Isolation of a new nonaborane cluster form: arachno-B(9)H(11).(PPh(3))(2).
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Journal Article↗
Biomedical subjects
L Barton
Publications and source records attributed to L Barton.
The nido-osmaboranes [2,2,2-(CO)(PPh(3))(2)-nido-2-OsB(5)H(9)] and [6,6,6-(CO)(PPh(3))(2)-nido-6-OsB(9)H(13)].
The structural characterization of the osmahexaborane 2-carbonyl-2,2-bis(triphenylphosphine)-nido-2-osmahexaborane(9), [Os(B(5)H(9))(C(18)H(15)P)(2)(CO)], (I), a metallaborane analogue of B(6)H(10), confirms the structure proposed from NMR spectroscopy. The structure of the osmadecaborane 6-carbonyl-6,6-bis(triphenylphosphine)-nido-6-osmadecaborane(13), [Os(B(9)H(13))(C(18)H(15)P)(2)(CO)], (IV), is similarly confirmed. The short basal B-B distance of 1.652 (8) A in (I), not bridged by an H atom, mirrors that in the parent hexaborane(10) [1.626 (4) A].
Journal Article↗
Nursery survival for infants of birth weight 500-1500 grams during 1982-1995.
OBJECTIVE: To evaluate nursery survival of very low birth weight infants (VLBW) over time, born in the same large inner-city hospital with a predominantly Hispanic population. METHODS: All liveborn VLBW infants weighing 500-1500 g at birth were included in four time periods of 2 years' duration during 1982 to 1995. Demographics were collected for the obstetric population. Clinical data were collected including maternal and infant perinatal factors. All infants were assigned a cause of death and infants dying with lethal anomalies were then excluded from further evaluations. RESULTS: Overall survival improved progressively (p = 0.0001) with dramatic improvement in survival of infants 500-750 g birth weight (BW) in period 4 (1994-1995). The number of lethal anomalies did not increase but accounted for a larger portion of deaths in period 4. Decreases in other causes of death over time reflected changes in perinatal care. Although the mothers were high-risk, none of the maternal factors evaluated showed any consistent effect on infant survival. Improved labor and delivery care was associated with improvement in Apgar scores, a decrease in intracranial hemorrhage/intraventricular hemorrhage as a cause of death and an improvement in survival between the first two periods. In spite of the increase in Cesarean sections for infants of 500-750 g BW and their improved survival in period 4, no clear advantage for Cesarean section could be demonstrated. The marked improvement seen in period 4 was associated with three changes in care: increased use of maternal steroids, administration of surfactant, and the use of newer ventilatory methods including high-frequency oscillatory ventilation. Although female gender has been reported to confer a protective influence for survival, this was not found in the final period. Black mothers comprised only about 2.5% of the total obstetric population but delivered approximately 10% of the VLBW infants. Despite the increased incidence of small for gestational age (SGA) among black infants, there were no differences in survival between blacks and Hispanics. Mean birth weight and gestational age in both survivors and nonsurvivors decreased significantly over the four time periods. In period 4, 50% survival occurred at a birth weight of 600-700 g and a gestational age of 23 weeks. CONCLUSION: Nursery survival improved throughout the period of the study from 1982 to 1995 but especially during period 4 (1994-1995). Improved survival was associated with changes in both maternal and infant care. In infants of BW 500-750 g, gestational age rather than birth weight was more closely associated with survival.
Black or African American↗
A model for the delivery of culturally competent community care.
AIM: To describe the proposed Culturally Competent Community Care (CCCC) model, and the process of development and testing of the model. BACKGROUND: Community health nurses are challenged to provide culturally competent care in all types of communities. However, existing models have not provided community nurses with specific guidelines, and none attempt to explain the effects of culturally competent care on populations in community settings. Therefore, it is necessary to develop a model that is comprehensive in its description of the dimensions of culturally competent care in community-based settings and that also requires a focus on ethnic populations. The model is essential for reducing racial and ethnic health disparities. METHODS: Based on literature review and concept analysis, three constructs of the Culturally Competent Community Care Model were developed. Two of the constructs, the health care system and health outcomes, were developed based on a literature review. The main construct of the model, cultural competence, was developed after a concept analysis, following the development and testing of the Cultural Competence Scale (CCS). Interviews with eight community health nurses and a survey by five community nurse experts were conducted in order to refine and confirm the dimensions of cultural competence and its impact on health outcomes. CONCLUSIONS: The proposed dimensions of culturally competent care are caring, cultural sensitivity, cultural knowledge, and cultural skills. This model focuses on the relationship between cultural competence and health outcomes for culturally diverse populations. The framework provides specific guidelines for community nurses in developing and assessing cultural competence and meeting the health needs of diverse communities.
