Gas embolization of the liver in a rat model of rapid decompression

Occurrence of liver gas embolism after rapid decompression was assessed in 31 female rats that were decompressed in 12 min after 42 min of compression at 7 ATA (protocol A). Sixteen rats died after decompression (group I). Of the surviving rats, seven were killed at 3 h (group II), and eight at 24 h (group III). In group I, bubbles were visible in the right heart, aortic arch, liver, and mesenteric veins and on the intestinal surface. Histology showed perilobular microcavities in sinusoids, interstitial spaces, and hepatocytes. In group II, liver gas was visible in two rats. Perilobular vacuolization and significant plasma aminotransferase increase were present. In group III, liver edema was evident at gross examination in all cases. Histology showed perilobular cell swelling, vacuolization, or hydropic degeneration. Compared with basal, enzymatic markers of liver damage increased significantly. An additional 14 rats were decompressed twice (protocol B). Overall mortality was 93%. In addition to diffuse hydropic degeneration, centrilobular necrosis was frequently observed after the second decompression. Additionally, 10 rats were exposed to three decompression sessions (protocol C) with doubled decompression time. Their mortality rate decreased to 20%, but enzymatic markers still increased in surviving rats compared with predecompression, and perilobular cell swelling and vacuolization were present in five rats. Study challenges were 1) liver is not part of the pathophysiology of decompression in the existing paradigm, and 2) although significant cellular necrosis was observed in few animals, zonal or diffuse hepatocellular damage associated with liver dysfunction was frequently demonstrated. Liver participation in human decompression sickness should be looked for and clinically evaluated.

Automatic detection of sleep macrostructure based on bed sensors

This study analyses the spectral components of the heart rate fluctuations of a new contact-less technology for sleep evaluation. Both heart beat interval (HBI) and movement activity were extracted from the multichannel ballistocardiographic (BCG) measurements, based on Emfit sensor foils placed into bed mattress. Powers spectral densities (PSD) of HBI have been compared with the ones obtained from the standard ECG during sleep stage 2. In addition, spectral features obtained from the contact-less technology and standard ECG has been used to automatically classify the sleep macrostructure through a time-varying autoregressive model and a Hidden Markov Model. Whole night recordings from six subjects were analyzed in this study. Spectral components did not show significant differences between the two measurements. Further, contactless technology achieved a total accuracy of 83 % and kappa index of 0.42, while standard ECG achieved an accuracy of 84 % and kappa index of 0.43 when compared to clinical sleep staging from polysomnography.

Sleep staging classification based on HRV: time-variant analysis

An algorithm to evaluate the sleep macrostructure based on heart rate fluctuations from ECG signal is presented. This algorithm is an attempt to evaluate the sleep quality out of sleep centers. The algorithm is made up by a) a time-variant autoregressive model used as feature extractor and b) a hidden Markov model used as classifier. Characteristics coming from the joint probability of HRV features were used to fed the HMM. 17 full polysomnography recordings from healthy subjects were used in the current analysis. When compared to Wake-NREM-REM given by experts, the automatic classifier achieved a total accuracy of 78.21+/-6.44% and a kappa index of 0.41+/-.1085 using two features and a total accuracy of 79.43+/-8.83% and kappa index of 0.42+/-.1493 using three features.

Preliminary use of ground-penetrating radar and electrical resistivity tomography to study tree roots in pine forests and poplar plantations

