Caloric Adequacy in the First Week of Mechanically Ventilated Patients has No Impact on Long-term Daily Life Activities

Aim and objective

The aim and objective of this study is to test the effect of an optimized caloric supply in the first week of intensive care unit (ICU) stay in mechanically ventilated patients on the ability to perform their activities of daily living (ADL) in the long-term.

Materials and methods

A prospective observational study comparing patients who achieved an adequate caloric target (≥80%) vs those whose target was inadequate (<80%). The primary outcome under study is the instrumental ADL (IADL) scale after 6 months of discharge.

Results

Ninety-two patients were evaluated in the ICU and 50 were alive at 6 months. Follow-up was lost for 3 patients and 47 patients were evaluated at ICU and after 6 months. Thirty-four patients reached the energetic target and 13 did not reach it. There was no significant variation in IADL.

Conclusion

The energy adequacy in the first week of hospitalization was achieved by most survivors; however, this conduct does not seem to have influenced the ability to perform ADL after 6 months of discharge.

How to cite this article

Dariano AP, Couto CFL, Rubin BA, Viana MV, Friedman G. Caloric Adequacy in the First Week of Mechanically Ventilated Patients has No Impact on Long-term Daily Life Activities. Indian J Crit Care Med 2020;24(12):1206–1212.

Limited brain diffusion of the glucocorticoid receptor agonist RU28362 following i.c.v. administration: implications for i.c.v. drug delivery and glucocorticoid negative feedback in the hypothalamic-pituitary-adrenal axis

The experiments described herein present a method for tracking diffusion of the glucocorticoid receptor agonist RU28362 in brain following i.c.v. drug administration. A useful property of glucocorticoid receptor is that it is primarily cytoplasmic when unbound and rapidly translocates to the nucleus when bound by ligand. Thus, removal of endogenous glucocorticoids by adrenalectomy allows us to identify brain regions with activated glucocorticoid receptor after i.c.v. glucocorticoid receptor agonist treatment by examining the presence or absence of nuclear glucocorticoid receptor immunostaining. We have previously demonstrated that an i.p. injection of 150 microg/kg RU28362 1 h prior to restraint stress is sufficient to suppress stress-induced hypothalamic-pituitary-adrenal axis hormone secretion [Ginsberg AB, Campeau S, Day HE, Spencer RL (2003) Acute glucocorticoid pretreatment suppresses stress-induced hypothalamic-pituitary-adrenal axis hormone secretion and expression of corticotropin-releasing hormone hnRNA but does not affect c-fos mRNA or fos protein expression in the paraventricular nucleus of the hypothalamus. J Neuroendocrinol 15:1075-1083]. We report here, however, that in rats i.c.v. treatment with a high-dose of RU28362 (1 microg) 1 h prior to stressor onset does not suppress stress-induced hypothalamic-pituitary-adrenal axis activity. We then performed a series of experiments to examine the possible differences in glucocorticoid receptor activation patterns in brain and pituitary after i.c.v. or i.p. treatment with RU28362. In a dose-response study we found that 1 h after i.c.v. injection of RU28362 (0.001, 0.1 and 1.0 microg) glucocorticoid receptor nuclear immunoreactivity was only evident in brain tissue immediately adjacent to the lateral or third ventricle, including the medial but not more lateral portion of the medial parvocellular paraventricular nucleus of the hypothalamus. In contrast, i.p. injection of RU28362 produced a uniform predominantly nuclear glucocorticoid receptor immunostaining pattern throughout all brain tissue. I.c.v. injection of the endogenous glucocorticoid receptor agonist, corticosterone (1 microg) also had limited diffusion into brain tissue. Time-course studies indicated that there was not a greater extent of nuclear glucocorticoid receptor immunostaining present in brain after shorter (10 or 30 min) or longer (2 or 3 h) intervals of time after i.c.v. RU28362 injection. Importantly, time-course studies found that i.c.v. RU28362 produced significant increases in nuclear glucocorticoid receptor immunostaining in the anterior pituitary that were evident within 10 min after injection and maximal after 1 h. These studies support an extensive literature indicating that drugs have very limited ability to diffuse out of the ventricles into brain tissue after i.c.v. injection, while at the same time reaching peripheral tissue sites. In addition, these studies indicate that significant occupancy of some glucocorticoid receptor within the paraventricular nucleus of the hypothalamus and pituitary is not necessarily sufficient to suppress stress-induced hypothalamic-pituitary-adrenal axis activity.

