Methane emission from a cool brown dwarf

Beyond our Solar System, aurorae have been inferred from radio observations of isolated brown dwarfs1,2. Within our Solar System, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for corresponding infrared features, but only null detections have been reported3. CWISEP J193518.59-154620.3. (W1935 for short) is an isolated brown dwarf with a temperature of approximately 482 K. Here we report James Webb Space Telescope observations of strong methane emission from W1935 at 3.326 μm. Atmospheric modelling leads us to conclude that a temperature inversion of approximately 300 K centred at 1-10 mbar replicates the feature. This represents an atmospheric temperature inversion for a Jupiter-like atmosphere without irradiation from a host star. A plausible explanation for the strong inversion is heating by auroral processes, although other internal and external dynamical processes cannot be ruled out. The best-fitting model rules out the contribution of H3+ emission, which is prominent in Solar System gas giants. However, this is consistent with rapid destruction of H3+ at the higher pressure where the W1935 emission originates4.

Evaluation of a Cooperia oncophora double-domain ASP-based vaccine against Cooperia spp. infections in cattle and sheep

A double-domain activation-associated secreted protein (dd-Co-ASP) isolated from the bovine small intestinal parasite Cooperia oncophora was previously shown to be an effective vaccine candidate to protect calves against a homologous challenge infection. The aim of this study was to investigate whether the dd-Co-ASP protein, purified from a Belgian C. oncophora isolate, would offer protection against a C. oncophora isolate from the southern hemisphere as well as other Cooperia species such as C. punctata in cattle and C. curticei in sheep. Two vaccination studies were performed, i.e. one in cattle and one in sheep, in which the protective effects of dd-Co-ASP, supplemented with Quil A as an adjuvant, were compared with an adjuvant control. Whereas our results showed a 75 % reduction in Cooperia spp. cumulative faecal egg counts, the results obtained in sheep demonstrated that dd-Co-ASP was ineffective in raising a protective immune response against a C. curticei challenge infection. Even though sequence analysis of the dd-Co-ASP gene revealed restricted sequence heterogeneity in the double domain ASP within and between bovine Cooperia species, the results of the vaccine study suggest that there is sufficient conservation at the protein level to yield cross-protection, holding promise for the development of a general Cooperia vaccine for use in cattle.

Remediation of mining soils by combining Brassica napus growth and amendment with chars from manure waste

Mining activities lead to important physical, chemical and biological effects on soil properties, generating severe impacts in the establishment and maintenance of vegetation. Assisted phytoremediation can be considered an environmentally friendly approach for soil remediation. In this study, two mining soils (PORT and GAM) were treated with 10%, by mass, of the following amendments: manure biochars prepared at 450 °C (BMW450) and 600 °C (BMW600), hydrochars prepared by hydrothermal carbonization (HTC) of manure at 190 °C (HWM190) and 240 °C (HMW240) and manure waste (MW). Brassica napus was used as a phytoextraction species. After 45 days of plant growth, soil samples were widely characterized, including microbial biomass carbon, enzymatic activity and metal content. In addition, plant biomass production, bioconcentration factor, translocation factor and metal uptake were determined. Experimental results showed that addition of biochars improved the As uptake by Brassica napus in both soils but just in the roots increasing bioconcentration factor between 22.1 and 39.5% for GAM soil and between 28.6 and 53.4% for PORT soil. Brassica napus cannot be considered as Zn accumulator in GAM soil samples and in the case of PORT samples, only the addition of BMW600 and HMW240 enhanced the phytoextraction process of Zn on the roots. Soil enzyme activity improved in hydrochar amended soils.

Eficacia reducida de derquantel y abamectina en ovinos y caprinos con Haemonchus sp resistentes a lactonas macrocíclicas

<p>Se presentan las observaciones efectuadas sobre la actividad de una combinación antihelmíntica conteniendo un nueva droga, el derquantel (spiroindoles) adicionada con abamectina (lactonas macrocíclicas) en ovinos y caprinos naturalmente parasitados por <em>Haemonchus sp</em>. En el conteo de huevos, la eficacia de la combinación mostró porcentajes de reducción variables y dependientes de los estadios parasitarios intervinientes al momento del tratamiento y al <em>status </em>previo de resistencia a las lactonas macrocíclicas. Se observó una eficacia alta (mayor al 99%) frente a la oviposición de estadios maduros de <em>Haemonchus sp </em>o cuando los antecedentes de las poblaciones parasitarias indicaban resistencia no marcada a las lactonas macrocíclicas. Por el contrario, eficacias inferiores (76 al 83%) se observaron cuando las poblaciones de este parásito mostraban resistencia severa a las lactonas macrocíclicas y los estadios inmaduros constituían la mayor parte de la población parasitaria al momento del tratamiento. Las combinaciones antihelmínticas tienen un interesante potencial de uso frente a poblaciones parasitarias de <em>Haemonchus sp </em>resistentes a los antihelmínticos, pero las presentes observaciones enfatizan la necesidad de evaluar a nivel de cada establecimiento la actividad de todos los antiparasitarios, sean estos formulados con viejas o nuevas drogas, si se pretende instaurar programas racionales para el control de estos nematodes</p>

Current of interacting particles inside a channel of exponential cavities: Application of a modified Fick-Jacobs equation

Recently a nonlinear Fick-Jacobs equation has been proposed for the description of transport and diffusion of particles interacting through a hard-core potential in tubes or channels of varying cross section [Suárez et al., Phys. Rev. E 91, 012135 (2015)]PLEEE81539-375510.1103/PhysRevE.91.012135. Here we focus on the analysis of the current and mobility when the channel is composed by a chain of asymmetric cavities and a force is applied in one or the opposite direction, for both interacting and noninteracting particles, and compare analytical and Monte Carlo simulation results. We consider a cavity with a shape given by exponential functions; the linear Fick-Jacobs equation for noninteracting particles can be exactly solved in this case. The results of the current difference (when a force is applied in opposite directions) are more accurate for the modified Fick-Jacobs equation for particles with hard-core interaction than for noninteracting ones.

