Adrenocortical, beta-endorphin and behavioral responses to graded stressors in differentially reared rats

Isolation rearing has long been suspected to alter hormonal and behavioral responses to stress. Two experiments were conducted to test the hypothesis that isolates are more timid or fearful than socially reared rats when exposed to novel test environments. In both, isolate response to 3 graded stressors was compared to that of socially-reared rats. In the first experiment, animals were handled, shocked or not treated prior to testing to produce three levels of conditioned fear. They were then tested on four paradigms previously shown sensitive to conditioned fear: open field activity, emergence latency, auditory startle, and latency to accept food from the experimenter. In the second experiment, rats were given a 0-, 5- or 20-min forced swim, then sacrificed for analysis of plasma corticosterone and pituitary and hypothalamic beta-endorphin. It was found that isolates showed little evidence of enhanced behavioral timidity, although rearing effects were seen on all 4 behavioral measures. Plasma corticosterone levels increased in a graded fashion over the course of the forced swim, but there was no effect of rearing conditions. While there were no effects of rearing or stress on hypothalamic beta-endorphin, pituitary beta-endorphin content was lower in females than in males, and isolate males had lower pituitary endorphin than social males. In summary, these experiments provide no evidence that isolation rearing produces a primary, global increase in fearfulness, but identify several behavioral and hormonal differences associated with differential housing in rats.     

CD4 lymphocytes in the blood of HIV(+) individuals migrate rapidly to lymph nodes and bone marrow: support for homing theory of CD4 cell depletion

Recent studies have provided evidence that macrophages from Th1-prone mouse strains respond with an M1 profile, and macrophages from Th2-prone mouse strains respond with an M2 profile, characterized by the dominant production of NO or TGF-beta 1, respectively. We have shown that peritoneal macrophages from IL-12p40 gene knockout mice have a bias toward the M2 profile, spontaneously secreting large amounts of TGF-beta 1 and responding to rIFN-gamma with weak NO production. Moreover, IL-12p40KO macrophages are more permissive to Trypanosoma cruzi replication than their wild-type littermate cells. Prolonged incubation with rIL-12 fails to reverse the M2 polarization of IL-12p40KO macrophages. However, TGF-beta 1 is directly implicated in sustaining the M2 profile because its inhibition increases NO release from IL-12p40KO macrophages. IFN-gamma deficiency is apparently not the reason for TGF-beta 1 up-regulation, because rIFN-gamma KO macrophages produce normal amounts of this cytokine. These findings raise the possibility that IL-12 has a central role in driving macrophage polarization, regulating their intrinsic ability to respond against intracellular parasites.     

Levels of cytokine in bronchoalveolar lavage (BAL) fluid in patients with pulmonary fibrosis due to sulfur mustard gas inhalation.

This study was designed to analyze cytokine levels in bronchoalveolar lavage (BAL) fluid of patients with pulmonary fibrosis (PF) and was performed at a University hospital. Nineteen veterans had mustard gas-induced PF, and 19 normal veterans were used as a control group. Chest roentgenograms, pulmonary function tests (PFTs), the percentage diffusing capacity of carbon monoxide (D(LCO)), high-resolution CT scans of the chest, and analyses of BAL fluids for five cytokines interleukin-8 (IL-8), IL-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), IL-12, and the growth factors transforming growth factor-beta (TGF-beta), insulin-like growth factor-1 (IGF-1), and epidermal growth factor (EGF) were performed in all cases. A transbronchial lung biopsy was done in all patients. There were significant differences in cytokine (IL-8, IL-1beta, IL-6, TNF-alpha, IL-12) levels of BAL fluid between patients with PF and healthy controls. TGF-beta, EGF, and IGF-1 levels were also significantly increased in patients with PF compared with controls. A significant negative correlation was observed between the percentage of D(LCO) and IL-8 levels in BAL fluid in patients with PF (r = -0.47, p = 0.04). A significant negative correlation was also seen between the percentage of D(LCO) and TGF-beta (r = 0.53, p = 0.02) in these patients. Except for the percentage and the absolute number of the BAL fluid neutrophils (r = 0.70, p = 0.001 and r = -0.62, p = 0.005, respectively), no correlation was found between D(LCO)% and the other BAL cells. Of all measured cytokines and growth factors, only IL-8 and TGF-beta showed a significant correlation with the degree of fibrosis (p = 0.004, p = 0.04). The increased levels of cytokines and growth factors in the BAL fluid suggest the possible causative mechanism in the lung in sulfur mustard gas-induced PF by recruitment of neutrophils and eosinophils into the lung.     

