Planning for Older Adult Day Programs in an Arab American Community: Perceptions From Older Adults, Caregivers, and Professional Providers.

Background and Objective: This study explored Arab American stakeholders' perceptions about potential future adult day programming to inform geriatric service providers about relevant services for culturally diverse older adults. Research Design and Method: Participants (N = 28) in five focus groups were recruited through a social service provider in Metropolitan Detroit, Michigan. Results were analyzed using thematic analysis. Results: Themes included basic requirements, promoting clear and transparent understanding of adult day programs (ADPs), respecting the person, social engagement and activities, explaining complex ethnic and geographic identities, and implementing diversity. Discussion and Implications: ADP service providers can enhance services by drawing on the life experiences, resilience, and creativity of older Arab Americans. Person-focused policies and programs that draw on the strengths of the diverse local community should be developed and communicated clearly for potential participants, family members, and service providers.

Congenital Aqueductal Stenosis: Findings at Fetal MRI That Accurately Predict a Postnatal Diagnosis.

BACKGROUND AND PURPOSE: Congenital aqueductal stenosis is a common cause of prenatal ventriculomegaly. An accurate diagnosis provides prognostic information and may guide obstetric management. The purpose of this study was to identify specific anatomic findings on prenatal MR imaging that can be used as predictors of congenital aqueductal stenosis. MATERIALS AND METHODS: Prenatal and postnatal MRIs of fetuses referred to our institution for ventriculomegaly between June 2008 and August 2015 were reviewed. Imaging findings in postnatally confirmed congenital aqueductal stenosis (disease group) were compared with those of ventriculomegaly cases from other causes (control group). Univariate analysis was performed using the Fisher exact test and the Wilcoxon rank test, and multivariate analysis, via the random forest method. RESULTS: Forty-three cases of ventriculomegaly had a confirmed postnatal diagnosis of congenital aqueductal stenosis. Thirty-two ventriculomegaly cases negative for congenital aqueductal stenosis were included in the control group. Dominant findings associated with an accurate prenatal diagnosis of congenital aqueductal stenosis on multivariate analysis included the following: enlarged inferior third ventricular recesses, enlargement of the lateral ventricles and third ventricle, and an abnormal corpus callosum. Findings that significantly increase the probability of congenital aqueductal stenosis (high positive predictive value) included the following: enlarged third ventricular recesses, aqueduct funneling, hemorrhage in the cerebral aqueduct, ventricular diverticulum, rhombencephalosynapsis, and dystroglycanopathy-related cerebellar dysplasia. CONCLUSIONS: Our study identified specific characteristics on fetal MR imaging that can be used as predictors of the diagnosis of congenital aqueductal stenosis. Most of these findings are secondary to the obstructive nature of the resulting hydrocephalus. Common associated malformations such as rhombencephalosynapsis and dystroglycanopathies should also increase the suspicion of congenital aqueductal stenosis when present with ventriculomegaly.

Effects of timing and duration of test period and diet type on intake and feed efficiency of Charolais-sired cattle.

Objectives of this experiment were to: 1) determine appropriate test length, timing, and repeatability of DMI, ADG, and efficiency over different biological time points; 2) determine the efficacy of using decoupled performance and intake data to generate accurate feed efficiency measures; and 3) determine the relationship between forage-and grain-feed efficiency measures. Over 2 yr, Charolais crossbred heifers ( = 308) and steers ( = 320) were fed for two 70 d periods and DMI, ADG, and 12th rib fat thickness were recorded. Steers were fed grain-based diets during the growing and finishing periods to determine the effects of test period and timing on DMI and feed efficiency. Heifers were fed forage during the growing period and grain during the finishing period to test the effect of diet type on measures of DMI and feed efficiency. For each 70 d test period, individual DMI was recorded using the GrowSafe (Airdrie, AB) system. Residual feed intake (RFI) was calculated for each test period. Total feeding period ADG (FP_ADG) was calculated for steers by regressing all weights taken from feedlot arrival to final BW, which was calculated by dividing HCW by a standard dressing percentage (63%). Dry matter intake and RFI were correlated (r 0.56; < 0.01, and 0.63; < 0.01, respectively) for the growing and finishing periods of grain-fed steers. Average daily gain was not repeatable ( = 0.11; 0.06) across both test periods for steers. However, growing and finishing ADG were correlated ( = 0.58; < 0.01, and = 0.69; < 0.01, respectively) to FP_ADG. To assess the potential of shortening the intake test, DMI was analyzed in 7 d increments for grain-fed steers during the growing and finishing periods. Regardless of test length, from 7 to 70 d, DMI was strongly correlated ( ≥ 0.87; < 0.01) to total DMI during the growing period. Heifer forage DMI was correlated ( = 0.58; < 0.01) to grain DMI; subsequently, forage and grain RFI were moderately correlated ( = 0.40; < 0.01). This study suggests that DMI is repeatable across varying stages of maturity in cattle, and accurate feed efficiency measures can be obtained in either the growing or finishing period. The relationship of forage and grain DMI and efficiency in heifers suggests that measures of DMI and feed efficiency in heifers are relevant, regardless of diet fed. Intake evaluation periods can be shortened with minimal effects on the accuracy of predicting individual animal DMI.

