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Biomedical subjects

L Matthews

Publications and source records attributed to L Matthews.

At least 55 records · Page 3Linked to original sources
PubMed1996

The predictive value of biophysical profiles and Doppler velocimetry for fetal acidosis in a low risk population.

Antenatal fetal monitoring is the principal means of distinguishing the fetus requiring imminent delivery from that which is coping well in utero. The ability to detect fetal compromise, defined by fetal acidosis, in a low-risk population was evaluated in a prospective study of 50 women undergoing a Caesarean section in the absence of labour. The sensitivity and positive predictive value of a modified biophysical profile (BPP) or Doppler velocimetry to detect a fetus subsequently born with an umbilical artery pH of less than 7.20 was poor. The incidence of fetal acidosis in the population under study was 8%. Interpretation of antenatal fetal assessments must be tempered by the clinical features of each case. Decisions to deliver should take into account the low sensitivity of these tests in the absence of other complicating factors.

Acidosis↗
PubMed1994

Bovine nuclear transfer embryos: oocyte activation prior to blastomere fusion.

Successful bovine nuclear transfer (NT) embryo production requires proper oocyte activation and transfer of a nucleus into this oocyte. However, the temporal relationship between these two events is unclear. The current study examined whether activation of the oocyte prior to fusion would induce nuclear swelling while also affecting development to morula and blastocyst stage and finally development to offspring. Aged oocytes can be activated by a number of techniques including exposure to room temperature. In this study oocyte activation was induced through three different means: reduced temperature culture alone, reduced temperature culture and calcium ionophore, and naturally, through the fertilization process. Electrofusion was carried out after the activation stimulus. When used in the NT procedure, activation of oocytes prior to fusion resulted in NT embryos that underwent nuclear swelling and had a high developmental rate to morula and blastocyst stages. Also, these NT embryos developed to normal offspring when transferred to recipient animals. The addition of a calcium ionophore treatment to the reduced temperature culture was not beneficial and resulted in less nuclear swelling. The use of enucleated fertilized oocytes as recipient cytoplasm for the new nucleus resulted in NT embryos developing to morula and blastocyst stages at the same rate as room temperature activated NT embryos. Therefore, improved embryo development can be obtained from NT embryos if the aged recipient oocyte is activated prior to the time of fusion. Also, offspring were obtained from these pre-activated NT embryos.

Animals↗
PubMed1994

Effect of allergen avoidance in infancy on allergic manifestations at age two years.

BACKGROUND: One hundred twenty children, identified before birth as being at high risk for atopy, were prenatally assigned to prophylactic or control groups. METHODS: The infants in the prophylactic group either received breast milk from mothers on an exclusion diet or an extensively hydrolyzed formula. Their bedrooms and living rooms were treated repeatedly with an acaricide, and they used polyvinyl-covered mattresses with vented head areas. The infants in the control group were fed conventionally, and no environmental control was recommended. RESULTS: A significant advantage, first demonstrated at 1 year of age, persists for children in the prophylactic group. They have less of any allergy or eczema, but the reduced prevalence of asthma is no longer significant. Only three children in the prophylactic group had positive skin prick test results compared with 16 in the control group, suggesting a significant reduction in sensitization. CONCLUSION: A dual approach to allergen avoidance, focusing on foods and aeroallergens, appears to be beneficial in selected high-risk infants. Avoidance of potent allergens in early life increases the threshold for sensitization in these high-risk infants. Whether sensitization has been avoided or merely deferred has yet to be proved.

Aging↗
PubMed1990

Quantification of transformation efficiency using a new method for clonal growth and selection of axenic Dictyostelium cells.

A new method for clonal growth of Dictyostelium axenic amoebae has been developed. Cells are plated in growth medium containing 1% ultra-low gelling temperature agarose. Cells grow normally in the agarose and form colonies up to several millimeters in diameter. When the colonies have grown to a sufficient size, they begin multicellular development. Pseudoplasmodia are formed, migrate to the surface of the agar, and then undergo fruiting body formation. Cells can be removed from the soft agarose colonies with a toothpick or by picking spores from the fruiting bodies. This method should be useful for drug, auxotrophic, and temperature selections where clonal maintenance of axenic colonies is important. This method has been used in combination with a selection for resistance to G418 to isolate independent colonies following DNA-mediated transformation. Several parameters in the calcium phosphate and electroporation transformation protocols have been optimized and the transformation frequency quantified. Independent transformed colonies are obtained at a frequency of 1 in 10(4) to 1 in 10(5) cells when integrating plasmids are introduced using calcium phosphate coprecipitation. The frequency is about tenfold higher when extrachromosomal shuttle vectors are introduced into cells.

Agar↗
PubMed1987

Bladder training after surgery for stress urinary incontinence: is it necessary?

Eighty-nine consecutive patients with a clinically and urodynamically proved diagnosis of genuine stress urinary incontinence entered this study. Forty women had a revised Pereyra procedure and 49 had a Burch retropubic urethropexy. All had a suprapubic Bonnano catheter for postoperative bladder drainage. Postoperatively, patients were randomly allocated to "bladder training" (N = 44) or "nonbladder training" (N = 45) protocols. "Bladder training" consisted of scheduled clamping and unclamping of the catheter, whereas the "nonbladder training" patients had continuous bladder drainage throughout their postoperative period. Postvoiding residual urine volume was measured twice daily after the patient had voided with a symptomatically full bladder. The catheter was removed once residual volume was 50 mL or less. The bladder training protocol had no effect on resumption of spontaneous voiding after surgery. There was no significant change in length of postoperative bladder catheterization or in urinary tract infection rate among women with or without bladder training.

Adult↗
PubMed1987

Suprapubic versus transurethral bladder drainage after surgery for stress urinary incontinence.

