Effect of proinflammatory cytokines (IL-6, TNF-alpha, IL-1beta) on hemodynamic performance during orthotopic liver transplantation

BACKGROUND

Proinflammatory cytokines (IL-6, IL-1beta, TNF-alpha) released during liver transplantation may affect hemodynamic stability. The aim of the present study was to analyze the association between IL-6, TNF-alpha, and IL-1beta and systemic vascular resistance during the phases of liver transplantation.

MATERIAL AND METHODS

The proinflammatory cytokines IL-6, IL-1beta, and TNF-alpha were analyzed in the blood of 20 consecutive patients who underwent transplantation. Blood samples were drawn from the pulmonary artery at serial times during surgery. Hemodynamic parameters were determined using a cardiac output monitor. Correlations between parameters were analyzed using the Spearman's rho and Kendall's tau-b methods.

RESULTS

Both in the vena cava and the pulmonary artery, significant association was observed between basal values of IL-6 during hepatectomy and systemic vascular resistance during the phases of liver transplantation: hepatectomy phase (r=.76, P=.02), anhepatic phase (r=.78, P=.03) and reperfusion phase (r=.87, P=.005).

CONCLUSIONS

Basal values of IL-6 may be considered a prognostic factor for hemodynamic performance during the phases of liver transplantation.

Defective human T-cell lymphotropic virus type I (HTLV-I) provirus in seronegative tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) patients

Infection with human T-cell lymphotropic virus type I (HTLV-I) have been associated with the development of the tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). We studied the presence of HTLV-I provirus in peripheral blood mononuclear cells (PBMC) from 72 Chilean patients with progressive spastic paraparesis by polymerase chain reaction: 32 seropositive and 40 seronegative cases. We amplified different genomic regions of HTLV-I using primers of 5' ltr, tax, env/tax, pX, pol and env genes. These genes were detected from all seropositive patients. The seronegative patients were negative with 5' ltr, pol, env, and pX primers. However, amplified product of tax and env/tax genes was detected from 16 and four seronegative patients, respectively. Three of them were positive with both genetic regions. The results of this study show that the complete HTLV-I provirus is found in 100% of seropositive cases. In seronegative cases, clinically very similar of seropositive cases, was found only tax gene in 42.5% (17/40) of patients. These results suggest the presence of a defective HTLV-I provirus in some seronegative patients with progressive spastic paraparesis, and suggest a pathogenic role of this truncate provirus for a group of TSP/HAM.

Excess molar enthalpies of mixtures of methyl derivatives of polyethylene glycol with 1-alkanol at 298.15 K and 101.3 kPa

Excess molar enthalpies (H E) of the binary mixtures containing tetraethylene glycol dimethyl ether (TEGDME) or polyethylene glycol 350 monomethyl ether with a 1-alkanol (1-propanol, 1-butanol, or 1-pentanol) at 298.15 K and atmospheric pressure were measured using a Calvet microcalorimeter. All the H E experimental values were positive and increase as the 1-alkanol length increases. The results are discussed qualitatively in terms of molecular interactions. The UNIFAC and DISQUAC group contribution models have been used to compare the predicted and the experimental values.Key words: excess enthalpy, 1-alkanol, polyether, binary system.

Analysis and toxicity of methomyl and ametryn after biodegradation

The controlled biodegradation of ametryn and methomyl has been performed, in accordance with the OECD Zahn-Wellens/EMPA procedure, by use of an enriched mixture of activated sludge collected from three domestic waste-water-treatment plants (WWTP). During the process concentrations of ametryn and methomyl in the water samples were isolated by solid-phase extraction (SPE); recovery rates were 98.9 and 93.2 for methomyl and ametryn, respectively. Liquid chromatography-mass spectrometry (LC-MS) was used to determine final pesticide concentrations and for metabolite identification. The efficiency of aerobic biodegradation of ametryn and methomyl was evaluated by measuring both the decrease in the concentration of the pesticides and global properties such as the chemical oxygen demand (COD). The acute toxicity of ametryn and methomyl was evaluated by use of the ToxAlert100 biological test, which is based on inhibition of the bioluminescence of Vibrio fischeri. There was significant correlation between results from primary and ultimate biodegradation and those from determination of toxicity. Pesticide concentrations were always reduced to below the limit of detection in less than 17 days. High COD removal (90-96%) was achieved in 28 and 18 days for methomyl and ametryn, respectively.

