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Biomedical subjects

J Self

Publications and source records attributed to J Self.

At least 19 recordsLinked to original sources
PubMed2006

Clinical outcome and service implications of screening women at increased breast cancer risk from a family history.

INTRODUCTION: The value of special screening for women at moderate breast cancer risk with a family history of breast cancer remains controversial. Little is known about recall rates, false negative outcomes and the impact on clinical service. Despite this, surveillance programmes within breast units have been established in the United Kingdom. PATIENTS AND METHODS: In our institution, screening of women at moderate (lifetime risk, 17-30%) and high risk (>30%) consisted of annual clinical examination and mammography from the age of 35 years. The active study period ran for four months and each patient was followed through a further screening cycle (whole study period), providing information on interval cancers and detection at the subsequent screen. RESULTS: One thousand one hundred and thirty-two women attended for their incident screen: 137 at high risk, 803 at moderate risk and 192 at standard risk. The median age at cancer diagnosis in the moderate risk group was 54 (range, 45-68) years and the high-risk group 51 (46-52) years, compared to 63 (45-69) years in the standard risk group. Seven cancers were diagnosed during the four-month active study period. Two patients were diagnosed with interval cancers and eight at the next screen, giving a cancer incidence in the whole study period of 17/1132 (1.5%). Thirteen patients had invasive cancer and four had ductal carcinoma in situ (DCIS) The median invasive tumour size was 15 had (range, 7-28)mm and the median DCIS size was 4 (2-30)mm. 10/13 (76.9%) invasive cancers were < or =20mm and 2/13 patients (15.4%) with invasive cancer were lymph node positive. The sensitivity and specificity of mammography were 85.7% and 98.8%, respectively. The mammogram recall rate was 27.6 per 1000. The benign to malignant surgery ratio was 8:17. CONCLUSION: Screening women at increased breast cancer risk is effective. Early detection and recall rates are comparable to that of older women attending the British National Breast Screening Programme.

Adult↗
PubMed2005

Comparison of standard eyelid margin closure using silk with a modified repair using 7/0 vicryl and a buried knot.

AIMS: To assess the efficacy and complications of eyelid margin closure with 7/0 Vicryl or Vicryl Rapide suture with a buried knot at the grey line and to compare this with standard closure using silk with an external knot. METHODS: Analysis of a prospective, non-comparative, interventional case series using 7/0 Vicryl or Vicryl Rapide with a buried grey-line knot (modified lid margin closure). Detailed assessment during the healing period was directed to (1) the lid margin profile, (2) the grey line suture and (3) the tissue reaction. Patients were seen for assessment within two days following surgery, at 14 days and at two months. A retrospective, comparative series of silk with an external knot (standard lid margin closure) and 7/0 Vicryl or Vicryl Rapide (modified lid margin closure) was also studied. An analysis was made of the hospital records of patients who had undergone direct lid margin closure with 7/0 Vicryl, Vicryl Rapide or silk. Short- and long-term complications were noted. RESULTS: The prospective series included 24 patients whose lid margin closure had been performed with the modified technique with 7/0 Vicryl or 7/0 Vicryl Rapide. All lids healed well and there was no difference between these two sutures. The retrospective series included 123 patients. Seventy-one patients had the modified technique using 7/0 Vicryl or Vicryl Rapide. Fifty-two patients had lid margin closure with the standard technique using 6/0 silk. All lids healed well. In summary, in both the prospective and retrospective groups, no significant complications were encountered and the healing was excellent. CONCLUSIONS: 7/0 Vicryl and Vicryl Rapide with a buried knot at the grey line allows excellent lid margin healing comparable with standard closure using silk. Vicryl sutures do not need to be removed.

Adult↗
PubMed2000

Reducing conditions produce a loss of neuroprotective efficacy of competitive but not non-competitive antagonists in a model of NMDA-mediated excitotoxicity in organotypic hippocampal slice cultures.

