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Biomedical subjects

R Milner

Publications and source records attributed to R Milner.

At least 73 records · Page 4Linked to original sources
PubMed1988

Development of the human coagulation system in the healthy premature infant.

This study was designed to determine the postnatal development of the human coagulation system in the healthy premature infant. Consecutive mothers of healthy premature infants born at either St Joseph's Hospital or McMaster University Medical Centre in Hamilton were asked for consent. One hundred thirty-seven premature infants (30 to 36 weeks of gestational age) entered the study. The premature infants did not have any major health problems and did not require ventilation or supplemental oxygen. Demographic information and a 20-mL blood sample were obtained in the postnatal period on days 1, 5, 30, 90, and 180. Between 40 and 96 premature infants were studied on each day for each of the following tests: prothrombin time, activated partial thromboplastin time, thrombin clotting time, plasminogen; 13 factor assays [fibrinogen, II, V, VII, VIII, IX, X, XI, XII, XIII, high-mol-wt kininogen (HMWK), prekallikrein (PK), von Willebrand factor (vWF)] and eight inhibitors [antithrombin III (AT-III), heparin cofactor II, alpha 2-antiplasmin, alpha 2-macroglobulin, alpha 1-antitrypsin, C1 esterase inhibitor, protein C (PC), and protein S (PS)]. A combination of biologic and immunologic assays were used. Between 30 to 36 weeks there was a minimal effect of gestational age for levels of AT-III, PC, and factors II and X only; therefore, the entire data set was used to generate reference ranges for these components of the coagulation system for premature infants. Next, the results for the premature infants were compared with those of a previously published study in 118 fullterm infants and with those for adults. An effect of gestational age was shown for plasminogen, fibrinogen, factors II, V, VIII, IX, XI, XII, HMWK, and all eight inhibitors. In general, the postnatal maturation towards adult levels was accelerated in premature infants as compared with the fullterm infants. By 6 months of age, most components of the coagulation system in premature infants had achieved near adult values.

Age Factors↗
PubMed1987

Oral vitamin E supplementation for the prevention of anemia in premature infants: a controlled trial.

Serum vitamin E levels are reduced in newborn infants. It has been reported that this deficiency is responsible, in part, for the development of anemia in premature infants during the first 6 weeks of life. The efficacy of vitamin E supplementation for the prevention of anemia in premature infants has been studied in a randomized, controlled, and blinded trial. Premature infants whose birth weights were less than 1,500 g were given, by gavage, 25 IU of dl-alpha-tocopherol or a similar volume of the drug vehicle. Treatment was continued for the first 6 weeks of life. A total of 178 infants were studied. Vitamin E levels were significantly higher in a supplemented group by day 3 and for the remainder of the 6-week period. At 6 weeks of age, there was no significant difference between the supplemented and unsupplemented groups in hemoglobin concentration, reticulocyte and platelet counts, or erythrocyte morphology. It is concluded that there is no evidence to support a policy of administering vitamin E to premature infants to prevent the anemia of prematurity.

Anemia, Neonatal↗
PubMed1987

Development of the human coagulation system in the full-term infant.

The investigation of many hemostatic defects in the newborn is limited by the lack of normal reference values. This study was designed to determine the postnatal development of the human coagulation system in the healthy full-term infant. Consecutive mothers of healthy full-term infants born at St Joseph's Hospital in the city of Hamilton were approached for consent. One hundred eighteen full-term infants (37 to 42 weeks' gestational age) were entered into the study. Demographic information and a 2-mL blood sample were obtained in the postnatal period on days 1, 5, 30, 90, and 180. Between 40 and 79 full-term infants were studied on each day for each of the coagulation tests. Plasma was fractionated and stored at -70 degrees C for batch assaying of the following tests: prothrombin time, activated partial thromboplastin time, thrombin clotting time, and factor assays (biologic): fibrinogen, II, V, VII, VIII, IX, X, XI, XII, and high-molecular weight kininogen. Factor XIII subunits A and S, von Willebrand factor, and the inhibitors antithrombin III, alpha 2-antiplasmin, alpha 2-macroglobulin, alpha 1-antitrypsin, C1 esterase inhibitor, protein C, and protein S were measured immunologically. Plasminogen, prekallikrein, and heparin cofactor II were measured by using chromogenic substrates. The large number of infants studied at each time point allowed us to determine the following: the range of normal for each test at five time points in the postnatal period; that coagulation tests vary with the postnatal age of the infant; that different coagulation factors show different postnatal patterns of maturation; and that near-adult values are achieved for most components by 6 months of life. In summary, this large cohort of infants studied consecutively in the postnatal period allowed us to determine the normal development of the human coagulation system in the full-term infant.

Aging↗
PubMed1986

Value of the lateral radiologic view of the chest in children with acute pulmonary illness.