In this study, we assess the possibility of using ground penetrating radar (GPR) and electrical resistivity tomography (ERT) as indirect non-destructive techniques for root detection. Two experimental sites were investigated: a poplar plantation [mean height of plants 25.7 m, diameter at breast height (dbh) 33 cm] and a pinewood forest mainly composed of Pinus pinea L. and Pinus pinaster Ait. (mean height 17 m, dbh 29 cm). GPR measures were taken using antennas of 900 and 1500 MHz applied in square and circular grids. ERT was previously tested along 2-D lines, compared with GPR sections and direct observation of the roots, and then using a complete 3-D acquisition technique. Three-dimensional reconstructions using grids of electrodes centred and evenly spaced around the tree were used in all cases (poplar and pine), and repeated in different periods in the pine forest (April, June and September) to investigate the influence of water saturation on the results obtainable. The investigated roots systems were entirely excavated using AIR-SPADE Series 2000. In order to acquire morphological information on the root system, to be compared with the GPR and ERT, poplar and pine roots were scanned using a portable on ground scanning LIDAR. In test sections analysed around the poplar trees, GPR with a high frequency antenna proved to be able to detect roots with very small diameters and different angles, with the geometry of survey lines ruling the intensity of individual reflectors. The comparison between 3-D images of the extracted roots obtained with a laser scan data point cloud and the GPR profile proved the potential of high density 3-D GPR in mapping the entire system in unsaturated soil, with a preference for sandy and silty terrain, with problems arising when clay is predominant. Clutter produced by gravel and pebbles, mixed with the presence of roots, can also be sources of noise for the GPR signals. The work performed on the pine trees shows that the shape, distribution and volume of roots system, can be coupled to the 3-D electrical resistivity variation of the soil model map. Geophysical surveys can be a useful approach to root investigation in describing both the shape and behaviour of the roots in the subsoil.

Building a topological and geometrical model of poplar tree using portable on-ground scanning LIDAR

The objectives of this research were to investigate the suitability of advanced technologies like 3D-Laser scanning to acquire fair and sound information on structural and architectural characteristics of poplar stand, and to map topology of above-ground tree structures. The study area was an intensive poplar plantation located ~10 km north-west of the city of Pavia within the 'Parco Regionale del Ticino', Italy. A forest inventory of the poplar stand was conducted in 2005 and three 14-year-old poplar trees were selected and felled. The main architectural characteristics of poplar trees (destructive measurement) were compared with indirect measurement carried out using a portable on-ground scanning LIDAR IMAGER 5003 combined with the JRC-Reconstructor and AMAPmod softwares. The method permitted us to make an accurate estimate of the vertical and horizontal structure of the stand, to evaluate the stem and branches morphology of selected trees at different height in the canopy, and to create and validate multiscale representations of poplar tree architecture.

Diffraction of partially coherent X-rays in clessidra prism arrays

When small triangular prisms are arranged in arrays which have an overall appearance like an hourglass (in Italian: clessidra) they can focus X-rays owing to a combined action of diffraction and refraction. From the optical point of view these objects can be regarded as a Fresnel variant of concave transmission lenses. Consequently they can provide larger apertures than purely refractive lenses. However, one has to recognize that clessidra lenses will strongly diffract as the lens structure is periodic in the direction perpendicular to the incident beam. In experiments the diffraction is reduced because it is difficult to illuminate the large apertures with a full spatially coherent wavefront. So the illumination is at best partially coherent. In order to interpret available experimental data for this condition, diffraction theory has been applied appropriately to the clessidra structure, taking into account the limited spatial coherence. The agreement between the theoretical simulations and experimental data is very good, keeping the lens properties at their projected values and allowing for only two free model parameters. The first is the lateral spatial coherence; the second is a lens defect, a rounding of all edges and tips in the structure. Both values obtained from the simulations have been found to be in agreement with expectations.

Whole-body evaluation of MIBG tissue extraction in a mouse model of long-lasting type II diabetes and its relationship with norepinephrine transport protein concentration

Accelerated cardiac washout of (123)I-metaiodobenzylguanidine (MIBG), which is clinically used as an index of cardiac neuropathy in diabetes, is ascribed to decreased norepinephrine reuptake into synaptic vesicles. However, accelerated washout frequently contrasts with preserved early tracer uptake, whose significance remains undetermined. The aim of this study was to investigate in a mouse model of long-lasting type II diabetes whether the mismatch between MIBG early uptake and washout is the consequence of a more generalized disorder of the autonomic nervous system.

METHODS

Nine mice were given low doses of streptozotocin by intraperitoneal injection for 5 consecutive days. At 7 mo after streptozotocin, MIBG kinetics were evaluated by heart and liver time-activity curves and by tracer accumulation in the bladder. Data were compared with those obtained in 10 sham mice and correlated with the cardiac and hepatic tissue expression of norepinephrine transporter (NET) as assessed with a (3)H-desipramine saturation binding assay.