Genetic characterization and phylogeny of human T-cell lymphotropic virus type I from Chile

Infection with Human T-Cell Lymphotropic Virus type I (HTLV-I) have been associated with the development of the HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Phylogenetic analyses of HTLV-I isolates have revealed that HTLV-I can be classified into three major groups: the Cosmopolitan, Central African and Melanesian. In the present study, we analyzed the tax, 5' ltr, gag, pol, and env sequences of proviruses of PBMC from ten HAM/TSP patients to investigate the phylogenetic characterization of HTLV-I in Chilean patients. HTLV-I provirus in PBMC from ten Chilean patients with HAM/TSP were amplified by PCR using primers of tax, 5' ltr, gag, pol, and env genes. Amplified products of the five genes were purified and nucleotide sequence was determined by the dideoxy termination procedure. DNA sequences were aligned with the CLUSTAL W program. The results of this study showed that the tax, 5' ltr, gag, pol, and env gene of the Chilean HTLV-I strains had a nucleotide homology ranged from 98.1 to 100%, 95 to 97%, 98.9 to 100%, 94 to 98%, and 94.2 to 98.5% respect to ATK-1 clone, respectively. According to molecular phylogeny with 5' ltr gene, the Chilean HTLV-I strains were grouped with each other suggesting one cluster included in Transcontinental subgroup.

Relationship between composition and structure in chitosan-based hybrid films

Chitosan/poly(aminopropylsiloxane) hybrid films were obtained by blending 3-(aminopropyl)siloxane oligomers (pAPS) with chitosan (CHI). The pAPS oligomers were prepared by the sol-gel method starting from 3-(aminopropyl)triethoxysilane. These hybrids were characterized by chemical, spectroscopic and morphological methods. Scanning electron micrographs of hybrid films of different composition revealed an organized microscopic pattern suggesting the existence of systematic interactions among their components. Comparison of the thermal stabilities and X-ray diffraction patterns as well as FT-IR spectra of the films with those of the pure components revealed that nanocomposites were formed. Similar studies of films including lithium perchlorate, as a third component, showed that addition of certain amount of lithium ions affected the structure of the CHI/pAPS films. When addition of the lithium salt exceeded the homogeneous incorporation limit, a little excess generated anisotropically oriented patterns in the hybrid films.

Functional antibody activity elicited by fractional doses of Haemophilus influenzae type b conjugate vaccine (polyribosylribitol phosphate-tetanus toxoid conjugate)

We evaluated the functional activities of antibodies, serum bactericidal activity (SBA), and immunoglobulin G (IgG) antibody avidity indices, using sodium thiocyanate (NaSCN) elution, elicited after vaccination with fractional doses of the Haemophilus influenzae type b conjugate (polyribosylribitol phosphate [PRP] conjugated to tetanus toxoid [PRP-T]) vaccine. A cohort of 600 infants from the Dominican Republic were randomized to receive one of three regimens of the PRP-T vaccine at ages 2, 4, and 6 months: full doses (10 microg of PRP antigen), one-half doses (5.0 microg), and one-third doses (3.3 microg) (J. Fernandez et al., Am. J. Trop. Med. Hyg. 62:485-490, 2000). Sixty serum samples, collected at age 7 months, with > or =2.0 microg of anti-PRP IgG per ml were randomly selected for avidity determinations. Geometric mean IgG concentrations were 13, 14, and 17 microg/ml for infants who received the full-dose (n = 19), one-half-dose (n = 19), and one-third-dose (n = 22) regimens, respectively. SBA geometric mean titers (1/dilution) were 85.0, 82.0, and 76.1 in sera from infants receiving the full-, one-half-, and one-third-dose regimens, respectively. Avidity indices (mean +/- standard error weighted average of NaSCN molar concentration x serum dilution factor) were 71.9 +/- 9.4, 123.6 +/- 26.8, and 150.9 +/- 24.9 for the full-, one-half-, and one-third-dose regimens, respectively. Upon comparison, the only significant difference (P = 0.024) found was a greater avidity index for sera from infants receiving the one-third-dose regimen than for sera from infants receiving the the full-dose regimen. We conclude that fractional doses elicit similar functional antibody activities in infants with > or = 2 microg of anti-PRP IgG per ml, corresponding to 89, 90, and 97% of infants receiving three doses of either the full concentration or one-half or one-third of the labeled concentration, respectively. This approach offers an alternative strategy for the prevention of H. influenzae type b disease in countries with limited resources.