Although expert committees have questioned the usefulness of lateral radiologic views of the chest without specific indications, many physicians commonly order both posteroanterior and lateral views in assessing pediatric patients who have signs and symptoms of acute chest disease. To investigate the usefulness of lateral view in children, three experienced physicians independently reviewed and interpreted the posteroanterior view alone and the posteroanterior and lateral views for 179 children 1 to 10 years of age. The films were made between 1980 and 1982 at McMaster University Medical Centre, Hamilton, Ont. A high level of agreement was found between the interpretations based on the posteroanterior view alone and those based on both views. Addition of the lateral view did not improve agreement between the interpretations and the final hospital chart radiologic diagnosis in a clinically significant manner, nor did the lateral view improve the accuracy of localization of radiologic abnormalities. Obtaining a lateral view whenever radiologic examination of the chest is indicated but when specific indications are lacking is unlikely to prove useful to experienced physicians in diagnosing and managing acute pulmonary illness in children.

Acute Disease↗
PubMed1985

Inhibition and activation of bovine heart NAD-specific isocitrate dehydrogenase by ATP.

In the absence of added calcium, inhibition of NAD-specific isocitrate dehydrogenase by ATP occurred without ADP (I0.5 = 1.8 mM) and with 0.2 mM ADP3- (I0.5 = 1.0 mM) at subsaturating substrate concentrations at pH 7.4. Inhibition by ATP was competitive with NAD+ in the presence and absence of ADP and was not reversed by magnesium citrate. No reversal of ATP inhibition by free Ca2+ was observed in the presence of ADP (0.2 mM). However, when ADP was absent, increasing Ca2+ first caused progressive reversal of ATP inhibition followed by activation by ATP. Without ADP, the S0.5 for calcium activation was 80-140 microM at ATP concentrations between 0.6 and 3.0 mM. The S0.5 for ATP activation, in the absence of ADP, was 1.1 and 2.1 microM when free Ca2+ was held constant at 0.1 and 1.0 mM, respectively. As in activation by ADP, ATP decreased the S0.5 for magnesium isocitrate without affecting V. However, in contrast to ADP, the activation by ATP occurred without lowering the Hill coefficient for the substrate. GDP activated the enzyme at relatively high concentrations of Ca2+ but not without added Ca2+.

Adenosine Diphosphate↗
PubMed1985

Associated cutaneous findings in nickel contact sensitivity.

A clinical survey of patients with nickel dermatitis has provided evidence of a significant association with one or more of the following reactions: contact reaction from adhesive tape, reaction from mosquito bites which lasts 1 week or longer, and a history of hives. The association of nickel contact dermatitis with at least one of the other reactions is termed contact sensitivity syndrome.

Adult↗
PubMed1983

Prospective study of school injuries: incidence, types, related factors and initial management.

The rates of school injuries were examined by means of a prospective study of 212 schools during the 1981-82 school year. The results showed an annual incidence rate of 5.4 injury events/100 children, which appears to be an underestimate of the actual rate. Of all the injury events 28.7% resulted in serious injuries. Injuries were significantly more frequent in the elementary as opposed to the secondary schools, and the boys were injured significantly more often than the girls. Most of the injuries occurred during athletic activities. Most of the children with either serious or minor injuries were sent to the school office or returned to the classroom, which indicates that the present level of first-aid training among school personnel is inadequate.

Adolescent↗
PubMed1983

Effect of delivery method on outcomes in the very low-birth weight breech infant: is the improved survival related to cesarean section or other perinatal care maneuvers?

The perinatal mortality rate among very low-birth weight infants has been decreased by 20% during the last 4 years of the 1973 to 1980 period here reported. The concurrent increase in the cesarean section rate from 11.9% to 49.1% during the same time frames has been assumed to be responsible for the improved outcome. The changes were most marked in the extremely low-birth weight group (less than 1,000 gm). The survival rates and cesarean section rates were examined among infants of similar birth weight and gestational age in the vertex presentation, in the same time frames. A similar or greater reduction in mortality rate (from 85% to 45%) was noted in the very low-birth weight vertex infants, whereas the cesarean section rate remained minimally and not significantly increased (14.2% to 22.2%). The interpretation of this finding is by no means clear but must include the hypothesis that the increased cesarean section rate may be incidental and in no way related to the improved outcome. The most statistically significant determinants of outcome remain birth weight and gestational age strata, with no significant difference in outcomes when the extremely low-birth weight group is analyzed separately from the entire very low-birth weight group. As yet unidentified perinatal care practices, other than cesarean section, may be more likely to affect outcome in this high-risk group.

Birth Weight↗
PubMed1983

Isotopic and enzymatic IgE assays in non-allergic subjects.