Mean-field approach for diffusion of interacting particles

A nonlinear Fokker-Planck equation is obtained in the continuous limit of a one-dimensional lattice with an energy landscape of wells and barriers. Interaction is possible among particles in the same energy well. A parameter γ, related to the barrier's heights, is introduced. Its value is determinant for the functional dependence of the mobility and diffusion coefficient on particle concentration, but has no influence on the equilibrium solution. A relation between the mean-field potential and the microscopic interaction energy is derived. The results are illustrated with classical particles with interactions that reproduce fermion and boson statistics.

Is "intra-operating room" thromboelastometry useful in liver transplantation? A case-control study in 303 patients

Coagulation monitoring during liver transplantation (LT) is, even today, fundamental to reduce blood loss during surgery. Thromboelastometry (TEM) is a proven technique for controlling the various parameters that influence coagulation. However, there are no studies linking "intra-operating room" TEM (orTEM) with LT outcomes. We describe a case-control study in 303 liver graft recipients analyzing variables associated with operative complications and long-term LT outcomes. The results showed that orTEM reduced the use of blood products in patients with Model for End-Stage Liver Disease scores of ≥ 21, retransplantation, and high surgical difficulty and important intraoperative bleeding. In addition, results in survival and postoperative complications were better when orTEM was used. In conclusion, we confirm that use of orTEM is associated with less use of blood products and a lower rate of complications after LT.

Donor characteristics that are associated with survival in liver transplant recipients older than 70 years with grafts

INTRODUCTION

The use of grafts from donors older than 70 years of age is increasing due to the decrease in the number of donors and the increase in waiting list patients.

MATERIAL AND METHODS

We undertook a univariate and multivariate analysis of 980 adult recipients of whole liver grafts, 129 of them from donors aged 70 years or older.

RESULTS

No differences were found in patient survival compared with recipients of younger grafts. There were no higher rates of rejection, vascular or biliary complications, postoperative bleeding, or infections, but older grafts were associated with graft dysfunction (P = .01) and a higher frequency of postoperative refractory ascites (P = .007), but without a greater need for retransplantation. As graft-associated factors, the joint presence in the donor of diabetes (P = .00; confidence interval [CI] = 0.04-0.117), hypertension (P = .00; CI = 0.22-0.39), and weight of more than 90 kg (P = .031; CI = 0.05-0.104) were suggestive of poor prognostic factors in recipient survival. Survival in hepatitis C virus (HCV) recipients or recipients aged older than 60 years was worse with donors aged older than 70 years, although not significantly so. With grafts from donors aged older than 80 years (n = 15), although patient survival rate was good (70% at 10 years), there was a higher rate of retransplantation (20%) and the early mortality rate was 13.3%.

CONCLUSIONS

Use of grafts from donors aged older than 70 years is safe, with similar survival to patients with younger grafts. The appearance of initial dysfunction with prolonged ascites may be due to a delay in reaching a correct functionality, but was not associated with increased mortality, complications, or need for retransplantation. It should also be avoided in recipients older than 60 years or with HCV. Grafts older than 80 years were associated with a good long-term patient survival but at the expense of a higher rate of retransplantation. However, it helps to reduce the time on the waiting list and, thus, mortality. We noted decreased survival associated with donor hypertension, diabetes, and obesity, so these donors should be selected more rigorously.

Antitumor efficacy of mammalian target of rapamycin inhibitor therapy in liver transplant recipients with oncological disease: a case-control study

INTRODUCTION

The reported incidences of de novo malignancy following orthotopic liver transplantation (OLT) are significantly greater than those in the general population. We have analyzed the efficacy of mammalian target of rapamycin inhibitor (mTORi) as immunosuppressant therapy in patients with de novo malignancies or those engrafted because of a primary liver cancer.

METHODS

We performed a case-control study of patients with hepatocellular carcinoma (HCC; n = 119), cholangiocarcinoma (n = 1) or de novo malignancies (n = 73). Thirty-seven patients with these tumors were treated with mTORi, and 167, with calcineurin inhibitors (CNI). Switching to mTORi was performed progressively, withdrawing the CNI over 15 days, until obtaining levels of 5-10 ng/dL.

RESULTS

No incidence of rejection, serious adverse events, or death was observed with an overall actuarial survival of 68.5% in the mTORi group versus 45.7% among the CNI group. Overall rates of tumor recurrence were 15.2% and 36.8%, respectively (P < .05). Among patients with HCC, survival was 100% of mTORi with and 61.5% among CNI patients, with tumor recurrence rates of 6.2% and 19.1%, respectively (P < .05).

DISCUSSION

Surprising differences in survival and tumor recurrence rates were observed among the mTORi-treated group compared with controls. Switching from CNI to mTORi immunosuppressant therapy appeared to be safe. It seems to be reasonable to employ this strategy in liver transplant patients with primary hepatic or "de novo" neoplasms.

Determination, validation and standardization of a CMV DNA cut-off value in plasma for preemptive treatment of CMV infection in solid organ transplant recipients at lower risk for CMV infection

BACKGROUND

Valganciclovir preemptive therapy guided by the viral load is the current strategy recommended for preventing CMV disease in CMV-seropositive Solid Organ Transplant Recipients (SOTR) at lower risk for developing CMV infection. However, universal viral load cut-off has not been established for initiating therapy.

