Mass Spectrometry Defines Lysophospholipids as Ligands for Chicken MHCY Class I Molecules.

Chicken (Gallus gallus) MHCY class I molecules are highly polymorphic yet substantially different from polymorphic MHC class I molecules that bind peptide Ags. The binding grooves in MHCY class I molecules are hydrophobic and too narrow to accommodate peptides. An earlier structural study suggested that ligands for MHCY class I might be lipids, but the contents of the groove were not clearly identified. In this study, lysophospholipids have been identified by mass spectrometry as bound in two MHCY class I isoforms that differ substantially in sequence. The two isoforms, YF1*7.1 and YF1*RJF34, differ by 35 aa in the α1 and α2 domains that form the MHC class I ligand binding groove. Lyso-phosphatidylethanolamine (lyso-PE) 18:1 was the dominant lipid identified in YF1*7.1 and YF1*RJF34 expressed as recombinant molecules and renatured with ß2-microglobulin in the presence of a total lipid extract from Escherichia coli. Less frequently detected were lyso-PE 17:1, lyso-PE 16:1, and lysophosphatidylglycerols 17:1 and 16:0. These data provide evidence that lysophospholipids are candidate ligands for MHCY class I molecules. Finding that MHCY class I isoforms differing substantially in sequence bind the same array of lysophospholipids indicates that the amino acid polymorphism that distinguishes MHCY class I molecules is not key in defining ligand specificity. The polymorphic positions lie mostly away from the binding groove and might define specificity in interactions of MHCY class I molecules with receptors that are presently unidentified. MHCY class I molecules are distinctive in bound ligand and in display of polymorphic residues.

Transitioning the eating experience in survivors of head and neck cancer.

PURPOSE: Applying the Social Cognitive Transition (SCT) Model of Adjustment as an interpretive framework, this mixed-methods case series explored how head and neck cancer (HNC) survivors participate in the dimensions of the eating experience (described as physiological, psychological, social, cultural). METHODS: This was a sub-study of a primary study, "The Natural History and Impact of Taste Change in Oncology Care." Qualitative interviews and quantitative data (questionnaires and exams) were intersected to examine and describe the complexities of transitioning the eating experience after treatment for HNC. Triangulation of qualitative and quantitative data within and across cases was examined to produce rich descriptions of the changes and transitions in the eating experience. RESULTS: Four case studies were detailed. All reported some taste and/or smell changes. Each case described worry about weight loss and the decreased ability to engage and finding meaning in the eating experience. Each expressed coping strategies that drew upon the social and cultural dimensions of their prior eating experience that brought meaning and purpose to the post-treatment eating experience. CONCLUSIONS: This case series explored the impact of taste and oral function and the participant's pre- and post-treatment mental model of the eating experience. Application of the SCT Model of Adjustment to the eating experience in adults with HNC provided a deeper insight into how cognitive adaptation and coping strategies supported transition in identity related to the eating experience following cancer therapy.

Identifying women at risk of weight gain after a breast cancer diagnosis: Results from a cohort of Australian women.

ISSUES ADDRESSED: This study aimed to identify risk factors associated with weight gain post a diagnosis of breast cancer in a cohort of Australian women. METHODS: In this retrospective clinical audit, objectively measured weight, age and menopause status, treatment type/s, grade, stage, oestrogen receptor and progesterone receptor (PR) status were extracted for 73 breast cancer patients from an ongoing breast cancer treatment quality assurance project. Weight gain or loss was classified as a body mass increase or decrease of ≥5% of weight at diagnosis. RESULTS: When compared to weight at diagnosis, 57% of patients maintained, 22% gained, and 21% lost weight at 24 months post-diagnosis. Factors associated with weight gain were a diagnosis of grade II (P < .001) or grade III (P < .001) compared to grade I breast cancer, and refusal of radiotherapy (P < .001). Factors associated with weight loss were being postmenopausal compared to premenopausal (P = .033), PR positive compared to PR negative (P < .001), refusal of chemotherapy (P < .001) and radiotherapy recommended (P < .001). CONCLUSIONS: The maintenance of weight in a majority of women in this cohort is a novel finding. Early identification of women at risk of weight gain post a breast cancer diagnosis can assist health professionals identify, and therefore assisting patients in the prevention and management of weight gain and associated sequela. Investigating the weight-related communications between a patient and specialist, their access to allied health professionals and social support may assist in understanding the overall positive changes in this cohort.