RESULTS

In diabetic mice, myocardial and liver MIBG retention was reduced at 2 h and was associated with both increased tracer washout and reduced NET density. The rate of myocardial washout correlated with the degree of urinary MIBG excretion.

CONCLUSION

The paradoxic observation of preserved early uptake associated with accelerated washout of MIBG in diabetes seems to be explained by a generalized disorder in NET function leading to reduced whole-body tracer removal from the blood and increased tracer availability for early myocardial uptake.

On the use of clessidra prism arrays in long-focal-length X-ray focusing

Clessidra (hour-glass) X-ray lenses have an overall shape of an old hour glass, in which two opposing larger triangular prisms are formed of smaller identical prisms or prism-like objects. In these lenses, absorbing and otherwise optically inactive material was removed with a material-removal strategy similar to that used by Fresnel in the lighthouse lens construction. It is verified that when the single prism rows are incoherently illuminated they can be operated as independent micro-lenses with coinciding image positions for efficient X-ray beam concentration. Experimental data for the line width and the refraction efficiency in one-dimensional focusing are consistent with the expectations. Imperfections in the structures produced by state-of-the-art deep X-ray lithography directed only 35% of the incident intensity away from the image and widened it by just 10% to 125 microm. An array of micro-lenses with easily feasible prism sizes is proposed as an efficient retrofit for the refocusing optics in an existing beamline, where it would provide seven-fold flux enhancement.

An approach to the design of reinforcement functions in real world, agent-based applications

The success of any reinforcement learning (RL) application is in large part due to the design of an appropriate reinforcement function. A methodological framework to support the design of reinforcement functions has not been defined yet, and this critical and often underestimated activity is left to the ability of the RL application designer. We propose an approach to support reinforcement function design in RL applications concerning learning behaviors for autonomous agents. We define some dimensions along which we can describe reinforcement functions; we consider the distribution of reinforcement values, their coherence and their matching with the designer's perspective. We give hints to define measures that objectively describe the reinforcement function; we discuss the trade-offs that should be considered to improve learning and we introduce the dimensions along which this improvement can be expected. The approach we are presenting is general enough to be adopted in a large number of RL projects. We show how to apply it in the design of learning classifier systems (LCS) applications. We consider a simple, but quite complete case study in evolutionary robotics, and we discuss reinforcement function design issues in this sample context.

Discovery of TH-302: An achiral hypoxia-activated cytotoxic prodrug

3515

Background: Selective targeting of the hypoxic compartment of the tumor microenvironment is both a challenge and an opportunity for discovering and developing new cancer therapeutics. Chronic and transient hypoxia underlie resistance to chemotherapeutics and radiation. We have taken a modular design approach to synthesize hypoxia-activated prodrugs. Different nitro-containing heterocyclic triggers were linked to bis alkylating phosphorous mustard toxins and profiled in in vitro and in vivo assays predictive of compound efficacy and pharmacokinetics (PK). Methods: Drug candidates were synthesized and characterized using standard synthetic methods. In vitro efficacy was assessed with cancer cell line cytotoxicity and clonogenic assays. In vivo efficacy was assessed with xenograft models in monotherapy and combination therapy modes. Results: Screening trigger-toxin combinations in H460 lung cancer cell proliferation assays under anoxic, hypoxic, and aerobic conditions yielded structure-activity relationships (SAR) and identified TH- 302, a 2-nitroimidazole triggered bromo analog of ifosfamide, as a potent and selective molecule. TH-302 exhibits in vitro proliferation IC50 values of 0.2, 5, and 90μM and clonogenic IC90 values of 0.1, 5, and 30μM under conditions of 0%, 0.6%, and 21% O2, respectively. In vitro profiling showed sufficient solubility, plasma and microsomal stability, resistance to drug efflux mechanisms, and PK. In vivo efficacy was assessed with the H460 ectopic xenograft model. TH-302 administered alone (100mpk, ip, Q3Dx5) or in combination with cisplatin (6mpk, iv, Q7Dx2) showed mean tumor volume growth delays to 500mm3 (TGD500) of 10 days for TH-302 alone, 4 days for cisplatin alone, and 20 days for the combination. These results have been confirmed and extended using different tumor models, dosing regimens, and combinations which included Taxol and 5-FU. TH-302 demonstrates dose-proportional PK in multiple species. Conclusions: TH-302, a novel hypoxia-activated cytotoxic prodrug, has promising preclinical in vitro and in vivo efficacy and selectivity and has entered IND-enabling studies. Acute and subchronic toxicology is underway in rats and dogs. We expect to file an IND for clinical studies of TH-302 this year.