Frontal-plane lateral border movements and chewing cycle characteristics

We studied the dental contact section of the chewing cycle, the most important section in terms of function (as it governs the effectiveness of food trituration). Specifically, we determined closing phase dental contact distance and lateral path inclination in a sample of healthy subjects, and investigated possible relationships between these variables and Ahlgren chewing cycle type. The chewing cycle was characterized in 63 healthy subjects by frontal plane kinesiography. In all cases kinesiographs were obtained for both right- and left-side chewing, with chewing gum as bolus. In all cases we determined closing phase dental contact distance, lateral path inclination and Ahlgren chewing cycle type. Most subjects (84%) showed 'normal' chewing cycles (Ahlgren types I-IV); inverted, contralateral and irregular cycles (types V-VII) were infrequent. Mean dental contact distance was 0.9 mm for right-side chewing and 1.2 mm for left-side chewing. Mean lateral path inclination was 35 degrees for right-side chewing and 37 degrees for left-side chewing. Normal chewing cycles are generally bilateral, whereas abnormal chewing cycles are never bilateral. Border movement distance does not differ in any consistent way between 'chopping' and 'grinding' chewing cycle types. Closing phase dental contact distance showed a significant positive correlation with lateral path inclination.

Endoscopic technique: a new model of subarachnoid hemorrhage in rats

It has become increasingly evident that the pathophysiology of cerebral vasospasm following subarachnoid hemorrhage (SAH) which described the ischemic consequences of cerebral arterial constriction is complex and multifactorial. In an attempt to study cerebral vasospasm, numerous investigators have used experimental animal models that resemble cerebral vasospasm in humans. No ideal model for SAH has been found as yet, and hence the quest for such a model continues. We developed an endoscopic technique that permits a direct vision of internal carotid artery and puncturing the artery to provoke SAH. This model will closely reflect the clinical setting of an aneurysm rupture. The onset of SAH was characterized by a sudden decrease of cerebral blood flow (CBF) and cerebral blood volume (CBV) by at least 40% in the first 20 min. Following this initial drop, there was an increase in the CBF and the CBV, however, they remained significantly below the base line values, at the end of 1 h. This study describes a new model of SAH in rat that simulates the clinical phenomenon of ruptured intracranial aneurysm that also produces cerebral vasospasm.

Internal ribosome entry site-mediated translation of a mammalian mRNA is regulated by amino acid availability

The cationic amino acid transporter, Cat-1, facilitates the uptake of the essential amino acids arginine and lysine. Amino acid starvation causes accumulation and increased translation of cat-1 mRNA, resulting in a 58-fold increase in protein levels and increased arginine uptake. A bicistronic mRNA expression system was used to demonstrate the presence of an internal ribosomal entry sequence (IRES) within the 5'-untranslated region of the cat-1 mRNA. This study shows that IRES-mediated translation of the cat-1 mRNA is regulated by amino acid availability. This IRES causes an increase in translation under conditions of amino acid starvation. In contrast, cap-dependent protein synthesis is inhibited during amino acid starvation, which is well correlated with decreased phosphorylation of the cap-binding protein, eIF4E. These findings reveal a new aspect of mammalian gene expression and regulation that provides a cellular stress response; when the nutrient supply is limited, the activation of IRES-mediated translation of mammalian mRNAs results in the synthesis of proteins essential for cell survival.

Messenger RNA isolation using novel PNA analogues

Homo-Thy hetero-oligomer probes composed of trans-4-hydroxy-L-proline based PNA-like (HypNA) monomers and phosphono PNA (pPNA) monomers demonstrated strong binding to complementary poly A+ RNA strands. We used a mixture of chimeric oligomers containing both "linear" and "clamping" PNA-analogues to develop an mRNA isolation procedure and demonstrate the improved recovery of RNA molecules with secondary structure at the 3'end as well as RNAs with short poly A tails.

