Associations of coffee consumption with markers of liver injury in the insulin resistance atherosclerosis study.

BACKGROUND: Coffee consumption has been associated with reduced risk of developing type 2 diabetes mellitus (T2DM) however, the mechanism for this association has yet to be elucidated. Non-alcoholic fatty liver disease (NAFLD) characterizes and predicts T2DM yet the relationship of coffee with this disorder remains unclear. Our aim was to investigate the associations of coffee with markers of liver injury in 1005 multi-ethnic, non-diabetic adults in the Insulin Resistance Atherosclerosis Study. METHODS: Dietary intake was assessed using a validated 114-item food frequency questionnaire. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and fetuin-A were determined in fasting blood samples and the validated NAFLD liver fat score was calculated. Multivariate linear regression assessed the contribution of coffee to variation in markers of liver injury. RESULTS: Caffeinated coffee showed significant inverse associations with ALT (ß = -0.08, p = 0.0111), AST (ß = -0.05, p = 0.0155) and NAFLD liver fat score (ß = -0.05, p = 0.0293) but not with fetuin-A (ß = 0.04, p = 0.17). When the highest alcohol consumers were excluded, these associations remained (ALT ß = -0.11, p = 0.0037; AST ß = -0.05, p = 0.0330; NAFLD liver fat score ß = -0.06, p = 0.0298). With additional adjustment for insulin sensitivity, the relationship with ALT remained significant (ALT ß = -0.08, p = 0.0400; AST ß = -0.03, p = 0.20; NAFLD liver fat score ß = -0.03, p = 0.27). There were no significant associations of decaffeinated coffee with liver markers. CONCLUSIONS: These analyses indicate a beneficial impact of caffeinated coffee on liver morphology and/or function, and suggest that this relationship may mediate the well-established inverse association of coffee with risk of T2DM.

Heterozygote carriers of mutations in the F11 gene, encoding Factor XI, have normal coagulation by thromboelastography during pregnancy.

BACKGROUND: Evidence to guide clinical decision-making in pregnant women who are usually asymptomatic, but identified as heterozygote carriers of F11 mutations, is lacking. We hypothesized that women identified on prenatal screening as heterozygous for a mutation in the F11 allele would have minimal evidence of an in vitro coagulation abnormality. METHODS: We prospectively enrolled women identified by prenatal screening as F11 mutation carriers and pregnant women who were presumed to be normal as controls. We collected blood during antepartum visits or at presentation for delivery and assessed Factor XI (FXI) coagulant activity level, as well as whole-blood coagulation, by thromboelastography. RESULTS: F11 mutation carriers had lower serum FXI activity levels than controls (51.2 ±â€¯8.5% vs 94.1 ±â€¯19.4%; P <0.0001). Thromboelastography values of all control subjects and F11 mutation carriers were within the normal range. The R-time was slightly longer in F11 mutation carriers (5.3 ±â€¯1.0 s vs 4.2 ±â€¯0.8 s, P <0.002), but no other statistically significant differences in thromboelastogram parameters were identified between groups. CONCLUSIONS: Despite lower FXI activity in the F11 mutation group, we found minimal differences in whole-blood measures of coagulation using thromboelastography. These findings support our hypothesis that a single copy of an F11 mutation does not produce significant evidence of an in vitro coagulation abnormality. Thromboelastography might be useful in determining the risk of neuraxial anesthesia in pregnant women, but additional work is required to establish the validity of this test.

Acetylcholinesterase density and turnover number at frog neuromuscular junctions, with modeling of their role in synaptic function.

Acetylcholinesterase (AChE) density at the neuromuscular junction of frog cutaneous pectoris muscle was determined by electron microscope autoradiography and biochemistry to be approximately 600 sites micron-2 of postsynaptic area, approximately 4-fold lower than all previous reports (mouse), whereas the hydrolytic turnover number was 9,500 s-1, well within the range (2,000-16,000 s-1) for AChE from other species. Monte Carlo computer simulations of miniature endplate currents showed that for vertebrate neuromuscular junctions with different morphologies, an AChE density of only approximately 400 sites microns-2 and a turnover number of only approximately 1,000 s-1 are sufficient for normal quantal currents. Above these critical lower limits, miniature endplate currents were essentially insensitive to AChE density and turnover number values up to 5,000 sites microns-2 and 16,000 s-1, respectively.

Physical analysis of the COR region: a cluster of six genes in Saccharomyces cerevisiae.

