Immunonutrition in surgical patients

PURPOSE OF THE REVIEW

To outline recent findings concerning the efficacy of immunonutrients in patients undergoing surgery.

RECENT FINDINGS

Surgery induces an inflammatory response that can become excessive and damaging in some patients. The major risk factors are pre-existing nutritional status and increasing levels of surgical stress. A range of nutrients, including several amino acids, antioxidant vitamins and minerals, omega-3 fatty acids, and nucleotides, are able to modulate inflammation and the associated oxidative stress, and maintain or improve immune function. Considering the overall treatment effect of immune-modulating nutrients, parenteral glutamine is recommended in patients receiving parenteral nutrition, while enteral glutamine should be considered for burn and trauma patients. Antioxidants, particularly selenium, should be considered for critically ill patients, and enteral formulas enriched with fish oils are recommended for patients with acute respiratory distress syndrome. Arginine-supplemented diets are not recommended. In summary, malnourished patients should receive preoperative artificial nutrition for at least 10 days prior to major surgery and for 7 days postoperatively. Enteral nutrition is the best support for these patients. The benefit of immune-enhancing diets in severely malnourished patients remains to be proven. Preoperative oral immunonutrition (arginine, omega-3 fatty acids, and nucleotides) is indicated for non-malnourished patients. Although patients with cancer exhibit some special metabolic features, preoperative immunonutrition is also indicated.

SUMMARY

Immunonutrition is effective in improving outcome in a wide range of patients, particularly in malnourished individuals. However, further research using larger, better-designed trials is needed to assess whether immune function is benefited, with an improved clinical outcome in vulnerable patients.

Immune responses to T-cell epitopes of SARS CoV-N protein are enhanced by N immunization with a chimera of lysosome-associated membrane protein

In our previous study by Gupta et al, dominant T-cell epitopes of SARS CoV-N(N) protein were predicted by software. The spectrum of interferon (IFN)-gamma responses of Balb/c mice immunized against two different forms of SARS CoV-N plasmid was then analyzed. A cluster of dominant T-cell epitopes of SARS CoV-N protein was found in the N-terminus (amino acids 76-114). On the basis of this study, four different plasmids were constructed: (i) DNA encoding the unmodified N (p-N) or N(70-122) (p-N(70-122)) as an endogenous cytoplasmic protein or (ii) DNA encoding a lysosome-associated membrane protein (LAMP) chimera with N (p-LAMP/N) or N(70-122) (p-LAMP/N(70-122)). The immune responses of mice to these four constructs were evaluated. The results showed marked differences in the responses of the immunized mice. A single priming immunization with the p-LAMP/N construct was sufficient to elicit an antibody response. Enzyme-linked immunospot (ELISpot) assay indicated that p-LAMP/N(70-122) and p-LAMP/N plasmids both elicited a greater IFN-gamma response than p-N. p-N and p-N(70-122) constructs induced low or undetectable levels of cytokine secretion. We also found that the p-LAMP/N(70-122) construct promoted a long-lasting T-cell memory response without an additional boost 6 months after three immunizations. These findings show that DNA vaccines, even epitope-based DNA vaccines using LAMP as chimera, can elicit both humoral and cellular immune responses.

Genes related to immunity, as expressed in the alfalfa leafcutting bee, Megachile rotundata, during pathogen challenge

Virtually nothing is known about disease resistance in solitary bees, so expressed sequence tag (EST) databases were developed to search for immune response genes in the alfalfa leafcutting bee. We identified 104 putative immunity-related genes from both healthy and pathogen-challenged bee larvae, and 12 more genes using PCR amplification. The genes identified coded for proteins with a wide variety of innate immune response functions, including pathogen recognition, phagocytosis, the prophenoloxidase cascade, melanization, coagulation and several signalling pathways. Some immune response genes were highly conserved with honey bee genes, and more distantly related to other insects. The data presented provides the first analysis of immune function in a solitary bee and provides a foundation for the further analysis of gene expression patterns in bees.

Spectral behavior of a terahertz quantum-cascade laser

In this paper, the spectral behavior of two terahertz (THz) quantum cascade lasers (QCLs) operating both pulsed and cw is characterized using a heterodyne technique. Both lasers emitting around 2.5 THz are combined onto a whisker contact Schottky diode mixer mounted in a corner cube reflector. The resulting difference frequency beatnote is recorded in both the time and frequency domain. From the frequency domain data, we measure the effective laser linewidth and the tuning rates as a function of both temperature and injection current and show that the current tuning behavior cannot be explained by temperature tuning mechanisms alone. From the time domain data, we characterize the intrapulse frequency tuning behavior, which limits the effective linewidth to approximately 5 MHz.

