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Biomedical subjects

S Ratcliffe

Publications and source records attributed to S Ratcliffe.

16 recordsLinked to original sources
PubMed2001

Characterization of the glycosylation profiles of Alzheimer's beta -secretase protein Asp-2 expressed in a variety of cell lines.

Amyloid 39-42 beta -peptides are the main components of amyloid plaques found in the brain of Alzheimer's disease patients. Amyloid 39-42 beta-peptide is formed from amyloid precursor protein by the sequential action of beta- and gamma-secretases. Asp-2 is a transmembrane aspartic protease expressed in the brain, shown to have beta-secretase activity. Mature Asp-2 has four N-glycosylation sites. In this report we have characterized the carbohydrate structures in this glycoprotein expressed in three different cell lines, namely Chinese hamster ovary, CV-1 origin of SV40, and baculovirus-infected SF9 cells. Biantennary and triantennary oligosaccharides of the "complex" type were released from glycoprotein expressed in the mammalian cells, whereas mannose-rich glycans were identified from glycoprotein synthesized in the baculovirus-infected cells. Site-directed mutagenesis of the asparagine residues at amino acid positions 153, 172, 223, and 354 demonstrate that the protease activity of Asp-2 is dependent on its glycosylation.

Alzheimer Disease↗
PubMed2001

Predicting western corn rootworm (Coleoptera: Chrysomelidae) larval injury to rotated corn with Pherocon AM traps in soybeans.

Crop rotation for portions of east central Illinois and northern Indiana no longer adequately protects corn (Zea mays L.) roots from western corn rootworm, Diabrotica virgifera virgifera LeConte. Seventeen growers in east central Illinois monitored western corn rootworm adults in soybean (Glycine max L.) fields with unbaited Pherocon AM traps during 1996 and 1997. In the following years (1997 and 1998), growers left untreated strips (no insecticide applied) when these fields were planted with corn. Damage to rotated corn by rootworms was more severe in untreated than in treated strips of rotated corn, ranging from minor root scarring to a full node of roots pruned. Densities of western corn rootworms in soybean fields from 1996 were significantly correlated with root injury to rotated corn the following season. Adult densities from 1997 were not significantly correlated with root injury in 1998, due to heavy precipitation throughout the spring of 1998 and extensive larval mortality. Twenty-eight additional growers volunteered in 1998 to monitor rootworm adults in soybean fields with Pherocon AM traps based on recommendations that resulted from our research efforts in 1996 and 1997. In 1999, these 28 fields were rotated to corn, and rootworm larval injury was measured in untreated strips. Based on 1996-1997 and 1998-1999 data, a regression analysis revealed that 27% of the variation in root injury to rotated corn could be explained by adult density in soybeans the previous season. We propose a sampling plan for soybean fields and a threshold for predicting western corn rootworm larval injury to rotated corn.

Agriculture↗
PubMed1998

The respiratory effects of tramadol in children under halothane an anaesthesia.

In a randomised double-blind, placebo-controlled study, the respiratory effects of intravenous tramadol (1 mg or 2 mg.kg-1) were compared with intravenous pethidine 1 mg.kg-1 under halothane anaesthesia. Children, ASA 1-2 between 2 and 10 years, presenting for inguinal surgery were studied. Once a steady state for halothane was reached, baseline recordings of end-tidal carbon dioxide, oxygen saturation, respiratory rate, tidal volume, minute volume, blood pressure and pulse rate were recorded. Intravenous tramadol 1 mg.kg-1 (T1) or 2 mg.kg-1 (T2) or pethidine 1 mg.kg-1 (PE) or placebo (PL) was then given according to a computer-generated randomisation. Further sets of recordings were taken at 5-min intervals for 20 min prior to commencement of surgery. The rate of recovery was assessed according to Aldrete scoring and the time and need for further analgesia were noted. The postoperative pain intensity was scored by means of a five-point verbal rating scale hourly for 6 h. Eighty-eight children, 22 per group, were studied. The mean age, weight and height were similar in each group. There was a statistically significant difference between the maximum decrease in respiratory rate and increase in end-tidal carbon dioxide between group PE and groups T1/T2 (p < 0.001). Thirteen episodes of apnoea occurred in the PE group, 11 requiring naloxone. The mean respiratory rate was lowest 5 min after injection in all groups. There was a slow increase in respiratory rate until incision in groups T1 and T2. Respiratory rate remained almost unchanged in PL until incision. The decreases in respiratory rate were reflected by increases in end-tidal carbon dioxide, the highest being recorded in the PE group. A lower intensity of pain in the first 2 h was noted in the three opioid groups. During the first 6 h, the proportion of patients requiring a further dose of analgesia was highest in PL and lowest in T2. Tramadol appears safe for use in children.

