Search PubMed⌕ Search

Biomedical subjects

K Reynolds

Publications and source records attributed to K Reynolds.

At least 73 records · Page 4Linked to original sources
PubMed1992

Epidural insertion: how far should the epidural needle be inserted before testing for loss of resistance?

The aim of this study was to determine the depth to which an epidural needle can safely be inserted before testing for loss of resistance. This ensures that the epidural needle is advanced far enough to encounter ligament thus avoiding the confusion that can occur when testing for loss of resistance whilst still in subcutaneous tissues. A survey of the distance between the skin and the epidural space in 400 obstetric patients was performed. Three hundred and ten midline epidurals showed a highly significant correlation (P<0.001) between the patient's pregnant weight and the distance to the epidural space. Using these data confidence limits were calculated in order to quantify the distance that the epidural needle could safely be inserted before testing for loss of resistance. Dividing the patient's pregnant weight by 25 will give this distance in centimetres. Seventy six paramedian approaches were performed and a less good correlation was found between the depth of the space and the woman's weight. There was no correlation with height or foot size.

Journal Article↗
PubMed1992

The sit-up test: an alternate clinical test for evaluating pediatric torticollis.

The sit-up test, a new evaluation method for differentiating between ocular and orthopaedic torticollis, was evaluated against the monocular occlusion test, using results of three-step testing for standardization. The study group consisted of 31 patients with torticollis between the ages of 4 and 12.5 years. Subjects were selected based only on their ability to cooperate with three-step testing. Three-step testing identified 27 of the 31 patients as having ocular torticollis, with the remaining 4 having an orthopaedic etiology. Sit-up testing correctly identified all 27 ocular torticollis patients, with no false positives or false negatives. Monocular occlusion testing detected at best 22 (81.4%) of the ocular torticollis patients, with no false positives.

Child↗
PubMed1992

Injuries associated with strenuous road marching.

Injuries were recorded during and up to 12 days after a maximal effort road march. Light infantry soldiers (N = 335) carried a total load of 46 kg over a 20 km course. Twenty-four percent of the soldiers suffered one or more injuries, resulting in 44 days of limited duty. All injuries involved the lower extremities and/or the back. Foot blisters and back problems were the most common complaints (35% and 23%, respectively, of the total injuries). These data indicate that units without recent road marching training can expect a high incidence of injuries as a result of a single demanding road march.

Adult↗
PubMed1992

Efficacy of antiperspirants on feet.

Nineteen male soldiers participated in a study of the effectiveness of two antiperspirants (aluminum chlorohydrate and aluminum zirconium tetrachlorohydrex glycine) in reducing foot-sweat accumulation and injuries. Each subject was tested before and after antiperspirant application, with a 1-hour treadmill march at 5.6 km/hour in a warm environment. Both antiperspirants decreased (p less than 0.05) foot-sweat accumulation over 50%. There was also a tendency, although not statistically significant, for subjects to incur fewer blisters with antiperspirant use. However, the antiperspirants also increased (p less than 0.05) the incidence of irritant dermatitis. Nevertheless, these data suggest that the application of antiperspirants to the feet has merit in reducing serious foot injuries (blisters, trench foot) exacerbated by wet feet.

Adult↗
PubMed1991

Paracetamol-associated luteinized unruptured follicle syndrome: effect on intrafollicular blood flow.

We are using transvaginal ultrasonography with color Doppler imaging to study changes in intrafollicular blood flow over the periovulatory period. We report here the findings from one volunteer (subject 9), who took two tablets of paracetamol (1000 mg) twice daily (between 07.00 and 08.00, and 18.00 and 19.00) for 2 consecutive menstrual cycle days (12 and 13) to alleviate a headache, which was shown retrospectively to have occurred within the duration of the luteinizing hormone (LH) surge in peripheral plasma. The drug appeared to have a profound effect on peak systolic blood velocity within the preovulatory follicle. Color (an index of blood velocity) disappeared and flow velocity waveforms were not detectable for at least 4 h. Color then re-appeared, but the peak systolic blood velocity had reduced by 69.8% (from 18.2 to 5.5 cm/s). The peak systolic blood velocity recovered subsequently to 16.3 cm/s, but the follicle did not rupture and continued to grow to a maximum diameter > 59 mm. There was no apparent effect of the drug on expected changes in the circulating levels of estradiol, LH, follicle stimulating hormone or progesterone. The secretory phase of the menstrual cycle lasted 13 days (i. e. day of LH peak to day of next menses minus one). We suggest that paracetamol taken at the time of the LH surge may affect intrafollicular peak systolic blood velocity and might inhibit ovulation. Possible molecular mechanisms are discussed.