Genotyping of the polymorphism within exon 1 of <i>Hormone Sensitive Lipase (LIPE)</i> Gene in three Chinese Yak (<i>Bos grunniens</i>) breeds by PCR-RFLP (Brief Report)

Abstract. The yak (Bos grunniens), a herbivore living on the Qinghai-Tibetan Plateau and its adjacent territories, is one of world’s most remarkable domestic animals. Over the past decades, research has been done on properties of yak meat at physiological and biochemical levels. In recent years, some candidate genes associating with meat quality and lipid metabolism in yak have been studied (MA et al. 2007, ZHONG et al. 2007). The Hormone Sensitive Lipase (LIPE) gene has been regarded as a candidate gene associating with lipid metabolism and meat quality. Several studies have reported the genetic variations in the LIPE genes of human and pig (TALMUD et al. 1998, KNOLL et al. 1998, WU et al. 1998, HARBITZ et al. 1999), whereas the yak LIPE gene polymorphism has not been investigated and no information is available. The aim of this study was to identify and characterize the genetic variation in Chinese yak LIPE at the DNA sequence level and genotyping of the polymorphism within LIPE in different yak breeds.

Craniopharyngiomas in the posterior fossa: a rare subgroup, diagnosis, management and outcomes

OBJECTIVE

Craniopharyngiomas with predominant pars in the posterior fossa are very rare and extremely overlooked. The clinical features, diagnosis and management are different from their sellar/suprasellar counterparts. The purpose of this study was to explore the differing characteristics of posterior fossa craniopharyngiomas.

METHODS

Seven patients with pathologically proven craniopharyngiomas located in the posterior fossa were retrospectively investigated. The clinical data and radiographic findings were presented and analysed.

RESULTS

The primary presentations included headache, diplopia, ataxia and hearing loss. All tumours were located in the retrochiasmatic area, and five of seven displayed a retroinfundibulum growth pattern. The predominant components of the tumours were located in the unilateral cerebellopontine angle (CPA) in six cases, and the bilateral CPA in one case. Total tumour resection was accomplished in five patients. There were transient cranial nerve deficits in three patients, and CSF leakage in one patient. Six patients fully recovered to normal conditions, but one patient had tumour regrowth and had to undergo a secondary resection.

CONCLUSIONS

Posterior fossa craniopharyngiomas are rare and may be considered an independent subgroup of classifications. Tumours arising from the sellar region and extending to the posterior fossa present with their own unusual set of characteristics. These tumours can be radically and safely removed with a combined supra- and intratentorial approach.

Age determination of plutonium material by alpha spectrometry and thermal ionization mass spectrometry

Age is a key parameter to deduce the history of a plutonium material. An experimental method using both alpha spectrometry and thermal ionization mass spectrometry has been developed for the age determination of plutonium material. This method is based on the parent/daughter pair 241Pu/241Am ratio and has been validated using several plutonium source of known age. The results obtained are in good agreement with the last purification date of plutonium source.

Optical coherence tomography differs in neuromyelitis optica compared with multiple sclerosis

BACKGROUND

Neuromyelitis optica (NMO) is associated with destructive inflammatory lesions, resulting in necrosis and axonal injury. Disability from multiple sclerosis (MS) is due to a combination of demyelination and varying axonal involvement. Optical coherence tomography (OCT), by measuring retinal nerve fiber layer (RNFL) as a surrogate of axonal injury, has potential to discriminate between these two conditions.

METHODS

Included were 22 subjects with NMO or NMO spectrum disorders and 47 with MS. Seventeen subjects with NMO and all with MS had a remote history of optic neuritis (ON) in at least one eye, at least 6 months before OCT. Linear mixed modeling was used to compare the two diagnoses for a given level of vision loss, while controlling for age, disease duration, and number of episodes of ON.

RESULTS

After ON, NMO was associated with a thinner mean RNFL compared to MS. This was found when controlling for visual acuity (56.7 vs 66.6 microm, p = 0.01) or for contrast sensitivity (61.2 vs 70.3 microm, p = 0.02). The superior and inferior quadrants were more severely affected in NMO than MS.

CONCLUSIONS

Optic neuritis (ON) within neuromyelitis optica (NMO) is associated with a thinner overall average retinal nerve fiber layer compared to multiple sclerosis, with particular involvement of the superior and inferior quadrants. This suggests that NMO is associated with more widespread axonal injury in the affected optic nerves. Optical coherence tomography can help distinguish the etiology of these two causes of ON, and may be useful as a surrogate marker of axonal involvement in demyelinating disease.

Association study of IFNAR2 and IL10RB genes with the susceptibility and interferon response in HBV infection