No significant financial relationships to disclose.

Analysis of heart rate variability to predict patient age in a healthy population

OBJECTIVES

To estimate age of healthy subjects by means of the heart rate variability (HRV) parameters thus assessing the potentiality of HRV indexes as a biomarker of age.

METHODS

Long-term indexes of HRV in time domain, frequency domain and non-linear parameters were computed on 24-hour recordings in a dataset of 63 healthy subjects (age range 20-76 years old). Then, as interbeat dynamics markedly change with age, showing a reduced HRV in older subjects, we tried to capture age-related influence on HRV by principal component analysis and to predict the subject age by means of a feedforward neural network.

RESULTS

The network provides good prediction of patient age, even if a slight overestimation in the younger subjects and a slight underestimation in the older ones were observed. In addition, the important contribution of non-linear indexes to prediction is underlined.

CONCLUSIONS

HRV as a predictor of age may lead to the definition of a new biomarker of aging.

On the feasibility of large-aperture Fresnel lenses for the microfocusing of hard X-rays

Like visible light, X-rays can also be focused by refraction in transmission lenses. For visible light this requires convex lenses while for X-rays one needs to use concave lenses instead. Both lens types can be lightened by the material removal strategy introduced by Fresnel, which results in a lens subdivided into zones. Until now, for the focusing of X-rays, stacks of standard lenses and of Fresnel lenses have mostly been produced. The first are dubbed compound refractive lenses, abbreviated as CRL. State-of-the-art systems of this kind now achieve almost theoretical performance for the focus size and the transmission. On the other hand, the latter Fresnel systems, which promise to provide larger apertures, are still in their infancy. This report discusses systematically the properties of two possible schemes for their realisation. It then compares the optimized apertures of these two schemes with those for CRLs. The best Fresnel lenses in this study are found to provide experimentally more than 50% of the expected refraction efficiency at 8.5 keV photon energy. The photon flux in their focus is then almost identical to that of perfect Be CRLs with the same focal length. This report will also interpret experimental data reported previously for other Fresnel lenses.

Direct Investigation of Orbital Ordering in a Colossal Magnetoresistance Manganite by Means of X-ray Linear Dichroism at the Mn L Edge

We have investigated for the first time the orbital ordering in a three-dimensional colossal magnetoresistance manganite, namely La(7/8)Sr(1/8)MnO3, by applying soft X-ray linear dichroism (XLD) to the Mn L edge. We found that the cooperative Jahn-Teller distorted orthorhombic phase, which is present at a temperature of 240 K, is probably accompanied by a predominantly cross type (x2 - z2)/(y2 - z2) orbital ordering. This result is discussed in the light of different exchange interaction models.

Uptake and utilization of nucleosides for energy repletion

In this paper, we report that cells undergoing metabolic stress conditions may use the ribose moiety of nucleosides as energy source to slow down cellular damage. In fact, the phosphorolytic cleavage of the N-glycosidic bond of nucleosides generates, without energy expense, the phosphorylated pentose, which through pentose phosphate pathway and glycolysis, can be converted to energetic intermediates. In this respect, nucleosides may be considered as energy source, alternative or supplementary to glucose, which may become of primary importance especially in conditions of cellular stress. In accordance with the role of these compounds in energy repletion, we also show that the uptake of nucleosides is increased when the energetic demand of the cell is enhanced. As cell model, we have used a human colon carcinoma cell line, LoVo, and the depletion of ATP, with a concomitant fall in the cell energy charge, has been induced by exclusion of glucose from the medium and pre-incubation with oligomycin, an inhibitor of oxidative phosphorylation. In these conditions of energy starvation, we show that the uptake of 2'-deoxyadenosine in LoVo cells is significantly enhanced, and that the phosphorylated ribose moiety of inosine can be used for energy repletion through anaerobic glycolysis. Our data support previous reports indicating that the phosphorylated ribose stemming from the intracellular catabolism of nucleosides may be used in eukaryots as energy source, and advance our knowledge on the regulation of the uptake of nucleosides in eukaryotic cells.