Congenital heart anomaly in newborns with congenital diaphragmatic hernia: a single-center experience.

OBJECTIVE: To evaluate the impact of the presence of a congenital heart anomaly (CHA) and its potential contribution to morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). METHODS: In this retrospective cohort study, prenatal and postnatal data of all newborns diagnosed with CDH between January 2004 and December 2012 in a single center were reviewed. Cases were classified into two groups: those with 'isolated' CDH and those with both CDH and CHA. Patients with CHA were further subclassified into those with a major or minor CHA based on the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1), and the Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery (STS-EACTS) scoring systems. Patients with associated non-cardiac anomalies, including 'syndromic cases', were excluded from the analysis. Primary and secondary outcomes were survival up to 1 year of age and a need for extracorporeal membrane oxygenation (ECMO), respectively. RESULTS: Of the 180 infants with CDH, 41 were excluded because of the presence of non-cardiac associated anomalies, 118 had isolated CDH and 21 had CDH with CHA (16 with minor and five with major CHA). Receiver-operating characteristics curve analysis demonstrated that the best cut-off for survival was when the score for CHA was ≤ 2 for both RACHS-1 (area under the curve (AUC), 0.74 (P = 0.04); sensitivity, 80.0%; specificity, 87.5%) and STS-EACTS (AUC, 0.83 (P = 0.03); sensitivity, 100%; specificity, 87.5%). Survival rate at 1 year was significantly lower in those with CHD and a major CHA (40.0%; P = 0.04) than in those with isolated CDH (77.1%) and those with CDH and a minor CHA (81.3%). We found no significant differences among the groups with regard to the need for ECMO. CONCLUSIONS: In general, a milder form of CHA does not appear to have a negative impact on the survival of infants with CDH. However, mortality appears to be significantly higher in infants with CDH and a major form of CHA. The scoring systems appear to be useful as predictors for classifying the effects of CHA in this population of patients.

Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography.

