facial nerve and geniculate ganglion, as well as of the ipsilateral medulla, were negative. DNA from HSV-1 was found by "Dot Blot hybridization" technique in 30% of the macerates of the geniculate ganglion and facial nerve and in 60% of the medulla macerate in those animals killed after one week and in 0% of both samples in those killed in the third week. The fact that the HSV-1 could be isolated in the geniculate ganglion of the facial nerve continues to support the possibility of this virus as the causal agent for facial palsy, either as a single disease or associated with other symptoms.

Subtotal colectomy vs. intraoperative colonic irrigation in the management of obstructed left colon carcinoma

PURPOSE

Whether primary anastomosis should be performed after segmental resection with intraoperative colonic irrigation or subtotal colectomy is not yet established in the surgical treatment of obstructive left colon carcinoma. In this prospective, nonrandomized study, we present the results of 66 patients undergoing one-stage surgery for obstructed left colon carcinoma.

PATIENTS AND METHODS

We compared two techniques, subtotal colectomy (35 patients) and intraoperative colonic irrigation with segmental resection and immediate anastomosis (31 patients).

RESULTS

The mortality rate was similar in both groups, 8.5 percent in the subtotal colectomy group and 3.2 percent in the intraoperative colonic irrigation group. The surgical complication rate was significantly higher in the intraoperative colonic irrigation group (41.9 percent) than in the subtotal colectomy group (14.2 percent; P < 0.05). Mean operating time was significantly lower in the subtotal colectomy group than in the intraoperative colonic irrigation group (P < 0.05). Both groups had a similar mean duration of hospital stay. Ten patients who underwent subtotal colectomy (31.2 percent) presented with diarrhea in the immediate postoperative period, which disappeared spontaneously or with antidiarrheal medication; a disabling diarrhea persisted in two patients only (6.2 percent).

CONCLUSION

We believe that subtotal colectomy is the treatment of choice for obstructed left-sided colonic carcinoma. Segmental resection with intraoperative colonic irrigation is more appropriate than subtotal colectomy only in patients with carcinomas of the rectosigmoid junction or with previous anal incontinence to avoid the appearance of postoperative diarrhea.

Surgical treatment of lung metastases of head and neck tumors

BACKGROUND

Head and neck tumors often spread to the lungs, with a variety of presentations. The ideal treatment for those patients is still controversial. Resection of lung metastases was shown to significantly influence overall survival of patients.

OBJECTIVE

To evaluate results of surgical resection of lung nodules in patients with head and neck primary tumors.

METHODS

A retrospective analysis was made of 53 patients with head and neck tumors and lung nodules (no other metastases detected in other organs) admitted to our department. They were separated into two groups: OPER (thoracotomy, n = 26), and NOTOPER (no thoracotomies, n = 27). Overall survival was compared (Kaplan-Meier, log-rank) between groups.

RESULTS

Overall median survival of all patients was 10 months, of OPER 20 months, and of NOTOPER 6 months (P <0.0001). Complete resection (n = 19) of lung metastases was associated with the greatest survival rate (median 23 months). Patients submitted to incomplete resection (n = 7) had a median survival of 16 months, compared with 7 months for patients who received only chemotherapy (n = 7) and 4 months for patients (n = 20) with no treatment (P <0.0001).

CONCLUSION

Resection of lung metastases offers a significant survival benefit for patients with head and neck primary tumors, when compared with the current chemotherapeutic regimens. It should be considered for all patients clinically fit and who present with no extrapulmonary disease.

The Physiological Relevance of Na+-Coupled K+-Transport

Plant roots utilize at least two distinct pathways with high and low affinities to accumulate K+. The system for high-affinity K+ uptake, which takes place against the electrochemical K+ gradient, requires direct energization. Energization of K+ uptake via Na+ coupling has been observed in algae and was recently proposed as a mechanism for K+ uptake in wheat (Triticum aestivum L.). To investigate whether Na+ coupling has general physiological relevance in energizing K+ transport, we screened a number of species, including Arabidopsis thaliana L. Heynh. ecotype Columbia, wheat, and barley (Hordeum vulgare L.), for the presence of Na+-coupled K+ uptake. Rb+-flux analysis and electrophysiological K+-transport assays were performed in the presence and absence of Na+ and provided evidence for a coupling between K+ and Na+ transport in several aquatic species. However, all investigated terrestrial species were able to sustain growth and K+ uptake in the absence of Na+. Furthermore, the addition of Na+ was either without effect or inhibited K+ absorption. The latter characteristic was independent of growth conditions with respect to Na+ status and pH. Our results suggest that in terrestrial species Na+-coupled K+ transport has no or limited physiological relevance, whereas in certain aquatic angiosperms and algae this type of secondary transport energization plays a significant role.

