Factors Affecting Adherence, Intake, and Perceived Palatability of Oral Nutritional Supplements: A Literature Review

Oral nutritional supplements (ONS) are a clinically effective and relatively inexpensive way to supplement the diet of patients with, or at risk of, undernutrition. Good adherence is a primary determinant of the effectiveness of ONS. However adherence can be problematic for those with the greatest clinical need, such as undernourished older adults. This review aimed to appraise the available literature for the factors (contextual, personal and product related) affecting patient adherence and perceived palatability of ONS, identify areas requiring improvement and uncover gaps in the evidence to guide the focus of future research. Contextual factors identified were healthcare staff and the timing of administration. Personal factors included sensory changes and motivation which alter experience of and desire to consume ONS. The product's sensory characteristics determined palatability and intake, but undesirable attributes, such as off-flavours, can stem from nutritional ingredients. The contribution made by aroma to older adults' experience of ONS was a comparatively under-researched area. Further research should address this evidence gap to optimise the flavour, aroma profile and palatability for undernourished older consumers, thereby optimising intake. A combined multidisciplinary effort involving strategic expansion of research, industry development and clinical practice should simultaneously address the factors identified, to provide the best approach to improve adherence.

Nightmare Rescripting: Using Imagery Techniques to Treat Sleep Disturbances in Post-traumatic Stress Disorder

Besides affecting 8% of the general population, nightmares are one of the most frequent symptoms of traumatized individuals. This can be a significant factor in the treatment of post-traumatic disorders; indeed, several studies demonstrated its strong predictive and prognostic value. Sleep disorders, nightmares in particular, could be very distressing for individuals and need targeted interventions, especially if they are associated with a PTSD diagnosis. To date, the best technique for the treatment of traumatic sleep disturbances seems to be Imagery Rehearsal Therapy (IRT), an empirically supported method. Through a review of the literature on this matter, this article aims to outline the incidence and consequences of nightmares in PTSD, illustrate how IRT could prove useful in their treatment, and investigate its clinical applications.

The relation between stimulated salivary flow and the temporal consumption experience of a liquid oral nutritional supplement

Use of oral nutritional supplements (ONS) in undernourished patients has proven clinical benefits, but this can be hampered by low adherence due to poor experience of palatability. Many patients, particularly older patients, experience hyposalivation which can cause taste changes and reduce the enjoyment of foods. The aim of this study was to investigate differences in the temporal consumption experience (comprising sensory perception, in-mouth aroma release and subjective appetite) of a clinically relevant portion of ONS, for groups differing in saliva flow rates (SFR). The SFR (mL/min) of thirty healthy individuals was measured on three occasions. This data was used to categorise individuals into three groups using quartile analysis: low flow (LF) (0.3–0.6 mL/min, n = 5), medium flow (MF) (0.7–1.2 mL/min, n = 16) and high flow (HF) (1.3–1.8 mL/min, n = 9). Over the consumption of eight 15 mL sips of ONS, individuals rated their sensory perception and subjective appetite perception using line scales. Additionally, in-mouth aroma release was measured for each sip, using atmospheric pressure chemical ionisation (APCI). Compared with the MF and HF group, the LF group reported a significantly greater increase of mouth-drying over increased sips (p = 0.02). The LF group also experienced significantly higher aftertaste perception (p < 0.001), and more intense in-mouth aroma release (p = 0.015), compared with the HF group. These findings occurred concurrently with relatively lower hunger sensations in the LF and MF group. Many patients who are prescribed ONS likely experience reduced salivary flow rates. The unique sensory experiences of these individuals should be considered in order to optimise palatability and nutritional intake.

•

A full portion of ONS was evaluated by three groups differing in saliva flow rates.

•

A sensory profiling method captured perceptual differences over repeated sips.

•

Mouth-drying built up most significantly for the low saliva flow group.

•

Intensity of aftertaste and aroma release was highest in the low saliva flow group.

•

Sensorial intensity of ONS may be associated with greater feelings of satiation.

Detectability of cochlear, acoustic nerve and brainstem potentials in a group of 'normal' preterm newborns recorded with insert earphone

Thirty-four 'normal' preterm newborns were tested at 40 weeks postconceptional age. To separate electromagnetic artifacts from cochlear potentials and subsequent auditory brainstem responses, a test was given using an insert earphone at 90, 70, 50, 30 dB nHL. The detectability of receptor potentials, waves I, III, V, as a function of stimulus intensity is described: at 90 dB nHL exclusively, we could always identify these peaks because of the better morphological distinctiveness of each potential. When trying to evaluate the acoustic pathway in premature newborns, we suggest that brainstem response audiometry should be performed at 90 dB nHL with an insert earphone.