OBJECTIVES: To describe a method of quantifying the amount of liver herniation in fetuses with isolated congenital diaphragmatic hernia (CDH) using two-dimensional ultrasonography and to correlate this finding with neonatal outcome. METHODS: Ultrasound images obtained from 77 consecutive fetuses that presented with isolated CDH between January 2004 and July 2012 were reviewed. Liver herniation and thoracic area were measured in a cross-sectional plane of the fetal chest at the level of the four-chamber view of the heart (the same section as is used to measure the lung area-to-head circumference ratio) and the ultrasound-derived liver-to-thoracic area ratio (US-LiTR) was calculated by dividing the liver herniation area by the thoracic area. Receiver-operating characteristics (ROC) curve analysis was used to evaluate the performance of US-LiTR in predicting neonatal outcome (survival to 6 months after delivery and need for extracorporeal membrane oxygenation (ECMO)). In addition, the US-LiTR was compared with the magnetic resonance imaging (MRI)-derived volume ratio (MRI-LiTR) and percentage of liver herniation (MRI-%LH). RESULTS: The overall neonatal mortality in the 77 cases with isolated CDH was 20.8% (16/77). ECMO was needed in 35.5% (27/76) of the newborns, with a survival rate of 52%. The US-LiTR was associated statistically with mortality (P < 0.01) and with the need for ECMO (P < 0.01). Good correlations were observed between US-LiTR and MRI-LiTR (r = 0.87; P < 0.001) and between US-LiTR and MRI-%LH (r = 0.90; P < 0.001). Based on ROC curve analysis, all three parameters had similar accuracy in predicting mortality (US-LiTR: area under the ROC curve (AUC), 0.78 (95% CI, 0.65-0.92), P < 0.01; MRI-LiTR: AUC, 0.77 (95% CI, 0.63-0.90), P < 0.01; MRI-%LH: AUC, 0.79 (95% CI, 0.65-0.92), P < 0.01, respectively) as well as the need for ECMO (US-LiTR: AUC, 0.72 (95% CI, 0.60-0.84), P < 0.01; MRI-LiTR: AUC, 0.73 (95% CI, 0.60-0.88), P < 0.01; MRI-%LH: AUC, 0.77 (95% CI, 0.64-0.89), P < 0.01, respectively). CONCLUSIONS: Two-dimensional ultrasound measurement of the amount of liver herniation in fetuses with isolated CDH is feasible and demonstrates a predictive accuracy for neonatal outcome similar to that of MRI.

Fetal lung volume and quantification of liver herniation by magnetic resonance imaging in isolated congenital diaphragmatic hernia.

OBJECTIVE: To determine associations between fetal lung and liver herniation volumes measured by magnetic resonance imaging (MRI) and mortality/need for extracorporeal membrane oxygenation (ECMO) in cases of isolated congenital diaphragmatic hernia (CDH). A secondary objective was to compare prenatal MRI parameters with two-dimensional ultrasound lung measurements. METHODS: A retrospective review of medical records of all fetuses with isolated CDH evaluated between January 2004 and July 2012 was performed. The following MRI parameters were measured at 20-32 weeks: observed/expected total fetal lung volume (o/e-TLV), predicted pulmonary volume (PPV), percentage of liver herniated into the fetal thorax (%LH) and the liver/thoracic volume ratio (LiTR). These were compared with the ultrasound-determined lung-to-head ratio (LHR) and the observed/expected LHR (o/e-LHR) in the same cohort. The predictive value of MRI and ultrasound parameters for mortality and the need for ECMO was evaluated by univariate, multivariate and factor analysis and by receiver-operating characteristics curves. RESULTS: Eighty fetuses with isolated CDH were evaluated. Overall mortality was 18/80 (22.5%). Two newborns died a few hours after birth. ECMO was performed in 29/78 (37.2%) newborns, with a survival rate of 48.3% (14/29). The side of the diaphragmatic defect was not associated with mortality (P = 0.99) or the need for ECMO (P = 0.48). Good correlation was observed among o/e-TLV, PPV, LHR and o/e-LHR as well as between %LH and LiTR (r = 0.89; P < 0.01); however, fetal lung measurements and measures of liver herniation were not correlated (all P > 0.05). All parameters were statistically associated with mortality or the need for ECMO. The best combination of measurements to predict mortality was o/e-TLV and %LH, with 83% accuracy. CONCLUSION: Mortality and the need for ECMO in neonates with isolated CDH can be best predicted using a combination of MRI o/e-TLV and %LH.

Needle core biopsy in the diagnosis of pediatric thyroid neoplasms: a single institution retrospective review.