Specific and time-dependent effects of glucocorticoid receptor agonist RU28362 on stress-induced pro-opiomelanocortin hnRNA, c-fos mRNA and zif268 mRNA in the pituitary

This study examined the effects of the glucocorticoid receptor (GR) agonist RU28362 on stress-induced gene expression in the pituitary of rats to investigate mechanisms of glucocorticoid negative feedback in vivo. In an initial experiment, acute restraint stress produced rapid (within 15 min) induction of c-fos mRNA, zif268 mRNA and pro-opiomelanocortin (POMC) hnRNA within the anterior and intermediate/posterior pituitary as determined by quantitative real-time polymerase chain reaction. Treatment with RU28362 (150 microg/kg, i.p.) 60 min before restraint inhibited adrenocorticotrophic hormone (ACTH) and corticosterone secretion and selectively suppressed the stress-induced increase in POMC hnRNA in the anterior pituitary gland. The failure of RU28362 to surpress the stress-induced rise in c-fos and expression of zif268 mRNA suggests that the central release of ACTH secretagogues was not affected at this time point by treatment with the GR agonist. Rather, the inhibition of ACTH release appeared to be due to a direct effect of RU28362 within the pituitary. A follow-up time-course study varied the interval (10, 60 or 180 min) between RU28362 pretreatment and the onset of restraint. The stress-induced increase in POMC hnRNA was completely blunted by RU28362 treatment within 10 min of treatment, although the stress induced hormone secretion, c-fos mRNA and zif268 mRNA were unaffected. The rapid inhibition of the stress-induced rise in POMC hnRNA in the anterior pituitary appears to reflect direct, GR-mediated suppression of POMC gene expression. RU28362 pretreatment 180 min before restraint onset was sufficient to suppress the stress-induced expression in the anterior pituitary gland of all three genes examined. Thus, the delayed negative feedback effects on hypothalamic-pituitary-adrenal axis activity that emerged after 180 min after glucocorticoid treatment were not evident at 60 min. Taken together, the data suggest that the inhibition of the stress-induced release of ACTH apparent within the first hour of glucocorticoid exposure is effected at the level of the pituitary gland. The delayed glucocorticoid effects evident 180 min after RU28362 treatment may include glucocorticoid actions in the brain and additional actions within the pituitary.

Habituation to repeated restraint stress is associated with lack of stress-induced c-fos expression in primary sensory processing areas of the rat brain

Rats repeatedly exposed to restraint show a reduced hypothalamic-pituitary-adrenal axis response upon restraint re-exposure. This hypothalamic-pituitary-adrenal axis response habituation to restraint does not generalize to other novel stressors and is associated with a decrease in stress-induced c-fos expression in a number of stress-reactive brain regions. We examined whether habituation to repeated restraint is also associated with adaptation of immediate early gene expression in brain regions that process and relay primary sensory information. These brain regions may not be expected to show gene expression adaptation to repeated restraint because of their necessary role in experience discrimination. Rats were divided into a repeated restraint group (five 1-hour daily restraint sessions) and an unstressed group (restraint naïve). On the sixth day rats from each group were either killed with no additional stress experience or at 15, 30 or 60 min during restraint. Immediate early gene expression (corticotrophin-releasing hormone heteronuclear RNA, c-fos mRNA, zif268 mRNA) was determined by in situ hybridization. A reduction in stress-induced hypothalamic-pituitary-adrenal axis hormone secretion (plasma corticosterone and adrenocorticotropic hormone) and immediate early gene expression levels in the paraventricular nucleus of the hypothalamus, the lateral septum and the orbital cortex was observed in repeated restraint as compared with restraint naïve animals. This reduction was already evident at 15 min of restraint. Unexpectedly, we also found in repeated restraint rats a reduction in restraint-induced c-fos expression in primary sensory-processing brain areas (primary somatosensory cortex, and ventroposteriomedial and dorsolateral geniculate nuclei of thalamus). The overall levels of hippocampal mineralocorticoid receptor heteronuclear RNA or glucocorticoid receptor mRNA were not decreased by repeated restraint, as may occur in response to severe chronic stress. We propose that repeated restraint leads to a systems-level adaptation whereby re-exposure to restraint elicits a rapid inhibitory modulation of primary sensory processing (i.e. sensory gating), thereby producing a widespread attenuation of the neural response to restraint.

Experimental neuritis induced by a mixture of neural antigens and influenza vaccines. A possible model for Guillain-Barré syndrome

We describe the development in rats of a possible model for Guillain-Barré syndrome (GBS): experimental neuritis (EN). The clinical symptoms, histopathology and the presence of antibody to nervous tissue are features that EN has in common with both GBS and experimental allergic neuritis (EAN), another GBS model. However, EN may be a more appropriate model than EAN for studying the role of autoimmune reactions in diseases such as GBS, which are triggered by various viruses or antigens, since EN depends on such agents being administered concomitantly with the syngeneic tissue.