Expression of a non-MDR2-coded liver phosphatidylcholine membrane transport protein in Xenopus laevis oocytes

Phosphatidylcholines (PC) are secreted into the bile via a membrane transport protein(s). Recently, evidence for ATP-dependent mdr2-encoded PC transport as well as for carrier-mediated PC transport had been reported. Therefore, we investigated whether mdr2 P-glycoprotein is involved in the transport of a water-soluble short chain phosphatidylcholine analogue L-alpha-dibutyroyl-PC (diC4PC) induced by expression of liver mRNA in Xenopus laevis oocytes. Expression of mouse and rat mdr2 cRNA did not result in diC4PC net uptake in Xenopus laevis oocytes. By contrast oocytes showed a similar carrier-mediated uptake activity for diC4PC after injection of mouse, rat and human liver total mRNA (Km 7.7, 9.6, and 11.6 mM). Antisense inhibition of mdr2 mRNA expression increased diC4PC uptake induced by total liver mRNA from mouse and rat. The present data prove the existence of a specific mRNA for a non-mdr2-coded cell membrane PC carrier in mouse, rat, and human liver which exhibits similar transport affinity for diC4PC as the PC carrier in rat liver canalicular membranes.

Gene expression of the B875 light-harvesting prepolypeptides from Rhodospirillum rubrum in Escherichia coli

The gene coding for the prepolypeptides of alpha and beta, obtained as a 429 bp fragment from chromosomal DNA of Rhodospirillum rubrum S1 by polymerase chain reaction amplification, were cloned in tandem into the high-level expression vector pOTSNco 12 for expression in Escherichia coli. The vector pOTSNco12 is a derivative of the pAS vector system, which contains the strong lambda PL promotor and is under tight control by the cI857 repressor encoded by the expression strain AR58. Induction of transcription from the lambda PL promotor is achieved by shifting the growth temperature from 32 to 42 degrees C. Expression of the gene products was monitored by sodium dodecylsulfate polyacrylamide gel electrophoresis and western blotting. The expressed B875 light-harvesting prepolypeptides were located in the E. coli inner membrane and could not be removed by washing with high salt. The amount of expressed B875 light-harvesting prepolypeptides was estimated to be about 0.1% of the total soluble protein.

Computed tomographic findings of brain and skull in myotonic dystrophy

Images

Development of stereological analysis software for the calculation of volume, number and surface density

COSAS, an acronym for COmputerized Stereological Analysis System, is software designed to facilitate the process of quantitative morphological analysis. It is a flexible, reliable, and easy to use software system which provides the biologist with a simple means for performing stereological analysis. It provides for estimation of volume and surface density and allows for direct calculation of diameter information from planimetric data. The latter capability is unique to COSAS and provides the ability to calculate longest and shortest diameters for convex profiles, enabling calculation of number density. Access to all intermediate calculations is possible, so the process of transformation of raw data into the stereological descriptors can be completely exposed. This serves two purposes: (1) it provides a means for tracing results; (2) the intermediate values can be utilized independently. This system was used to analyze peroxisomes in tissues from patients with Zellweger's disease and neonatal-onset adrenoleukodystrophy. The system was also used to facilitate an immunocytochemical analysis of cytochrome P450 topology in the endoplasmic reticulum membrane.

Stereological analysis of peroxisomes and mitochondria in intestinal epithelium of patients with peroxisomal deficiency disorders: Zellweger's syndrome and neonatal-onset adrenoleukodystrophy

Peroxisomes, participants in lipid metabolism, have been shown to be altered in liver in two metabolic diseases in which long-chain fatty acids accumulate in tissues: Zellweger's syndrome and neonatal adrenoleukodystrophy (ALD). The intestine also plays a role in lipid metabolism, and we have had the opportunity to compare peroxisomes in normal intestinal epithelium with those from patients with Zellweger's syndrome and neonatal ALD at the electron microscopic level by using the combined techniques of cytochemistry and stereological analysis. Peroxisomes were numerous in intestinal epithelium of the normal individuals. They were ellipsoidal in shape with average diameters of 0.37 by 0.56 micron and filled with coarsely granular, DAB+ content. Peroxisomes in the intestinal epithelium of the ALD patient were similar in appearance and number but smaller in size (0.28 by 0.44 micron). Peroxisomes of normal appearance were absent from the intestinal epithelium of patients with Zellweger's syndrome; DAB+ content, however, was observed in rare, membrane-bound structures of much smaller size (0.12 by 0.19 micron). In liver of patients with Zellweger's syndrome, peroxisomes are lacking; in neonatal ALD they are abnormal in appearance and greatly reduced in number. The presence of rare minute peroxisomes in the intestinal epithelium in Zellweger's syndrome and of small peroxisomes in this epithelium in neonatal ALD indicate that peroxisomes in the intestinal epithelium are affected in these diseases, but to a lesser extent than in the liver. In the ALD intestinal epithelium, DAB+ material was also seen in long, sinuous, tubular or cisternal elements intermingled and occasionally in continuity with peroxisomes. It is suggested that these represent the early stages of peroxisome formation, the peroxisomal reticulum as originally envisioned by Lazarow, while the rare structures seen in Zellweger's represent rudiments of such a reticulum. Lamellar inclusions and clear spaces occurred in the cytoplasm adjacent to these structures indicating either that material accumulated there had been extracted during fixation or that these regions are more susceptible to autolysis. Mitochondria are also involved in lipid metabolism and have been reported to be abnormal in Zellweger's tissue. No qualitative differences were observed in the mitochondria of the intestinal epithelia examined in this study. Although quantitation revealed a greater mean volume, number, and surface density of mitochondria in the intestinal epithelia of neonatal ALD, it was not a statistically significant difference in all cases.