PURPOSE: Our institution routinely utilizes needle core biopsy (NCB), instead of fine needle aspiration, in the evaluation of pediatric thyroid nodules. This practice initially arose from limited cytopathology services in our hospital. Given the lack of information regarding the utility of NCB in diagnosing pediatric thyroid neoplasms, we set out to review our institution's experience with this technique. METHODS: We performed a single institution retrospective chart review of all children who underwent thyroidectomy for primary thyroid pathology. RESULTS: Seventy-four patients, with a mean age of 12.9 ± 4.5 (SD) years, underwent partial or total thyroidectomy between 2002 and 2010. Seven of these patients had medically refractive hyperthyroidism. The remaining 67 patients had one or more thyroid nodules as identified by ultrasound. 24 (36 %) of these cases were malignant on final pathology. 14 (58 %) of the malignant cases were papillary thyroid carcinoma. 46 of the thyroid nodule cases underwent pre-operative NCB. Biopsy results for these patients were non-diagnostic in 6 (13 %), benign in 11 (24 %), atypical in 17 (37 %), and malignant in 12 (26 %). There were no complications arising from NCB. Sensitivity of NCB for diagnosing papillary carcinoma (PC) and follicular neoplasm was calculated at 0.88 (0.47-1.0, 95 % CI) and 0.84 (0.60-0.97, 95 % CI), respectively. Of the 28 patients not undergoing preoperative NCB, 12 underwent hemithyroidectomy, with one patient (8 %) requiring completion thyroidectomy for PC. Overall, the sensitivity of NCB in diagnosing PC and follicular thyroid neoplasms was 0.85 (0.55-0.99, 95 % CI), while the specificity was 0.63 (0.42-0.82, 95 % CI). CONCLUSIONS: Needle core biopsy appears to have a low rate of associated complications, and its sensitivity for diagnosing PC and follicular neoplasm is comparable to what has been reported for fine needle aspiration biopsy in a similar patient population.

Diagnosis of pentalogy of cantrell in the fetus using magnetic resonance imaging and ultrasound.

We report two cases of pentalogy of Cantrell diagnosed in utero using a combination of fetal echocardiography and magnetic resonance imaging. The cardiac component consisted of tetralogy of Fallot in the first fetus and ventricular septal defect in the second fetus. Whereas fetal echocardiography allowed accurate delineation of the cardiac anatomy, prenatal magnetic resonance imaging allowed clearer delineation of the extent of the thoracic and abdominal wall defects. Fetal magnetic resonance imaging in conjunction with prenatal echocardiography allows optimal assessment of the fetus with ectopia cordis, which has significant implications from the standpoint of preoperative planning and providing prognostic information. This report represents the first description of applying magnetic resonance imaging in combination with echocardiography toward a better understanding of this clinical entity in the fetus.

Survival of rat or mouse ventral mesencephalon neurons after cotransplantation with rat sertoli cells in the mouse striatum.

Transplanting cells across species (xenotransplantation) for the treatment of Parkinson's disease has been considered an option to alleviate ethical concerns and shortage of tissues. However, using this approach leads to decreased cell survival; the xenografted cells are often rejected. Sertoli cells (SCs) are testis-derived cells that provide immunological protection to developing germ cells and can enhance survival of both allografted and xenografted cells. It is not clear whether these cells will maintain their immunosuppressive support of cografted cells if they are transplanted across species. In this study, we investigated the immune modulatory capacity of SCs and the feasibility of xenografting these cells alone or with allografted and xenografted neural tissue. Transplanting xenografts of rat SCs into the mouse striatum with either rat or mouse ventral mesencephalon prevented astrocytic infiltration of the graft site, although all transplants showed activated microglia within the core of the graft. Surviving tyrosine hydroxylase-positive neurons were observed in all conditions, but the size of the grafts was small at best. SCs were found at 1 and 2 weeks posttransplant. However, few SCs were found at 2 months posttransplant. Further investigation is under way to characterize the immune capabilities of SCs in a xenogeneic environment.

Mobilized peripheral blood cells administered intravenously produce functional recovery in stroke.

Filgratism (granulocyte colony stimulating factor, G-CSF)-mobilized peripheral blood progenitor cells (PBPCs) have replaced bone marrow (BM) as a preferred source of autologous stem cells, in light of the faster hematologic recovery and lesser supportive care requirement exhibited by PBPC transplants. Other hematopoietic stem cells, like the human umbilical cord blood-derived stem cells (hUCBs), and nonhematopoietic stem cells have been shown to improve motor function in rodent models of injury and degenerative disease. In the present study we transplanted either G-CSF-mobilized PBPCs or hUCBs in rats 24 h after permanent middle cerebral artery occlusion (MCAO), and assessed their behavioral abnormalities in spontaneous activity and spontaneous motor asymmetry. In both transplanted groups of rats we observed a significant reduction of the stroke-induced hyperactivity compared with nontransplanted, stroked animals. In addition, transplantation of G-CSF PBPC and hUCB cells prevented the development of extensive motor asymmetry. Our findings raise the possibility that PBPCs could provide a novel transplantation therapy to treat stroke.