OBJECTIVES

Our goal was to define and validate a standardized cut-off determined in plasma by real-time PCR assay for initiating preemptive therapy in this population.

STUDY DESIGN

A prospective cohort study of consecutive cases of CMV-seropositive SOTR was carried out. The cut-off value was determined in a derivation cohort and was validated in the validation cohort. Viral loads were determined using the Quant CMV LightCycler 2.0 real-time PCR System (Roche Applied Science) and results were standardized using the WHO International Standard for human CMV.

RESULTS

A viral load of 3983 IU/ml (2600 copies/ml) was established as the optimal cut-off for initiating preemptive therapy in a cohort of 141 patients with 982 tests and validated in a cohort of 252 recipients with a total of 2022 test. This cut-off had a 99.6% NPV indicating that the great majority of patients at lower risk will not develop CMV disease without specific antiviral therapy. The high sensitivity and specificity (89.9% and 88.9%, respectively) and the relatively small numbers of patients with CMV disease confirm that real-time PCR was optimal.

CONCLUSIONS

We have established a cut-off viral load for starting preemptive therapy for CMV-seropositive SOT recipients. Our results emphasized the importance of a mandatory follow-up protocol for CMV-seropositive patients receiving preemptive treatment.

Liver transplantation in patients with cryptogenic cirrhosis: long-term follow-up

OBJECTIVE

The objective of this study was to evaluate long-term survival, histological diagnoses, and mobility of patients with cryptogenic cirrhosis (CC) treated with orthotopic liver transplantation (OLT).

PATIENTS AND METHODS

We performed a retrospective analysis of 35 patients who underwent transplantation with CC among 800 OLT patients. There were no differences in gender, mean age of 47 years, average MELD (Model for End-stage Liver Disease) of 16, and hepatocellular carcinoma incidence (8%).

RESULTS

In 28.6% of patients, the diagnosis of CC was wrong. There was no incidence of an acute rejection episode and a low incidence of complications, although the postoperative mortality rate was 20%, of chronic rejection was 25%, and recurrence of disease was 4%. Cumulative at 3-, 5-, and 10-year survivals were lower than the other OLT. Survival was lower in patients receiving suboptimal grafts.

CONCLUSIONS

One of 3 patients who underwent transplantation for CC had a specific etiologic diagnosis. The chronic rejection rate and postoperative mortality rate were higher than other etiologies, and survivals at 5, 10, and 15 years were lower than other OLT.

The 1985 central chile earthquake: a repeat of previous great earthquakes in the region?

A great earthquake (surface-wave magnitude, 7.8) occurred along the coast of central Chile on 3 March 1985, causing heavy damage to coastal towns. Intense foreshock activity near the epicenter of the main shock occurred for 11 days before the earthquake. The aftershocks of the 1985 earthquake define a rupture area of 170 by 110 square kilometers. The earthquake was forecast on the basis of the nearly constant repeat time (83 +/- 9 years) of great earthquakes in this region. An analysis of previous earthquakes suggests that the rupture lengths of great shocks in the region vary by a factor of about 3. The nearly constant repeat time and variable rupture lengths cannot be reconciled with time- or slip-predictable models of earthquake recurrence. The great earthquakes in the region seem to involve a variable rupture mode and yet, for unknown reasons, remain periodic. Historical data suggest that the region south of the 1985 rupture zone should now be considered a gap of high seismic potential that may rupture in a great earthquake in the next few tens of years.

Oil spill in the Rio de la Plata estuary, Argentina: 1. Biogeochemical assessment of waters, sediments, soils and biota

Aliphatic (ALI) and aromatic (ARO) hydrocarbon concentrations, composition and sources were evaluated in waters, sediments, soils and biota to assess the impact of approximately 1000 tons of oil spilled in Rio de la Plata coastal waters. Total ALI levels ranged from 0.4-262 microg/l in waters, 0.01-87 microg/g in sediments, 5-39 microg/g in bivalves, 12-323 microg/g in macrophytes to 948-5187 microg/g in soils. ARO varied from non-detected 10 microg/l, 0.01-1.3 mug/g, 1.0-16 microg/g, 0.5-6.9 microg/g to 22-67 microg/g, respectively. Offshore (1, 5, 15 km) waters and sediments were little affected and contained low background hydrocarbon levels reflecting an effective wind-driven transport of the slick to the coast. Six months after the spill, coastal waters, sediments, soils and biota still presented very high levels exceeding baseline concentrations by 1-3 orders of magnitude. UCM/resolved aliphatic ratio showed a clear trend of increasing decay: coastal waters (3.3) < macrophytes (6.7) < soils (9.4) < offshore sediments (13) < coastal sediments (17) < clams (52). All environmental compartments consistently indicated that the most impacted area was the central sector close to Magdalena city, specially low-energy stream embouchures and bays which acted as efficient oil traps. The evaluation of hydrocarbon composition by principal component analysis indicated the predominance of biogenic (algae, vascular plant cuticular waxes), background anthropic, pyrogenic and diagenetic hydrocarbons, offshore and in non-impacted coastal sites. In contrast, polluted stations presented petrogenic signatures characterized by the abundance of isoprenoids, low molecular weight n-alkanes and methylated aromatics in different stages of alteration. The petrogenic/biogenic ratio (<n-C22 + isoprenoids/n-C15 + n-C17 + > n-C23) and petrogenic/pyrogenic relationship (methylated/unsubstitued PAH) discriminated the samples according to the different degree of impact. The following paper present the results of the study of the progress of hydrocarbon disappearance in sediments and soils 13 and 42 months after the spill.

