N-nitro- -arginine methylester is protective against ethanol-induced gastric damage in cholestatic rats

In this study the effect of nitric oxide (NO) synthesis inhibition on ethanol-induced gastric damage was evaluated in bile duct-ligated, sham-operated and unoperated rats. The animals were injected intraperitoneally with saline, -arginine (200 mg/kg) or N^G-nitro- -arginine methylester ( -NAME) in doses of 5, 15 and 30 mg/kg, 30 min before ethanol administration. The animals were killed 1 h after ethanol administration and their stomachs were removed for measurement of gastric mucosal damage. The results showed that -NAME significantly enhanced the development of gastric mucosal lesions in sham-operated and unoperated rats, while in bile duct-ligated animals, -NAME decreased and -arginine enhanced the potentiation of ethanol-induced gastric mucosal damage. The plasma level of nitrite and nitrate was also measured and was significantly higher in bile duct-ligated rats than in control groups. The results suggest that inhibition of NO synthase with -NAME has different effects on ethanol-induced gastric damage in cholestatic groups and in normal rats and that these effects can be explained by overproduction of NO in bile duct-ligated animals.     

Effect of occupational exposure to ammonia on enzymatic activities of catalase and mono amine oxidase

The study was carried out to investigate the effect of ammonia inhalation on a total number of 60 male subjects from an urea production plant located in Alexandria. Laboratory investigations were carried out for 30 exposed and 30 controlled subjects. The results showed statistically significant inhibition (p<0.01) in the activity of catalase enzyme among the exposed than the control subjects. The inhibition could lead to deleterious effects on electrical stability, permeability and fluidity of membranes, which could affect the liver and brain to be more susceptible to hepatotoxic and neurotoxic alterations. The present work showed a significant inhibition (p<0.01) of monoamine oxidase (MAO) activities and significant increase (p<0.05, 0.01) in liver function activities among exposed subjects than the control subjects.     

Comparison of patient-controlled sedation with either methohexitone or propofol

We studied 42 patients undergoing oral surgery under local anaesthesia with i.v. sedation, allocated randomly to receive either methohexitone (group M) or propofol (group P) for patient-controlled sedation (PCS). Group M patients self-administered 2.5-mg (0.5 ml) bolus doses of methohexitone and group P, 5-mg (0.5 ml) doses of propofol, without a lockout. The 0.5-ml bolus dose was delivered over 7.2 s for both drugs. The procedure was completed satisfactorily in all patients. Patients in both groups achieved their desired levels of sedation. No patient lost verbal contact. Group M patients had higher heart rates during the procedure. The lowest SpO2 values recorded were 92% and 95% for group P and group M, respectively. Immediately after operation patients in group M reported that they felt more sleepy than those in group P (P < 0.01) but there were no differences at subsequent times. The results of the psychomotor tests were comparable for the two groups after operation, except for the "posting box task" at 15 min after operation when the mean decrement (compared with preoperative performance) was - 3% for group P and -13% for group M (P < 0.05). More patients in group P complained of pain in their hand. We conclude that methohexitone is a suitable alternative drug to propofol for PCS.      

Novelty and Familiarity Activations in PET Studies of Memory Encoding and Retrieval

Nine young right-handed men viewed colored pictures of people,scenes, and landscapes. Then, 24 hr later while undergoing PETscanning, they viewed previously studied (OLD) pictures in onetype of scan, and previously not seen (NEW) pictures in another.The OLD-NEW subtraction of PET images indicates familiarity,and the NEW-OLD indicates novelty. Familiarity activations,signalling aspects of retrieval, were observed in the left andright frontal areas, and posterior regions bilaterally. Noveltyactivations were in the right limbic regions, and bilaterallyin temporal and parietal regions, including area 37. These latteractivations were located similarly to novelty activations inprevious PET studies using visual words and auditory sentences,suggesting the existence of brain regions specializing in transmodalnovelty assessment The effects of novelty are seen both be haviorallyand in replicable patterns of cortical and subcortical activation.We propose a "novelty/encoding hypothesis": (1) novelty assessmentrepresents an early stage of long-term memory encoding; (2)elaborate, meaning-based encoding processes operate on the incoming information to the extent of its novelty, and therefore(3) the probability of long-term storage of information vanesdirectly with the novelty of the information.     

Influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses.