Electronic Structure of A- and B-Site Doped Lanthanum Manganites: A Combined X-ray Spectroscopic Study

The electronic properties of a series of colossal magnetoresistance (CMR) compounds, namely LaMnO3, La(1-x)Ba(x)(MnO3 (0.2 < or = x < or = 0.55), La(0.76)Ba(0.24)Mn(0.84)Co(0.16)O3, and La(0.76)Ba(0.24)Mn(0.78)Ni(0.22)O3, have been investigated in a detailed spectroscopic study. A combination of X-ray photoelectron spectroscopy (XPS), X-ray emission spectroscopy (XES), X-ray absorption spectroscopy (XAS), and resonant inelastic X-ray scattering (RIXS) was used to reveal a detailed picture of the electronic structure in the presence of Ba, Co, and Ni doping in different concentrations. The results are compared with available theory. The valence band of La(1-x)()Ba(x)MnO3 (0 < or = x < or = 0.55) is dominated by La 5p, Mn 3d, and O 2p states, and strong hybridization between Mn 3d and O 2p states is present over the whole range of Ba concentrations. Co-doping at the Mn site leads to an increased occupancy of the e(g) states near the Fermi energy and an increase in the XPS valence band intensity between 0.5 and 5 eV, whereas the Ni-doped sample shows a lower density of occupied states near the Fermi energy. The Ni d states are located in a band spanning the energy range of 1.5-5 eV. XAS spectra indicate that the hole doping leads to mixed Mn 3d-O 2p states. Furthermore, RIXS at the Mn L edge has been used to probe d-d transitions and charge-transfer excitations in La(1-x)Ba(x)MnO3.

Focusing X-rays with simple arrays of prism-like structures

This report discusses the optimization strategy, the theoretical background and first experimental data of a new refractive lens for focusing X-rays. In order to reduce the absorption of X-rays in this transmission lens, optically passive material was removed from the necessarily concave lens shape in a highly regular pattern. The feature dimensions require lens production and replication by deep X-ray lithography, which allows shaping in only one dimension. Consequently such a lens can focus in one direction only, so a crossed lens pair is needed for two-dimensional focusing. The single lens is composed of two large prisms of millimetre size, which touch each other at one of the tips, like an old sand clock. Each large prism contains a highly regular structure of essentially identical prism-like smaller segments. The first lens prototypes focused an X-ray beam with a vertical size of 500 microm and a photon energy of 8 keV to a line with a width of only 2.8 microm. This is only slightly worse than the line width of 1.73 microm expected for its focal length of f = 2.18 m. The photon density enhancement in the focus was 25, but could have been larger as the lens can intercept a beam height of 2.6 mm.

[4 + 2] cycloadditions of nitroalkenes in water. Highly asymmetric synthesis of functionalized nitronates

The [4 + 2] cycloadditions of (E)-2-aryl-1-cyano-1-nitroalkenes 1 with achiral and enantiopure vinyl ethers 2 and 3 carried out in sole water are reported. These reactions occur in a heterogeneous phase under mild conditions and are fast and highly stereoselective. By using (-)-N,N-dicyclohexyl-(1S)-isoborneol-10-sulfonamide as a chiral auxiliary, the cycloadditions are totally asymmetric. The face selectivity is discussed in terms of the shape of the chiral auxiliary and the reactive conformation of vinyl ether.

[Maternal smoking in pregnancy]

OBJECTIVE

In the last years has been a progressive increase of tabagism in the female sex. This study wanted to examine the influence of the pregnancy on voluntary practices and especially on smoking.