Patch use in the arctic ground squirrel: effects of micro-topography and shrub encroachment in the Arctic Circle.

We investigated the roles of vegetation structure, micro-topographic relief, and predator activity patterns (time of day) on the perception of predatory risk of arctic ground squirrels (Urocitellus parryii), an abundant pan-Arctic omnivore, in Arctic Circle tundra on the North Slope of Alaska, where tundra vegetation structure has been predicted to change in response to climate. We quantified foraging intensity by measuring the giving-up densities (GUDs) of the arctic ground squirrels in experimental foraging patches along a heath-graminoid-shrub moist tundra gradient. We hypothesized that foraging intensity of arctic ground squirrels would be greatest and GUDs lowest, where low-stature vegetation or raised micro-topography improves sightlines for predator detection. Furthermore, GUDs should vary with time of day and reflect 24-h cycles of varying predation risk. Foraging intensity varied temporally, being highest in the afternoon and lowest overnight. During the morning, foraging intensity was inversely correlated with the normalized difference vegetation index (NDVI), a proxy for vegetation productivity and cover. Foraging was additionally measured within landscapes of fear, confirming that vegetative and topographic obstructions of sightlines reduces foraging intensity and increases GUDs. We conclude that arctic ground squirrels may affect Arctic Circle vegetation of tundra ecosystems, but these effects will vary spatially and temporally.

Assessment of association between rapid fluctuations in serum sodium and intraventricular hemorrhage in hypernatremic preterm infants.

AIM: This study aims to determine the association between the rapid fluctuations in serum sodium and intraventricular hemorrhage (IVH) or death in hypernatremic preterm infants. STUDY DESIGN: Single center observational study including 216 infants < 1,000 g birth weight and <29 weeks gestational age, who had serum sodium levels monitored at least every 12 hours. Logistic regression analyses were used to identify which of the commonly cited risk factors for IVH, including the rapid (to the extent of ≥10 and ≥15 mmol/L/d) rise or fall in serum sodium, was associated with the primary outcome of any IVH, or the secondary composite outcome of severe IVH or death during the first 10 days of life in hypernatremic infants. RESULTS: Of 216 infants, 126 (58%) studied developed hypernatremia (serum sodium ≥ 150 mmol/L). IVH was more frequent in hypernatremic infants (p = 0.01). Presence of hypernatremia was an independent risk factor for IVH on logistic regression analysis (p = 0.022, odds ratio 2.0, 95% confidence interval: 1.1-3.8). Rapid (≥ 10 and ≥ 15 mmol/L/d) rise or fall in serum sodium in hypernatremic infants was not associated with the outcomes. CONCLUSION: Hypernatremia per se, but not the rapid fluctuations (not exceeding 10-15 mmol/L/d) in serum sodium was independently associated with IVH.

Humanization of antibodies using heavy chain complementarity-determining region 3 grafting coupled with in vitro somatic hypermutation.

A method for simultaneous humanization and affinity maturation of monoclonal antibodies has been developed using heavy chain complementarity-determining region (CDR) 3 grafting combined with somatic hypermutation in vitro. To minimize the amount of murine antibody-derived antibody sequence used during humanization, only the CDR3 region from a murine antibody that recognizes the cytokine hßNGF was grafted into a nonhomologous human germ line V region. The resulting CDR3-grafted HC was paired with a CDR-grafted light chain, displayed on the surface of HEK293 cells, and matured using in vitro somatic hypermutation. A high affinity humanized antibody was derived that was considerably more potent than the parental antibody, possessed a low pm dissociation constant, and demonstrated potent inhibition of hßNGF activity in vitro. The resulting antibody contained half the heavy chain murine donor sequence compared with the same antibody humanized using traditional methods.

Simultaneous surface display and secretion of proteins from mammalian cells facilitate efficient in vitro selection and maturation of antibodies.

A mammalian expression system has been developed that permits simultaneous cell surface display and secretion of the same protein through alternate splicing of pre-mRNA. This enables a flexible system for in vitro protein evolution in mammalian cells where the displayed protein phenotype remains linked to genotype, but with the advantage of soluble protein also being produced without the requirement for any further recloning to allow a wide range of assays, including biophysical and cell-based functional assays, to be used during the selection process. This system has been used for the simultaneous surface presentation and secretion of IgG during antibody discovery and maturation. Presentation and secretion of monomeric Fab can also be achieved to minimize avidity effects. Manipulation of the splice donor site sequence enables control of the relative amounts of cell surface and secreted antibody. Multi-domain proteins may be presented and secreted in different formats to enable flexibility in experimental design, and secreted proteins may be produced with epitope tags to facilitate high-throughput testing. This system is particularly useful in the context of in situ mutagenesis, as in the case of in vitro somatic hypermutation.