Gas-phase basicities for ions from bradykinin and its des-arginine analogues.

Apparent gas-phase basicities (GB(app)s) for [M + H]+ of bradykinin, des-Arg1-bradykinin and des-Arg9-bradykinin have been assigned by deprotonation reactions of [M + 2H]2+ in a Fourier transform ion cyclotron resonance mass spectrometer. With a GB(app) of 225.8 +/- 4.2 kcal x mol(-1), bradykinin [M + H]+ is the most basic of the ions studied. Ions from des-Arg1-bradykinin and des-Arg9-bradykinin have GB(app) values of 222.8 +/- 4.3 kcal x mol(-1) and 214.9 +/- 2.3 kcal x mol(-1), respectively. One purpose of this work was to determine a suitable reaction efficiency 'break point' for assigning GB(app) values to peptide ions using the bracketing method. An efficiency value of 0.1 (i.e. approximately 10% of all collisions resulting in a deprotonation reaction) was used to assign GB(app)s. Support for this criterion is provided by the fact that our GB(app) values for des-Arg1-bradykinin and des-Arg9-bradykinin are identical, within experimental error, to literature values obtained using a modified kinetic method. However, the GB(app)s for bradykinin ions from the two studies differ by 10.3 kcal x mol(-1). The reason for this is not clear, but may involve conformation differences produced by experimental conditions. The results may be influenced by salt-bridge conformers and/or by conformational changes caused by the use of a proton-bound heterodimer in the kinetic method. Factors affecting the basicities of these peptide ions are also discussed, and molecular modeling is used to provide information on protonation sites and conformations. The presence of two highly basic arginine residues on bradykinin results in its high GB(app), while the basicity of des-Arg1-bradykinin ions is increased by the presence of two proline residues at the N-terminus. The proline residue in the second position folds the peptide chain in a manner that increases intramolecular hydrogen bonding to the protonated N-terminal amino group of the proline at the first position.

Further studies on the effects of topical lactate on amino acid efflux from the ischemic rat cortex.

A rat four-vessel cerebral occlusion model was used to examine the effects of D-lactate and oxamate, a lactate dehydrogenase inhibitor, on cortical window superfusate levels of amino acids, glucose and L-lactate. Superfusate levels of aspartate, glutamate, taurine, GABA and phosphoethanolamine rose during ischemia and then declined during reperfusion. Glycine and alanine levels tended to increase during reperfusion, whereas glutamine levels were lower. Serine levels were not altered. Glucose levels declined rapidly during ischemia and recovered during reperfusion. Lactate levels were sustained during ischemia and increased during reperfusion. Unlike L-lactate, which attenuated ischemia/reperfusion (I/R) evoked amino acid release (J.W. Phillis, D. Song, L.L. Guyot, M.H. O'Regan, Lactate reduces amino acid release and fuels recovery of function in the ischemic brain, Neurosci. Lett. 272 (1999) 195-198), topical application of D-lactate (20 mM), which is not used as an energy substrate, enhanced the I/R release of aspartate, glutamate, GABA and taurine into cortical superfusates, and also elevated L-lactate levels above those in the controls. Glucose levels were not altered. Oxamate (20 mM) application elevated the pre-ischemia levels of alanine, glycine and GABA and those of GABA during ischemia. Levels of all amino acids, with the exception of phosphoethanolamine, were elevated during reperfusion. Oxamate, an inhibitor of lactate dehydrogenases 1 and 5, did not alter the pattern of efflux of glucose and L-lactate. In the presence of oxamate, L-lactate (20 mM) failed to inhibit amino acid release. The failure of D-lactate to attenuate amino acid release confirms the inability of this isomer to act as a metabolic substrate. The oxamate data indicate that inhibition of lactate dehydrogenase is detrimental to the viability of cortical cells during I/R, even though extracellular lactate levels are elevated. The pre-ischemia increases in alanine and glycine are suggestive of elevations in pyruvate as a result of the block of its conversion to lactate, with transamination reactions converting pyruvate to form these amino acids. In summary, the results further substantiate the concept of a role for L-lactate as a cerebral energy substrate.