Clinical Competence↗
Two iridanonaborane compounds.
Two iridanonaborane compounds, 4-carbonyl-5,6:8,9-bis-muH-4-hydrido-4-bis(trimethylphosphine)-4-irida-arachno-nonaborane(12), [IrH(B8H12)(C3H9P)2(CO)], (Ia), and 2-carbonyl-2,5:6,9:8,9-tri-muH-4-chloro-2-bis(trimethylphosphine)-2-irida-nido-nonaborane(11), [Ir(B8H10Cl)(C3H9P)2(CO)], (II), are described. Compound (II) shows evidence of effective chlorine-substituent migration during its formation.
Journal Article↗
Strategies for mechanical ventilation.
With the advancement of veterinary critical care medicine, an increasing number of veterinary patients are being supported with positive-pressure ventilation. Animals with potentially reversible ventilatory failure (PaCO2 > 60 mmHg) caused by neuromuscular disease or pulmonary parenchymal disease or with pulmonary parenchymal disease causing hypoxemia (PaO2 < 60) despite supplemental oxygen are candidates for ventilatory support. The equation of motion for the respiratory system is defined and is used to describe the potential interactions between the patient and the ventilator. Commonly used modes of ventilation are described in terms of control and phase variables. The intent of this report is to aid clinicians in choosing an optimal ventilatory strategy for each patient that will best achieve the desired physiologic goals with minimal detrimental side effects.
Animals↗
Causes of death in the extremely low birth weight infant.
OBJECTIVE: To present primary and secondary causes of death confirmed by autopsy for the extremely low birth weight infant. METHODS: A total of 111 infants weighing between 300 and 1000 g at birth who died and were autopsied at our hospital during the 4-year period 1990-1993 were retrospectively reviewed. Clinical, pathologic, and laboratory data were retrieved including results of placental examinations and autopsy cultures. Primary and secondary causes of death were assigned by the authors. RESULTS: Infection was the most common primary cause (56/111) followed by respiratory distress syndrome/bronchopulmonary dysplasia (24/111) and congenital defect (15/111). Immaturity as an only cause appeared almost exclusively in infants weighing <500 g at birth. Infection was significantly underdiagnosed clinically with most of these deaths attributed to immaturity or respiratory distress syndrome. In only 1 case was intraventricular hemorrhage considered the primary cause of death although it was present as a secondary cause in 19/111. Infections were divided into congenital (30/56) and acquired (26/56) by time of death. The congenital infections (</=48 hours) consisted of pneumonia and chorioamnionitis/funisitis attributable to maternal enteric organisms. Causative bacteria were obtained in pure culture in a number of these cases. The acquired infections were mainly caused by yeasts and nosocomial bacteria. Sixty-seven percent of the deaths occurred in the first 2 days and 12% were beyond the neonatal period at 29 to 104 days. Care was not initiated or was withdrawn in 50% of the infants, usually within the first 4 hours. CONCLUSIONS: Infection of the amniotic fluid leading to pneumonia was the major cause of death in the extremely low birth weight infant. Accurate cause of death can not be reliably ascertained without an autopsy accompanied by examination of the placenta in the early deaths. Antibiotic treatment of the mother and infant may have reduced the deaths from infection. Early failure to respond to neonatal intensive care may well indicate presence of a congenital pneumonia.
Amniotic Fluid↗
Applications of comparative genomic hybridisation in constitutional chromosome studies.
G band cytogenetic analysis often leads to the discovery of unbalanced karyotypes that require further characterisation by molecular cytogenetic studies. In particular, G band analysis usually does not show the chromosomal origin of small marker chromosomes or of a small amount of extra material detected on otherwise normal chromosomes. Comparative genomic hybridisation (CGH) is one of several molecular approaches that can be applied to ascertain the origin of extra chromosomal material. CGH is also capable of detecting loss of material and thus is also applicable to confirming or further characterising subtle deletions. We have used comparative genomic hybridisation to analyse 19 constitutional chromosome abnormalities detected by G band analysis, including seven deletions, five supernumerary marker chromosomes, two interstitial duplications, and five chromosomes presenting with abnormal terminal banding patterns. CGH was successful in elucidating the origin of extra chromosomal material in 10 out of 11 non-mosaic cases, and permitted further characterisation of all of the deletions that could be detected by GTG banding. CGH appears to be a useful adjunct tool for either confirming deletions or defining their breakpoints and for determining the origin of extra chromosomal material, even in cases where abnormalities are judged to be subtle. We discuss internal quality control measures, such as the mismatching of test and reference DNA in order to assess the quality of the competitive hybridisation effect on the X chromosome.
