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Biomedical subjects

R Milner

Publications and source records attributed to R Milner.

At least 37 records · Page 2Linked to original sources
PubMed1993

Variation in lumbar spine and femoral neck bone mineral measured by dual energy X-ray absorption: a study of 329 normal women.

Reference ranges used in dual energy X-ray absorptiometry (DXA) have previously used piecewise linear fits to the whole data set for spine or femur bone mineral density (BMD) as a function of age. In a study of 329 Caucasian normal women we present a refinement to the normal range by fitting straight lines between quinquennial mean values of BMD for each site measured (lumbar spine, femoral neck and Ward's triangle). From the age of 40 years onwards the premenopausal women demonstrated minimal loss of BMD whereas postmenopausal women showed a rapid loss amounting to 27% in the lumbar spine, 27% in the femoral neck and 38% in the Ward's triangle region in the age range under examination. Comparison of quinquennial means for pre and postmenopausal women in age bands 45-49 years and 50-54 years shows that at these ages postmenopausal BMD is significantly lower than premenopausal BMD (P < 0.05). This finding suggests that separate normal ranges should be used for pre and postmenopausal women. As reduction in the production of oestrogen is a major factor in postmenopausal bone loss and oestrogen function is related to years since menopause (YSM), a more logical way of displaying postmenopausal normal BMD ranges would be in terms of YSM rather than chronological age. Such data are given in this paper.

Absorptiometry, Photon↗
PubMed1992

Induction of labor as compared with serial antenatal monitoring in post-term pregnancy. A randomized controlled trial. The Canadian Multicenter Post-term Pregnancy Trial Group.

BACKGROUND: The rates of perinatal mortality and neonatal morbidity are higher for post-term pregnancies than for term pregnancies. It is not known, however, whether the induction of labor results in better outcomes than does serial fetal monitoring while awaiting spontaneous labor. METHODS: We studied 3407 women with uncomplicated pregnancies of 41 or more weeks' duration. The women were randomly assigned to undergo induction of labor or to have serial antenatal monitoring and spontaneous labor unless there was evidence of fetal or maternal compromise, in which case labor was induced or cesarean section was performed. In the induction group, labor was induced by the intracervical application of prostaglandin E2. Serial antenatal monitoring consisted of counts of fetal kicks, nonstress tests, and assessments of amniotic-fluid volume. The outcomes we measured were the rates of perinatal mortality, neonatal morbidity, and delivery by cesarean section. RESULTS: Among the 1701 women in the induction group, 360 (21.2 percent) underwent cesarean section, as compared with 418 (24.5 percent) of the 1706 women in the monitoring group (P = 0.03). This difference resulted from a lower rate of cesarean section performed because of fetal distress among the women in the induction group (5.7 percent vs. 8.3 percent, P = 0.003). When two infants with lethal congenital anomalies were excluded, there were no perinatal deaths in the induction group and two stillbirths in the monitoring group (P not significant). The frequency of neonatal morbidity was similar in the two groups. CONCLUSIONS: In post-term pregnancy, the induction of labor results in a lower rate of cesarean section than serial antenatal monitoring; the rates of perinatal mortality and neonatal morbidity are similar with the two approaches to management.

Adult↗
PubMed1992

Snowmobile-related deaths in Ontario: a 5-year review.

OBJECTIVES: To investigate the demographic characteristics and circumstances surrounding fatal snowmobile accidents in Ontario, to examine the risk factors and to observe any fatality trends over the study period. DESIGN: Case series. PATIENTS: All 131 people who died accidentally while operating a snowmobile in Ontario from 1985-86 to 1989-90. Records were obtained from the chief coroner's office; registration data were obtained from the Ministry of Transportation. RESULTS: Although the absolute number of deaths increased each year, owing to a rapid increase in the number of registered snowmobiles, the risk of death from snowmobile accidents remained relatively constant. Deaths occurred most frequently in northeastern Ontario. Youths and men predominated among the victims. Fatal accidents occurred more often on lakes (in 66% of the cases in which this information was known) than on roads (in 26%) or trails (in 8%). Weekend fatalities predominated, and deaths occurred most often during times of suboptimal lighting (from 4 pm to 8 am). The driver was killed in 84% of the cases in which the person's role was known. Alcohol use before death was implicated in 69% of the cases, the level exceeding the Ontario legal limit in 59%. CONCLUSION: Snowmobile-related deaths result from factors that are generally avoidable. Strategies need to be instituted to reduce the rate of these events.