PATIENTS AND METHODS

140 women with a mean age of 33.05 years and with a mean gestational age of 28.56 weeks (range 5-42) were interviewed. Each one received a questionnaire about social and psychosocial status, a schedule about style of living (CAGE), a questionnaire "How much do you drink" (from SQQ) and a series of questions about smoking.

RESULTS AND CONCLUSIONS

Our study suggests that the tabagism decreases in the greatest part of pregnant women, and them increases again after child birth. Pregnancy gets women both to finish and to decrease smoking apart from social status and any variant contemplated.

[Lifestyle and drinking habits during pregnancy]

BACKGROUND

It has been reported that a high consumption of alcohol during pregnancy is correlated to fetal alcohol syndrome and other perinatal problems. Less is known about the effects linked to moderate and limited drinking during pregnancy.

METHODS

A study was carried out in 140 pregnant women: the mean age was 33.05 +/- 5.22, whereas the gestational age was 28.56 +/- 12.1 weeks (range 5-42). Each woman was asked to compile a form giving personal details and details of psychosocial behaviour, a lifestyle questionnaire (CAGE) and a form entitled "How much do you drink" based on SQQ.

RESULTS

22.2% of women reported that they had drunk alcohol during the month prior to the interview. Of these, 15% had not altered their habits, 0.8% had increased their alcohol consumption and 6.4% had reduced it. Wine was the form of alcohol most frequently consumed. Only one woman was positive to the SQQ test, and only one pregnant woman was positive to CAGE.

CONCLUSIONS

This study shows that dietary behaviour was correct in the majority of cases.

The Italian version of the Family Assessment Device

The aim of the study was to evaluate in a heterogeneous. Italian sample (n = 340) the psychometric properties of the Italian version of the Family Assessment Device (FAD), a 60-item questionnaire assessing family functioning. The questionnaire was administered to psychiatric (n = 116), medical (n = 114) and non-clinical samples (n = 110). In a sample of 30 non-clinical subjects the temporal stability of the FAD was investigated. The results showed a good temporal stability for Problem Solving, General Functioning. Communication, and Affective Responsiveness scales, and a good internal reliability of the scale. Factor analysis of the Italian version provided discrepancies with the hypothesized structure of the instrument, leading to the identification of seven slightly different dimensions. The proposed seven-factor model of the instrument did not provide a good fit to our data. The results of our study suggest the need for a major improvement in the adaptation of the FAD in the Italian setting.

Oligonucleotide analogues: an overview

The medicinal chemistry effort directed toward improving antisense and antigene oligonucleotides has synthesized a large number of phosphate, ribose and heterocyclic base analogues. The phosphorothioate linkage is currently still the analogue linkage of choice for antisense studies. This is despite many years of effort to find alternatives that overcome the limitations of phosphorothioates. A number of modifications to phosphate and ribose have resulted in enhanced binding to RNA as measured by Tm, but generally the biological effects have been less dramatic. Currently, the most potent oligonucleotides have capitalized on recruiting the cellular enzyme RNase H to perform sequence-specific destruction of a targeted RNA. Virtually all modifications to phosphate or ribose other than phosphorothioate result in the loss of this recruitment. Chimeric strategies have overcome this limitation. Affinity and potency can additionally be improved by modifying the Watson-Crick-pairing heterocycles. Recent years have brought much consensus in terms of the mechanism of action of antisense oligonucleotides. A controversial area is the ability of oligonucleotides to permeate cells in whole animals. This issue will determine if antisense and triple helix technology results in practical broad-based therapeutics.

Pheochromocytoma in dogs: 61 cases (1984-1995)