Six genes, CYC1, UTR1, UTR3, OSM1, tRNAGly, and RAD7, have been localized within an 8-kilobase region on chromosome X of the yeast Saccharomyces cerevisiae. The physical structures and the transcripts of these genes were identified by analyzing a normal strain and six deletion mutants by genomic blotting, transcriptional analysis, and gene disruption procedures. The well-studied CYC1 gene encodes iso-1-cytochrome c; the tRNAGly gene encodes a tRNA; deletion of OSM1 and RAD7 causes sensitivity to hypertonic medium and UV irradiation, respectively. There were no observable phenotypes in strains having deletions of the UTR1, UTR3, and tRNAGly gene. The high density of transcripts, with little or almost no intragenic regions, indicates that the chromosomal organization of S. cerevisiae resembles the chromosomal organization of procaryotes rather than higher eucaryotes.

Effect of nutritional state and allopurinol on purine metabolism in the rat small intestine.

The effect of fasting and refeeding on the uptake and retention of purines by the small intestine of the rat was studied in vivo. Short-term uptake and incorporation into nucleotides of the purine bases adenine, guanine and hypoxanthine and the nucleoside inosine were evaluated in the proximal jejunum. After 5 min, more label was recovered in the intestinal contents in fasted rats, indicating that total absorption was reduced. However, intestinal retention of purines (50 nmol dose) was elevated with fasting (27.2 vs. 16.6 nmol/g for adenine, 5.7 vs. 3.0 nmol/g for guanine and 16.1 vs. 7.4 nmol/g for hypoxanthine, for fed vs. fasted, respectively). After 1 day of refeeding, retention remained elevated for adenine (27.4 nmol/g) and guanine (5.5 nmol/g). After 3 days of refeeding intestinal weight and retention of labeled purines returned to the unfasted levels. Nucleotide formation from all purine bases was greater in the intestinal tissue of fasted as compared to fed rats (25.4 vs. 11.4 nmol/g for adenine, 1.32 vs. 0.24 nmol/g for guanine, and 2.84 vs. 0.82 nmol/g for hypoxanthine). At a higher dose (3000 nmol) hypoxanthine and inosine were retained to a greater extent in the fasted than in the fed state. Pretreatment with allopurinol (a xanthine oxidase inhibitor) reduced the absorption of hypoxanthine, increased the retention of label in the tissue 4-fold or more, and elevated nucleotide formation 10-fold or more. Fasting and allopurinol treatment, both known affectors of xanthine oxidase activity, enhanced both the retention of dietary purine and nucleotide formation.

Correlation of endothelin-1 and transforming growth factor beta 1 with malignancy and vascularity in human gliomas.

Because the prominent neovascularization characteristic of high grade primary brain tumors is composed mostly of vascular smooth muscle cells (VSMC), we studied the expression of the potent smooth muscle mitogen endothelin-1 (ET-1) and one of its secretagogues, transforming growth factor beta 1 (TGF-beta 1) in a series of astrocytic tumors. TGF-beta 1 is also of interest due to its known activity as an angiogenic factor. Using immunohistochemical methods, we examined 30 surgical cases: 10 glioblastoma multiforme, 10 anaplastic astrocytomas, and 10 low-grade astrocytomas. Using a monoclonal antibody to TGF-beta 1 and a polyclonal antibody to ET-1, we detected both growth factors in all cases of glioblastoma examined. In cases of anaplastic astrocytoma, 4 tumors were positive for both factors; 2 contained only ET-1; 2 contained only TGF-beta 1; and 2 exhibited no tumor cell immunoreactivity for either factor. In low-grade astrocytoma, 4 of 10 tumors showed weak ET-1 immunoreactivity; 2 of those contained TGF-beta 1 immunopositive tumor astrocytes: 6 tumors were negative for both factors. In all tumors that expressed both factors, serial sections showed that regions of ET-1 immunopositivity also tended to be positive for TGF-beta 1. Endothelial cells within all tumors were positive for ET-1. ET-1 and TGF-beta 1 are present in human astrocytomas and their expression correlates with tumor vascularity and malignancy. These results suggest roles for both ET-1 and TGF-beta 1 in the growth and progressive angiogenesis of the human glioma.

Expression of a wheat alpha-gliadin gene in Saccharomyces cerevisiae.