Analgesics, Opioid↗
PubMed1995

Tramadol.

Explore the source record for details and available documents.

Analgesics, Opioid↗
PubMed1992

Teaching family-centered perinatal care in family medicine, Part 2.

Pregnancy, childbirth, postpartum, and infant care are a continuum in the family life cycle for which the family physician is especially qualified to provide primary, comprehensive care. The purpose of this paper is to document and share the controversies, wisdom, and knowledge about caring for women and their families before, during, and after pregnancy. Family physicians can be leaders in developing an appropriate perinatal care system for the community. The level of care the family physician chooses to provide is discretionary. However, the family physician should be invested in ensuring that all families receive the greatest benefit from pregnancy, birth, and the newborn experience. Interest in perinatal care in family medicine is increasing, as reflected by the growing numbers participating in the Society of Teachers of Family Medicine Working Group on Family-Centered Perinatal Care. The authors of this article, who are active in this working group, hope that this information is useful in designing a balanced curriculum and delivery system for perinatal care in family medicine training programs.

Anesthesia, Obstetrical↗
PubMed1990

The parental origin of the extra X chromosome in 47,XXX females.

We used X-linked DNA polymorphisms to study the parental origin of X chromosome nondisjunction in 28 47,XXX live-born females. Errors in oogenesis accounted for 26 of the cases, with the majority of these being attributable to an error at meiosis I. We observed an association between advanced parental age and meiosis I nondisjunction--but not meiosis II nondisjunction--in the maternally derived cases. In studies of recombination we found little evidence for an association between pairing failure and X chromosome nondisjunction, but our results suggest that increased recombination near the centromere may play a role in the etiology of the 47,XXX condition.

Adolescent↗
PubMed1982

The personality and psycho-sexual development of boys with 47 XXY chromosome constitution.

Twelve XXY boys identified at birth in a population screening study were followed up at a mean age of 16.7 yr and compared with a control group of chromosomally normal boys matched for age and social class. Assessment of personality and psycho-sexual development showed the XXY boys to be more timid and less self-confident and to have problems in relating to their peer group than the controls. They also showed some evidence of delayed or impaired development of sexual interest. In general, the differences were not marked. Possible causes for these differences and potential methods of preventing them are discussed.

Adolescent↗
PubMed1980

A G-band study of chromosomes in liveborn infants.

The results of a chromosome survey of 3993 liveborn infants, the majority of which have been studied using G-banding, are reported. The frequency of all types of chromosome abnormalities detected was similar to that found in previous newborn surveys, which were carried out on different socio-economic structure, but the incidence of aneuploid chromosome abnormalities was comparable in the two localities.

Aneuploidy↗
PubMedDate not supplied

Teaching family-centered perinatal care in family medicine, Part I.

Pregnancy, childbirth, postpartum, and infant care are a continuum in the family life cycle for which the family physician is especially qualified to provide primary, comprehensive care. The purpose of this paper is to document and share the controversies, wisdom, and knowledge about caring for women and their families before, during, and after pregnancy. Family physicians can be leaders in developing an appropriate perinatal care system for the community. The level of care the family physician chooses to provide is discretionary. However, the family physician should be invested in ensuring that all families receive the greatest benefit from pregnancy, birth, and the newborn experience. Interest in perinatal care in family medicine is increasing, as reflected by the growing numbers participating in the Society of Teachers of Family Medicine Working Group on Family-Centered Perinatal Care. The authors of this article, who are active in this working group, hope that this information is useful in designing a balanced curriculum and delivery system for perinatal care in family medicine training programs.

Curriculum↗