Dissociation of multiply charged negative ions for hirudin (54-65), fibrinopeptide B, and insulin A (oxidized).

Collision-induced dissociation (CID) was performed on multiply deprotonated ions from three commercial peptides: hirudin (54-65), fibrinopeptide B, and oxidized insulin chain A. Ions were produced by electrospray ionization in a Fourier transform ion cyclotron resonance mass spectrometer. Each of these peptides contains multiple acidic residues, which makes them very difficult to ionize in the positive mode. However, the peptides deprotonate readily making negative ion studies a viable alternative. The CID spectra indicated that the likely deprotonation sites are acidic residues (aspartic, glutamic, and cysteic acids) and the C-terminus. The spectra are rife with c, y, and internal ions, although some a, b, x, and z ions form. Many of the fragment ions were formed from cleavage adjacent to acidic residues, both N- and C-terminal to the acidic site. In addition, neutral loss (e.g., NH3, CH3, H2O, and CO2) was prevalent from both the parent ions and from fragment ions. These neutral eliminations were often indicative of specific amino acid residues. The fragmentation patterns from several charge states of the parent ions, when combined, provide significant primary sequence information. These results suggest that negative mode CID of multiply deprotonated ions provides useful structural information and can be worthwhile for highly acidic peptides that do not form positive ions in abundance.

Measuring consumer experiences with primary care.

OBJECTIVE: To assess the adequacy of the Primary Care Assessment Tool-Child Edition (PCAT-CE) for evaluating the attainment of the key characteristics of primary care services for children and youth. DESIGN: Community-based telephone survey. SETTING: Specific political subdivision in Washington, DC. PARTICIPANTS: Four hundred fifty parents/guardians of offspring 18 years of age or less. MEASURES: Reliability, validity and principal component analysis of 5 scales representing key aspects of the 4 cardinal domains of primary care included in the PCAT-CE. In addition, 2 subdomains (first contact use and extent of affiliation with a primary care source) were included as indices to describe overall patterns of use and affiliation with the particular source of care. RESULTS: Most scales had adequate internal consistency, test-retest reliability, and construct validity. The principal components factor analysis yielded 5 separate factors. These corresponded to the subdomains of first contact accessibility; coordination of care; characteristics of the professional-patient relationship over-time; and comprehensiveness (both services available and indicated services received). CONCLUSIONS: Psychometric assessment supported the integrity and general adequacy of the PCAT-CE for assessing the characteristics and quality of primary care for children and youth. Testing of revised versions in a variety of different settings is underway. A major component of this testing is to explore the possibility of reducing the number of items while retaining sufficient detail about each component of primary care to make judgements about people's experiences with that care.

Towards the neural basis for hypersociability in a genetic syndrome.

Williams syndrome (WMS), a rare disorder with a distinctive profile of medical, psychological, neurophysiological and neuroanatomical characteristics, results from hemizygous deletion of about 20 genes. The phenotype exhibits specific dissociations in higher cognitive functions: general cognitive deficits but spared linguistic abilities; extreme spatial cognitive deficits, but intact face processing. Of special interest is an unusual social phenotype in WMS: an overly friendly, engaging personality and excessive sociability with strangers. In this first experimental study of social behavior in WMS, we report that WMS subjects show an abnormal positive bias in their social judgments of unfamiliar individuals, consistent with their behavior in real life. Our findings contribute to an understanding of the neural and genetic bases of human social behavior.

Effects of cysteic acid groups on the gas-phase reactivity and dissociation of [M + 4H]4+ ions from insulin chain B.