In order to establish normal values in an adult population for serum IgE concentration, sera were obtained from 446 ambulatory Canadian caucasian subjects with negative allergy histories. A standard isotopic procedure, the Phadebas paper radioimmunosorbent test (PRIST), was compared with the new enzymatic counterpart, the Phadezyme PRIST. By the isotopic method, serum IgE concentrations in women and men were comparable from one age group to another with no age-related trend in the seven age groups examined (15-20, 21-30, 31-40, 41-50, 51-60, 61-70, above 70). The median and 95th percentile units (U)/ml respectively were 17.5 and 145 for 224 women and 25.5 and 275 for 222 men. Mean values +/- 1 SD for women were 43 +/- 102 and for men, 58 +/- 137. Levels were significantly higher in men as a group. Sera with IgE concentrations above 100 U and a sampling of additional sera were tested for specific IgE antibodies to 13 common allergens by the radioallergosorbent test (RAST). After exclusion of RAST-positive sera, the mean U/ml values +/- 1 SD were 22 +/- 29 for 204 women and 37 +/- 54 for 196 men. Geometric mean U/ml values for these sera were 14.6 for women and 22.3 for men and the median and 95th percentile U/ml respectively for the women were 15 and 66, for the men, 24 and 135. These 95th percentile values are considered the upper limits of normal in this population. The RAST identification of antibodies to allergens to which sensitization was demonstrated provided a potential explanation for serum IgE concentrations above 100 U/ml in less than 30% of the sera in this population with negative allergy histories. The isotopic method and the counterpart enzymatic method (Phadezyme PRIST) were highly comparable; the correlation coefficient (r) for all the sera was +0.93 (P less than 0.001). IgE levels were significantly higher in male smokers than non-smokers by both methods but these differences were not significant in women.

Female↗
PubMed1982

Follow-up of infants 501 to 1,500 gm birth weight delivered to residents of a geographically defined region with perinatal intensive care facilities.

In an attempt to minimize the selection bias inherent in reporting the outcome of premature infants from a particular neonatal intensive care unit, this study presents data on all 294 live births 501 to 1,500 gm birth weight born to residents in the Hamilton-Wentworth region during 1973-78. The survival rate was 31.9% in infants less than or equal to 1,000 gm and 82.6% in infants between 1,001 to 1,500 gm. In all, 184 infants (62.6%) were discharged alive and 37 of these had weight less than or equal to 1,000 gm. The mean BW of the survivors was 1,216 +/- 214 gm and the mean gestation was 30.0 +/- 2.9 weeks, with 18.0% being small-for-gestational age. Neurologic handicaps including cerebral palsy, hydrocephalus, microcephaly, blindness, deafness, and mental retardation occurred in 30/179 (16.8%) survivors. The incidence of neurologic handicaps was 30% among babies who received IPPV versus 10% in those who did not. Within the IPPV and non-IPPV groups, there were no significant differences in handicap rates by 500 gm BW class.

Catchment Area, Health↗
PubMed1980

Canadian pediatricians: demographic characteristics, perceptions of training, and continuing medical education.

A nationwide survey of Canadian pediatricians was undertaken to answer questions about demographic and practice characteristics, perceptions of the quantity and quality of residency training in relation to the realities of practice, and the patterns of use and the value of continuing medical education. The findings included a lower average age of pediatricians from that determined 10 years earlier, a higher proportion of women practising pediatrics, and higher proportions of pediatricians entering practice in smaller communities, doing geographic full-time university work and doing mainly consulting work. Pediatrics is still perceived as an attractive discipline, but there is dissatisfaction with the quantity and quality of training in adolescent medicine, ophthalmology, dermatology, psychosocial pediatrics and orthopedics. The changing patterns of continuing medical education among the most recent certificants suggest a need for journals and professional societies to assess how they can better meet the needs of Canadian pediatricians in this area.

Canada↗
PubMed1980

A randomized clinical trial of the Leboyer approach to childbirth.

To examine the effects of the Leboyer method of delivery, we randomly assigned 56 women to either a Leboyer or a conventional delivery and used a variety of clinical and behavioral measures to assess the outcome in mother and child. No differences were noted in maternal or newborn morbidity, in infant behavior in the first hour of life, at 24 or 72 hours post partum, or at eight months of age; or in maternal perceptions of her infant and the experience of giving birth, except that eight months after delivery, mothers who had used the Leboyer method were more likely to say that the event had influenced their child's behavior (P = 0.05). Women who expected a Leboyer delivery had shorter active labors (P = 0.03), suggesting that psychologic factors (expectations) influence physical outcomes in perinatal medicine. Our results suggest that the Leboyer procedure has no advantage over a gentle, conventional delivery in influencing infant and maternal outcomes.

Behavior↗