Experimental data indicate that NMDA receptor activation is strongly implicated in the pathogenesis of cerebral ischaemia. However, the results from in vivo studies are equivocal, with NMDA antagonists being active in only some models. It has recently been demonstrated that competitive and non-competitive NMDA antagonists behave differently under normal and ischaemic conditions. These studies have used organotypic hippocampal slice cultures to investigate whether this disparity is due to redox-modulation of the NMDA receptor which occurs in ischaemia. NMDA-mediated toxicity was concentration dependent with little damage occurring with less than 10 microM NMDA and maximal damage produced by 30 microM. NMDA toxicity was significantly enhanced by pre-treatment with 1 mM dithiothreitol, a reducing agent, such that damage occurred at 1 nM NMDA, and maximal damage was produced by 10 microM. The efficacy of MK-801 was not altered by reducing conditions, but the EC50 of the competitive antagonist APV was increased by 20-fold. These data strongly suggest that the neuroprotective efficacy of NMDA antagonists is significantly altered under ischaemic conditions, and that more beneficial effects will be obtained with antagonists having a higher affinity for the receptor in the reduced configuration.

Animals↗
PubMed2000

Reducing conditions significantly attenuate the neuroprotective efficacy of competitive, but not other NMDA receptor antagonists in vitro.

Inappropriate activation of NMDA receptors during a period of cerebral ischaemia is a crucial event in the pathway leading to neuronal degeneration. However, significant research has failed to deliver a clinically active NMDA receptor antagonist, and competitive NMDA antagonists are ineffective in many experimental models of ischaemia. The NMDA receptor itself has a number of modulatory sites which may affect receptor function under ischaemic conditions. Using rat organotypic hippocampal slice cultures we have investigated whether the redox modulatory site affects the neuroprotective efficacy of NMDA receptor antagonists against excitotoxicity and experimental ischaemia (OGD). NMDA toxicity was significantly enhanced in cultures pretreated with a reducing agent. The noncompetitive antagonist MK-801 and a glycine-site blocker were equally neuroprotective in both normal and reduced conditions, but there was a significant rightward shift in the dose-response curves of the competitive antagonists APV and CPP and the uncompetitive antagonist memantine. OGD produced neuronal damage predominantly in the CA1 region, which was prevented by MK-801 and memantine, but not by APV or CPP. Inclusion of an oxidizing agent during the period of OGD had no effect alone, but significantly enhanced the neuroprotective potency of the competitive antagonists. These data clearly demonstrate that chemical reduction of the redox modulatory site of the NMDA receptor decreases the ability of competitive antagonists to block NMDA receptor-mediated neuronal damage, and that the reducing conditions which occur during simulated ischaemia are sufficient to produce a similar effect. This may have important implications for the design of future neuroprotective agents.

2-Amino-5-phosphonovalerate↗
PubMed1999

Frontal brain electrical activity in infants of depressed and nondepressed mothers: relation to variations in infant behavior.

In previous studies, infants of depressed mothers have been found to exhibit reduced left frontal brain electrical activity (EEG). The left frontal region has been hypothesized to mediate social approach behaviors and positive affective expression. These findings raise important questions about the cause and nature of atypical EEG patterns in infants of depressed mothers. The present study begins to address some of these questions by examining whether or not variations in patterns of frontal brain activity in infants of depressed and nondepressed mothers are related to variations in infant behavior as observed in naturalistic situations. If such relations exist, are they specific to certain behaviors hypothesized to be mediated by the frontal region (i.e., positive approach behaviors)? Frontal and parietal brain electrical activity was recorded from 14- to 15-month old infants of depressed versus nondepressed mothers during a baseline condition and during conditions designed to elicit interest and positive affect. Infant behavior was observed in naturalistic play conditions, with and without mother, on a separate day from EEG testing. Mothers provided information on infant temperament. Infants of depressed mothers showed less affection and touching of their mothers. For infants of depressed mothers only, reduced left frontal brain activity was found to be related to lower levels of affection toward mother, but not to infant temperament. Furthermore, increased generalized frontal activation was found to be related to higher levels of negative affect, hostility, and tantrums and aggression. Relations between infant brain activity and behavior were not found for parietal EEG activity. These results suggest that infant frontal electrical brain activity is related to variations in infant behavior, especially those involved in positive affiliative behavior and the expression and regulation of negative affect. The nature and cause of atypical patterns of brain activity and question of whether such atypical patterns of frontal brain activity predispose infants to affective disorders in later life are discussed.