Impairments of the protein C system and fibrinolysis in infection-associated stroke

BACKGROUND AND PURPOSE

Infection/inflammation appears to be an important predisposing risk factor for brain infarction, but little is known regarding underlying molecular mechanisms. We examined the hypothesis that patients with brain infarction preceded by infection/inflammation within 1 week could be identified by a distinctive procoagulant laboratory profile characterized by abnormalities in the protein C system and endogenous fibrinolysis.

METHODS

We performed a case-control study examining the relationship between preceding systemic infectious/inflammatory syndromes and selected immunohematologic variables in 36 patients with acute brain infarction and 81 control subjects (community control subjects [n = 47] and hospitalized nonstroke neurological patient controls [n = 34]).

RESULTS

The stroke group had a lower mean level of the circulating antithrombotic enzyme activated protein C (APC) (4.33 +/- 0.34% [log-transformed percentage of control value, mean +/- SD]) than community control subjects (4.51 +/- 0.27%, P < .02) or hospitalized neurological patient controls (4.57 +/- 0.31%, P < .005). The lowest circulating APC levels were found in the stroke group with antecedent infection/inflammation within 1 week preceding index brain infarction (4.23 +/- 0.4%, n = 12). Within the stroke group, circulating APC levels were inversely related to IgG isotype anticardiolipin antibody titers (r = -.55, P < .001). Only the stroke group with infection/inflammation within 1 week had elevated plasma C4b binding protein compared with control subjects (141 +/- 61% versus 112 +/- 44%, P < .05). Stroke patients with antecedent infection/inflammation had a distinctively lower ratio of active tissue plasminogen activator to plasminogen activator inhibitor (0.11 +/- 0.04, n = 9) than other stroke patients (0.19 +/- 0.06, n = 9, P < .01) and control subjects (0.22 +/- 0.16, n = 17, P < .02).

CONCLUSIONS

Impairments in the protein C pathway and endogenous fibrinolysis may contribute to the increased risk for brain infarction after recent (< or = 1 week) infection/inflammation. A decrease in the circulating anticoagulant APC may be related to elevated antiphospholipid antibody titers.

Castleman's disease restricted to the infratemporal fossa

Giant lymph node hyperplasia (Castleman's disease) is usually reported as a solitary mediastinal tumour, although involvement of other anatomical sites and a multicentric form have been reported. We describe a rare case of Castleman's disease due to its localisation (the left infratemporal fossa) and histology (plasma-cell variant). A brief review of the main clinico-histological characteristics of Castleman's disease is also presented.

Design, synthesis, and biological evaluation of ellipticine-estradiol conjugates

Three ellipticine-estradiol conjugates were synthesized in an effort to target the cytotoxicity of ellipticine to estrogen-receptor positive cells. The three conjugates were prepared with linker chains extending from the 17 alpha position of the estradiol to N-2 (compound 3), N-6 (compound 4), and C-9 (compound 5) positions of ellipticine. The ellipticine-estradiol conjugates were evaluated for their abilities to bind to estrogen receptors, to inhibit topoisomerase II, and for their cytotoxicities in human cancer cell lines. Conjugates 3 and 5 displayed weak binding affinities of 0.132 and 0.303 for the estrogen receptor (relative to estradiol = 100), while conjugate 4 did not show any detectable binding to the estrogen receptor. Compound 3 was a moderate inhibitor of topoisomerase II (IC50 24.1 microM), while 4 and 5 were inactive. Conjugate 3 was consistently more cytotoxic (GI50 values 1-10 microM) than compounds 4 and 5 (GI50 values 10-100 microM) in a variety of human cancer cell lines. None of the compounds displayed any selectivity for estrogen-receptor positive cell lines, which probably reflects their weak affinities for estrogen receptors.

Activated protein C resistance in ischemic stroke not due to factor V arginine506-->glutamine mutation

BACKGROUND AND PURPOSE

Resistance to activated protein C (APC), a natural plasma anticoagulant, is the most common identifiable risk factor for venous thromboembolic disease. One point mutation in coagulation factor V that renders it APC-resistant is found in >90% of APC-resistant venous thrombosis patients. To determine the prevalence of APC resistance and of this factor V mutation in stroke, we screened a group of ischemic stroke patients.

