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Biomedical subjects

D Gibson

Publications and source records attributed to D Gibson.

At least 91 records · Page 5Linked to original sources

Decrease in plasma prostaglandin E2 is not essential for the establishment of continuous breathing at birth in sheep.

Depression of prostanoid concentrations by indomethacin induces continuous breathing in fetal sheep, but it is not known whether this is associated with changes in fetal behaviour. Furthermore, the relationship between changes in prostaglandin E2 (PGE2) concentration after delivery and the appearance of continuous breathing has not been examined. We hypothesized that the decrease in fetal PGE2 by infusion of indomethacin would induce continuous breathing and a change in behaviour such that the fetus should come to resemble a newborn lamb; and coinciding with the establishment of continuous breathing at birth, PGE2 concentrations would decrease to a critical level below that present in the fetus. We found that continuous breathing in fetal sheep induced by infusion of indomethacin was related to a decrease in PGE2 from 436 +/- 114 to 189 +/- 73 pg/ml (P less than 0.005) but that this was not associated with fetal wakefulness. In addition, measurements of carotid arterial PGE2 concentrations showed that the beginning of continuous breathing after birth occurred at a plasma concentration of PGE2 of 1245 +/- 260 pg/ml, a value about three times higher than the 422 +/- 53 pg/ml measured in the fetus during breathing activity. Together these findings suggest that PGE2 is not primarily involved in the establishment of continuous breathing at birth.

Animals↗

Age and pattern of intellectual decline among Down syndrome and other mentally retarded adults.

A comparison was made of Down Syndrome and other mentally retarded young adults in community work and residential settings for differences in cognitive profile across age groups using the Wechsler Intelligence Scale for Children. Evidence is of a significant erosion of test scores, especially performance scale scores for the non-DS mentally retarded subjects from the third to fourth decades of life. The Down Syndrome cohort remained relatively stable for cognitive profile over time with the notable exception of the Block Design subtest which declined significantly over the two decades; and in contrast with the control sample. Further investigation is suggested in the event that the Block Design subtest has potential as a diagnostic 'marker' for the early identification of DS individuals likely to be most susceptible to premature Alzheimer's-like senile dementia.

Activities of Daily Living↗

Aggregated early intervention effects for Down's syndrome persons: patterning and longevity of benefits.

Pooled findings from 21 early intervention demonstration studies for Down's syndrome infants and children yield consistency of short-term benefits in the growth of finer motor skills, simple social repertoire and DQ/IQ scores, but conflicting evidence in support or not of benefits in the gross motor, linguistic and cognitive/academic domains. Support for the tenacity of gains, on follow-up to the early years of primary schooling, is disappointing. It is recommended that: (1) intervention programmers view the key working assumptions and ideological positions governing present practices more critically; (2) intervention curricula reflect the unique biological and behavioural properties of the syndrome, taking into account individual differences which are independent of etiological label; and (3) care delivery systems be based more fully on multidisciplinary collaboration, especially between the health sciences and education fields.

Child Development↗

Soybean oil emulsion administration during parenteral nutrition in the preterm infant: effect on essential fatty acid, lipid, and glucose metabolism.

To examine the effect of a soybean oil emulsion on essential fatty acid, lipid, and glucose metabolism, preterm infants were randomized to receive 0.5 g/kg/d lipid for 5 days (n = 10, group 1) or 0.5 increased to 2.0 g/kg/d over 5 days (n = 11, group 2). Triene/tetraene ratios did not change in group 1, but decreased in group 2. In both groups, plasma phospholipid linoleate (percent and micrograms per milliliter) increased, the increase being greater in group 2. In both groups, percent content of arachidonate and 5,8,11-eicosatrienoate decreased, and that of oleate remained unchanged. In contrast, absolute content of arachidonate and oleate tended to increase, and that of 5,8,11-eicosatrienoate remained unchanged. At a lipid intake of 0.5 g/kg/d, no infants had hyperlipemia. When lipid intake exceeded 1.0 g/kg/d, the frequency of hypertriglyceridemia (triglycerides greater than 200 mg/dL) and free fatty acidemia, with the free fatty acid/molar albumin ratio exceeding 6:1, increased. Plasma glycerol increased slightly, but was substantially less than the rise in enzymatically determined triglycerides. Hyperglycemia was self-limiting and did not require alteration in dextrose intake. Thus, (1) infusion of a soybean oil emulsion at 0.5 to 2.0 g/kg/d maintains essential fatty acid status and phospholipid arachidonate concentrations; (2) significant hyperlipemia occurs when lipid intake exceeds 1.0 g/kg/d; (3) hyperglycemia associated with lipid infusion tends to be self-limiting and may not require alteration in lipid or dextrose intake; and (4) enzymatically determined triglycerides may be used to monitor lipid tolerance, provided that allowance is made for a small but systematic overestimation resulting from the rise in plasma glycerol.