Morphological components of herpesvirus. III. Localization of herpes simplex virus type 1 nucleocapsid polypeptides by immune electron microscopy

Herpes simplex virus type 1 (HSV-1) nucleocapsids were observed in the electron microscope after their reaction with IgG's purified from the sera of rabbits immunized with the individual nucleocapsid polypeptides. The combining sites of NC1, the major capsid protein (mol. wt. 154K), were distributed over the entire capsid surface. This result provides further evidence that NC1 represents the major hexamer constituent. NC2 (mol. wt. 50K) was less widely distributed and appeared to be located at capsid vertices; that antigen may be a constituent of the pentamers or of peripentameric hexamers. One or both of NC3 and NC4 (mol. wt. 40K and 38K) were also located all over the capsid, possibly at positions interior to those of NC1. One or both may represent the intercapsomeric fibrils, hexamer-associated protein or material associated with the pericore. The locations of the other nucleocapsid polypeptides could not be determined.

Induction of sister chromatid exchanges in human diploid fibroblasts by mutagens with and without rat liver microsomal activation

The frequency of sister chromatid exchange (SCE) in WI-38 cells was estimated by the 5-bromodeoxyuridine (BrdUrd)-dye technique after one hour's exposure to cyclophosphamide (CY), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO), and maleic hydrazide (MH) with and without the addition of rat liver microsomal suspension (S-9) fraction with cofactors (S-9 mix). CY at concentrations from 1 x 10(-5) M to 1 x 10(-3) M with S-9 mix increased the number of SCEs per cell in a dose-dependent manner. Without S-9 mix, CY at concentrations below 1 x 10(-3) M failed to produce more SCEs than the controls. MNNG at 1 x 10(-8) M and 4NQO at 1 x 10(-7) M without S-9 produced significant increases in SCEs per cell. Addition of S-9 during treatment slightly decreased the effects of MNNG and 4NQO in the formation of SCEs. MH was tested at pH 6.4 and pH 7.6. At pH 7.6, MH at 1 x 10(-3)M without S-9 mix inhibited cell multiplication, but did not cause a significant increase of SCEs per cell. There were no interactions between MH (2 x 10(-4) M) and S-9 mix nor between MH and the pH levels tested. These results indicate that in the presence of metabolic activation, SCE formation in human diploid fibroblasts in vitro may be used as a potential assay for mutagenicity.

Polymyxin B release of unnicked cholera toxin subunit A

Polymyxin B treatment of Vibrio cholerae 569B grown with or without lincomycin released an extracytoplasmic pool of free unnicked cholera toxin subunit A.

Lincomycin increases synthetic rate and periplasmic pool size for cholera toxin

Increased enterotoxigenicity of Vibrio cholerae 569B grown with low concentrations of lincomycin, previously described in terms of increased extracellular biological activity (capillary permeability factor and fluid accumulation in ligated rabbit ileal loops), was further characterized. Polyacrylamide gel electrophoresis and single radial immunodiffusion showed that lincomycin-stimulated cells produced increased molar quantities of cholera toxin (CT) both extra- and intracellularly. The intracellular CT was released in comparable amounts by sonication, deoxycholate extraction, and polymyxin B treatment. Polymyxin B release of CT was nearly complete under conditions wherein only 6% of total cellular beta-galactosidase was released, implying a periplasmic pool of CT in stimulated cells. No intracellular choleragenoid (CT subunit B) was found in stimulated cells by polymyxin B release. No proteolysis of 14C-labeled CT was detected after prolonged incubation with sonicated nonstimulated cultures or sonicated concentrated cells. These data support the conclusion that the stimulatory effect of lincomycin involves an increase in the rate of synthesis of the CT molecule, and argue against alternative models involving inhibition of putative normal degradation of CT, increased release of otherwise cell-bound CT, or activation of inactive, or less active, forms of CT.

Immunopharmacologic properties of 1,6-bis[2-(diethylamino)ethoxy]xanthen-9-one dihydrochloride (Wy-15297)

When tested in a series of immunopharmacologic assays, the interferon inducer, WY-15297, was shown to lack activity in early vascular and humoral phases of the inflammatory response, while it was quite effective against the immunologic phase. The profile of activity of Wy-15927 was, however, unlike those previously described for reference antiinflammatory and immunosuppressive drugs and this may represent one of a new class of immunopharmacologic agents capable of selectively modulating the lymphoreticular system.