METHODS

Hispanic ischemic stroke patients were screened using two different activated partial thromboplastin time-based assays. One assay using neat patient plasma determined APC resistance, and the other assay using patient plasma diluted into factor V-deficient plasma determined APC-resistant factor V, including the Arg506-->Gln mutation. Results were compared with those in 31 Hispanic control subjects of similar ages.

RESULTS

Six of 63 (9.5%) stroke patients had APC resistance compared with none of 31 (0%) control subjects. No patient or control subject had APC-resistant factor V, ie, the factor V Arg506-->Gln mutation.

CONCLUSIONS

In Hispanic patients with ischemic stroke, the incidence (approximately 10%) of APC resistance is not caused by the factor V Arg506-->Gln mutation. APC resistance not caused by this factor V mutation may be a risk factor for ischemic stroke in this population.

Synthesis of a series of cytotoxic 2-acyl-1,2-dihydroellipticines which inhibit topoisomerase II

An array of novel 2-acyl-1,2-dihydroellipticines was prepared and evaluated for in vitro cytotoxicity in a variety of human cancer cell lines. The ellipticine analogs were also tested for inhibition of topoisomerase II in both decatenation and cleavable complex formation assays. Some of the new ellipticine derivatives were prepared by acylation of ellipticine with acid chlorides in tetrahydrofuran, followed by reduction of the intermediate 2-acylellipticinium ions with sodium cyanoborohydride. Others were synthesized by acylation of ellipticine with p-nitrophenyl chloroformate, reduction of the 2-acylellipticinium ion with sodium cyanoborohydride, and displacement of the p-nitrophenoxide anion with a variety of oxygen and nitrogen nucleophiles. The cytotoxicities of the new 2-acyl-1,2-dihydroellipticines varied widely, and correlated well with their topoisomerase II inhibitory activities.

Crocin, safranal and picrocrocin from saffron (Crocus sativus L.) inhibit the growth of human cancer cells in vitro

Extracts of saffron (Crocus sativus L.) have been reported to inhibit cell growth of human tumor cells. In order to study the cytotoxic effect of the characteristic compounds of saffron spice, we have isolated crocin, crocetin, picrocrocin and safranal. Doses inducing 50% cell growth inhibition (LD50) on HeLa cells were 2.3 mg/ml for an ethanolic extract of saffron dry stigmas, 3 mM for crocin, 0.8 mM for safranal and 3 mM for picrocrocin. Crocetin did not show cytotoxic effect. Cells treated with crocin exhibited wide cytoplasmic vacuole-like areas, reduced cytoplasm, cell shrinkage and pyknotic nuclei, suggesting apoptosis induction. Considering its water-solubility and high inhibitory growth effect, crocin is the more promising saffron compound to be assayed as a cancer therapeutic agent.

Complications of supraglottic laryngectomy for carcinomas of the supraglottis and the base of the tongue

The medical records of patients with either a supraglottic carcinoma (n = 193) or a base of tongue carcinoma (n = 56) who underwent a supraglottic laryngectomy were studied. Because of aspiration total laryngectomy was required in 9.8% and 21.4% of patients with supraglottic and base of tongue carcinomas, respectively, being related to locally advanced stage of disease in the base of tongue and to an age older than 65 years in the case of supraglottic carcinomas. The non-decannulation rates were 23.8% and 50% in supraglottic and base of tongue tumours respectively. Post-operative radiotherapy did not influence the decannulation rate, but advanced local disease and age did. Post-operative mortality in the first month after the operation was 2.6% in supraglottic tumours and 3.6% in base of tongue tumours.

Biliary secretion in suckling goats: the effect of maternal milk and of a lamb milk replacer

A total of 45 preruminant goats were fed either goat milk or a milk substitute. The postnatal development of bile secretion and biliary lipids composition of suckling goats and the influence upon these parameters of maternal milk substitution were studied during the first month of life. Samples of hepatic and gallbladder bile were obtained from kids of 1, 7, 14, 21 and 28 day-old. Bile flow rate, cholesterol, total bile salts and phospholipids were measured. Our results show that the quality of the protein and fat used in the elaboration of the milk replacer, affects the evolution of both hepatic bile flow and biliary lipids composition. Differences between gallbladder and hepatic bile composition show a scarce concentration capacity of the gallbladder with both diets and at all ages studied.

