Extracellular matrix-associated cytokines regulate CD4+ effector T-cell responses in the human intestinal mucosa.

Extracellular matrix (stroma) regulation of mucosal T-cell function is incompletely understood. In this study, we uncovered a role for intestinal stromal products in the innate regulation of effector T cells. Stroma-conditioned media (S-CM) derived from the normal human intestinal stroma (transforming growth factor-ß (TGF-ß)(hi)/interleukin (IL)-6(lo)/IL-1ß(lo)) significantly downregulated T-cell proliferation and interferon-γ (IFN-γ) production compared with S-CM derived from the inflamed Crohn's mucosa (TGF-ß(hi)/IL-6(hi)/IL-1ß(hi)). Antibody neutralization studies showed that TGF-ß in normal S-CM inhibited T-cell proliferation and IFN-γ production, whereas IL-6 plus IL-1ß in Crohn's S-CM promoted T-cell proliferation, and IL-1ß alone promoted IFN-γ and IL-17 release. Importantly, normal S-CM inhibited T-bet expression, whereas Crohn's S-CM activated signal transducer and activator of transcription 3, suggesting that discordant T-cell responses are regulated at the transcription factor and signaling levels. These findings implicate stromal TGF-ß in the downregulation of T-cell 2 responses in the normal intestinal mucosa, and stromal IL-6 and IL-1ß in the promotion of Th1 and Th17 responses in the inflamed Crohn's mucosa, suggesting an innate regulatory function for the intestinal extracellular matrix.

Commercial recombinant human beta-nerve growth factor and adult rat dorsal root ganglia contain an identical molecular species of nerve growth factor prohormone.

Examination of commercial recombinant human beta-nerve growth factor (rh-beta-NGF) preparations with polyclonal antibodies specific to 13-kDa NGF and pro-NGF-specific domains revealed the presence of high-molecular-mass immunoreactive proteins, including a 60-kDa NGF prohormone. On incubation with a mixture of N- and O-specific glycosidases, the 60-kDa NGF pro-hormone generated a 32-kDa protein corresponding to the molecular size of NGF precursor predicted by the cloned human NGF cDNA. Highly sensitive chemiluminescence immunoblot analysis of adult rat dorsal root ganglia, spinal cord, and colon tissues with NGF- and pro-NGF domain-specific antibodies also revealed the presence of high-molecular-mass proteins, including the 60-kDa NGF prohormone. Based on the presence of the 60-kDa NGF prohormone in dorsal root ganglia and its efferent tissues, we suggest that proteolytically unprocessed, glycosylated NGF prohormone may mediate interactions between neurons and the tissues they innervate.

Brain infarction in children with diabetic ketoacidosis.

During the last 10 years, five children were treated at Childrens Hospital Los Angeles for acute, persistent neurologic loss during diabetic ketoacidosis (DKA). Four were transferred from local hospitals after the neurologic crisis. Computed tomography (CT) studies showed one or more areas of brain infarction in each patient, and none had evidence of diffuse cerebral edema. As three of the five patients had been treated for cerebral edema before their CT, brain edema may have been present initially. Our findings emphasize the importance of brain infarction as a cause of persistent neurologic loss in children with DKA.

Proliferation-related responses in rat astrocytes to epidermal growth factor.

The signals which regulate the proliferation of astrocytes have relevance to both normal developmental processes and abnormal states of gliosis or glial tumor formation. We have extended studies of astrocyte proliferation and related responses in primary cultures of rat telencephalic cortical astrocytes as a result of treatment with epidermal growth factor. Epidermal growth factor stimulates the rate of DNA synthesis five fold and maintains the rate of protein synthesis. The stimulation occurs at a dose of 2 ng/ml and is greater in higher density cultures than in lower density cultures, perhaps representing a relative starvation for the growth factor. The astrocyte response is still present even after being cultured 3 1/2 weeks in serum-free and non-growth factor or hormone-supplemented media. Combined immunofluorescence and thymidine autoradiography disclose that glial fibrillary acidic protein containing cells are the cells synthesizing DNA in response to the growth factor, and combined rhodamine and fluorescein-linked stains disclose that epidermal growth factor is in the glial fibrillary acidic protein containing cells. Proliferation-related 2-deoxyglucose uptake is stimulated at approximately the same dose as DNA synthesis is stimulated, but the time course is relatively slow, maximizing at 48 hr. Ornithine decarboxylase is stimulated in 6 hr indicating more rapid nuclear stimulation by the signal. In conclusion, epidermal growth factor has a clear direct interaction with glial fibrillary acidic protein-containing cells which is greater in higher density cultures, is still present in long-quiescent cells, and includes DNA synthesis, cell cycle progression, hexose uptake, and polyamine synthesis.