This report presents the clinical, laboratory, imaging, and pathologic findings in 61 dogs with pheochromocytoma by retrospective evaluation of medical records. Pheochromocytomas were diagnosed by histopathologic examination of tissue specimens in all dogs. Special stains (chromogranin A and synaptophysin) also were used to confirm the chromaffin cell origin of the tumors. Epidemiologic findings were in agreement with previous studies, indicating that pheochromocytomas affect middle-aged to older dogs with no apparent gender or breed predilection. The tumor was considered clinical in 21 dogs (34%), was responsible for abnormalities related to a space-occupying mass in 7 dogs (11%), and was an incidental finding in 35 dogs (57%). The hematologic and biochemical findings were nonspecific. Hypertension was detected in 10 of 23 (43%) dogs tested, but all hypertensive dogs had concurrent diseases that may have contributed to hypertension. Abdominal ultrasonography was the most commonly used imaging procedure, with a mass detected in the region of the adrenal glands in 20 of 40 (50%) dogs examined. In 4 of the 20 dogs (20%), invasion of the caudal vena cava was identified. Surgery was performed in 17 dogs (28%) with immediate death or euthanasia of 5 dogs. Survival after surgery ranged from 1 day to 3.25 years. Pheochromocytomas were locally invasive in 39% of affected dogs and produced metastases in 13% of the cases. Common sites for metastases included regional lymph nodes, liver, lung, kidney, spleen, and bone. A high frequency of concurrent neoplasia (54%), including endocrine neoplasia, was identified.

Initial small-volume hypertonic resuscitation of shock and brain injury: short- and long-term effects

BACKGROUND

Initial small-volume hypertonic saline resuscitation of a combined hemorrhagic shock and head injury model was studied.

METHODS

Twenty-three sheep underwent hemorrhage (20 mL/kg) and parietal freeze injury followed by initial bolus resuscitation with lactated Ringer's solution (40 mL/kg) or 7.5% hypertonic saline (HS) (4 mL/kg). Cardiac index was maintained with lactated Ringer's solution for either 2 or 24 hours. Parietal lobe water content, blood volume, and blood flow were determined. Intracranial pressure (millimeters of mercury) was followed.

RESULTS

Overall fluid requirements (milliliters per kilogram) were less at 2 and 24 hours with HS resuscitation. Early intracranial pressure was less with HS resuscitation. Brain water contents were similar between groups. Blood flow in injured and blood volume in uninjured parietal lobe were less for HS at 2 hours, although not different at 24 hours.

CONCLUSIONS

Less fluid was needed in the short- and long-term with HS resuscitation. Early intracranial pressure was higher with lactated Ringer's solution resuscitation, possibly in part owing to increased blood volume.

Inhibition of dengue virus by novel, modified antisense oligonucleotides

Five different target regions along the length of the dengue virus type 2 genome were compared for inhibition of the virus following intracellular injection of the cognate antisense oligonucleotides and their analogs. Unmodified phosphodiester oligonucleotides as well as the corresponding phosphorothioate oligonucleotides were ineffective in bringing about a significant inhibition of the virus. Novel modified phosphorothioate oligonucleotides in which the C-5 atoms of uridines and cytidines were replaced by propynyl groups caused a significant inhibition of the virus. Antisense oligonucleotide directed against the target region near the translation initiation site of dengue virus RNA was the most effective, followed by antisense oligonucleotide directed against a target in the 3' untranslated region of the virus RNA. It is suggested that the inhibitory effect of these novel modified oligonucleotides is due to their increased affinity for the target sequences and that they probably function via an RNase H cleavage of the oligonucleotide:RNA heteroduplex.

Hypertonic saline (7.5%) versus mannitol: a comparison for treatment of acute head injuries

Hypertonic saline (7.5% NaCl = HS) was compared with 20% mannitol (MAN), for the treatment of increased intracranial pressure (ICP), in a large animal model of head injury. Sheep were instrumented for hemodynamic and ICP monitoring and fluid administration. Elevated ICP (20-25 mm Hg) was produced by inflating an epidural balloon for 1 hour. Animals were then given a bolus of 250 mL of either HS (n = 7) or MAN (n = 7) and monitored for 2 hours. No significant differences in hemodynamic variables were noted between groups. The ICP decreased to the same degree in both groups during the 2 hours of observation (HS = 11 +/- 3.8 mm Hg; MAN = 8 +/- 2 mm Hg). Brain water contents were also similar (HS = 3.68 +/- 0.09 mL H2O/g dry wt; MAN = 3.83 +/- 0.08 mL H2O/g dry wt). The 7.5% NaCl was equally effective in treating elevated ICP caused by a space-occupying lesion when compared with 20% mannitol. Hypertonic saline has the additional benefit of rapid cardiovascular resuscitation of associated hemorrhagic shock with small-volume infusion.