Effect of cervical spinal cord stimulation on regional blood flow and oxygenation in advanced head and neck tumours

BACKGROUND

Tumour ischaemia leads to decreased delivery of oxygen, chemotherapy and radiosensitisers. Hypoxia in head and neck (H&N) tumours is an important adverse prognostic factor. Spinal cord stimulation (SCS) is a well-established neurosurgical technique in the treatment of several ischaemic syndromes. This prospective study evaluated the effect of cervical-SCS on common carotid artery (CCA) blood flow and tumour oxygenation in patients with advanced H&N cancer.

PATIENTS AND METHODS

Sixteen patients with advanced H&N tumours were enrolled. Cervical-SCS devices were inserted subcutaneously prior to commencement of scheduled chemoradiotherapy. Pre- and post-SCS measurements were as follows: (i) tumour oxygenation (mmHg) using polarographic probes; (ii) blood flow quantification (ml/min) and diastolic and systolic velocimetry (cm/s) in the CCA using colour Doppler.

RESULTS

After SCS, median tumour oxygenation increased in two-thirds of patients (34%; P = 0.023), all patients had improved CCA blood flow (50%; P <0.001) and almost all patients showed an increased CCA diastolic velocity (26%; P = 0.003) and systolic velocity (20%; P = 0.011).

CONCLUSIONS

Cervical-SCS increased tumour oxygenation and CCA blood flow, and could enhance the loco-regional delivery of oxygen, radiosensitising and chemotherapeutic drugs. Cervical-SCS as adjuvant in chemoradiotherapy of these tumours warrants further investigation.

Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot of nonspecific and specific viral proteins frequently detected in different antigen preparations of bovine leukemia virus

Bovine leukemia virus (BLV) infection in cattle is seldom manifested clinically, and is routinely diagnosed by serologic tests such as enzyme-linked immunosorbent assay or Western blot (WB). Because of the difficulty in interpreting WB results, the aim of the present study was to determine which of the bands observed in WB were specifically produced by BLV and which corresponded to nonspecific proteins, either derived from medium components or of a cellular nature. Five different BLV antigen preparations from 2 cell lines (FLK-BLV and BLV-bat2) frequently used for the production of BLV antigen were compared. The protein profiles of these antigen preparations were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis and WB. Fetal calf serum, required for cellular growth and important in induction of viral transcription in vitro, was identified as a source of irrelevant proteins. In this study, 15 nonspecific protein bands in the growth medium were observed. These bands interfered with the interpretation of results. A nonspecific protein (25 kD) that was highly reactive in cell lysate preparation from BLV-bat2 was also detected. The unequivocal identification of protein bands, both specific and nonspecific, seen in WB is important not for understanding the protein profile of antigen preparations but also for determining if an animal is BLV positive or negative.

Reagentless biosensors based on self-deposited redox polyelectrolyte-oxidoreductases architectures

Reagentless fructose and alcohol biosensors have been produced with a versatile enzyme immobilisation technique which mimics natural interactions and flexibility of living systems. The electrode architecture is built up on electrostatic interactions by the sequential adsorption of redox polyelectrolytes and redox enzymes giving rise to the efficient transformation of substrate fluxes into electrocatalytic currents. All investigated multilayer structures were self-deposited on 3-mercapto-1-propanesulfonic acid monolayers self-assembled on gold electrodes. Fructose dehydrogenase, horseradish peroxidase (HRP) and the couple HRP-alcohol oxidase were electrochemically connected with a cationic poly[(vinylpyridine)Os(bpy)2Cl] redox polymer (RP) interface in a layer-by-layer self-deposited architecture. The dependence of the distance on the electrochemical response of this interface was also studied showing a clear decrease in the Faradaic current when the distance to the electrode surface was increased. The sensitivities obtained for each biosensor were 19.3, 58.1 and 10.6 mA M(-1) cm(-1) for fructose, H2O2 and methanol, respectively. The sensitivity values can be easily controlled by a rational deposition and manipulation of the charge in the catalytic layers. The electrostatic assembly of the electrochemical interface and the catalytic layers resulted in integrated biochemical systems in which mass transfer diffusion and heterogeneous catalytic and electron transfer steps are efficiently coupled and can be easily manipulated.

In vitro infection of cells of the monocytic/macrophage lineage with bovine leukaemia virus

The oncogenic retrovirus bovine leukaemia virus (BLV) primarily infects B cells. Most infected animals remain asymptomatic for long periods of time before an increase in circulating B cells or localized tumours can be observed. This long clinical latency period may be explained by cells of the monocyte/macrophage lineage (M/M) becoming infected and acting as a reservoir for the virus, as shown for other retroviruses (human immunodeficiency virus-1, feline immunodeficiency virus). M/M cells in different stages of differentiation (HL-60, THP-1, U-937, J774, BGM, PM2, primary macrophages of sheep and cows) were cultured with BLV produced by permanently infected donor cells (FLKBLV and BLV-bat(2)). Donor cells were inhibited from multiplying by either irradiation or treatment with mitomycin C. In other experiments, supernatant from donor cells containing virus was used. In co-culture with the donor cells, the less differentiated monocytic cells showed severe cellular changes such as differentiation, vacuolization, cell lysis and membrane blebbing; apoptosis was a frequent phenomenon. Budding and extracellular viruses were also observed. The more differentiated macrophage cells, although they showed less signs of infection by microscopy, had a complete BLV protein profile, as seen by Western blotting; bands corresponding to p24CA (Gag) and its precursors were clearly seen. In addition, gp51SU was identified by syncytia formation assays. It is concluded that M/M cells may be infected by BLV, the consequences of the infection differing according to the type of cell.