Fibroblast growth factor inhibits epidermal growth factor-induced responses in rat astrocytes.

The signals which regulate the proliferation of astrocytes have relevance to normal developmental processes, transformational loss of growth control, and reactive gliosis present in many brain disease states. We have studied, in primary cultures of rat astrocytes, a sequential interaction of two growth factors, epidermal growth factor (EGF) and fibroblast growth factor (FGF), which may be relevant to the brain in these conditions. EGF is a strong mitogen and stimulator of 2 deoxyglucose (2 DG) transport with no effect on plating of cells, and FGF is a lesser mitogen and 2 DG uptake stimulator. However, when FGF is given to the cells as a pretreatment, FGF strongly inhibits the ability of EGF to stimulate both DNA synthesis and 2 DG uptake. The inhibition of EGF stimulation by FGF is across the EGF dose-response curve, present at high and low culture densities, and stable for at least 3 days. Specificity is indicated by lack of inhibition by PDGF pretreatment and much less inhibition of fetal calf serum-induced stimulations than EGF-induced stimulation. Cell counts confirmed that the FGF pretreatment also inhibits EGF stimulation of cell division. Because of FGF brain derivation and angiogenic and neurotropic functions, it may serve as a regulator of EGF-astrocyte interactions in processes such as development, gliomatous transformation, and neural regeneration.

Fibroblast growth factor pretreatment reduces epidermal growth factor-induced proliferation in rat astrocytes.

Epidermal Growth Factor (EGF) is mitogenic for purified rat astrocytes in primary tissue culture. A combined concomitant treatment by EGF and Fibroblast Growth Factor (FGF) does not reduce the proliferation effect of EGF, however when the astrocytes are pretreated with FGF, their response to an EGF stimulation is reduced by 70%. This inhibition of EGF stimulation by FGF pretreatment is consistent across the EGF dose response curve and perhaps represents a mechanism for local modulation of astrocyte mitogenic effects.

Arterial blood gas derangements associated with death and intracranial hemorrhage in premature babies.

We evaluated to what extent acidosis and alkalosis and their respiratory and metabolic components during the first 12 hours of life occurred prior to early neonatal death and postnatal intracranial hemorrhage among 206 low birth weight, intubated premature babies participating in a clinical trial of phenobarbital prophylaxis for intracranial hemorrhage. Time-weighted indices included the time each baby spent with abnormal values of pH, PaCO2 and HCO3-. Babies whose birth weight was less than 1 kg suffered adversities associated with prolonged pH less than 7.35. Heavier birth weight babies were at increased risk of adversity if their pH fell below 7.2. Babies who were not severely acidotic initially, but became so within hours, were at prominently increased risk of death and hemorrhage. Babies who had a mild increase of PaCO2 between 45 and 60 mmHg were less likely to develop germinal matrix hemorrhage than their peers who had more severe hypercapnia. A time-weighted measure of metabolic deficit correlated with death, but not with hemorrhage. Prolonged exposure to pH greater than 7.55 was associated with reduced risk of subependymal/intraventricular hemorrhage and death, especially in babies below 1 kg birth weight. We conclude that acidosis is an antecedent of intracranial hemorrhage in low birth weight premature babies, that duration of exposure might convey important risk information, and that birth weight is a correlate of vulnerability to some pH disturbances.

Neonatal intracranial hemorrhage and phenobarbital.

We enrolled 280 intubated babies with birth weights of less than 1,751 g in a double-blind randomized prospective clinical trial to evaluate whether phenobarbital influences the likelihood of developing subependymal-intraventricular-intraparenchymal hemorrhage. Phenobarbital was associated with an increased risk of developing any subependymal-intraventricular-intraparenchymal hemorrhage and was not associated with a diminished risk of either severe hemorrhage or germinal matrix hemorrhage. This increased risk was apparent even after we considered the influence of phenobarbital levels, timing of phenobarbital administrations, institutional differences, quality of ultrasound scans, gestational age- and birth weight-specific effects, ascertainment bias, and other possible confounders of phenobarbital administration.

Childhood Köhlmeier-Degos disease with atypical skin lesions.

We report clinical and pathologic findings in a 16-year-old boy whose disease began in infancy with maculopapular skin lesions, followed by cyclic nodular cutaneous eruptions, intermittent enlargement of liver and spleen, episodic abdominal pain, and sporadic unexplained fever. Subsequently, various ophthalmologic disturbances, along with a multitude of neurologic signs and symptoms, dominated the clinical picture. The CNS bore the brunt of pathologic changes, characterized by widespread leptomeningeal fibrosis, ventricular enlargement, and multiple brain infarcts. Striking intimal thickening led to narrowing or occlusion of almost all the medium-sized and small extraparenchymal arteries.