We have studied the influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. In a double-blind, placebo-controlled trial of immunotherapy in 40 adult hay fever sufferers, clinical improvement was accompanied by a decrease in the size of the late-phase skin response. When the immunotherapy-treated group was compared with the placebo group, analysis of skin biopsies obtained 24 h after intradermal allergen revealed a significant reduction in the number of infiltrating CD3+ (P = 0.04) and CD4+ (P = 0.009) cells and a trend for a decrease in EG2+ eosinophils (P = 0.08). Treatment did not influence allergen-induced recruitment of CD8+ cells, neutrophils, or macrophages. Unexpected increases in expression of CD25 (P = 0.006) and HLA-DR (P = 0.007) were observed in the actively treated group. In situ hybridization using a panel of riboprobes demonstrated "TH2-type" (IL-4, IL-5) cytokine mRNA responses in both groups of patients. In contrast, significant hybridization for IL-2 (8/16 patients, P = 0.02) and for interferon-gamma (6/16 patients, P = 0.04) was observed only in the actively treated group. These findings indicate that immunotherapy is associated with suppression of allergen-induced CD4+ T lymphocyte infiltration, but among the cells that are recruited, there is upregulation of CD25 and HLA-DR. At least in this model, immunotherapy does not appear to affect expression of TH2-pattern cytokines in response to allergen exposure, but expression of mRNA for Th1-type cytokines was enhanced in half of the patients. The results support the view that immunotherapy may possibly be working through induction of T cell tolerance.     

The clinical manifestations of systemic lupus erythematosus: a Cairo-Glasgow co-operative study.

The clinical features of 78 patients with SLE seen in Cairo and Glasgow are reviewed. Raynaud's phenomenon was recorded more frequently here than in previous series. The value of serial measurements of anti-DNA antibodies, C3 and C4 in the management of SLE is discussed. Although antibodies to native DNA paralleled the disease course in only a minority of SLE patients anti-DNA antibodies were present during all major SLE exacerbations and could be diagnostically useful. Serious systemic infections complicating the management of SLE patients could occur and their diagnosis is discussed.     

Interlaboratory variability of rotational chair test results II: analysis of simulated data.

Standardization of rotational chair testing across laboratories has not been achieved because of differences in test protocol and analysis algorithms. The Interlaboratory Rotational Chair Study Group was formed to investigate these differences. Its first study demonstrated significant variability in calculated results using actual patient data files. No estimation of accuracy could be made, however, because the "true" values of response parameters were unknown. In this study we used simulated "patient" data files to further explore the differences among analysis algorithms. We found a high degree of agreement and accuracy across laboratories using automated analysis of high signal-to-noise/low-artifact data for gain, phase, and asymmetry. Variability increased significantly for the lower signal-to-noise ratio/higher artifact files. Operator intervention generally improved accuracy and decreased variability, but there were cases in which operator intervention reduced accuracy.     

Confocal microscopy for real-time detection of oral cavity neoplasia.

PURPOSE: The goal of this study was to characterize features of normal and neoplastic oral mucosa using reflectance confocal microscopy. EXPERIMENTAL DESIGN: Oral cavity biopsies were acquired from 17 patients at the Head and Neck Clinic of The University of Texas M. D. Anderson Cancer Center who were undergoing surgery for squamous cell carcinoma within the oral cavity. Reflectance confocal images were obtained at multiple image plane depths from biopsies within 6 h of excision. After imaging, biopsies were fixed in 10% formalin and submitted for routine histological examination. Reflectance confocal images were compared with histological images from the same sample to determine which tissue features contribute to image contrast and can be potentially imaged using in vivo confocal microscopy. RESULTS: Confocal images were successfully acquired from 15 biopsy pairs from 17 patients. Depth-related changes in cell diameter and nuclear density were observed at multiple anatomical sites within the oral cavity. In squamous cell carcinomas, densely packed, pleomorphic tumor nuclei could be visualized with distinct differences in nuclear density and morphology distinguishable between confocal images of neoplastic and nonneoplastic oral cavity. Other features of noncancerous and cancerous oral tissue that could be identified in the confocal images included areas of inflammation, fibrosis, muscle fibers, and salivary glands. CONCLUSIONS: Our results support the potential for this tool to play a significant role in the clinical evaluation of oral lesions, real-time identification of tumor margins, and monitoring of response to therapeutic treatment.     

Effects of Systemic Hyperoxia on Eustachian Tube Ventilatory Function

Middle ear negative pressure and effusions, decreased middle ear compliance, and abnormal tympanometry results have been described after diving on oxygen. Middle ear gas hyperoxia has been shown to down-regulate the eustachian tube ventilatory function (ETVF). The purpose of the present study was to investigate to what extent systemic hyperoxia in the face of air-equivalent middle ear gas composition might interfere with the ETVF. ETVF was investigated in four young adult female cynomolgus monkeys by the forced-response and inflation-deflation tests using air while the animals breathed either room air or 100% normobaric oxygen. Higher opening, closing, and steady-state pressures were observed under systemic hyperoxia. The percentage of the applied pressure equalized, and the maximal pressure change on a single swallow in the deflation test were both lower under hyperoxic conditions. The results show that systemic hyperoxia might impair ETVF. This observation adds to our understanding of the pathophysiology of middle ear dysfunction observed after diving on oxygen.