A vector was constructed that directs the expression of foreign genes in the yeast Saccharomyces cerevisiae. This vector contains an expression site that was constructed by in vitro modification of the iso-1-cytochrome c (CYC1) gene of S. cerevisiae. The expression of heterologous sequences can be experimentally controlled by catabolite control sequences, promoter and transcription initiation sequences and termination sequence derived from the CYC1 gene. A portion of a genomic wheat alpha-gliadin gene consisting of the entire 861 bp of protein-coding sequence, 18 bp of 5' leader sequence and 54 bp of 3'-noncoding sequence was inserted into the expression site. A CYC1::alpha-gliadin transcript of approx. 1050 nucleotides was synthesized in transformed yeast under the control of the CYC1 regulatory region. The transcripts terminated within the alpha-gliadin 3'-noncoding region, near a nucleotide sequence similar to the yeast transcription termination consensus sequence. The alpha-gliadin was immunochemically detected in total protein extracts from transformed cells and accounted for approx. 0.1% of the total cellular protein. The size of alpha-gliadin synthesized in yeast is the same as that of mature wheat alpha-gliadin. This is consistent with recognition and cleavage of the signal peptide by yeast. Due to the amino acid composition of alpha-gliadin, the availability of glutamine tRNA is a potential translational limitation to high-level synthesis in yeast.

A simple method for maintaining large, aging populations of Caenorhabditis elegans.

This paper describes a technique capable of establishing and maintaining large, age-synchronous populations of the nematode Caenorhabditis elegans. The technique has three essential components: a rich chemical medium; a method for producing and harvesting mass quantities of eggs; and 5-fluorodeoxyuridine (FUdR), an inhibitor of DNA synthesis. A culture of worms is filtered through glass wool or a wire screen to isolate young larvae. Eggs laid by these worms after they mature are collected over a period of 4-6 hours and allowed to hatch. A low level of FUdR (25 microM) is added just before the larvae reach maturity. This timing is important to avoid developmental abnormalities. The adults lay eggs in the presence of FUdR but the eggs do not hatch, which maintains the synchrony of the culture. Many aging characteristics appear to be similar in treated and untreated worms, such as the time of cessation of egg production, the appearance of visible and behavioral age-related changes, and the mean lifespan. This system thus seems suitable for large-scale biochemical analysis of certain aspects of aging in C. elegans.

The development of drawing in children with congenital focal brain injury: evidence for limited functional recovery.

Children with pre- or perinatal injury to right hemisphere (RH) brain regions show impairment of spatial integrative functions similar to that observed among adults with comparable injury. Unlike adults, children show considerable improvement with development on a range of spatial construction tasks which require spatial integration. Such gains could reflect true recovery of spatial integrative abilities. Alternatively, the improvement could be more limited in scope, reflecting the development of compensatory strategies which are task specific and allow the children to circumvent, rather than overcome, their primary spatial disorders. The studies presented here examined this distinction within the context of drawing tasks in which the child was first asked to draw a house and then an impossible house. The impossible house task was designed to examine the extent to which children rely on graphic formulas in generating organized drawings. The results showed that while all of the children with RH injury make considerable progress in free drawing into the school age period, they are very reliant on the use of graphic formulas. When given a task which requires them to alter their drawings, they did not change the spatial configuration of the depicted object. Rather they found alternate ways to render the object 'impossible'.

Affective facial expression in infants with focal brain damage.

Children are fluent affective communicators by their first birthday. The development of affective facial expression in infants with focal brain damage thus provides a promising context in which to investigate the developing neural substrates of emotions. We examined both positive and negative affective expression in 12 infants (6-24 months) with pre- or perinatal unilateral focal brain damage (6RHD and 6LHD) and their age- and gender-matched controls. Infants were videotaped in free and semi-structured tasks. Interactions were microanalytically coded, including the use of FACS. Both normal and babies with posterior LHD exhibited the full range of appropriate affective expressions. In contrast, infants with posterior RHD showed marked affective impairment to positive, but not to negative simulation.

Absence of nerve-dependent conversion of rapidly degrading to stable acetylcholine receptors at adult innervated endplates.

It has been suggested that acetylcholine receptors newly inserted into adult innervated endplates have a rapid degradation rate, but are normally converted to a stable, slowly degrading form in a nerve-dependent fashion. Denervation therefore should eliminate conversion and cause pre-existing unconverted receptors to continue degrading rapidly. We tested this model of nerve-dependent conversion in mouse sternomastoid muscle, using quantitative electron microscopic autoradiography in order to specifically examine degradation of receptors at identified endplate membrane. Prior to denervation, we labelled the receptors with sequential alpha-bungarotoxin exposures, using conditions designed to maximize the predicted effect of denervation. However, we observed no difference in the rate of receptor degradation at innervated and denervated endplates up to seven days after denervation (at which time accelerated degradation of pre-existing stabilized receptors is known to begin in this muscle). The regulation of endplate acetylcholine receptor metabolic turnover is a complex and still largely undefined issue, related to many factors such as subunit composition, cytoskeleton and basement membrane composition, muscle activity, and neural influences. In particular, the nerve's influence on the normal stabilization of receptors at innervated adult endplates has been controversial. Our data indicate that slow degradation is probably an inherent property of newly inserted junctional receptors, and argue against nerve-dependent conversion and stabilization. Based on the present data, however, we cannot rule out the presence of a small nerve-independent subpopulation that degrades rapidly. The molecular mechanisms involved in establishing and maintaining a stable population of adult endplate acetylcholine receptors remain to be established.