Disorders of perceived auditory lateralization after lesions of the right hemisphere

The disorders of perceived auditory lateralization after unilateral damage of the cerebral hemispheres were investigated by dichotic presentation of pure tones, lateralization being obtained by interaural intensity differences. Observations were made on 107 unilateral brain-damaged patients and 30 normal subjects who were required to localize the perceived position of fused sound images. The images were generated by dichotic stimuli delivered through headphones and the patients were asked to point the perceived position. A clear-cut hemispheric asymmetry was found. Whereas left brain-damaged patients and right brain-damaged patients without visual field defects were not impaired in this task in comparison with controls, the performance of right brain-damaged patients with visual field defects was defective, with a systematic directional error towards the right side, that is, the side ipsilateral to the damaged hemisphere. The defect of auditory lateralization involved both the half-space contralateral to the lesion and the ipsilateral one. Different hypotheses are discussed in order to explain the present results. It is argued that they cannot easily be interpreted in terms of defective processing of sensory information and the proposal is made that lesions of the right hemisphere may produce a distortion of the internal representation of egocentric space to the right, yielding a systematic error of auditory lateralization are discussed.

Air and bone conduction brain stem responses in adults and infants

Air and bone conduction brain stem responses were recorded in 20 adults and 20 infants (16-20 months postconceptional age) with normal hearing. The stimuli were administered using a shielded TDH-39 headphone and a standard B-70A vibrator. Our results show that adults and infants have similar air and bone conduction brain stem thresholds. The comparison of input latency functions obtained with air and bone conduction clicks indicates that the acoustic stimulus generated by the bone vibrator excites more apical regions than that stimulated by the air conduction transient. This is related to the spectrum of the bone conduction click which has an energy peak at 1-2 kHz. Furthermore we found that the difference in latency between adults and infants for air-conducted clicks decreases along with the stimulus intensity and the latencies tend to overlap near the threshold.

Influence of pre-voicing duration on dichotic performance

When two speech messages are presented to normal subjects in a dichotic listening task, the stimuli presented to the right ear are generally reported first and more accurately than signals presented to the left ear. Although a normal Italian speaker produces approximately 100 ms of pre-voicing, we found that the maximum dichotic interference (shown by a slightly larger right-ear advantage and fewer double-correct trials) occurred for stimuli with 30-ms pre-voicing. These data indicate that the duration of pre-voicing is important for intelligibility of Italian stop consonants.

Dichotic performance of Italian subjects tested with english and Italian stop consonant-vowel stimuli

15 normal-hearing, right-handed Italian subjects were tested dichotically with Italian and English stop consonant plus vowel combinations (CVs). The stimuli were modified on a computer-based routine so that the pre-voicing of Italian voiced CVs was 30 ms long. In this condition, a significant right-ear advantage and a consistent lag effect were observed with both Italian and English stimuli. In addition, no significant differences between the two types of stimuli (English and Italian) were observed in the dichotic performances (except when using the 90-ms lag, which resulted in a significant difference in performance).

Comparison between brainstem-evoked response audiometry and behavioral audiometry in 270 infants and children

The authors refer their results obtained with brainstem-evoked response audiometry (BSERA) and behavioral audiometry in a group of 270 children (aged from 6 months to 12 years) divided into subjects with (group A) and without (group B) reliable audiograms. In group A an agreement between the two methods was found in 77% of cases and a serious discrepancy in 5%. In group B an agreement was found only in 34% of cases, while a serious discrepancy was found in 20% of the children. BSERA was useful because many diagnostic mistakes were avoided. The authors think that BSERA is a reliable technique, as their data show, but in at least 4 cases they found that BSERA gave a hearing level much higher than that obtained with behavioral audiometry or that observed in the children's responses to everyday sounds. Since click gives only partial information of the tonal field and because it is possible to make technical mistakes, the authors believe that BSERA must not be used as the only diagnostic test but that it should be part of a test battery which includes, at least, behavioral audiometry and impedance audiometry.

Auditory function in guinea pigs treated with netilmicin and other aminoglycoside antibiotics

The following aminoglycoside antibiotics netilmicin, sisomicin, gentamicin, and kanamycin were submitted to a comparative study of their ototoxicity using both reflexological (Preyer's pinnareflex) and electrophysiological (near and far field) methods. The daily s.c. administration of sisomicin, gentamicin, and kanamycin for 21 days provoked a dose-related impairment of the cochlear function, detected with all the employed techniques. On the other hand, a very low ototoxic effect of netilmicin was demonstrated with electrophysiological but not with the reflexological evaluation. The reliability of the methods used in these experiments is also compared.