[Comparative study of the antiviral properties of histones of animal and plant origin]

The antiviral properties of histones of animal (thymus) and plant (French beans) origin were studied in plants and with a plant virus, tobacco mosaic virus (TMV). Histones of the thymus and French beans were shown to be able to inhibit TMV reproduction. The antiviral properties of histones were found to depend on their concentration, pH, and to be determined by the modes of their introduction into leaves. The manifestation of the antiviral properties of histones seems to require not only their direct contact with virus but also a certain exposure on the leaf. The similarities of antiviral protective mechanisms of plants and animals determined by substances of the protein nature are discussed.

Induction of Escherichia coli and Vibrio cholerae enterotoxins by an inhibitor of protein synthesis

Enterotoxigenic Escherichia coli or Vibrio cholerae 569B (Inaba) grown in the presence of the antibiotic lincomycin, an inhibitor of protein synthesis, produced elevated levels of heat-labile enterotoxin or choleragen, respectively, as assayed by both vascular permeability factor and capacity to elicit fluid accumulation in rabbit ileal loops. This induction of enterotoxin did not reflect either a coupling of lincomycin resistance with increased enterotoxigenicity or an effect of lincomycin on cellular release of enterotoxin, since spontaneously isolated lincomycin-resistant mutants of both E. coli and V. cholerae still required lincomycin for induction, and large increases in E. coli permeability factor activity were found intracellularly as well as extracellularly. After the period of exponential growth, E. coli became refractory to induction by lincomycin, although most of the induced enterotoxin activity appeared only after this period. No increase in copy number of the enterotoxin plasmid in E. coli 711 (P307) was found in induced cells by analysis of deoxyribonucleic acid reassociation kinetics. These and other data suggest that synthesis of enterotoxin, or at least its accumulation, is normally limited by cellular factors whose synthesis is preferentially inhibited by lincomycin. A possible connection between this phenomenon and lincomycin-associated diarrhea is considered.

Development of a purified cholera toxoid. III. Refinements in purification of toxin and methods for the determination of residual somatic antigen

The addition of an ultrafiltration step to the purification procedures previously described for cholera toxin (Rappaport et al., (1974) permitted the preparation of highly purified antigenic toxoids essentially free of somatic antigen(s). The purity of such toxoids is established: (i) by the absence of more than about one part limulus amebocyte lysate (LAL)-positive endotoxin per 10(5) parts toxoid and (ii) by the inability of the toxoids to elicit a significant rise in rabbit vibriocidal antibody. The antigenicity of the toxoids is demonstrated by their ability to produce the same high levels of rabbit serum antitoxin as are produced by comparable toxoids containing small amounts of somatic antigen. The results also indicate that amounts of somatic antigen of the order of less than or equal to 1 mug/100 mug of toxoid do not exert an adjuvant effect on the toxoid, at least with respect to circulating antitoxin. Other data show that, where present, the ability of somatic antigen to elicit vibriocidal antibody is influenced by the immunization schedule employed and that a correlation exists between the LAL-determined endotoxin content of the toxoids and their ability to stimulate vibriocidal antibody. Somatic antigen-free toxoids, purified and tested by the refinements herein described, were prepared for use in the National Institutes of Health sponsored field trials, and data pertaining to their purity and antigenic properties are presented.

[Localization of the Meler's reaction with ethanol catalase trap in the chain of photosynthetic electron transport]

The common view of photosystem I as the action site of catalase and ethanol at oxygen uptake in chloroplasts are based on indirect data on this reaction. That is why the question on Mehler reaction localization in electron transport chain with ethanolcatalase trap has been investigated anew. It has been demonstrated that oxygen uptake with catalase and ethanol does not decrease in presence of dibromothymoquinone (2,5-dibromo-3-methyl-6 isopropyl-p-benzoquinone--DBTQ) which blocks electron transfer to photosystem I at plastoquinones level. The summation of oxygen uptake activities is observed on the combined action of catalase and ethanol with any of the Mehler reagents functioning in photosystem I (methylviologen,FMN, epinephrine, ferredoxin). Catalase and ethanol in contrast to methylviologen have no effect on photooxidation rate of reduced dichlorphenolindophenol in photosystem I. The quatum yield of oxygen uptake with catalase and ethanol versus wave length of actinic light shows a distinct maximum in the photosystem II absorption area and a "red drop" in the longware area. The obtained data show that the Mehler reaction with catalase and ethanol takes place in photosystem II only.