Accidents↗
PubMed1992

Effect of capsaicin on gastric mucosal injury and blood flow following bile acid exposure.

Topical bile acid at low pH stimulates gastric mucosal blood flow (GMBF), thereby limiting injury to surface epithelial cells (SEC). Capsaicin-sensitive afferent neurons (ASN) are possible mediators of the GMBF response and, therefore, of mucosal protection. In order to investigate the effect of topical capsaicin (ASN stimulant) and topical lidocaine (ASN inhibitor) on SEC exfoliation and GMBF, vascularized wedges of canine gastric corpus were mounted in lucite chambers. Mucosae were pretreated for 15 min with saline (NSS), 160 microM capsaicin (CAP), 4% lidocaine (LIDO), or CAP and LIDO, followed by a 30-min exposure to acid test solution (ATS; pH 1.2). The same mucosae were then pretreated in an identical fashion followed by a second 30-min exposure to 5 mM taurocholate (5 TC; pH 1.2). Parameters evaluated during both ATS and 5 TC periods were the luminal accumulation of DNA (DNAE, a sensitive marker of SEC exfoliation) and GMBF measured using radiolabeled microspheres. It was found that, relative to NSS pretreatment, CAP pretreatment increased GMBF and decreased DNAE during exposure to both ATS and 5 TC. LIDO blocked the CAP effect on GMBF but not on DNAE. Thus, ASN stimulation by CAP enhances GMBF and is protective. ANS inhibition blocks CAP's GMBF increase but not its protective capabilities. Therefore, augmentation of GMBF is not the only mechanism by which ASNs blunt SEC exfoliation.

Animals↗
PubMed1992

Bone ultrasonic attenuation in women: reproducibility, normal variation and comparison with photon absorptiometry.

The reproducibility of two methods of measuring broadband ultrasonic attenuation (BUA) in the calcaneus have been studied. An improvement in reproducibility in vivo from 9.6% to 2.8% between old and new techniques has been observed. Measurements of the calcaneus using BUA were correlated with measurements of bone mineral density measured by dual energy x-ray absorptiometry in the lumbar spine, femur and total body and bone mineral content in the distal and proximal forearm measured by single photon absorptiometry. For the older BUA technique the correlation coefficients ranged between r = 0.27 and r = 0.34. For the newer BUA technique the correlation coefficients ranged between r = 0.49 and r = 0.62 and were all significant (P less than 0.001).

Absorptiometry, Photon↗
PubMed1992

Bronchodilators for treatment of mild bronchiolitis: a factorial randomised trial.

A randomised double blind trial was conducted to determine the efficacy of inhaled bronchodilators, salbutamol and ipratropium bromide, compared with placebo in the treatment of bronchiolitis. Patients, who were 2 months to 2 years of age and without underlying cardiac or pulmonary disease, received drug 1 (salbutamol or saline placebo) followed one hour later by drug 2 (ipratropium bromide or placebo). Both agents were administered every four hours. The patients were allocated to one of four groups according to a factorial design. The four groups were similar in demographic characteristics, initial oxygenation, and clinical score. The change in oxygen saturation of recipients of both agents was significantly better than that of recipients of salbutamol alone or ipratropium bromide alone. This change, however, was not statistically different from that of the control group. No difference was observed in the clinical score or hospital duration. Inhaled bronchodilators did not improve the condition of hospitalised mild bronchiolitis.

Albuterol↗
PubMed1992

The physician and Down syndrome: are attitudes changing?

A survey of attitudes of pediatricians, child neurologists, and pediatric surgeons toward Down syndrome is compared with a similar study reported in 1975. A contemporary physician would be much more aggressive in treating a child with Down syndrome who has associated anomalies such as duodenal atresia or congenital heart disease. Few would recommend institutionalization of a person with Down syndrome; the majority expect that such individuals could productively spend their adult lives in group homes. Positive changes in physicians' attitudes during the past 15 years have been influenced by parent advocacy groups, court decisions, and studies showing that the ultimate intellectual and social skills of Down syndrome children are greater than was previously believed. The most prominent variable associated with attitudes was the physician's age: the older the physician, the more likely he or she would be nonsupportive of active treatment on behalf of the Down syndrome individual. These findings suggest that ongoing education of medical students and pediatric residents in the field of developmental disabilities and bioethics is required in order to promote well-informed advocacy for the mentally handicapped.