Differential inhibition of Maillard protein fluorescence by nitric oxide donors

The nitric oxide donors nitroprusside (NP) and S-nitroso-N-acetylpenicillamine (SNAP) were added repeatedly over a prolonged period into a protein fructation system of 0.05 M fructose and BSA. These additions inhibited Maillard reaction advanced-stage fluorescence generation in a dose-dependent manner without affecting initiation of glycation. NP caused 66% inhibition whereas SNAP caused only 30% inhibition at maximum dose. The lower inhibition by SNAP possibly reflects an interference caused by N-acetylpenicillamine and mediated by a metal-dependent enhanced free-radical generation. We propose that the inhibition of fluorescence results from mutual annihilation between nitric oxide and free radicals, such as OH*, produced during fructation. In vivo generated nitric oxide may play a protective role in cells against the deleterious effect of free radicals that are associated with the augmented fructose autoxidation and fructation that occurs in diabetes.

Inhibition of zinc metallopeptidases by flavonoids and related phenolic compounds: structure-activity relationships

Flavonoids and other benzopyrone substances, having an appropriate hydroxylation profile, may inhibit the metalloenzymes leucine aminopeptidase (LAP), aminopeptidase M (AP-M), and carboxypeptidase A (CP-A). A structural feature that evidently favours the interaction between flavonoids and the three metalloenzymes is the 2,3-double bond conjugating the A and B rings and conferring a planar structure. This can be considered virtually indispensable for inhibition of the three metallopeptidases, though the hydroxylation profile required differed for each of the enzymes, and the interaction mechanism and behaviour also differed. The inhibitory effect of flavonoids on LAP was reversible, and to be effective the flavonoid had to have conjugated A and B rings and ortho-dihydroxylation on at least one of the aromatic rings. This same requirement was essential for inhibition by coumarins and was attributed to a catechol-like mechanism of interaction. The inhibitory effects on AP-M were due to inactivation of the enzyme, irreversibly altered by flavonoids with a 2,3-double bond and a minimum of one hydroxyl substituent on each of the aromatic rings. With CP-A, conjugation of the A and B rings enhanced the inhibitory effect of flavonoids, though it was not strictly required. The interaction between the polyphenolic substances tested and the two zinc aminopeptidases was not reversed by adding zinc to the reaction medium, indicating that the inhibition is not due to the coordination of the phenolic hydroxyl groups with the catalytical zinc of active site, though the presence of zinc affected the interaction behaviour differently according to each substance's hydroxylation profile.

Comparison of four tests to evaluate the reactivity of rabbit sera against envelope or Gag-related proteins of bovine leukemia virus (BLV)

Bovine leukemia virus (BLV) has a long latency period during which animals are inapparently infected, may spread the disease, and are only detected by serological techniques or by the most cumbersome molecular biology techniques. We have compared techniques for detecting either total antibodies (ELISA), anti-p24 and Gag-related proteins (Western blot), or anti-gp51 (agar gel immunodiffusion, AGID, and syncytia inhibition, SI) in rabbits inoculated experimentally with inocula of variable immunogenicity. The two tests to detect antibodies to gp51 correlated well in sera clearly positive or clearly negative by either one, but correlation was poor in the intermediate groups. All sera positive by AGID were also positive by ELISA, but results did not agree in sera negative by AGID, ELISA proving to be more sensitive. Western blot was a good technique for detecting antibodies against Gag-related proteins. However, no band was identified to clearly correspond to anti-Env-related proteins. As for other retroviruses, testing of animals for infection with BLV should include the detection of antibodies anti-Gag and anti-Env proteins.

Macrophages infected with bovine leukaemia virus (BLV) induce humoral response in rabbits

BLV is a lymphotropic retrovirus which infects mainly B-cells. However, the possible infection of cells of the monocyte/macrophage lineage (M/M) might explain some aspects of the disease such as latency or disease progression. We infected sheep M/M with BLV either by culturing M/M with supernatant containing virus, or coculturing M/M with persistently infected cell lines. These BLV-infected M/M were inoculated into rabbits and the serological response was followed for two years. ELISA results using adsorbed sera showed a persistent production of specific antibodies from as early as the first week post inoculation. Two tests were used to detect the response against envelope glycoprotein gp51: Agar gel immunodiffusion (AGID) and a virus neutralization test read as syncytia inhibition (SI). Sera were positive by AGID after the second or third inoculation. Neutralizing titres (SI) were higher than those seen in control rabbits inoculated with persistently infected cell lines, suggesting that the virus may be expressed better in M/M. Gag-related proteins were analyzed by Western Blot (WB). Sera from rabbits inoculated with BLV-infected M/M recognized as many viral proteins as sera from BLV immunized control rabbits or infected cows, and this profile did not change with repeated inoculations. All these results suggest that BLV may infect M/M, where viral proteins are actively expressed to the point that they induce a humoral immune response in animals, and that animals get persistently infected.

Taxonomic note: a proposal for reviewing the interpretation of the CAMP reaction between Listeria monocytogenes and Rhodococcus equi

The discrepancies between the current description of the CAMP test between Listeria monocytogenes and Rhodococcus equi in the latest edition of Bergey's Manual of Determinative Bacteriology (L. monocytogenes is described as CAMP test negative with R. equi) and routine findings (positive reactions are usually described in many laboratories) make it advisable to review the current interpretation of the CAMP test to avoid confusion among people working in microbiological laboratories. Overall, 98.4% of the L. monocytogenes strains examined in this study, regardless of their source or the intensity of their hemolytic activity, displayed a synergic hemolytic reaction (CAMP phenomenon) with R. equi, indicating that L. monocytogenes can generally be considered CAMP positive with R. equi. We propose that L. monocytogenes, together with Listeria ivanovii, should be considered CAMP test positive with R. equi (circular or racket and semicircular or shovel shapes, respectively).