Morphological components of herpesvirus. II. Preservation of virus during negative staining procedures

The disruption of envelopes and the fragmentation of capsids of equine herpes-virus type I observed in negatively stained samples were attributed to viral dehydration on carbon films during preparation for electron microscopy. Prior fixation of virus with OSO4 or glutaraldehyde and subsequent application of negative stain before drying minimized envelope disruption and virtually eliminated the occurrence of capsomere sheets and broken capsids. This sample procedure significantly improves electron microscopic evaluation of herpesvirus samples.

Activation of Heat-labile Escherichia coli enterotoxin by trypsin

Trypsin-treated, cell-free filtrates derived from enterotoxigenic Escherichia coli, strain H197 (O78:H11), exhibited a fourfold or greater increase in heat-labile vascular permeability factor activity and a 10-fold or greater increase in the ability to stimulate secretion of growth hormone by cultured rat pituitary cells. In contrast, trypsin-treated filtrates were not different from untreated filtrates in their ability to elicit a secretory response in ligated rabbit intestinal loops. However, incubation of culture filtrate in ligated intestinal loops, or with rabbit intestinal fluid (in vitro), resulted in at least a twofold increase in permeability factor that did not occur in the presence of trypsin inhibitor or with heat-inactivated intestinal fluid. Moreover, trypsin inhibitor could reduce the secretory response to culture filtrate. These findings suggest that activation of heat-labile E. coli enterotoxin by host enzymes may play a role in the development of a full pathogenic effect.

Development of a purified cholera toxoid. II. Preparation of a stable, antigenic toxoid by reaction of purified toxin with glutaraldehyde

Evidence is presented which confirms that cholera toxoids obtained by reaction of purified toxin with Formalin possess the ability to partially reactivate both in vivo and in vitro. At the same time, conditions are presented for the preparation of stable, antigenic cholera toxoids by reaction of purified toxin with glutaraldehyde. Treatment of purified cholera toxin with approximately 200 mol of glutaraldehyde per mol of toxin at pH 7.8 reproducibly resulted in the preparation of toxoids which: (i) possessed less than 20 bluing doses per 100 mug; (ii) did not reactivate in vivo or in vitro; (iii) precipitated with, and neutralized antitoxin; (iv) elevated prolonged serum antitoxin in immunized rabbits; (v) protected immunized guinea pigs against toxin skin challenge; and (vi) lent themselves to enhanced antigenicity by means of an in situ adjuvant system which may be suitable for man. Acrylamide gel electrophoresis and molecular sieve chromatography of a series of glutaraldehyde-derived toxoids suggested that the reaction products consisted of monomeric and polymeric species and that the proportion of higher-molecular-weight species was determined by the relative concentrations of toxin and glutaraldehyde. The results suggested a relationship between complete and irreversible elimination of toxicity and the formation of higher-molecular-weight toxoids.

Development of a purified cholera toxoid. I. Purification of toxin

The enterotoxin from Vibrio cholerae is selectively concentrated from cell-free culture supernatant by co-precipitation with hexametaphosphate and is further purified by adsorption on aluminum hydroxide powder. The bulk of residual somatic antigen becomes insoluble upon lyophilization of the toxin preparation and is removed by centrifugation of the rehydrated material. Other contaminants are eliminated by treatment with activated carbon. Preparations of toxin, purified by this method, have been characterized by: (i) a single immunoprecipitin line against polyvalent antisera; (ii) homogeneity on acrylamide gels; (iii) specific activities on the order of 22 limit-of-bluing doses/mug; (iv) ultraviolet spectra characteristic of pure protein; and (v) overall yields on the order of 50%, irrespective of purification scale. Such preparations, however, have been shown to contain trace amounts of somatic antigen when they are intensively tested either for their ability to elevate serum vibriocidal antibody titers in immunized rabbits or for their ability to increase resistance of immunized mice to live vibrio challenge. In the latter test system, the level of residual somatic antigen per 50 mug of toxin (toxoid) antigen generally did not exceed 0.025% of the Division of Biological Standards reference vaccine, V. cholerae Inaba IN-12. Methods for elimination of this small amount of somatic antigen have been investigated and are discussed. The particular combination of purification steps which are presently described have been easily and reproducibly applied on a production scale to prepare gram amounts of toxin with a high degree of purity, even under a variety of initial conditions.

Disruption of adenovirus type 7 by lithium iodide resulting in the release of viral deoxyribonucleic acid

Adenovirus type 7 exposed to solutions of LiI was progressively converted into slower sedimenting deoxyribonucleic acid (DNA)-containing particles, and, ultimately, under proper conditions, DNA free or almost free from protein was released from the virus. The degree of viral degradation was dependent on the time of treatment, on the temperature, and on the concentration of the reagent.