Chromosome Banding↗
Identification and localization of an immunoreactive AMPA-type glutamate receptor subunit (GluR4) with respect to identified photoreceptor synapses in the outer plexiform layer of goldfish retina.
L-glutamate, the main excitatory synaptic transmitter in the retina, is released from photoreceptors and evokes responses in second-order retinal neurons (horizontal, bipolar cells) which utilize both ionotropic and metabotropic types of glutamate receptors. In the present study, to elucidate the functional roles of glutamate receptors in synaptic transmission, we have identified a specific ionotropic receptor subunit (GluR4) and determined its localization with respect to photoreceptor cells in the outer plexiform layer of the goldfish retina by light and pre-embedding electron-microscopical immunocytochemistry. We screened antisera to mammalian AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate)-preferring ionotropic glutamate receptors (GluR 1-4) of goldfish retina by light- and electron-microscopical immunocytochemistry. Only immunoreactive (IR) GluR4 was found in discrete clusters in the outer plexiform layer. The cones contacted in this manner were identified as long-wavelength ("red") and intermediate-wavelength ("green") cones, which were strongly immunoreactive to monoclonal antibody FRet 43 and antisera to goldfish red and green-cone opsins; and short-wavelength ("blue") cones, which were weakly immunoreactive to FRet 43 but strongly immunoreactive with antiserum to blue-cone opsin. Immunoblots of goldfish retinal homogenate with anti-GluR4 revealed a single protein at M(r) = 110 kDa. Preadsorption of GluR4 antiserum with either the immunizing rat peptide, or its goldfish homolog, reduced or abolished staining in retinal sections and blots. Therefore, we have detected and localized genuine goldfish GluR4 in the outer plexiform layer of the goldfish retina. We characterized contacts between photoreceptor cells and GluR4-IR second-order neurons in the electron microscope. IR-GluR4 was localized to invaginating central dendrites of triads in ribbon synapses of red cones, semi-invaginating dendrites in other cones and rods, and dendrites making wide-cleft basal junctions in rods and cones; the GluR4-IR structures are best identified as dendrites of OFF-bipolar cells. The results of our studies indicate that in goldfish retina GluR4-expressing neurons are postsynaptic to all types of photoreceptors and that transmission from photoreceptors to OFF-bipolars is mediated at least in part by AMPA-sensitive receptors containing GluR4 subunits.
Amino Acid Sequence↗
Clinical significance of prenatal ultrasonographic intestinal dilatation in fetuses with gastroschisis.
OBJECTIVE: Our purpose was to evaluate the clinical significance of intestinal dilatation detected by prenatal ultrasonographic examination in fetuses with gastroschisis. STUDY DESIGN: A retrospective chart review was performed of all patients cared for at Los Angeles County/University of Southern California Women's and Children's Hospital with the prenatal diagnosis of gastroschisis over a 7-year period (1988 through 1995). Patients were divided into two groups on the basis of the presence or absence of ultrasonographically measured fetal bowel diameter of > or = 17 mm. Neonatal outcomes of the two groups were compared. RESULTS: Twenty-one patients met the entry criteria during the study period. Fetuses with maximal bowel diameter of > or = 17 mm did not have a longer time to full oral feeding, a longer initial hospital stay, or a greater need for bowel resection when compared with fetuses with a bowel diameter < 17 mm. Two newborns underwent bowel resection because of intestinal atresia. Prenatal ultrasonographic examination failed to show significant bowel dilatation in either infant. CONCLUSION: Our data suggest that prenatal evidence of intestinal dilatation in fetuses with gastroschisis does not predict immediate neonatal outcome. Thus this finding is not an appropriate indication for preterm delivery in the absence of other evidence of fetal compromise.
Adult↗
Penoscrotal transposition and associated anomalies: report of five new cases and review of the literature.