Coupling mammalian cell surface display with somatic hypermutation for the discovery and maturation of human antibodies.

A novel approach has been developed for the isolation and maturation of human antibodies that replicates key features of the adaptive immune system by coupling in vitro somatic hypermutation (SHM) with mammalian cell display. SHM is dependent on the action of the B cell specific enzyme, activation-induced cytidine deaminase (AID), and can be replicated in non-B cells through expression of recombinant AID. A library of human antibodies, based on germline V-gene segments with recombined human regions was used to isolate low-affinity antibodies to human ß nerve growth factor (hßNGF). These antibodies, initially naïve to SHM, were subjected to AID-directed SHM in vitro and selected using the same mammalian cell display system, as illustrated by the maturation of one of the antibodies to low pM K(D). This approach overcomes many of the previous limitations of mammalian cell display, enabling direct selection and maturation of antibodies as full-length, glycosylated IgGs.

Multiple sclerosis in pregnancy.

Multiple sclerosis is the most common chronic neurologic disability in young adults in their childbearing ages of 20 to 45. The disease affects more women than men, which prompts discussion of pregnancy-related issues in a woman with multiple sclerosis. Preconceptual counseling to discuss the safety of medications in pregnancy, the antepartum period along with what the patient can expect during birth, and the postpartum period will be discussed.

The Exploration of the Eating Experience in Adults with Celiac Disease: A Phenomenological Qualitative Study.

BACKGROUND: The adjustment to a strict gluten-free diet for adults diagnosed with celiac disease (CD) may lead to changes in the eating experience affecting the physical, social, and emotional states. OBJECTIVE: Through the application of the Social Cognitive Transition Model of Adjustment, the aim of the study was to explore the adjustment in the eating experience in adults recently diagnosed with CD and transitioning to a gluten-free diet. DESIGN: This was a qualitative phenomenological study conducted using semistructured interviews. PARTICIPANTS AND SETTING: Seventeen adults from the midwestern United States who were diagnosed with CD between 6 months and 5 years before the study were recruited using social media CD sites and snowball sampling. Participants completed a semistructured interview on Zoom and the Celiac Disease Adherence Test and CeliacQ-7 questionnaires from May to November 2020. STATISTICA ANALYSES PERFORMED: Two trained qualitative researchers engaged in four steps to reduce and contextualize the data: horizontilization, reduction and elimination, clustering and thematizing, and composition of textural description. During analysis, the Social Cognitive Transition Model of Adjustment was incorporated for organization of themes and text description. RESULTS: There was moderate to high dietary adherence in 14 of 17 participants and quality of life scores ranged from 19 to 43 (median = 33). Five themes emerged aligning with Social Cognitive Transition Model of Adjustment, describing the adjustment in pre- and postdiagnosis eating experience and the coping and behaviors enacted during adjustment to a gluten-free diet. CONCLUSIONS: In individuals with CD, moving beyond problem solving and identifying psychosocial and emotional attributes in the adoption of a gluten-free diet need to be considered to promote maintenance of quality of life and dietary adherence.

Surfactant replacement therapy in the neonate: beyond respiratory distress syndrome.

Surfactant-replacement therapy is a life-saving treatment for preterm infants with respiratory distress syndrome, a disorder characterized by surfactant deficiency. Repletion with exogenous surfactant decreases mortality and thoracic air leaks and is a standard practice in the developed world. In addition to respiratory distress syndrome, other neonatal respiratory disorders are characterized by surfactant deficiency, which may result from decreased synthesis or inactivation. Two of these disorders, meconium aspiration syndrome and bronchopulmonary dysplasia, might also be amenable to surfactant-replacement therapy. This paper discusses the use of surfactant-replacement therapy beyond respiratory distress syndrome and examines the evidence to date.

Joint attention and oromotor abilities in young children with and without autism spectrum disorder.