Effect of age and nerve injury on cross-excitation among sensory neurons in rat dorsal root ganglia

Spike activity in dorsal root ganglion (DRG) neurons depolarizes passive neighbors that share the same ganglion. We asked whether age or prior nerve injury affect this 'cross-depolarization' signal. Intracellular recordings made from excised DRGs in vitro revealed that the prevalence and duration of cross-depolarization were no greater in adult than in young rats, and that its amplitude was significantly smaller in adults. The amplitude of cross-depolarization was not affected by nerve injury. The decrease in membrane input resistance (R(in)) observed during cross-depolarization was less than that expected from equivalent depolarization alone. This affirms prior evidence that the neural process underlying cross-depolarization causes a net increase in R(in).     

The role of Casoni’s skin test and indirect haemagglutination test in the diagnosis of hydatid disease

Casonis skin test and indirect haemagglutination test (IHA) are still used in Turkey. The preoperative IHA test or Casonis skin test results of 120 patients with surgically confirmed hydatidosis were retrospectively studied during 1997–2004. At the same period, 306 patients with non-hydatid disease had serologic results for echinococcosis. The sensitivity of immediate intradermal reaction, delayed intradermal reaction, and IHA were 70, 62, and 56%, respectively. Casonis skin test components had higher sensitivity than IHA (P<0.01). The specificity of immediate intradermal reaction, delayed intradermal reaction, and IHA were 87, 85, and 84%, respectively. Cystic lesions in non-hydatid patients were localised commonly in the lungs. The occurrence of hydatid disease for pulmonary, hepatic, and renal cysts was 19, 54, and 5%, respectively. An immediate skin reaction to crude hydatid antigens is more useful than IHA.     

Stage, survival and delays in lung, colorectal, prostate and ovarian cancer: comparison between diagnostic routes

BACKGROUND: Very few studies have reported cancer outcomes of patients referred through different routes, despite the prominence of current UK cancer urgent referral guidance. AIM: This study aimed to compare outcomes of cancer patients referred through the urgent referral guidance with those who were not, with respect to stage at diagnosis, survival, and delays in diagnosis. Design of study: Analysis of hospital records. SETTING: One hospital trust in England. METHOD: The records of 889 patients diagnosed in 2000-2001 with one of four types of cancer were analysed: 409 with lung cancer; 239 with colorectal cancer; 146 with prostate cancer; and 95 with ovarian cancer. Outcome measures were diagnostic stage, survival, referral and secondary care delays. RESULTS: For lung cancer, urgent referrals had more advanced TNM (tumor, node, metastasis) stage than patients diagnosed through other routes (P = 0.035) and poorer survival (P = 0.020). There was no difference in stage or survival for the other cancers. For each cancer, a higher proportion of urgent referrals was seen within 2 weeks. Secondary care delays for lung and colorectal cancer were shorter for inter-specialty referrals. CONCLUSION: For patients with lung cancer, the guidance appears to be prioritising those in the more advanced stages of disease. This was not the case for the other three cancers. Referral delays were shorter for patients urgently referred, as is the intention of the guidance. The avoidance of delays in outpatient diagnostics probably accounts for shorter secondary care delays for inter-specialty referrals.     