8,11,14-Eicosatrienoic Acid↗

The structure of habilitation.

Biographic, program and background variables traditionally employed in the habilitation program and accountability literature were assembled for 75 mentally handicapped adults who had completed a three year comprehensive program of training and up to three years of subsequent community placement. Factor analysis treatment yielded 12 input and 4 output factors, the nature of which suggests a greater role for cognitive and clinical variables in the overall structure of habilitation than has been supported by the habilitation services accountability literature to date.

Adult↗

Approval need in self-reports of addicts and family members.

Ample evidence documents the tendency of research subjects to attribute to themselves socially desirable traits and to deny having socially undesirable qualities. This tendency is particularly marked among subjects who are defensive, lacking in self-esteem, or sensitive to status differences. Drug addicts often have all of these characteristics. This paper examines the extent to which need for social approval is reflected in methadone patients' and family members' self-reports of personal and family functioning. Results demonstrate the importance of taking the approval motive into account when conducting research with this population. Addicts tend to deny negative things about themselves and their families, while family members tend to exaggerate their own and their families' positive qualities. Implications for drug treatment programs and researchers are discussed.

Adult↗

Asynchronous left ventricular wall motion early after coronary thrombosis.

To study regional wall motion early in the development of acute myocardial infarction, left ventriculograms performed in 24 patients before thrombolysis and within 3.5(1.2) (mean (SD] hours of the onset of pain were digitised frame by frame. Isometric and contour plots of regional wall motion were constructed. In 19 patients (seven with anterior descending, eight with right, and four with circumflex disease) thrombosis was demonstrated on an underlying stenosis. In 10 patients the two remaining coronary arteries were normal, and in nine, one or both showed important disease. Mean values of global indices of left ventricular function, including end diastolic volume, ejection fraction, peak ejection and filling rates, and cavity shape changes were all within normal limits, though end systolic volume was significantly raised. Total systolic amplitude of wall motion was normal in the affected area in all but seven patients (four with anterior descending, two with right, and one with circumflex thrombosis). Dyskinesis of more than 2 mm was seen in only three patients, all with thrombosis of the anterior anterior descending coronary artery, and hyperkinesis was present in four. The commonest abnormality of wall motion was hypokinesis during ejection followed by prolonged inward motion during isovolumic relaxation, which was seen in four patients with anterior descending, seven with right, and three with circumflex artery thrombosis. This was preceded by outward motion during isovolumic contraction and delayed inward motion during ejection in eight with right or circumflex thrombosis. Five of six patients without thrombosis had simple hypokinesis or dyskinesis without asynchrony. Disease of other coronary arteries did not affect the pattern of wall motion seen after right or circumflex coronary artery occlusion but it reduced the incidence of delayed inward motion along the free wall after thrombosis of anterior descending artery. Thus early after acute coronary thrombosis asynchronous wall motion is commoner than simple hypokinesis or dyskinesis. Its persistence suggests that in the setting of coronary artery thrombosis in man, residual contractile activity may persist for up to six hours after the onset of symptoms.

Acute Disease↗

Changes in left ventricular regional asynchrony after intracoronary thrombolysis in patients with impending myocardial infarction.

Ventriculograms obtained before and a mean (SD) of 4.3 (2.5) weeks after intracoronary thrombolysis in 23 patients who were treated within 3.5 (3.1) hours of the onset of pain were examined for changes in asynchronous left ventricular wall motion. Lysis was achieved in 19 patients, and in 16 the affected artery was still patent at restudy. Angiograms were digitised frame by frame. Left ventricular volumes, ejection fraction, and peak ejection rate were all unchanged after thrombolysis, whereas peak filling rate fell, whether or not patency was achieved or maintained. Regional wall motion was examined by means of isometric and contour plots. The area supplied by the affected coronary artery showed simple hypokinesis or akinesis in 10 cases, which was unchanged at the second study in nine and improved in one. The commonest manifestation of asynchrony was delayed inward motion during isovolumic relaxation. This was present in 12 cases with or without associated hypokinesis; after thrombolysis wall motion improved significantly in eight and returned to normal in six, significantly more frequently than it did in patients with simple hypokinesis. Dyskinesis (three patients) and hyperkinesis (five patients) resolved in all. Outward wall motion during isovolumic relaxation reverted to normal in four out of five cases, and outward motion during isovolumic contraction reverted to normal in five out of seven. The frequency of improvement was also increased when the circulation to the affected segment was not compromised by an important residual stenosis. Flow in the affected artery was re-established or maintained significantly less frequently when simple hypokinesis or akinesis was present at the first study. These observations provide further evidence that asynchronous wall motion early after acute myocardial infarction represents residual contractile activity, and suggest that knowledge of its presence and distribution may be useful in assessing patients on whom thrombolysis is performed.