Hormonal regulation of the contractile response induced by okadaic acid in the rat uterus

The contractile effect of okadaic acid (OA), a highly selective inhibitor of protein serine/threonine phosphatases, was analyzed in the rat uterus during the estrous cycle and during the course of pregnancy. Contractile effects were related to circulating levels of estrogen and progesterone and to mRNA levels of myosin light chain kinase (MLCK) and of myosin light chain protein phosphatase catalytic (PP1-delta) and larger regulatory subunit (MYPT). Both in nonpregnant and pregnant uteri, OA (20 microM) induced a transient contraction, which after plateauing, slowly decreased. In the nonpregnant uterus, the amplitude of this contraction varied at different stages of the estrous cycle, being higher at proestrus and lower at diestrus. In the pregnant uterus, the contraction to OA increased significantly during the course of pregnancy, reaching a maximum in day 21 pregnant rats, and declined after delivery. Whatever the day of pregnancy, the amplitude of the contraction to OA was not significantly modified when obtained in Ca(2+)-free solution. The magnitude of the OA-induced contraction in spontaneously cycling and pregnant rats was positively correlated to the ratio of estrogen/progesterone serum levels. Reverse transcription-polymerase chain reaction assays on myometrial tissue demonstrated that mRNA expression of PP1-delta and MYPT was higher at early (day 3) than at late (day 21) pregnancy. MLCK mRNA levels were similar in day 3 and day 21 pregnant rats. These data suggest that changes in the expression and activity of myosin phosphatase may contribute to modulating the level of uterine contractile force during the estrous cycle, pregnancy, and labor.

A 50-kDa membrane protein mediates sialic acid-independent binding and infection of conjunctival cells by adenovirus type 37

The ocular tropism of adenovirus type 37 (Ad37) does not correlate with the wide distribution of the 46-kDa coxsackievirus and adenovirus receptor (CAR), the major receptor for most adenovirus serotypes. We previously found that Ad37 infects and binds well to conjunctival cells (Chang C), but poorly to lung epithelial (A549) cells that express CAR and hypothesized that this serotype uses a distinct receptor that is selectively expressed on conjunctival cells. To test this, we produced particles of a fiber-deleted Ad5 vector containing the Ad37 fiber protein. The "pseudotyped" vector infected Chang C cells better than A549 cells using a CAR-independent pathway. Ad37 binding was calcium-dependent and was abolished by protease digestion of cell surface proteins. Using a virus overlay protein blot assay (VOPBA), we detected calcium-dependent Ad37 binding to 50- and 60-kDa membrane proteins on permissive Chang C cells. In contrast, calcium-dependent binding was detected with only the 60-kDa protein on nonpermissive A549 cells. Ad19p, a closely related serotype that failed to bind to conjunctival cells, recognized the 60-kDa, but not the 50-kDa, protein. Ad37 has been reported to use sialic acid instead of CAR as a cell receptor on A549 cells. Pretreatment of Chang C cells with neuraminidase abolished Ad37 binding to only the 60-kDa protein, suggesting that sialic acid mediates Ad37 binding to the 60-kDa protein. The pseudotyped Ad37 vector was also able to infect neuraminidase-treated Chang C cells. Thus, subgroup D adenoviral binding to the 50-kDa protein is calcium-dependent and cell type- and serotype-specific, whereas binding to the 60-kDa protein is not necessary for infection of conjunctival cells. Together, these data suggest that the 50-kDa protein is the major receptor for Ad37 on conjunctival cells.

Proton magnetic resonance spectroscopy (1H-MRS) of the thalamus in schizophrenia

This study applied (1)H-MRS in the thalamus of schizophrenic patients and healthy subjects. There were no differences in the metabolite ratios (NAA/Cr, Cho/Cr or mI/Cr) between the two groups. Relationships were noted between NAA/Cr and age in patients with a trend toward this correlation in controls, suggesting an effect of age on the metabolism of the thalamus.