A recent genome-wide association study discovered that two polymorphisms, interferon (IFN) alpha receptor 2 (IFNAR-2) F8S and interleukin 10 receptor (IL10RB) K47E, were associated with susceptibility to hepatitis B virus (HBV) infection in Africa. Here, we reevaluate the effects of the two polymorphisms on HBV susceptibility in the Chinese Han population, and extended the study to look at their association with IFN response in chronic hepatitis B (CHB). We included 341 patients with CHB and 341 unrelated controls presenting with asymptotic HBV self-limited infection, who were well matched in age and sex. In the CHB group, 101 patients had been treated with peg-IFN-alpha-2a for 48 weeks and followed up for 24 weeks to determine the clinical response, resulting 34 individuals with sustained virological response (SVR) and 67 individuals with nonsustained response (NR). Subgroups in the CHB group were divided according to the viral loads, HBeAg and maternal HBsAg status. The association with the susceptibility to HBV infection was only observed for IL10RB K47E when we compared the individuals with persistent HBV infection through nonmaternal transmission to the controls with asymptomatic self-limited HBV infection. Further, we found that the IFNAR2-8SS genotype was associated with HBeAg negative patients (OR = 0.316, 95% CI: 0.121-0.825, P = 0.019) and that the IFNAR2-8F allele was associated with the risk to high viral loads (OR = 1.667, 95% CI: 1.148-2.420, P = 0.007). In addition, the IFNAR2-8FF genotype predisposed to higher MxA gene induction and correlated with sustained IFN response (OR = 0.348, 95% CI: 0.129-0.935, P = 0.036). Haplotype analysis based on polymorphisms of three single-nucleotide polymorphisms, MxA - 88 G/T, IFNAR-2 F8S and IL10RB K47E showed that the haplotype distribution was significantly different between the SVR and NR groups (P = 0.040). This study suggests that IFNAR2 may play an important role in determining IFN response and clinical phenotypes of HBV infection in the Chinese Han population.

Pharmacokinetics of 20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol and its active metabolite after oral and intravenous administration in rat

The pharmacokinetics behaviour of 20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol (25-OCH3-PPD) and its active metabolite after oral and intravenous administration in rats were studied. Rats were administered 2.5, 5.0, and 10 mg kg(-1) 25-OCH3-PPD orally after an overnight fasting or by intravenous injection of 5 mg kg(-1) 25-OCH3-PPD via the tail vein. Plasma concentration-time profiles of 25-OCH3-PPD and its active metabolite 25-O-demethylated (25-OH-PPD) in rats were monitored by liquid chromatography-tandem mass spectroscopy (HPLC-MS-MS). The 25-O-demethylated metabolite appears to be a pathway in the phase I metabolism of 25-OCH3-PPD in rats. The plasma concentration of the metabolite was higher than that of the parent compound.

Optical coherence tomography is less sensitive than visual evoked potentials in optic neuritis

OBJECTIVES

Determine the utility of optical coherence tomography (OCT) to detect clinical and subclinical remote optic neuritis (ON), its relationship to clinical characteristics of ON and visual function, and whether the retinal nerve fiber layer (RNFL) thickness functions as a surrogate marker of global disease severity.

METHODS

Cross-sectional study of 65 subjects with at least 1 clinical ON episode at least 6 months prior. Measures included clinical characteristics, visual acuity (VA), contrast sensitivity (CS), OCT, and visual evoked potentials (VEP).

RESULTS

Ninety-six clinically affected optic nerves were studied. The sensitivity of OCT RNFL after ON was 60%, decreasing further with mild onset and good recovery. VEP sensitivity was superior at 81% (p = 0.002). Subclinical ON in the unaffected eye was present in 32%. VEP identified 75% of all subclinically affected eyes, and OCT identified <20%. RNFL thickness demonstrated linear correlations with VA (r = 0.65) and CS (r = 0.72) but was unable to distinguish visual categories <20/50. RNFL was thinner with severe onset and disease recurrence but was unaffected by IV glucocorticoids. OCT measurements were not related to overall disability, ethnicity, sex, or age at onset. The greatest predictor for RNFL in the unaffected eye was the RNFL in the fellow affected eye.

CONCLUSIONS

Visual evoked potentials (VEP) remains the preferred test for detecting clinical and subclinical optic neuritis. Optical coherence tomography (OCT) measures were unrelated to disability and demographic features predicting a worse prognosis in multiple sclerosis. OCT may provide complementary information to VEP in select cases, and remains a valuable research tool for studying optic nerve disease in populations.

Induction of protective cytotoxic T-cell responses by a B-cell-based cellular vaccine requires stable expression of antigen

B cell-based cellular vaccines represent a promising approach to active immunotherapy of cancer complementing the use of dendritic cells, especially in pediatric patients and patients with low bone marrow reserves. B cells can be easily prepared in large numbers and readily home to secondary lymphoid organs, the primary site of induction of cytotoxic T lymphocyte (CTL) responses. However, most B cell-based vaccines tested so far failed to induce functional and protective CTLs in in vivo models. Here we demonstrate that B cells activated via the Toll like receptor-9 (TLR-9) and CD40 up-regulate surface expression of MHC and costimulatory molecules, produce IL-12, and exhibit potent antigen-presenting properties in vitro. Importantly, while administration of peptide-coated or transiently transfected B cells fails to induce immune responses, therapeutic immunization with low numbers of genetically modified B cells stably expressing antigen results in an induction of functional CTLs and protection against the growth of tumor in an animal model. Following activation, B cells partially loose their ability to home to organized lymphoid tissue due to the shedding of CD62L; however, this property can be restored by expression of protease-resistant mutant of CD62L. In summary, the data presented in this report suggest that genetically modified activated B cells represent a promising candidate for a cancer vaccine eliciting functional systemic CTLs.