Disseminated toxoplasmosis following T cell-depleted related and unrelated bone marrow transplantation.

More than 95% of reported cases of disseminated toxoplasmosis following BMT have occurred following an unmodified transplant. Most have been fatal, diagnosed at autopsy and without antemortem institution of specific therapy. From 1989 to 1999, we identified 10 cases of disseminated toxoplasmosis, in 463 consecutive recipients of a T cell-depleted (TCD) BMT. Transplants were from an unrelated donor (n = 5), an HLA-matched sibling (n = 4) or an HLA-mismatched father (n = 1). In 40%, both the donor and recipient had positive IgG titers against T. gondii pre-transplant; in 30%, only the recipient was sero-positive. Three recipients of an unrelated TCD BMT developed toxoplasmosis despite both donor and host testing negative pretransplant. All 10 patients presented with high grade fever. CNS involvement ultimately occurred in seven patients, with refractory respiratory failure and hypotension developing in nine. Eight of 10 cases were found only at autopsy, involving the lungs (n = 7), heart (n = 5), GI tract (n = 5), brain (n = 8), liver and/or spleen (n = 5). The only survivor, treated on the day of presentation with fever and headache, was diagnosed by detection of T. gondii DNA by polymerase chain reaction (PCR) performed on the blood and spinal fluid. This study demonstrates the similar incidence of toxoplasmosis following TCD BMT and that reported post T cell-replete BMT, and underscores the need for rapid diagnostic tests in an effort to improve outcome.

Respiratory syncytial virus infection following hematopoietic stem cell transplantation.

Respiratory syncytial virus, one of the most common causes of respiratory infections in immunocompetent individuals, is frequently spread to recipients of HSCT by family members, other patients, and health care workers. In immunosuppressed individuals, progression from upper respiratory tract disease to pneumonia is common, and usually fatal if left untreated. We performed a retrospective analysis of RSV infections in recipients of autologous or allogeneic transplants. The incidence of RSV following allogeneic or autologous HSCT was 5.7% and 1.5%, respectively. Of the 58 patients with an RSV infection, 16 of 21 patients identified within the first post-transplant month, developed pneumonia. Seventy-two percent of patients received aerosolized ribavirin and/or RSV-IGIV, including 23 of 25 patients diagnosed with RSV pneumonia. In this aggressively treated patient population, three patients died of RSV disease, each following an unrelated HSCT.

Effects of gamma irradiation on the midgut ultrastructure of Glossina palpalis subspecies.

In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population's reproductive rate. Tsetse fly (Glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. However, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. After G. palpalis palpalis and G. p. gambiensis were subjected to 130 Gy gamma radiation, their midgut damage and recovery were monitored by electron microscopy. The first sign of damage was atrophy and loss of the microvillous border from epithelial cells. The rate of cell degeneration increased, with young as well as old cells being affected and cellular debris filling the ectoperitrophic space. Muscle cells were destroyed, patches of basal lamina were left bare, intracellular virus- and rickettsia-like organisms became more frequent, and many replacement cells became unusually large. Partial recovery occurred from the 10th day postirradiation. Such changes in midgut ultrastructure and the corresponding inhibition of functions may increase the susceptibility of the fly to trypanosome infection.

Hemispheric asymmetries in global and local processing: evidence from fMRI.

Functional magnetic resonance imaging (fMRI) was used to explore the brain substrate associated with global and local processing of visuospatial patterns. Systematic differences in activation, consistent with differences observed in reaction time data collected under conditions of visual hemifield presentation, were found in occipitotemporal regions of the right and left hemispheres. Within the right hemisphere, area of activation and fractional signal changes were greater under conditions of global processing than under local processing conditions. In the left hemisphere, activation to global and local input was high and comparable.

Molecular typing of Trichomonas vaginalis isolates by HSP70 restriction fragment length polymorphism.