Journal Article↗
PubMed1991

Mechanistic studies of two amino acid racemases of broad substrate specificity from Pseudomonas striata and Aeromonas caviae.

The conversion of L-[alpha-2H]alanine in H2O and unlabeled L-alanine in 2H2O into D-alanine, under nearly irreversible conditions, with the amino acid racemase from Pseudomonas striata showed significant internal transfer of the alpha-hydrogen. This result has been interpreted as being indicative of a single base mechanism for the racemization. The relative rates of deuterium incorporation into unlabeled D- and L-methionine by the two amino acid racemases of broad substrate specificity from P. striata and Aeromonas caviae, were measured in 2H2O. The results showed a markedly different pattern, dependent upon the configuration of the initial substrate; with D-methionine as substrate deuterium is incorporated into both enantiomers at approximately the same rate, but with L-methionine as substrate deuterium is incorporated considerably faster into the D than the L enantiomer. These results argue against a single base mechanism of racemization for these enzymes and are best rationalized in terms of a double base model where only one of the bases undergoes proton (deuterium) exchange with the solvent while the amino acid is enzyme-bound. The interpretation of the earlier experiment needs to be considered in light of these results.

Aeromonas↗
PubMed1991

Activity of the beta-retinoic acid receptor promoter in transgenic mice.

LacZ reporter gene constructs were used to analyze the murine retinoic acid receptor beta (mRAR beta) gene promoter in transgenic mice. LacZ expression in transgenic mouse embryos with 250 bp of promoter sequences closely parallels that of RAR beta between embryonic days 8.5 and 12.5. This indicates that the -1 to -250 promoter region contains most regulatory elements required for tissue specific expression. Additional elements in the -250 to -625 region are required for high expression levels after day 12.5. Elements in the -625 to -3100 region are necessary to reproduce the RAR beta expression in the meninges and the eye mesenchyme. The expression pattern of the transgene and the endogenous RAR beta, as revealed by in situ hybridization, suggests an important role of the RAR beta in the developing nervous system.

Amino Acid Sequence↗
PubMed1991

Determination of the nodal point position in the pseudophakic eye.

The optics of the schematic eye have been described by Gullstrand and Listing (System of Ophthalmology (ed. H. Kimpton), Vol. 5, C. V. Mosby, London (1970], data being averaged from a series of adult eyes with a crystalline lens. A ray of light from the height of any given object passing, undeviated, through the nodal point will determine the height of its image on the retina. The nodal point positions, therefore, are fundamental in determining image size, and any eye-to-eye variation in a patient will control the amount of aniseikonia. The optics of the pseudophakic eye are described together with a scientific method for determining the nodal point positions, and the implications are discussed.

Cornea↗
PubMed1991

Aniseikonia: a method of objective assessment in pseudophakia using geometric optics.

There have been various reports in the literature regarding the limits that separate acceptable from disturbing aniseikonia. A criterion value of 5% is often quoted but actual values in pseudophakia may vary from 2% to 10%, depending on the type and position of implant used. In the accompanying paper we have reported a method by which image size can be calculated in the pseudophakic eye. Using this method a series of patients with anterior and posterior chamber implants were analysed and the image size for both eyes of each patient determined. This was compared with the patient's subjective appreciation.

Aniseikonia↗
PubMed1991

Effect of variations in peptide sequence on anti-human milk fat globule membrane antibody reactions.

Monoclonal anti-mucine antibodies BC1, BC2 and BC3 produced using human milk fat globule membrane react with a synthetic peptide p1-24 (PDTRPAPGSTAPPAHGVTSAPDTR) representing the repeating amino acid sequence of the mucin core protein. The minimum epitope recognized by these three monoclonal antibodies (mAb) in p1-24 was contained in the five amino acids APDTR. To analyse the variation of position of the epitope, various modifications of the APDTR sequence were made by synthesizing peptides and testing by direct binding and inhibition enzyme-linked immunosorbent assays. Firstly, peptides p13-32 and C-p13-32, in which the epitope APDTR was placed in the middle instead of the C-terminal as in p1-24, were examined. These peptides had a greater reaction with mAb BC1, BC2 and BC3 compared with the reaction with p1-24. Secondly, A-p1-24 and TSA-p1-24 were made wherein two APDTR epitopes were present--these peptides were shown to bind two IgG antibody molecules. Finally, the contribution of each amino acid in the APDTR epitope was studied using the pepscan polyethylene rods, making all 20 of the amino acid substitutions in each position for SAPDTR (the minimum epitope APDTR with an adjacent amino acid S). In the 120 peptides examined there were some 'permissible' substitutions in A, D and T but not in P or R for BC1 and BC2; there were more 'permissible' substitutions for BC3; different substitution patterns were found with each antibody and some substitutions gave an increased reaction compared with the native peptide SAPDTR. The studies are of value in analysing the reaction of antibodies with epitopes expressed in breast cancer and in determining the antigenicity of synthetic peptides.