Hybridization properties of deoxyoligonucleotides containing anthraquinone pseudonucleosides

Achiral pseudonucleosides bearing an anthraquinone moiety have been incorporated into deoxyoligonucleotides in internal, 3' and 5' positions. The ability of these modified deoxyoligonucleotides to hybridize to complementary RNA and DNA was investigated using Tm measurements. The anthraquinone was shown to enhance binding to a complementary RNA when linked to the 3' and 5' end. Pseudonucleoside substitutions on the 3' end of an oligonucleotide are also shown to confer serum stability to the oligonucleotide.

Autosomal dominant neuromuscular disease with cylindrical spirals

Cylindrical spirals (CS) have been reported in muscle biopsies from five individual cases, as well as in two belonging to one family where there was another affected member, clinically associated with cramps, pain, stiffness and/or weakness. Here we studied muscle biopsies of a 70-yr-old mother and her 52-yr-old son, the latter with an associated neuropathy, both with late clinical onset in whose family at least 10 other members, spanning five generations, were diversely affected by muscular weakness, gait disorders, motor impairment and/or scoliosis, featuring an autosomal dominant trait with variable expression. CS as the main pathological findings were observed by light microscopy mostly in type 2 fibres, consisting of subsarcolemmal or intermyofibrillar granular and/or rod-like clusters, bluish with haematoxylin, bright red with Gomori's modified trichrome, non- or lightly reactive with PAS, faintly coloured with NADH-TR, non-reactive with SDH or ATPase, strongly stained with non-specific esterase and myoadenylate deaminase. Ultrastructurally, CS appeared as concentrically wrapped lamellae 1-2 microns in diameter. On occasion CS merged into tubular vesicular structures strongly resembling tubular aggregates (TA). Dilation of terminal cisternae (TC) in their proximity supports an origin from the sarcoplasmic reticulum (SR). Variable gene expression possibly explains both the highly diverse clinical compromise and time of onset.

Phosphoramidate analogues of DNA: synthesis and thermal stability of heteroduplexes

The deoxyoligonucleotide 5' AATCGGGCATGGATT (15-mer) was synthesized containing 12 phosphoramidate linkages derived from 2 primary and 2 secondary amines. The oligonucleotides were purified by reverse phase HPLC and characterized by PAGE. The thermal stability of the duplexes derived from these compounds, when hybridized to the complementary diester linked oligomer, were determined and compared to the diester and methanephosphonate oligomer. The results indicated that all analogue oligomers form less stable duplexes then the diester oligomer. A large difference was observed between primary and secondary amine derived phosphoramidates.

Saccharomyces cerevisiae secretes and correctly processes human interferon hybrid proteins containing yeast invertase signal peptides

Synthetic oligonucleotides coding for the yeast invertase secretion signal peptide were fused to the gene for the mature form of human interferon (huIFN-alpha 2). Two plasmids (E3 and F2) were constructed. E3 contained the invertase signal codons in a reading frame with the mature huIFN-alpha 2 gene. F2 had a deletion of the codon for alanine at amino acid residue-5 in the invertase signal and an addition of a methionine codon located between the coding sequences for the invertase signal and mature huIFN-alpha 2. Both hybrid genes were located adjacent to the promoter from the 3-phosphoglycerate kinase gene on the multicopy yeast expression plasmid, YEp1PT. Yeast transformants containing these plasmids produced somewhat more IFN than did the same expression plasmid containing the IFN gene with its human secretion signal sequence. HuIFN-alpha 2, purified from the medium of yeast cells containing E3, was found to be processed at the correct site. The huIFN-alpha 2 made by plasmid F2 was found to be completely processed at the junction between the invertase signal (a variant) and the methionine of methionine-huIFN-alpha 2. These results strongly suggested that the invertase signal (or its variant) attached to huIFN was efficiently recognized by the presumed signal recognition particle and was cleaved by the signal peptidase in the yeast cells. These results also suggested that amino acid changes on the right side of the cleavage site did not necessarily prevent cleavage or secretion.