Subtyping isolates of Trichomonas vaginalis is an essential tool for understanding the epidemiology of this common sexually-transmitted disease. Restriction fragment length polymorphism (RFLP) analysis employing a probe from the heat-inducible cytoplasmic HSP70 gene family hybridized with EcoR I-digested genomic DNA was used in the molecular typing of Trichomonas isolates. Analysis of five American Type Culture Collection (ATCC) reference strains and 31 Jackson, Mississippi, isolates from six male and 21 female patients, revealed 10 distinct RFLP pattern subtypes of Trichomonas. The subtypes were temporally stable and cosmopolitan. The RFLP profiles seen in Maryland, Ohio, Massachusetts, and New York ATCC strains were identical to those of some Mississippi isolates, even though the samples were isolated 10-35 years apart. There was no correlation between metronidazole resistance and RFLP subtype with resistant isolates from eight patients distributed among six different subtypes.

Denervation induced changes in subcellular pools of 16S acetylcholinesterase activity from adult mammalian skeletal muscle.

Acetylcholinesterase (AChE) inhibitors which differ in lipid solubility and thus in their ability to penetrate cell membranes were utilized to study the effects of denervation on discrete pools of 16S AChE from endplate regions of adult rat anterior gracilis muscle. Such pools have been interpreted as extra- and intracellular fractions of endplate 16S AChE activity. Denervation caused an almost immediate decay of intracellular 16S AChE, and a later (12-18 h) but roughly parallel decrease in its extracellular counterpart. Thus, the level at which the motor nerve exerts its primary regulatory influence on adult mammalian skeletal muscle endplate 16S AChE activity appears to be within muscle cells. This influence may affect the molecule's synthesis, assembly, and/or degradation.

Intra- versus extracellular recovery of 16S acetylcholinesterase following organophosphate inactivation in the rat.

Acetylcholinesterase (AChE) inhibitor treatments were used to study the temporal course of intra- versus extracellular 16S AChE recovery in endplate regions of adult rat anterior gracilis muscles previously exposed to a brief, in situ application of diisopropylfluorophosphate (DFP). Following such enzymatic inactivation (95-100%), extracellular 16S AChE recovery began significantly later than that of intracellular (onset at approximately 36 and 12 h, respectively) but, once begun, progressed at approximately the same rate (1.32%/h). The recovery of AChE molecular form activities subsequent to identical DFP-inactivation was blocked to a large extent (65-85%) by in vivo treatment with cycloheximide, a protein synthesis inhibitor. These results support the hypothesis that extracellular 16S AChE at mammalian skeletal muscle motor endplates is primarily derived from complete, previously assembled 16S molecules originating in myofibers.

Neural plasticity and cognitive development.

It has been well documented that the effects of early occurring brain injury are often attenuated relative to later occurring injury. The traditional neuropsychological account of these observations is that, although the developing neural system normally proceeds along a well-specified maturational course, it has a transient capacity for plastic reorganization that can be recruited in the wake of injury. This characterization of early neural plasticity is limited and fails to capture the much more pervasive role of plasticity in development. This article examines the role of neural plasticity in development and learning. Data from both animal and human studies show that plasticity plays a central role in the normal development of neural systems allowing for adaptation and response to both exogenous and endogenous input. The capacity for reorganization and change is a critical feature of neural development, particularly in the postnatal period. Subtractive processes play a major role in the shaping and sculpting of neural organization. However, plasticity is neither transient nor unique to developing organisms. With development, neural systems stabilize and optimal patterns of functioning are achieved. Stabilization reduces, but does not eliminate, the capacity of the system to adapt. As the system stabilizes, plasticity becomes a less prominent feature of neural functioning, but it is not absent from the adult system. The implications of this broader view of plasticity for our understanding of development following early brain damage are discussed.

Drawing abilities in Williams syndrome: a case study.

Children with Williams syndrome (WS) have been reported to exhibit an unusual cognitive profile characterized by marked preservation of linguistic abilities and poor visuospatial abilities against a backdrop of generalized mental retardation. Much of the data documenting this profile come from studies of older children and adults with WS. Very few studies have reported findings from the preschool and early school-age period. As a result, little is known about the early development of cognitive processes in children with WS. Capirci, Sabbadini, and Volterra (1996) reported data from a longitudinal case study of early language development in a young child with WS. This article presents the longitudinal profile of visuospatial abilities in this same child. Data on copying and free drawing collected over a period extending from late preschool to early school age are reported. It is clear from these data that this child does indeed exhibit deficits in visuospatial abilities. Her performance clearly improved with age, but deficits persist.