PURPOSE: This study examined the relationship between joint attention ability and oromotor imitation skill in three groups of young children with and without Autism Spectrum Disorder using both nonverbal oral and verbal motor imitation tasks. Research questions addressed a) differences among joint attention and oromotor imitation abilities; b) the relationship between independently measured joint attention and oromotor imitation, both nonverbal oral and verbal motor; c) the relationships between joint attention and verbal motor imitation during interpersonal interaction; and d) the relationship between the sensory input demands (auditory, visual, and tactile) and oromotor imitation, both nonverbal oral and verbal motor. METHOD: A descriptive, nonexperimental design was used to compare joint attention and oromotor skills of 10 preschool-aged children with ASD, with those of two control groups: 6 typically developing children (TD), and 6 children with suspected Childhood Apraxia of Speech (sCAS) or apraxic-like symptoms. All children had at least a 3.0 mean length utterance. RESULTS: Children with ASD had poorer joint attention skills overall than children with sCAS or typically developing children. Typically developing children demonstrated higher verbal motor imitation skills overall compared to children with sCAS. Correlational analyses revealed that nonverbal oral imitation and verbal motor imitation were positively related to joint attention abilities only in the children with ASD. Strong positive relationships between joint attention in a naturalistic context (e.g., shared story experience) and oromotor imitation skills, both nonverbal oral and verbal motor, were found only for children with ASD. These data suggest there is a strong positive relationship between joint attention skills and the ability to sequence nonverbal oral and verbal motor movements in children with ASD. The combined sensory input approach involving auditory, visual, and tactile modalities contributed to significantly higher nonverbal oral and verbal motor imitation performance for all groups of children. CONCLUSIONS: Verbal children with ASD in this study had difficulties with both the social and cognitive demands of oromotor imitation within a natural environment that demanded cross-modal processing of incoming stimuli within an interpersonal interaction. Further, joint attention and oral praxis may serve as components of an important coupling mechanism in the development of spoken communication and later developing socialcognitive skills.

Behavioral and physiological responses to child-directed speech of children with autism spectrum disorders or typical development.

Young boys with autism were compared to typically developing boys on responses to nonsocial and child-directed speech (CDS) stimuli. Behavioral (looking) and physiological (heart rate and respiratory sinus arrhythmia) measures were collected. Boys with autism looked equally as much as chronological age-matched peers at nonsocial stimuli, but less at CDS stimuli. Boys with autism and language age-matched peers differed in patterns of looking at live versus videotaped CDS stimuli. Boys with autism demonstrated faster heart rates than chronological age-matched peers, but did not differ significantly on respiratory sinus arrhythmia. Reduced attention during CDS may restrict language-learning opportunities for children with autism. The heart rate findings suggest that young children with autism have a nonspecific elevated arousal level.

Retrospective analysis of the efficacy and tolerability of levetiracetam in patients with metastatic brain tumors.

Seizures are a common complication of metastatic brain tumors (MBT), affecting approximately 27-50% of all patients during the course of their illness. Treatment of tumor-induced seizures is often inadequate with traditional antiepileptic drugs (AED) due to a variety of factors, including activation of glutamatergic NMDA receptors, alterations of neuronal input pathways, and tumor growth. Levetiracetam (LEV) is a 2nd generation non-enzyme inducing AED with a novel mechanism of action, binding to neuronal synaptic vesicle protein SV2A, that has been previously shown to reduce seizure activity in patients with primary brain tumors. Due to its unique mechanism of action, it has been postulated that LEV may also be effective in controlling seizures from MBT. A retrospective chart review was performed of all Neuro-Oncology Center patients with MBT who had received LEV for seizure control. Thirteen patients were reviewed with a median age of 55.1 years (range: 34-70). Six patients had breast cancer, five had lung cancer, and two had melanoma. LEV was used as an add-on AED in seven patients (54%) and as monotherapy in six patients (46%), with a median dose of 1,000 mg/day (range: 500-3,000). The baseline median seizure frequency was one ictal event every other day. After the addition of LEV, the median seizure frequency was reduced to 0 per week. The seizure frequency was reduced to less than 50% of the pre-LEV baseline in 100% of patients (P=0.0002, Sign test), with 10 patients (77%; confidence interval: 46-95%) noting complete seizure control. The most common adverse event was somnolence and headache, noted in 3 of 13 patients (23%). LEV was very effective and well tolerated in MBT patients with seizures and should be considered for add-on therapy or as a substitute AED for monotherapy.