Summation of fibre potentials and the e.m.g.-force relationship during the voluntary movement of a forearm

A linear mathematical model of the electromyogram (e.m.g.) has been developed for the biceps muscle. The number of motor units (and therefore muscle fibres) contributing to the resultant e.m.g. at any stage of movement has been found from the force analysis of elbow flexion. The depths of various motor units and the phase difference between the recruitment of any two motor units have been formulated using a spiral spread of recruitment sequence. The attenuation of individual motor-unit action potentials due to varying depths has been taken into consideration, and due regard has been taken of the length-tension diagram of a muscle while performing the force analysis. Attention has been focused on the flexion of the elbow joint, in which a method of finding the individual contribution of the biceps and brachialis muscles has been developed and applied. The results predicted by the model have been verified by experiments. The model can also be extended to the e.m.g. of other fast skeletal muscles. The conditions and limitations for such generalisations have been stated and discussed.     

Apoptotic body engulfment by a human stellate cell line is profibrogenic

Hepatocyte apoptosis and stellate cell activation are both features of chronic liver diseases, but a relationship between these events has not been explored. In macrophages, engulfment of apoptotic bodies induces expression of transforming growth factor-beta (TGF-beta), a profibrogenic cytokine. We examined whether a similar response occurs in stellate cells. Fluorescently labeled hepatocyte apoptotic bodies were added to cultures of primary and immortalized human stellate cells. Stellate cells, but not hepatocytes, readily engulfed apoptotic bodies in a time-dependent manner as assessed by confocal microscopy. The activation of primary and immortalized human stellate cells after incubation with apoptotic bodies, as well as their fibrogenic activity, was indicated by an increase in alpha-smooth muscle actin (primary cells), TGF-beta1, and collagen alpha1(I) mRNA (primary and immortalized cells). The profibrogenic response was dependent upon apoptotic body engulfment, because nocodazole, a microtubule-inhibiting agent, blocked both the engulfment and the increase of TGF-beta1 and collagen alpha1(I) mRNA. As described in primary rodent stellate cells, up-regulation of collagen alpha1(I) mRNA was inhibited by a PI-3K inhibitor (LY294002) and a p38 mitogen-activated protein kinase inhibitor (SB203580) in LX-1 cells. In conclusion, these data support a model in which engulfment of hepatocyte apoptotic bodies by stellate cells leads to a fibrogenic response by eliciting a kinase-signaling pathway.     

Labeling of cells with ferumoxides-protamine sulfate complexes does not inhibit function or differentiation capacity of hematopoietic or mesenchymal stem cells

Two FDA-approved agents, ferumoxides (Feridex), a suspension of superparamagnetic iron oxide (SPIO) nanoparticles and protamine sulfate, a drug used to reverse heparin anticoagulation, can be complexed and used to label cells magnetically ex vivo. Labeling stem cells with ferumoxides-protamine sulfate (FePro) complexes allows for non-invasive monitoring by MRI. However, in order for stem cell trials or therapies to be effective, this labeling technique must not inhibit the ability of cells to differentiate. In this study, we examined the effect of FePro labeling on stem cell differentiation. Viability, phenotypic expression and differential capacity of FePro labeled CD34 + hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC) were compared with unlabeled control cells. Colony-forming unit (CFU) assays showed that the capacity to differentiate was equivalent for labeled and unlabeled HSC. Furthermore, labeling did not alter expression of surface phenotypic markers (CD34, CD31, CXCR4, CD20, CD3 and CD14) on HSC, as measured by flow cytometry. SDF-1-induced HSC migration and HSC differentiation to dendritic cells were also unaffected by FePro labeling. Both FePro-labeled and unlabeled MSC were cultured in chondrogenesis-inducing conditions. Alcian blue staining for proteoglycans revealed similar chondrogenic differentiation for both FePro-labeled and unlabeled cells. Furthermore, collagen X proteins, indicators of cartilage formation, were detected at similar levels in both labeled and unlabeled cell pellets. Prussian blue staining confirmed that cells in labeled pellets contained iron oxide, whereas cells in unlabeled pellets did not. It is concluded that FePro labeling does not alter the function or differentiation capacity of HSC and MSC. These data increase confidence that MRI studies of FePro-labeled HSC or MSC will provide an accurate representation of in vivo trafficking of unlabeled cells.