We present the largest single series of cases (n = 5) of penoscrotal transposition (PST) with carefully documented nongenitourinary/anal anomalies, none of which fell into categories of known syndromes, associations, sequences or chromosome disorders. Several unexpected anomalies were observed including coloboma of the iris and retina, hydrocephalus, microcephaly, diaphragmatic hernia, tracheo-esophageal fistula/esophageal atresia and cleft palate. The most frequent anomalies other than PST were renal defects (100%) such as renal agenesis and dysplasia, imperforate anus (60%), central nervous system anomalies (60%) and preaxial upper limb defects (40%). Cardiovascular defects (atrial septal defect, double aortic arch with vascular ring) were noted in only one case. The surviving patients (3/5) had postnatal growth failure and mental retardation. Our 5 PST patients are compared to 16 well-documented cases from the literature. The overall incidence of various extragenital abnormalities were: renal (90%), mental retardation (60%), imperforate anus (33%), central nervous system (CNS) anomalies (29%), vertebral defects (29%), preaxial limb defects (24%) and congenital heart disease (19%). PST is a rare heterogenous anomaly, the detection of which should warrant careful clinical evaluation to rule out other anomalies, especially of the urinary system, gastrointestinal tract, upper limbs, craniofacial region and central nervous system. PST may be a localized field defect involving the genitourinary system; however, the wide variety of more distant defects noted in our series and the literature would raise doubt about that assumption. The high frequency of growth deficiency and mental retardation has also not been given due respect as accompanying problems associated with PST.
Abnormalities, Multiple↗
Computer-assisted video evaluation of surgical skills.
Compact video cameras have allowed the review of operations in self-directed learning sessions. Controlling the video viewing process by computer allows the selection of specific videotape segments containing the desired psychomotor skills to be evaluated--in this study, the steps involving laparoscopic tubal banding. Six faculty members were able to evaluate 23 videotapes efficiently without knowledge of the resident operator's identity. Because the computer allowed selection of only those frames of the videotape containing the skills to be evaluated, the duration of videotape seen was reduced by an average of 34% from the actual surgical time, with an increase in time saved as experience with the system was gained. Faculty members evaluated these events using a self-made checklist. It was possible to calculate the performance scores of each resident for the individual psychomotor skill components of the reviewed procedure. Computer-assisted video evaluation of surgical skills is technically feasible, allowing time-efficient review by multiple evaluators. With the development of psychometrically valid checklists for use with this technology, computer-assisted video evaluation of surgical skills may provide a new, innovative means of assessing surgical skills and training.
Clinical Competence↗
Joint hyperlaxity and its long-term effects on joints.
The range of movement at a joint varies between individuals. Reasons for this include inherited collagen structure in the joint capsule and ligaments, inherited shape of the bony articulating surfaces and neuromuscular tone which may be acquired and is modified by training. Methods for quantifying the range of movement at joints are described and compared, including the hyperextensometer and the Carter and Wilkinson score. Clinical patterns of joint hyperlaxity and their correlation with aetiology are discussed. Joint hyperlaxity may be advantageous in certain sports. Coaches need to be aware of optimum methods for improving it as well as for guarding against injury. Conversely, physiotherapists may learn from sports physiologists in the management of symptoms arising from patients who have hyperlax joints. Joint stability reduces the risk of injury. Joint hyperlaxity may also be associated with premature osteoarthritis but this is not always so. Joint instability may be the most potent cause though a radiological survey of retired teachers of physical education conducted by our Unit failed to show a higher incidence of osteoarthritis after a life spent in sport than in sedentary controls. However, certain factors that place some individuals at particular risk were identified.
Humans↗
Ethics, profit and patients: when pharmaceutical companies sponsor medical meetings.
A series of dynamic changes underway in Washington could transform the manner in which physicians learn of new pharmaceutical therapies. The potential impact of these changes is likely to significantly affect the manner in which physicians learn about and prescribe medications for years to come; the ultimate effect on patient care has yet to be measured, however.
Attitude of Health Personnel↗
Levi's corporate AIDS programme.
AIDS is a contemporary phenomena that has been extensively covered by the media but its impact on the employers of the sufferers is only now being measured and assessed. This article describes the personnel policies that have been developed by one particular organization to deal with the problem. Educational and training programmes have been initiated and management given clear directives to ensure that high morale and productivity are maintained during potentially adverse situations.
Acquired Immunodeficiency Syndrome↗
Congenital depression of the fetal skull.
One hundred forty-seven cases of congenital skull depression are analyzed, including two presented by the authors, and a review of the literature follows. A management plan emphasizing a conservative approach is outlined.
Adult↗
Congenital hypothyroidism in Spanish-surnamed infants in southern California: increased incidence and clustering of occurrence.
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California↗
Defense against HRC ruling.
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Acquired Immunodeficiency Syndrome↗