Cholesterol oxidase from Rhodococcus equi is likely the major factor involved in the cooperative lytic process (CAMP reaction) with Listeria monocytogenes

The CAMP reaction between Listeria monocytogenes and Rhodococcus equi was studied by a diffusion assay. Listeria monocytogenes displayed identical cooperative haemolytic effect with supernatant cultures of R. equi or with commercial cholesterol oxidase (COX). This result, even with enzymes of different sources (commercial COX is obtained from Pseudomonas spp.) suggests that this enzyme secreted by R. equi has a crucial role in the synergistic haemolytic (CAMP) reaction with L. monocytogenes. The mechanism of the cooperative lytic process between L. monocytogenes and R. equi may represent a different and novel mechanism reaction, in which the COX may not act as a conventional second-step factor, and a reaction different to the direct interaction with the cholesterol of the erythrocyte membrane may be involved.

[The effect of gallopamil and propranolol in patients with ischemic cardiopathy and moderate depression of ventricular function]

BACKGROUND

Calcium channel blockers have been wide and successfully used in the treatment of coronary heart disease. Gallopamil, a metoxylic derivative of verapamil, has many of its properties and so, caution is recommended when given to patients with depressed left ventricular function. Clinical studies about this effect are scarce, and we have assessed it in patients with coronary heart disease and diminished left ventricular function.

METHODS

We studied 20 patients in a cross-over, randomized, double-blind study during three weeks active periods with two intercalating washout placebo periods of one week. Patients had history of previous myocardial infarction, positive exercise stress test and ejection fraction ranging from 30% to 50% by echocardiography.

RESULTS

There were no significant differences between each drug and corresponding placebo on either systolic or diastolic function. When we compared both drugs, patients showed a milder increase in area under E after propranolol than after gallopamil (p < 0.008). Clinical episodes of cardiac failure were not reported, and ejection fraction did not change.

CONCLUSIONS

Both gallopamil and propranolol can be used in patients with coronary heart disease and moderately depressed left ventricular ejection fraction.

Fructated protein is more resistant to ATP-dependent proteolysis than glucated protein possibly as a result of higher content of Maillard fluorophores

Glycation by fructose (fructation) renders bovine serum albumin more refractory to degradation by an ATP-dependent proteolytic system from reticulocytes than glycation by glucose (glucation). It appears that the decrease in the protein's susceptibility to degradation is a complex effect of the various protein-bound moities that are generated at the different stages of the Maillard reaction and not only the result of primary amino group blockage. Advanced Maillard reaction fluorescent components may induce a decrease in proteolysis, whereas the intermediate Amadori groups possibly may enhance degradation. However, the inhibitory effect on degradation of the fluorophores would predominate at higher levels of glycation. Resistance of intracellular fructated proteins to ATP-dependent degradation may lead to alterations in the function of cells with an active sorbitol pathway and, in this way, underlie the complications of diabetes.

Prediction on admission of in-hospital mortality in patients older than 70 years with acute myocardial infarction

STUDY OBJECTIVE

To identify the differential characteristics regarding risk factors, presentation, and clinical status on hospital admission in patients aged 70 years or older with acute myocardial infarction (MI) of less than 24 h of evolution, compared with patients younger than 70 years, and to analyze possible factors that could affect mortality on admission in the group of patients older than 70 years.

STUDY DESIGN

Of 1,289 patients admitted in the coronary care unit with acute MI during the period 1988 to 1991, with a delay from onset of symptoms of less than 24 h, we defined two groups according to age: younger than 70 years (group 1) and 70 years or older (group 2) in order to analyze the possible predictive factors for mortality on hospital admission in patients older than 70 years (n = 322). By means of univariate analysis, we studied clinical variables that were present on admission; age; sex; medical history of diabetes, cerebrovascular accident, stable angina, previous MI, cardiac failure, right bundle branch block, and atrial fibrillation; previous treatment with digoxin, calcium antagonists, angiotensin-converting enzyme inhibitors (ACEI), antiaggregants or beta-blockers; location and extension of the acute MI, and thrombolysis. The association between mortality, as the dependent variable, and all other variables, as independent variables, was evaluated using a stepwise logistical regression procedure.

RESULTS

In patients older than 70 years of age, the model included the following as independent predictors of mortality: female sex (odds ratio [OR], 2.59); complete right bundle branch block (CRBBB) (OR, 4.88); Q-wave MI (OR, 0.35 for non-Q-wave MI); and Forrester grade 2 to 3 (OR, 6.36) and 4 (OR, 80.14).

CONCLUSIONS

In patients with acute MI and older than 70 years at the time of admission to the coronary care unit, together with the variables indicating the degree of hemodynamic involvement and the extension of the acute MI, factors such as female sex and CRBBB stand out as independent predictors of mortality.

Total colectomy and "J" pouch ileo-anal pull through without temporary diverting ileostomy in the management of ulcerative colitis

Anal sphincter saving operations are currently the procedures of choice for most patients with ulcerative colitis. In this study we review the experience of The Mayagüez Medical Center, Department of Surgery with 18 patients who underwent a total abdominal colectomy, rectal mucosectomy and "J" pouch ileoanal pull through without a temporary diverting ileostomy in the management of ulcerative colitis. The complications that are associated with this procedure in our patients are: wound infection, postoperative leak, early stricture and intestinal obstruction. Only one patient died and it was due to a massive pulmonary embolism. Finally, we conclude that this procedure should be reserved for well nourished, psycho-logically stable young patients who are willing to tolerate the complications associated with it.