Fifty-one patients with clinical and urodynamic diagnoses of stress urinary incontinence were randomly allocated to either suprapubic (N = 24) or transurethral (N = 27) bladder drainage after vaginal surgery for stress incontinence (revised Pereyra procedure). Postoperative use of suprapubic bladder drainage significantly reduced febrile morbidity (calculated as fever index; P less than .01) and length of hospitalization (P less than .05). Postoperative normal bladder functions resumed more quickly when suprapubic drainage was used (P less than .05), so that most patients did not need bladder catheterization upon discharge, as opposed to more than half of those with Foley catheters, who left the hospital with a catheter in place (P less than .05). We conclude that it is both beneficial and cost-effective to use suprapubic bladder drainage after a Pereyra operation for stress urinary incontinence.

Adult↗
PubMed1983

(3-sn-Phosphatidyl)cholines (lecithins) in amniotic fluid.

Many currently used thin-layer chromatographic methods for phospholipid assay rely on charring the developed plate in the presence of cupric acetate. Saturated acyl phospholipids do not react. We find that substitution of cupric sulfate results in detection of both saturated and unsaturated phospholipids. By exploiting the difference with the two reagents, one can separately estimate the amounts of saturated phospholipid. The method described here is reproducible, and we illustrate its use in determinations of (3-sn-phosphatidyl)cholines (lecithins) in amniotic fluid from problem pregnancies.

Amniotic Fluid↗
PubMed1982

Lymphocyte cyclic AMP levels antepartum and postpartum as an indirect assessment of the immune system during pregnancy.

The literature dealing with the immunological state of the pregnant woman has been conflicting. The concentrations and activity of a number of hormones and proteins which modify lymphocytic activity have been measured both in vivo and in vitro during pregnancy. Most of the differences between reported studies can be reconciled to technical or experimental variations. In some instances, the purported suppressive effects of embryonic proteins such as HCG have actually been caused by the impurity of the preparation studied. We have attempted to approach the question of whether or not the pregnant woman is immunosuppressed by studying a regulatory material in the lymphocytes. It is known that cAMP is a mirror of lymphocytic activity and that low levels of cAMP may indicate a high degree of reactivity, while high levels are present when lymphocyte reactivity is low. In an initial study, ten women volunteered to have blood drawn in the last trimester and two months postpartum. Cyclic AMP was extracted from lymphocyte-enriched leukocytes and stored until all samples were available from all patients so that the analysis could be made simultaneously. Five samples were obtained from healthy nonpregnant women in the same age range. Postpartum and nonpregnant women were found to have significantly elevated levels of cAMP as compared to the lymphocytes obtained in the third trimester of pregnancy. The experiments were then repeated using seven more patients. The same significant increase in postpartum lymphocyte cAMP concentrations were found. The precise reason(s) for this is not known, but may be due to increased suppressor cell activity.

Cyclic AMP↗
PubMed1981

Psychosocial functioning of children with cystic fibrosis.

The adjustment of children with cystic fibrosis as rated by parents and teachers was compared to that of physically healthy siblings, normal children, and other chronically ill children. The findings indicated that children with cystic fibrosis achieved an age-adequate level of adjustment at home and school. Adjustment was largely unrelated to the severity of cystic fibrosis. As a group, chronically ill children had less adequate adjustment as rated by parents. However, severe adjustment problems were relatively rare. These findings are consistent with a growing body of literature which suggests that children with cystic fibrosis can cope reasonably well with life tasks and that emotional disturbance is not an inevitable consequence of the disease. Future studies of the cystic fibrosis population should study factors which differentiate adjusted from maladjusted children.

Adolescent↗
PubMed1980

Families of incest: a collation of clinical impressions.

The present paper provides a collation of the impressions of clinical workers regarding families in which father-daughter incest has incurred. Responses of the workers indicate that the incestuous relationship is typically not limited to one or two sexual encounters, but the relationship can become a stable part of family life. The sexual interactions appear to parallel sexual practices in non-incestuous relationships. Daughters involved in incest are viewed as submissive, passive, fearful, whereas the fathers are viewed as dominating, impulsive, and using violence or threats to obtain the daughters sexual co-operation. Mothers are viewed as weak and as failing to provide help for their daughters. The picture of the family in which father-daughter incest occurs is one in which unhappy people are unable to establish satisfying human relationships.

Adolescent↗
PubMed1979

Determining continuing education interests of medical technologists: an initial step.

Continuing education is an ever-increasing need for medical technologists who want to maintain and upgrade their professional knowledge and skills. Professional groups strive to develop programs to meet a diversity of needs. Planning groups often encounter difficulty during the program development process as they identify topics and select effective educational strategies for presentation. In order to help identify topics of interest and desirable educational methods for the continuing education of laboratory personnel, a continuing medical technology education interest assessment tool was developed and used by a medical technology continuing education committee. Development and use of this assessment tool and resulting statistical survey results formed the basis for two continuing education courses, both considered highly successful.

Education, Continuing↗
PubMedDate not supplied

Absence of the ductus venosus with direct connection between the umbilical vein and right atrium.

Abnormalities of the ductus venosus are rare. We present the case of a dichorionic, diamniotic twin pregnancy in which complete absence of the ductus venosus, with direct communication between the umbilical vein and right atrium, was detected in one infant on antenatal ultrasonography. Autopsy confirmed the aberrant course of the umbilical vein, which also had an abnormal histological structure. Associated congenital anomalies included an ostium secundum type atrial septal defect, absent inferior vena cava, single left pulmonary vein, stenosed right pulmonary artery, proliferation of the hepatic arterioles with reduction of portal venules, and a duplex ureter. The literature is reviewed and pathogenesis relevant to this case is discussed.

Abnormalities, Multiple↗