Adult↗
PubMed1991

Effects of high fat diets on hibernation and adipose tissue in Turkish hamsters.

The effects of dietary fat saturation and fat content on hibernation and several properties of white and brown adipose tissue (WAT and BAT, respectively) were investigated in Turkish hamsters (Mesocricetus brandti). Male hamsters were housed in a long photoperiod (LD 16:8) at 23 degrees C and fed one of three diets: (1) chow (6.5% fat per weight), (2) chow + 13.5% vegetable oil (OIL, 20% fat per weight [largely unsaturated fat]) and (3) chow + 13.5% vegetable shortening [(SHORTENING, 20% fat per weight (largely saturated fat)]. Five weeks later body weights had stabilized and the animals were transferred to a short photoperiod (LD 8:16) at 3 degrees C. At the peak of the hibernation season (17 weeks) the animals were sacrificed within 24 h of arousal. Chow-fed hamsters had the greatest percentage of animals hibernating and days found torpid compared with the two fat-fed groups, with no differences found between the latter two groups for these measures. There were no differences between hibernating (HIB) and non-hibernating (NON-HIB) hamsters across or within the diet groups for any of the BAT measures [uncoupling protein content, mitochondrial mass, lipoprotein lipase (LPL) activity, and in vivo lipogenesis], nor were there significant effects of the diet on these measures. CHOW- and OIL-fed HIB hamsters showed decreases in body weight. All HIB groups had decreases in each carcass component, several fat pad weights, testes weight, and food intake. No consistent differences in WAT LPL activity or in vivo lipogenesis were found between HIB and NON-HIB hamsters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1991

Leukotriene receptor blockade reduces bile acid-induced superficial gastric mucosal injury.

Leukotriene C4 and D4 are putative mediators of the severe gastric mucosal injury caused by a variety of topical irritants. The purpose of this present study was (1) to investigate the effect of pretreatment with topical leukotriene C4 and D4 on the more superficial injury caused by low concentrations of bile acid and (2) to determine the effect of leukotriene receptor blockade, alone and during leukotriene pretreatment, on this injury. Prior to injury with topical 5 mM acidified taurocholate (pH 1.2) rat stomachs were pretreated with either normal saline, leukotriene C4 or D4, SKF-104353 (a leukotriene receptor antagonist), SKF-104353/LTC4, or SKF-104353/LTD4. Injury was assessed by measuring hydrogen ion flux and DNA efflux, a marker of gastric mucosal cell exfoliation. Both LTC4 and LTD4 significantly increased bile acid-induced luminal hydrogen ion loss and DNA efflux. Leukotriene receptor blockade not only blocked this effect, but also significantly decreased the injury from bile acid alone. Thus, both LTC4 and LTD4 exacerbate the superficial gastric mucosal injury caused by physiologic concentrations of bile acids. Leukotriene receptor blockade with SKF-104353 completely blocks these effects and reduces injury from bile acid alone.

Animals↗
PubMed1991

White cell depletion of red cell and pooled random-donor platelet concentrates by filtration and residual lymphocyte subset analysis.

This study comparing the relative white cell (WBC)-depleting efficiency of single and double filtration used two filters and new, sensitive, and reliable methods for performing WBC counts on WBC-depleted blood products. A single filtration of red cell (RBC) concentrates with a cotton-wool filter reduced WBC content by 98.64 percent, but the range of residual WBCs was wide, and many filtered units still contained more than the theoretical immunizing dose of 5 to 10 x 10(6) WBCs. A second filtration, however, always produced RBC units that had less than 5 x 10(6) WBCs. Although the degree of WBC depletion observed after a single filtration of a 6-unit pool of random-donor platelet concentrates was greater with a polyester filter than with the cotton-wool filter (98.92 vs. 98.14% reduction, respectively, when mean prefiltration WBC count was less than 600 x 10(6], in both cases, 25 percent of filtered products still contained greater than 5 x 10(6) WBCs; a second filtration (with the cotton-wool filter), however, produced units that were always below the immunizing dose. All double-filtered platelet concentrates had less than 10(6), and one-half had less than 10(4) residual WBCs. Platelet loss was similar with both filters (+/- 16% loss with one filtration). The effectiveness of the filters in producing products that were WBC-depleted below the immunizing dose was dependent on the prefiltration WBC content (but not on the age of the units), and it may be worthwhile to employ methods to ensure that total prefiltration WBC count of the product is less than 400 x 10(6).(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1991

Hepatitis B and human immunodeficiency virus infection in street youths in Toronto, Canada.