Double-sandwich enzyme-linked immunosorbent assay (ELISA) with murine monoclonal antibodies for detection of staphylococcal enterotoxin B

Three monoclonal antibodies (MAbs) which react specifically with staphylococcal enterotoxin B (SEB) were studied for their suitability for use in ELISA. One of them (MAb B14) worked well as a coating antibody; MAb B12 was shown to be a good probing antibody (conjugated with peroxidase) when ELISA plates were coated with MAb B14. This effective pair of MAbs (B14-B12PO) is able to detect 0.625 ng SEB ml, and to distinguish between SEB and other proteins present in food extracts.

Transformation of Aspergillus parasiticus using autonomously replicating plasmids from Aspergillus nidulans

A genetic transformation system for the aflatoxin-producing fungus Aspergillus parasiticus using two autonomously replicating plasmids from A. nidulans (ARp1 and pDHG25) is reported. Transformation frequencies using the plasmid pDHG25 were from 5 x 10(2) to 2.5 x 10(4) transformants per 10(6) viable protoplasts and microgram DNA. The stability of the plasmids in the transformants was also studied. This transformation system offers a new opportunity to clone genes related to aflatoxin production using appropriate aflatoxin-defective mutants.

A red pigment synthesized by an Aspergillus parasiticus mutant as a possible new intermediate in the aflatoxin biosynthetic pathway

The isolation of a red pigment from an Aspergillus parasiticus mutant obtained by 366 nm u.v. light treatment of A. parasiticus NRRL 2999 is described. Studies of conversion in aflatoxin B1 and G1 suggest that the red pigment could be a possible new intermediate in the aflatoxin biosynthetic pathway not described to date, and this has been verified by studies in gas chromatography/mass spectrometry. The solubility and stability characteristics under refrigeration storage, and the influence of the temperature and the pH on its production by the A. parasiticus mutant were also studied. It grew best at 30 degrees C and pH 6. The red pigment was most soluble in ethyl acetate. The results obtained in water are emphasized where there was high stability.

Chloramphenicol extraction from milk by using the diphasic dialysis method followed by liquid chromatographic determination

An economical, fast, and simple method for the extraction and liquid chromatographic determination of chloramphenicol (CAP) in milk is described. CAP is extracted by using a recently developed membrane-based method named "diphasic dialysis." CAP is detected and quantitated in the organic solvent used in dialysis without additional cleanup steps by reversed-phase liquid chromatography and UV detection (270 nm). The determination limit of CAP in milk was about 5 micrograms/L, although as little as 1 microgram/L could be detected under optimal working conditions.

Transduodenal sphincteroplasty--how we do it

Transduodenal Sphincteroplasty can be performed in a simple reproducible and low morbidity fashion. The surgical technique used by the Department of Surgery of the Mayagüez Medical Center is presented.

[Myocardial infarct during pregnancy. Treatment of the acute phase and of labor. Apropos a case and a review of the literature]

An acute myocardial infarction, is an infrequent complication in pregnant women. We present the case of a 29-years-old patient who suffered 2 acute myocardial infarction in relation with her two pregnancies. The first acute myocardial infarction occurred the third day after delivery, and the second, during the seventh month of the second pregnancy. In the latter, delivery was vaginal, with epidural anaesthesia. A coronary angiogram showed coronary arteries without significant narrowings, as well as an aneurysm of the left ventricle. A review of the literature published so far is made in the discussion.

An Inverted Double Seismic Zone in Chile: Evidence of Phase Transformation in the Subducted Slab

Data from two microseismic field experiments in northern Chile revealed an elongated cluster of earthquakes in the subducted Nazca plate at a depth of about 100 kilometers in which down-dip tensional events were consistently shallower than a family of compressional earthquakes. This double seismic zone shows a distribution of stresses of opposite polarity relative to that observed in other double seismic zones in the world. The distribution of stresses in northern Chile supports the notion that at depths of between 90 to 150 kilometers, the basalt to eclogite transformation of the subducting oceanic crust induces tensional deformation in the upper part of the subducted slab and compressional deformation in the underlying mantle.

[The female sex and mortality after acute myocardial infarct]

INTRODUCTION

To study the possible influence of gender on in-hospital mortality in patients suffering acute myocardial infarction.

PATIENTS AND METHODS

We analyzed 1,951 consecutive patients admitted to our Coronary Unit between January 1986 and December 1991 with this diagnosis and with a delay of no more than 24 hours prior to admission.

RESULTS

In-hospital mortality was 12.8% in the 1,603 males and 25.6% in the 348 females (p < 0.001). Age, previous history of: not smoking, diabetes, heart failure, stable angina, myocardial infarction, stroke, right branch block, atrial fibrillation, and treatment with digoxin were variables significantly associated with greater mortality (p < 0.05) as well as the localization of the infarction, the Forrester grade and/or presence of atrioventricular block on admission and not treatment with intravenous fibrinolytics and beta-blockers. Multivariate analysis of variables associated with mortality (selection criterion for variable entry p < 0.20) shows that age, gender, previous angina, situation and extension of the infarction determined by ECG and Forrester on admission are independent predictors of in-hospital mortality.

CONCLUSIONS

Gender is an independent predictor of in-hospital mortality in acute myocardial infarction (female/male odds ratio = 1.63).