Gas-phase ion/molecule reactions and collision-induced dissociation (CID) were conducted on [M + 4H]4+ of insulin chain B. This Fourier transform mass spectrometry work involved ions from the oxidized peptide (with two cysteic acid residues) and its reduced form (with two cysteine residues). Kinetic behavior during deprotonation and hydrogen/deuterium exchange reactions indicates that insulin B (ox) ions have two distinct structural types. In contrast, insulin B (red) ions have only one major reacting population, which has a more compact structure than the oxidized ions. No significant differences in fragmentation patterns for the two insulin B (ox) populations were observed when CID was performed as a function of deprotonating reaction time. However, markedly different fragmentation was found between [M + 4H]4+ of insulin B (ox) and (red). Therefore, the presence of cysteic acid groups in insulin B (ox) significantly impacts dissociation and presumably structure. This suggests that some insulin B (ox) ions are zwitterionic, with the five basic sites protonated and one cysteic acid group deprotonated. Molecular dynamics calculations revealed several viable structures that are consistent with the experimental results. For example, the most stable form of the reduced ion, which is unprotonated at the His10, is very compact and has lost the alpha-helix of native insulin. Low energy structures for the oxidized ions include a zwitterion with an intraionic interaction between anionic Cyx7 and cationic His10, as well as a nonzwitterionic conformer that lacks a proton at Phe1; both structures retain the alpha-helix. These structures may account for the two experimentally observed isomers, although others are possible. In addition, experiments on oxidized insulin B were conducted from methanolic solution, which may denature the conformation, and pure aqueous solution, which may leave a native conformation. These differences in solvent composition had no effect on the gas-phase results.

Negative ion postsource decay time-of-flight mass spectrometry of peptides containing acidic amino acid residues.

Acidic peptides have been studied by negative ion postsource decay (PSD) matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The peptides contained from 5 to 16 residues and were chosen on the basis of their patterns of the acidic residues. Using typical MALDI sample preparation techniques employing an acidic matrix, gastrin I (1-14), and epidermal mitosis inhibiting pentapeptide yielded much larger deprotonated ion signals, [M - H]-, than protonated ions, [M + H]+. This may be due to their absence of basic residues, coupled with their arrays of acidic residues. The PSD fragmentation of the peptide negative ions showed that an array of acidic residues, as in gastrin I (1-14), yielded simple spectra containing mainly backbone cleavage ions from the C-terminus. Hirudin (54-65), which contains two sets of two consecutive Glu residues, and fibrinopeptide A and fibrinopeptide B, with isolated acidic residues, also showed backbone cleavages as common fragment ions. In addition, the two sets of isolated consecutive amino acid residues in Cys(Bzl)84-CD4 (81-92) and hirudin (54-56) yielded internal ions from the cleavages at the (O=C)-NH bond between the acidic residues. Also observed were ions with unique side chain losses, such as the loss of C6H4O from a tyrosine residue and SCH2C6H5 and CH2C6H5 from a benzylated cysteine residue. Compared to the positive mode, the negative-ion PSD yielded fewer fragments which usually involved only one type of backbone cleavage (e.g., [Yn - H2O]-). These simple spectra aided interpretation. Overall, the acidic peptides studied yielded negative ion PSD spectra that were useful for peptide sequencing.

Consumer experiences and provider perceptions of the quality of primary care: implications for managed care.

BACKGROUND: The purpose of this study was to determine the extent to which consumer and provider reports of primary care differ according to particular characteristics of the primary care setting. METHODS: A random sample of consumers was surveyed by telephone in a defined geographic area of Washington, DC, to determine their experiences with care provided to a randomly chosen child. The primary care provider of each respondent was sent a parallel survey. Scores were obtained for each of two subdomains in the four cardinal primary care domains (first contact, longitudinality, comprehensiveness, and coordination) and for three related domains (family centeredness, community orientation, and cultural competence). Differences between settings that did or did not impose limitations on autonomy for referrals and between fee-for-service and capitated settings were ascertained. RESULTS: Both consumers and their providers in settings characterized by high degrees of limitation on physician autonomy or by capitation reported better first-contact accessibility and a greater range of services available than did consumers in settings with low degrees of limitation, or by fee-for-service reimbursements to physicians. Consumers but not providers reported better family centeredness in these settings. Most other differences favored these settings as well, but these were not consistently statistically significant for both providers and consumers in both types of settings. CONCLUSIONS: The quality of primary care services in different settings can be ascertained by using an instrument with demonstrated reliability and convergent validity. Although certain types of settings, in the particular geographic area studied, appear to perform better in several key aspects of the primary care, replication of the study in other areas would be useful judging the performance of the newer types of settings to be superior to more conventional care for general populations.