Hepatitis B and human immunodeficiency virus are transmitted by venereal contact or by the sharing of used needles during drug use. A questionnaire was administered to street youths admitting to prostitution and to a group denying prostitution, as well as to sexually active adolescents who lived with their family and were attending an adolescent medical clinic. The age, gender, race, number of sexual partners, condom use, illicit drug use, anal intercourse and admission to prostitution were recorded for each of the subjects. Serology was obtained for hepatitis B markers and human immunodeficiency virus antibody. Multiple regression analysis was performed to determine the factors which might predict hepatitis B serologic status. A single subject, who admitted to prostitution, was found to be human immunodeficiency virus-seropositive. Seven of 43 (16%) admitted prostitutes compared with 1 of 44 (2%) other street youth and none of 27 controls demonstrated anti-hepatitis B surface antibodies. The higher rate of seropositivity in admitted prostitutes was statistically significant (P less than 0.0097). Two seropositive prostitutes had IgM hepatitis B core antibody suggesting recent infection. Two factors, number of partners (P less than 0.0007) and practice of anal intercourse (P less than 0.05), were identified in the multiple regression analysis as predictive of seropositivity. Thus adolescents who live on the street are at increased risk for becoming infected with hepatitis B virus. The difficulty in ensuring vaccine coverage in this population would support calls for including hepatitis B vaccination as part of childhood immunization.

Adolescent↗
PubMed1991

Failure of supplementation with vitamin E to prevent bronchopulmonary dysplasia in infants less than 1,500 g birth weight.

In a randomized trial to determine whether oral vitamin E reduced stages III and IV bronchopulmonary dysplasia (BPD) by 50%, 268 infants were randomly allocated, after stratification by birth weight and severity of disease, to receive vitamin E 25 units or an indistinguishable placebo. The experimental (E) group and the control (C) group were similar in weight, gestational ages, Apgar scores, severity of illness, and initial oxygen and ventilator exposure. Serum vitamin E levels were significantly different within 48 h of administration and remained well above normal adult levels from the first week of life in the experimental group. There was no difference in the rates of early death, BPD at 28 days, or mortality from BPD. Severity was similar and no difference was seen in the incidence of necrotizing enterocolitis or sepsis. There was no evidence that vitamin E supplementation offered protection against chronic lung disease in infants less than 1,500 g birth weight.

Bronchopulmonary Dysplasia↗
PubMed1990

The demography of primary biliary cirrhosis in Ontario, Canada.

The demographics of primary biliary cirrhosis in Ontario, Canada, are described. Two hundred and twenty-five primary biliary cirrhosis patients were identified by 85 of 502 gastroenterologists (or internists) practicing in Ontario acute care hospitals that have 150 or more beds. Two hundred and six patients were verified as being antimitochondrial antibody-positive, resulting in an incidence of 3.26 per million per year and a prevalence of 22.39 per million. Questionnaire data were obtained on 88.5% of these patients. Twenty-nine percent of the patients were found to be asymptomatic. Geographical clustering and racial predisposition were not seen. No increase in breast cancer prevalence was noted. By the time the diagnosis of primary biliary cirrhosis was established, the patients had consulted a median number of 3.5 physicians. Fatigue was reported as the most disabling symptom. The diagnosis of primary biliary cirrhosis in patients referred from across the province of Ontario was independently confirmed by us, using standard criteria (antimitochondrial antibody testing and liver biopsy), and was found to be reliable.

Autoantibodies↗
PubMed1990

Percutaneous ablation of gallstones.