Coronary Angiography↗

Evaluation of an inpatient decentralized pharmacy team program in an HMO setting.

Decentralized drug distribution and clinical pharmacy services were implemented on two nursing units, orthopedics and oncology, of a health maintenance organization-owned hospital. The use of targeted high-cost drugs was assessed before and during the decentralized pharmacy services intervention on the experimental units and on a comparison unit. Other assessments included a survey of nurses from the experimental units and surveillance of telephone encounters between the central pharmacy and the experimental units. In the experimental units, there were significant changes in cefazolin therapy for prophylaxis, aminoglycoside therapy, and metoclopramide use from baseline to the intervention periods. Cefazolin use for prophylaxis essentially remained the same in the comparison unit. Telephone encounters decreased substantially from the before- to the during-program period. An increase in the proportion of inappropriately drawn aminoglycoside blood levels was also noted in the during-program period. Decentralized pharmacy services appeared to reduce the cost of targeted drugs and improve communications with the nursing units.

Cefazolin↗

X-ray structure of the major adduct of the anticancer drug cisplatin with DNA: cis-[Pt(NH3)2(d(pGpG))].

Crystals of the adduct of the anticancer drug cis-diamminedichloroplatinum(II), cis-DDP, with d(pGpG), its putative target on DNA in the cancer cell, have been obtained and used in an x-ray crystallographic study to elucidate the molecular structure to atomic resolution. Each of the four crystallographically independent cis-[Pt(NH3)2(d(pGpG))] molecules is comprised of a square-planar platinum atom bonded to two ammonia ligands and two N(7) atoms of guanosine nucleosides from the same chain. Base stacking of the two adjacent guanine rings is completely disrupted by coordination to the cis-(Pt(NH3)2)2+ unit. Comparison of the backbone and deoxyribose ring torsion angles with those found by previous (nuclear magnetic resonance spectroscopy) studies of this adduct in solution demonstrates that the solid state geometry is substantially the same as that in solution. The relevance of these results to the molecular mechanism of action of cis-DDP is discussed.

Cisplatin↗

Methadone applicant dropouts: impact of requiring involvement of friends or family in treatment.

This paper examines attrition among applicants to a methadone maintenance program before and after it began to require that applicants have a relative or close friend willing to act as a treatment sponsor. Few applicants were unable to locate sponsors. The dropout rate was greater for Blacks than for Hispanics and Anglo Whites both before and after the sponsor requirement was introduced. However, young addicts, addicts with recent drug histories, and singles were somewhat less likely to enter treatment after the requirement was introduced. Implications for drug treatment clinicians and administrators are discussed.

Adult↗

Malaria and tropical splenomegaly syndrome in the Anga of Morobe Province.

The Hamtai speaking Anga of the Upper Watut valley have long been considered to be unique in their response to recurrent malaria. Given sufficient exposure, the vast majority develop tropical splenomegaly syndrome concomitantly with their acquisition of effective immunity, whereas elsewhere this disease occurs sporadically. The present study indicates that the Menya of the Tauri valley, a related Angan group, respond similarly, in terms of frequency and degree of gross splenomegaly. On the other hand, the Kapau valley, the traditional homeland of the Hamtai, lying between the Watut and Tauri valleys, remains for the most part free of malaria. It is suggested that all Anga will respond to recurrent malarial infection in the same atypical manner; and that this response results from lack of appropriate genetically-determined mechanisms for mounting efficient immune responses to this infection, significant exposure to which is a relatively recent event for these people.

Adult↗

Accurate diagnosis of early ectopic pregnancy.

Commonly used preoperative diagnostic procedures were analyzed for their ability to predict the presence of early ectopic pregnancy. Patients presenting to the emergency room with acute onset of pelvic pain were evaluated with culdocentesis, pelvic ultrasonography, and qualitative serum and urine pregnancy testing. Clinical examination and urine pregnancy testing were found to be poor predictors of either the presence or absence of an early ectopic pregnancy. The combination of a sensitive serum human chorionic gonadotropin (hCG) determination and pelvic ultrasonography accurately predicted ectopic pregnancy in 93% of proved cases. This predicted accuracy was superior to that of culdocentesis alone or in combinations of culdocentesis and ultrasound or qualitative serum pregnancy testing.

Adult↗