Amino Acid Sequence↗
PubMed1991

Soldier performance and mood states following a strenuous road march.

Eighty-nine soldiers performed a maximal effort 20-km road march, carrying a total load of 46 kg. Compared to pre-march values, post-march marksmanship accuracy decreased 26% for number of target hits and 33% for distance from the centroid of the target. Maximal grenade throw distance decreased 9%, but there was no change in maximal vertical jump height. The Profile of Mood States questionnaire revealed an 82% increase in self-reported fatigue and 38% decrease in vigor. Significant decrements in some aspects of military performance occur when soldiers march rapidly with heavy loads over long distances.

Affect↗
PubMed1991

Ovarian cancer screening.

Ovarian cancer will kill more women this year than cancer of the uterine corpus and cervix combined. Outcome is stage dependent. At stage IV, the five year survival rate is about 4.5%, but at stage I it may be well over 90%. Overall, regardless of stage, about 30% of women with ovarian cancer will be alive five years after its diagnosis. The fact that changes in treatment over the past two decades have done little to alter these depressing figures has led to a reassessment of our approach to this problem. It has been proposed that earlier diagnosis of the condition will lead to improved patient outcome. Because the disease is asymptomatic in its earliest stages in the majority of cases, this has prompted the search for a reliable screening test that could be used to detect the cancer when it is still confined within the capsule of the ovary. This paper discusses these issues, assesses the different techniques available to screen for ovarian cancer, and comments on possible future developments.

Antigens, Neoplasm↗
PubMed1990

Synthetic peptides reactive with anti-human milk fat globule membrane monoclonal antibodies.

Mammary mucins are increased in amounts in breast cancer patient sera, and most anti-breast cancer antibodies react with such mucins. One such mucin is found in human milk fat globule membrane and consists predominantly of O-linked sugars and a protein core. Partial complementary DNA clones for the protein core have recently been obtained. The nucleotide sequence is of interest as it contains a 60-base pair repeat, giving rise to a repeated 20-amino acid sequence (PDTRPAPGSTAPPAHGVTSA). Peptides with various lengths were synthesized using this sequence and the adjacent 4 amino acids (PDTR). Three anti-human milk fat globule membrane antibodies produced in our laboratory (BC1, BC2, and BC3) were tested to determine their reactivity with these synthetic peptides. Using three different assays (direct enzyme-linked immunosorbent assay test on peptides, direct enzyme-linked immunosorbent assay test on bovine serum albumin-conjugated peptides, and an inhibition test with the peptides in liquid, rather than solid phase), it was shown that APDTR was the minimum amino acid sequence required to form a reactive epitope with all 3 antibodies, although individual differences in the reactivities of the antibodies were noted. The addition of alanine (A) converted a nonreactive PDTR peptide to a reactive one, and the deletion of arginine (R) did the reverse; thus APDTR is the smallest peptide which reacts with these anti-human milk fat globule membrane antibodies.

Amino Acid Sequence↗
PubMed1990

Virtual simulation in the clinical setting: some practical considerations.

Virtual simulation departs from normal practice by replacing conventional treatment simulation with 3-dimensional image data and computer software. Implementation of virtual simulation requires the ability to transfer the planned treatment geometry from the computer to the treatment room in a way which is accurate, reproducible, and efficient enough for routine use. We have separated this process into: (a) immobilization of the patient; (b) establishment and alignment of a practical coordinate system for the patient/couch system; and (c) setup of the patient/couch been addressed by the use of hemi- or full-body foam casts, the second by use of an alignment jig on the treatment couch, and the third with the aid of a patient coordinate system referenced to easily located landmarks. Phantom studies and clinical practice have shown these techniques to be practical and effective within reasonable clinical bounds.

Computer Simulation↗
PubMed1990

The five year school medical--time for change.

School medical records of 1000 children born in 1981 were studied retrospectively. They showed that once known medical problems and those screened for by the school nurse (hearing, vision, growth) were excluded, only 17 problems requiring treatment were discovered: speech (n = 10), development (n = 3), undescended testes (n = 3), and phimosis (n = 1). This indicates that routine screening by a nurse, backed up by selective medical examination by the school doctor, is efficient and effective.

Child, Preschool↗