Evaluation of topical retinoids for cutaneous pharmacological activity in Yucatan microswine

The pharmacological effects of retinoids on skin have been studied primarily in test systems using small animals, such as mice and rabbits. Because of potentially significant differences in skin permeation and metabolism between small animals and humans, we have used Yucatan microswine as an alternative model for testing topical retinoids. Microswine skin resembles human skin, functionally and anatomically, more closely than most other species. In these studies, microswine skin was treated topically with retinoids for 5 consecutive days per week for 5 weeks. We found microswine epidermis to be functionally responsive to retinoids in that it undergoes hyperplasia and shows an increase in transepidermal water loss (TEWL). All-trans-retinoic acid, and its analogs, 13-cis-retinoic acid, 4-hydroxy-retinoic acid and 4-oxo-retinoic acid all caused epidermal thickening and increased TEWL. The three analogs were less potent than all-trans-retinoic acid. A synthetic retinoid, TTNPB, potently induced epidermal hyperplasia and increased TEWL, but a close structural analog, m-carboxy-TTNPB, which is also inactive on nuclear retinoic acid receptors, was without effects on microswine epidermis. These findings show that microswine are useful for evaluating the cutaneous effects of topical retinoids. This model could be of value in identifying retinoids with potential clinical activity.

Identification of candidate residues for interaction of protein S with C4b binding protein and activated protein C

Protein S is a plasma factor essential for prevention of thrombosis, partly due to its activity as a cofactor for the plasma anticoagulant protease-activated protein C. To expand knowledge about structure-function relationships in homologous protein S molecules, studies of protein S from different species have been performed. Protein S anti-coagulant activity in human, monkey, bovine, and porcine plasma has been inactivated by purified human C4b binding protein (C4BP) with dose-dependence, suggesting that each protein S can bind human C4BP and that only the free form of each is anti-coagulantly active. Purified porcine protein S has a 10-fold higher Kd for human C4BP than has human protein S. Protein S residues 420-434 provide an essential binding site for the negative regulator C4BP. cDNA sequences show that protein S residues 420-434 are highly conserved in all four species with the notable exception of Lys-429-Ile in porcine protein S. Differences between porcine and human protein S, e.g. Lys-429-Ile, Lys-43-Ala, Ser-197-Leu, Ser 199-Phe, Glu-463-Gly, Lys-571-Glu, Asn-602-Ile, Gln-607-Pro, may contribute to the decreased affinity of porcine protein S for human C4BP. Moreover, the species specificity of cofactor activities of various species of protein S is determined for human versus bovine-activated protein C, and these results, combined with sequence comparisons, agree with previous evidence that the thrombin-sensitive region and the first epidermal growth factor domain of protein S, i.e. residues 47-116, are responsible for recognition of activated protein C.

A comparison of active site binding of 4-quinolones and novel flavone gyrase inhibitors to DNA gyrase

The activity of 4-quinolone antibacterials at the enzyme target level is based on the well known and reported observations that 4-quinolone antibacterials target the Gyr A subunit of the DNA gyrase holoenzyme, inhibiting supercoiling while facilitating the "cleavable complex". Such inhibition can be observed by running the in vitro DNA gyrase supercoiling inhibition assay or the "cleavable complex" DNA gyrase assay. Although potency of the gyrase inhibitor is dependent on many factors including permeability and pharmacokinetics, the inherent potency of a gyrase inhibitor lies in its activity against the target enzyme. We have examined the binding activity of novel flavones [Bioorganic & Med. Chem. Letters 3:225-230, 1993] to Escherichia coli DNA gyrase and have found differences in binding consistent with inhibition of DNA gyrase supercoiling and ability to facilitate the cleavable complex, but of different rank order. [3H]norfloxacin was used in vitro competition studies with test compounds, pBR322 and E. coli DNA gyrase. Binding affinity results indicate the rank order of greatest to weakest binding (ability to compete with [3H]norfloxacin) of test compounds: Levofloxacin = ciprofloxacin > ofloxacin > norfloxacin > flavone compounds (including ellagic acid, quercetin, and compounds 5a through 5n [Bioorganic & Med. Chem. Letters 3:225-230, 1993]). Such differences in binding ability of the 4-quinolones and flavones to the ternary complex of DNA.DNA gyrase.drug, as compared to the catalytic inhibition and "cleavable complex" data, suggests a more complex binding of flavones than the previously hypothesized models for 4-quinolone binding.