Age-dependent structural changes in intact human lenses detected by synchrotron radiation X-ray scattering. Correlation with Maillard reaction protein fluorescence

To understand alterations in the spatial organization of the crystallins, the major determinant of lens transparency, the x-ray scattering by intact normal human lenses from individuals 6-82 years of age was measured using synchrotron radiation. The angular dependence of the integrated scattering intensity is consistent with short-range order within the crystallin assemblies. A significant change in the scattering patterns of the lenses occurs after 55 years of age, in parallel with an increase of the fluorescence of the urea-insoluble crystallin fraction. This correlation suggests a gradual derangement of the short-range order as a result of cross-linking of the crystallin subunits by advanced Maillard reaction products that are generated by the continuous reaction of sugars, such as glucose or fructose, with proteins.

Serological response in rabbits to Listeria monocytogenes after oral or intragastric inoculation

The serological response in rabbits against Listeria monocytogenes after oral or intragastric inoculation was investigated. Both the number of sero-positive animals and the average serum titres were higher in animals inoculated by the oral route. This difference was especially marked in rabbits inoculated with the lower dose (1 x 10(3) colony-forming units (cfu)), which developed a strong serological response (average serum titre of 1280 after 4 inoculations) in most of the inoculated animals (80%), without any clinical signs. The implication of these results in the epidemiology of listeriosis is discussed.

Repair and enterotoxin synthesis by Staphylococcus aureus after thermal shock

To study repair and enterotoxin synthesis, four staphylococcal strains (FRI-100, FRI-137, FRI-472, and S6) were subjected to sublethal heat treatment, transferred to four liquid repair media (1% powdered skim milk in distilled water, complex medium, M9 minimal salt medium, and saline solution), and then incubated at different temperatures. Powdered skim milk proved to be the most efficient medium for promoting the repair of injured cells, particularly at 37 degrees C. Minimal salt medium also gave good results. Salt tolerance also increased at 4 degrees C, although it did not reach normal values. After 6 h of incubation at 37 degrees C in powdered skim milk, strain FRI-100 synthesized detectable amounts of enterotoxin A. After 10 h of incubation in the same medium at the same temperature, enterotoxins were detected in all of the strains.

Experimental intramammary infection of ewes with Staphylococcus aureus subsp anaerobius

The susceptibility of the ovine mammary gland to experimental infection with Staphylococcus aureus subsp anaerobius was studied in five lactating Churra ewes. The left mammary gland of each ewe was inoculated with bacteria while the right halves remained untreated and served as a control. A rapid cellular response was elicited in all inoculated glands. The reaction of inoculated mammary glands varied from that of clinical mastitis (ewes C and D) to subclinical mastitis (ewes B and E) or merely to a transient increase of somatic cell counts (ewe A). S aureus subsp anaerobius is less pathogenic for ewes by the intramammary route than S aureus since doses of about 10(8) bacteria caused clinical mastitis in only two of the inoculated animals.

Determination of patulin by reversed-phase high-performance liquid chromatography with extraction by diphasic dialysis

A simple and economical method has been developed for the determination of patulin in apple juice. The sample is extracted with ethyl acetate in a diphasic dialysis system, and the extract is cleaned up by elution from a Sep-Pak cartridge. Patulin is detected and determined by reversed-phase high-performance liquid chromatography using a Novapak C18 column and an ultraviolet detector. The lower detection limit is 1 microgram l-1 and the recovery is 85% at the 20 micrograms l-1 level.

Evaluation of complement activity by an enzyme immunoassay

An ELISA-type assay useful for the evaluation of the complement activity in serum is described. Aggregated pooled human IgG (IgGn) prepared so as to exclude large and small aggregates, to resemble soluble circulating immune complexes, was used to coat polystyrene microwells to serve as initiator of complement activation. Fresh serum, at different dilutions, as the source of the complement to be evaluated was added and the plate incubated 90 min at 37 degrees C. Then, a peroxidase-labeled antihuman C3c antibody was added to react with the bound C fragments. This was followed by 2,2'-azino-di-3-ethyl benzothiazoline sulfonic acid (ABTS), as the color reagent used for detection of the enzyme activity. In this system, theoretically, the levels of activating and regulatory complement components are evaluated up to the level of C3 splitting. The assay was applied in healthy volunteers to set normal values and in 15 patients suffering from systemic lupus erythematosus making possible the differentiation of those with normal and low complement levels.

Applicability of an immunoblot technique combined with a semiautomated electrophoresis system for detection of staphylococcal enterotoxins in food extracts

We studied the usefulness of an immunoblot technique for the detection of staphylococcal enterotoxins (SEs) in strains and food extracts. Food samples (milk, yogurt, hot dog sausage, cheese, and mayonnaise) were artificially contaminated with SEA through SEE. Protein A did not interfere with the results; it appeared on electrophoresis gels as bands with molecular weights higher than those of the SEs. Other food proteins were not revealed by the technique. The immunoblot technique proved to be fast, specific, and sensitive for the detection of SEs in foods.

Murine monoclonal antibodies against staphylococcal enterotoxin B: production and characterization

A group of 14 monoclonal antibodies (mAbs) to staphylococcal enterotoxin B (SEB) were obtained by fusion of Sp2/O myeloma cells with spleen cells from female BALB/c mice immunized with commercial SEB. The antibodies belonged to IgG1 and IgG2b subclasses. We evaluated the anti-SEB titres, competition assays and sensitivity of detection by indirect ELISA. Reactivity and cross-reactivity were also studied by indirect ELISA and confirmed by immunoblotting. All the mAbs reacted with SEB and with a second band which had a different electrophoretic mobility and probably represents an aggregate of SEB or SEB bound to membranes. Three mAbs reacted only with SEB and the rest showed cross-reactions with SEC1. No reactions were observed against any other serovar (SEA, SED and SEE) or other proteins.