The purpose of this study was to determine if gallstones could be safely and effectively ablated in the pig using a proprietary percutaneous rotor-tipped catheter, the Kensey-Nash Lithotrite (KNL). All gallstones in a single human gallbladder were defined as a gallstone set. Human gallstone sets not meeting current treatment criteria for extracorporeal shock wave lithotripsy (ESWL) were placed in the gallbladder (GB) of male pigs (N = 8; 80-100 kg). A percutaneous transhepatic guide wire was put into the GB and the abdomen closed. The KNL was then introduced under fluoroscopy using the Seldinger technique and activated. Gallstone ablation was monitored by tactile and auditory feedback to the operator and by fluoroscopy. Once completed the device was withdrawn, the GB irrigated, and the 9F sheath removed. Animals were sacrificed immediately (Group 1, N = 4) and at 28 +/- 5 days (Group 2, N = 4). Gallstones were ablated in 26 +/- 8 min. No pig had significant hemorrhage, GB perforation, or pancreatitis. One acute animal had stone fragments greater than 2 mm in the gallbladder. No other animals had any fragments greater than 1 mm present in the GB, cystic duct, common duct, ampulla, or duodenum. Histologic examination of the GB showed acute hemorrhagic mucosal injury in Group 1 and extensive mucosal regeneration with some stone fragment granulomata and mural fibrosis in Group 2. We conclude that percutaneous gallstone ablation with the KNL is safe and effective in this short-term pig model and appears to be a safe procedure for gallstone ablation. Long-term safety and effectiveness remain to be demonstrated. This device should be useful for treatment of symptomatic gallstones in patients not treatable by ESWL.

Animals↗
PubMed1989

Decreased disability rate among 3-year-old survivors weighing 501 to 1000 grams at birth and born to residents of a geographically defined region from 1981 to 1984 compared with 1977 to 1980.

In this article we report the survival and morbidity rates for all live-born infants weighing 501 to 1000 gram at birth and born to residents of a defined geographic region from 1977 to 1980 (n = 255) compared with 1981 to 1984 (n = 266). During these periods, there were no changes in the proportion of infants delivered at the tertiary care center or community hospitals (171/84 vs 194/72); use of the tertiary care center increased only slightly, from 84% to 91%; and changes in neonatal management were mainly in improvements in diagnostic and monitoring techniques. When infants were grouped according to birth weights in 100 gm increments, survival improved significantly only for infants weighing between 501 and 600 gm at birth (2% vs 20% p less than 0.001). There were no differences in the overall survival rates to hospital discharge (46% vs 48%). The prevalence of neurosensory impairments was 24% in period 1 and 17% in period 2. There was a significant improvement in the proportion of infants considered to have disabilities by a functional classification assigned at 3 years corrected age (50% vs 27%, p less than 0.001), but only for infants weighing more than 800 gm at birth (49% vs 22%, p less than 0.001). Infants delivered at the community hospitals had a higher prevalence of neurosensory impairments compared with infants delivered at the tertiary care center (period 1, 35% vs 21%, not significant; period 2, 37% vs 14%, p less than 0.05). These data are encouraging; further efforts should be directed toward assessing which, if any, components of perinatal care are contributing to the improvement in morbidity rates.

Academic Medical Centers↗
PubMed1989

Evaluation of a new method of detection of nosocomial infection in the pediatric intensive care unit: the Infection Control Sentinel Sheet System.

To improve the efficiency of nosocomial infection detection, a highly structured system combining initial reporting by the bedside night nurse of symptoms possibly related to infection with follow-up by the infection control nurse (ICN) was developed: The Infection Control Sentinel Sheet System (ICSSS). Between July 1, 1987 and February 28, 1988, a prospective comparison of results obtained through ICSSS and daily bedside observation/chart review by a full-time trained intensivist was undertaken in the pediatric intensive care unit (PICU). Ratios of nosocomial infections and nosocomially-infected patients were 15.8 and 7.0 respectively among 685 admissions; included are seven infections identified only through the ICSSS so that the "gold standard" became an amalgamation of the two systems. The sensitivity for detection of nosocomially-infected patients by bedside observation/chart review and ICSSS was 100% and 87% respectively. The sensitivity for detection of standard infections (blood, wound and urine) was 88% and 85% respectively. The sensitivity for detection of nosocomial infections at all sites was 94% and 72% respectively. Missed infections were minor (e.g., drain, skin, eye), required physician diagnosis (e.g., pneumonia), were not requested on the sentinel sheet (SS) (e.g., otitis media), related to follow-up of deceased patients or were minor misclassifications or failures to associate with device (e.g., central-line related). Daily PICU surveillance by the ICN required only 20 minutes a day. The ICSSS appears highly promising and has many unmeasured benefits.

Bias↗