Amino acid supplementation improves cell-specific functions of the rat hepatocytes exposed to human plasma

Maintaining hepatocyte function during plasma exposure is critical for the successful development of hepatocyte-based bioartificial liver assist systems. Past attempts to culture hepatocytes in plasma yielded discouraging results. Using a stable culture model based on sandwiching hepatocytes between two layers of collagen gel, we investigated the effect of hormone and amino acid supplementation during exposure of rat hepatocytes to heparin-treated human plasma for 1 week. Morphology and hepatocyte-specific functions were evaluated for hepatocytes cultured in Dulbecco's Modified Eagle medium (DMEM), nonsupplemented plasma, plasma supplemented with hormones, or with hormones plus amino acids. Amino acids were supplemented at four-fold concentration of Basal Medium Eagle with 4 mM glutamine, whereas hormones included 7.5 microg/mL of hydrocortisone and 50 microU/mL of insulin. Cuboidal structure and bile canaliculi formation were observed throughout the 1-week exposure period for control hepatocytes in DMEM and for hepatocytes cultured in hormone supplemented plasma. Albumin and urea synthesis rates of hepatocytes in hormone plus amino acid supplemented plasma during the last day of plasma exposure were 60.4 +/- 13.7 and 75.6 +/- 6.5 (microg/day per 1 x 10(6) cells, mean +/- SD), respectively, comparable to cultures in standard culture medium. On the other hand, hepatocytes exposed to nonsupplemented plasma suffered significant morphological and functional damage. The results of this study indicate that hormone plus amino acid supplementation help to restore function in hepatocytes exposed to plasma.     

Interleukin-1β and anaphylatoxins exert a synergistic effect on NGF expression by astrocytes

C3a and C5a anaphylatoxins are proinflammatory polypeptides released during complement activation. They exert their biological activities through interaction with two G protein-coupled receptors named C3aR and C5aR, respectively. In the brain, these receptors are expressed on glial cells, and some recent data have suggested that anaphylatoxins could mediate neuroprotection. In this study, we used RT-PCR and ribonuclease protection assays (RPA) to investigate the role of anaphylatoxins on neurotrophin expression by the human glioblastoma cell line T98G and by rat astrocytes. Our data show that for both cell types, anaphylatoxins upregulate expression of NGF mRNA. This response depended on a G protein-coupled pathway since pre-treatment of cells with pertussis toxin (PTX) completely blocked NGF mRNA increases. This effect was anaphylatoxin-specific since pre-incubation with anti-C3a or anti-C5aR antibodies abolished the effects of C3a and C5a, respectively. The regulation of NGF mRNA by anaphylatoxins was not accompanied by translation into protein expression, but there was a significant synergic effect of anaphylatoxins/IL-1b costimulation. Our demonstration of involvement of anaphylatoxins in the NGF release process by astrocytes suggests that C3a and C5a could modulate neuronal survival in the CNS.     

Collision tumour of the oesophagus: a challenge for histological diagnosis.

An unusual case of mantle cell lymphoma metastasising to squamous cell carcinoma of the oesophagus, in a 62 year old Chinese man, is reported. A histological diagnosis based on examination of a small endoscopic biopsy specimen, in the absence of detailed clinical information, may be difficult, as the lymphoma component can be mistaken for reactive lymphoid infiltrate which is sometimes present adjacent to squamous cell carcinoma. Correlation with the clinical history, careful assessment of the subtle histological changes, and use of ancillary methods such as immunohistochemistry are most helpful in making the correct diagnosis. This case also illustrates further the possible occurrence of lymphomatous infiltrates surrounding other lesions in patients with a previous or concurrent history of lymphoma.     

Cognitive function in depression: a distinct pattern of frontal impairment in melancholia?

