Space flight has many negative effects on human physiology, including bone and muscle loss. These are some of the systems on which intakes of fish and n‐3 fatty acids have positive effects. These ...effects are likely to occur through inhibition of inflammatory cytokines (such as TNFα) and thus inhibition of downstream NF‐κB activation. We documented this effect in a 3D cell culture model, where NF‐κB activation in osteoclasts was inhibited by eicosapentaenoic acid, an n‐3 fatty acid. We have extended these studies and report here (a) NF‐κB expression in peripheral blood mononuclear cells of Space Shuttle crews on 2‐wk missions, (b) the effects of n‐3 fatty acid intake after 60 d of bed rest (a weightlessness analog), and (c) the effects of fish intake in astronauts after 4 to 6 mo on the International Space Station. After Shuttle flights of ~2 wk, NF‐κB p65 expression at landing was increased (P <0.001). After 60 d of bed rest, higher intake of n‐3 fatty acids was associated with less N‐telopeptide excretion (Pearson r = −0.62, P < 0.05). Higher consumption of fish during flight was associated with higher bone mineral density (Pearson r = −0.46, P < 0.05). Together with our earlier findings, these data provide mechanistic cellular and preliminary human evidence of the potential for n‐3 fatty acids to counteract bone loss associated with spaceflight. This study was supported by the NASA Human Research Program.
Acid-reducing drugs can cause increased growth of microbes, including fungus, because of high gastric pH. Our purpose was to evaluate the occurrence of mycotic infection in patients with duodenal ...ulcer on anti-ulcer therapy and to compare the effects of cimetidine, famotidine, and omeprazole. Eighty patients with duodenal ulcer (62 males and 18 female patients, 16-65 years old) were evaluated for mycotic infection before and after 6 weeks of therapy (cimetidine, 20 patients; famotidine, 40 patients; omeprazole, 20 patients). Mycotic infection was diagnosed by endoscopic biopsy from the ulcer edge subjected to smear, culture, and histopathology and by endoscopic brush samples and gastric aspirate. On the basis of these studies, patients were categorized as having no fungal growth, saprophytic growth, or significant fungal growth. Thirty-five (43.8%) patients had evidence of fungus before ulcer therapy, and 16 of the 35 (20%) had significant fungal growth. The fungal isolation rate was higher in older patients (> and = 45 years of age) and in those with an ulcer size > and = 2 cm. While there was no significant increase in the total number of patients with evidence of fungus after therapy (n = 36), there was a significant increase in those with significant growth (n = 27, p < 0.05) compared with pretreatment status. We found that posttreatment gastric pH of > and = 4 was associated with a higher fungal positivity rate (59.4%) than pH values < 4 (32.4%, p < 0.05). However, neither the type of drug used nor the response in terms of ulcer healing correlated with the presence of fungus. Regardless of the type of drug used, acid-reducing therapy is associated with increased significant fungal growth.
Epstein-Barr virus (EBV) reactivation and cell-mediated immune (CMI) responses were followed in 16 Antarctic expeditioners during winter-over isolation at 2 Australian National Antarctic Research ...Expedition stations. Delayed-type hypersensitivity (DTH) skin testing was used as an indicator of the CMI response, that was evaluated 2 times before winter isolation and 3 times during isolation. At all 5 evaluation times, 8 or more of the 16 subjects had a diminished CMI response. Diminished DTH was observed on every test occasion in 4/16 subjects; only 2/16 subjects exhibited normal DTH responses for all 5 tests. A polymerase chain reaction (PCR) assay was used to detect EBV DNA in saliva specimens collected before, during, and after the winter isolation. EBV DNA was present in 17% (111/642) of the saliva specimens; all 16 subjects shed EBV in their saliva on at least 1 occasion. The probability of EBV shedding increased (P = 0.013) from 6% before or after winter isolation to 13% during the winter period. EBV appeared in saliva during the winter isolation more frequently (P < 0.0005) when DTH response was diminished than when DTH was normal. The findings indicate that the psychosocial, physical, and other stresses associated with working and living in physical isolation during the Antarctic winter result in diminished CMI and an accompanying increased reactivation and shedding of latent viruses.
Improved methods are needed for field diagnosis of onchocerciasis, to support efforts aimed at elimination of the disease. A rapid-format card test was evaluated that detects IgG4 antibodies to ...recombinant Onchocerca volvulus antigen Ov16 with serum samples from patients with onchocerciasis and with various types of control serum samples. The sensitivity of the test with serum samples from 106 microfilariae-positive subjects was 90.6%. The test was equally sensitive with serum samples obtained from patients in Africa and Latin America. Specificity was excellent; positive tests were observed for 2 of 38 serum samples from patients with other filarial infections and for 1 of 23 serum samples from patients with nonfilarial helminth infections. The 3 “falsepositive” serum samples were from West Africans who could have been coinfected with onchocerciasis. No positive tests were observed with nonendemic serum samples from normal adults, patients with autoimmune disorders, or patients with the hyper-IgE syndrome. This new test holds great promise as a simple tool for diagnosis of onchocerciasis.
As logistical access for space research becomes more limited and NASA prepares for exploration-class missions, ground-based spaceflight analogs will increase in importance for biomedical ...countermeasures development. A monitoring of immune parameters was performed during the NASA Flight Analogs Project bed rest study (without countermeasure); to establish 'control' data against which future studies (with countermeasure) will be evaluated. Some of the countermeasures planned to be evaluated in future studies may impact immune function.
The immune assessment consisted of: leukocyte subset distribution, early T cell activation, intracellular cytokine profiles, latent viral reactivation, virus specific T cell levels and function, stress hormone levels, and a behavioral assessment using stress questionnaires.
In general, subjects did not display altered peripheral leukocyte subsets, constitutive immune activation, altered T cell function, or significant latent viral reactivation (EBV, VZV). Levels of constitutively activated T cells (CD8+/CD69+) and virus-specific T cells (CMV and EBV) decreased during the study. Cortisol levels (plasma and saliva) did not vary significantly during 90-d bed rest.
These data demonstrate the absence of significant immune system alteration and physiological stress during 90-d bed rest, and establish control data against which future studies (including countermeasures) may be compared.
Esophageal intramural pseudodiverticulosis (EIP) is a rare disease, characterized by multiple, small flask-shaped diverticula in the esophageal wall, and best demonstrated on single-contrast barium ...examination. Though the condition is often associated with reflux esophagitis, Candida esophagitis, and esophageal dysmotility, corrosive-acid injury is not a commonly recognized cause. In a radiological study involving 59 patients with sequelae of corrosive-acid injury of the upper gastrointestinal (GI) tract, evaluated over a 5-year period, 14 cases (23.7%) of EIP were found. Esophageal stricture was a constant association; the diverticula tended to involve either the entire length of the stricture or its upper part. There was, however, no correlation between the length of the stricture and number of diverticula (p greater than 0.05). Endoscopic dilatation resulted in relief of dysphagia, and the diverticula regressed in number of disappeared altogether. Our experience suggests that EIP is a common sequelae of esophageal acid injuries, and that diverticula tend to form at the site of initial contact between acid and susceptible esophageal mucosa. Stricture dilatation leads to reduction or total disappearance of the diverticula.
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