BACKGROUND: Although depressed patients demonstrate impaired performance on a range of neuropsychological tests, there is little research that examines either frontal cognitive deficits or possible differences in test performance between melancholic and non-melancholic subtypes. METHODS: Depressed subjects were administered a broad neuropsychological battery. In an overall analysis, 77 depressed subjects were compared with 28 controls. In a second set of analyses, the depressed sample was divided into melancholic and non-melancholic subsets according to DSM-III-R, the CORE system and the Newcastle scale. These depressed subsets were contrasted to controls and with each other using ANCOVA controlling for age, IQ, simple reaction time and Hamilton Depression scores where appropriate. RESULTS: The total depressed sample was impaired on most mnemonic tasks, simple reaction time and Trails B. Similar findings applied to DSM-III-R melancholic and non-melancholic subjects. When defined by the CORE and Newcastle (narrower definitions of melancholia), melancholic patients were additionally impaired on WCST (perseverative response) and (for Newcastle) digit symbol substitution. In contrast, the cognitive performance of the CORE and Newcastle-defined non-melancholic patients was largely unimpaired. CONCLUSIONS: Using narrower definitions of melancholia, i.e. CORE and (in particular) Newcastle, melancholic patients were impaired on mnemonic tasks and tasks of selective attention, and set-shifting while non-melancholic subjects were largely unimpaired in their cognitive performance. These differences may be due to impairment of specific neuroanatomical regions in narrowly defined melancholic patients, in particular the anterior cingulate.     

GABAergic boutons establish synaptic contacts with the soma and dendrites of cuneothalamic relay neurons in the rat cuneate nucleus

This study investigates the synaptic relation between -aminobutyric acid-immunoreactive (GABA-IR) and cuneothalamic relay neurons (CTNs) in the rat cuneate nucleus. Retrograde transport of wheat germ agglutinin conjugated with horseradish peroxidase complex (WGA-HRP) was used to label CTNs while anti-GABA immunogold serum was used for the detection of GABA-IR boutons associated with CTNs. With these procedures, immunogold-labelled GABA-IR boutons were found to form axosomatic, axodendritic and axospinous synapses with the WGA-HRP-labelled but immunonegative CTNs. Quantitative estimation showed that the mean ratios of GABA-IR to GABA-immunonegative boutons making synaptic contacts with somata, proximal dendrites, and distal dendrites were 47.9%, 49.1% and 34.7%, respectively. Statistical analysis showed that the incidence of GABA-IR boutons on the somata and proximal dendrites of CTNs was significantly higher than on the distal dendrites. Our results indicate that GABA is the primary inhibitory neurotransmitter in the cuneate nucleus, thereby emphasizing the importance of postsynaptic inhibition on cuneothalamic relay neurons.     

Specific binding proteins for human chorionic gonadotrophin in a patient with trophoblastic disease

Human chorionic gonadotrophin (hCG) is present in high concentration in patients with trophoblastic disease. The hCG concentration parallels tumor activity. The first known case of an endogenous binder for hCG in the serum of a patient with trophoblastic disease is reported. The patient's hCG concentration was not detectable when analyzed by a radioimmunoassay using a double antibody method; however, it was positive by a radioimmunoassay using polyethylene glycol precipitation. A high serum blank was also observed in this patient. This led the authors to suspect the presence of an endogenous binder for hCG. Scatchard analysis of the patient's serum revealed a high affinity binder with Ka = 1 x 10(10) M(-1), concentration of binding site = 2 x 10(-11) M. This investigation strongly suggested a specific binder(s) for hCG in the serum of this patient.     

Identification of testis development and spermatogenesis-related genes in human and mouse testes using cDNA arrays

We have constructed cDNA microarrays from the human testis large insert cDNA library, containing 9216 genes, together with several housekeeping genes. The cDNA microarrays were used to identify gene expression differences between human fetal and adult testes. Of >8700 hybridized clones, 731 exhibited significant differential expression characteristics. About 7500 genes were identified when the same cDNA microarrays were used for hybridization with cDNA probes from mouse testis, with 256 genes having significant differential expression between the age of 1-4 weeks. Among these genes, 101 were identified as critically related to testis development and possibly to spermatogenesis since they were found in both human and mouse testes, and expressed differentially at different stages of testis development. Of the 101 development-related genes, 59 full-length cDNAs have been sequenced previously, while the full-length cDNAs of the other 42 genes have not been published. We have obtained 11 full-length sequences of the 42 genes and deposited them in the GenBank. The conserved testis development-related genes found in both human and mouse testes may include genes that are likely to be involved in testicular functions, especially spermatogenesis, thus providing a basis for further functional characterization of the genes in mouse models.