Depression↗
PubMed1996

Influence of calcium and environmental temperature on performance of first-cycle (phase 1) commercial leghorns.

An experiment was conducted to determine whether optimizing profits, as well as eggshell and skeletal strength, by manipulation of dietary Ca level has any influence on either egg weight, egg production or feed consumption during the first 12 wk of production (Weeks 20 to 32, Phase 1). Hens were housed at two environmental temperatures (15.6 to 23.3 and 21.1 to 28.9 C) and fed six diets from 20 to 32 wk of age containing 2.5 to 5.0% Ca with increments of 0.5% and with ME levels ranging from 2,719 to 2,950 kcal/kg, respectively. Egg specific gravity, egg production, egg weight, and feed consumption were determined at weekly or biweekly intervals. At 32 wk of age, plasma Ca, bone density, and bone breaking strength were determined. Results indicated that environmental temperature had no influence on egg production but hens housed at the lower environmental temperature had an increase in egg weight, egg specific gravity, and feed consumption. Increasing dietary Ca level increased egg production, egg specific gravity, feed consumption, ionic plasma Ca, bone density, and bone breaking strength and had no adverse effect on egg weight. It was concluded that Hy-Line W-36 hens could be fed diets containing as much as 5% Ca with no adverse effect on egg production, egg weight, or feed consumption and that Hy-Line W-36 hens (Phase 1) under conditions described should be fed diets containing a minimum of 4.25% Ca (3.4 to 3.6 g per hen per d) to 4.5% Ca (3.6 to 3.8 g per hen per d). Calcium intake should range from 3.0 g per hen per d at 21 wk of age to 4.2 g per hen per d at 32 wk of age.

Animal Husbandry↗
PubMed1991

Design and evaluation of a posterior laminar clamp spinal fixation system.

A new spinal instrumentation system for posterior applications was designed with the intent of minimizing intrusion of hardware into the neural canal during and postinsertion. Basic biomechanical measurements of posterior pullout strength led to the establishment of a clamp as an effective mechanism for gaining purchase on the vertebral lamina. These experiments defined the appropriate instrumentation size, as well as establishing that there was no loss of strength with the spinous process removed and the posterior laminar cortex compromised. There was no statistically significant difference between the maximum pullout strength achievable, using a band around the lamina as a control, and that produced by the implant system, in the thoracic spine. Comparative testing of a prototype system in flexion, extension, lateral bending, and torsion showed that the system, in general, had stiffness greater than segmental wiring and less than or equal to Cotrel-Dubousset fixation.

Biomechanical Phenomena↗
PubMed1989

Using nurses for preventive activities with computer assisted follow up: a randomised controlled trial.

OBJECTIVE: To assess whether an organised programme of prevention including the use of a health promotion nurse noticeably improved recording and follow up of cardiovascular risk factors and cervical smears in a general practice that had access to computerised cell and recall. DESIGN: Randomised controlled trial. SETTING: General practice in inner London. PATIENTS: All 3206 men and women aged 30-64 registered with the practice. INTERVENTION: The intervention group had their risk factors ascertained and followed up by the health promotion nurse and the general practitioner, whereas those in the control group were managed by the general practitioner alone. END POINT: Recording and follow up of blood pressure and cervical smears after three years. Recording of smoking, family history of ischaemic heart disease, and serum cholesterol concentrations were also examined. MEASUREMENTS AND MAIN RESULTS: When the trial was stopped after two years the measurements of blood pressure in the preceding five years were 93% (1511/1620) v 73% (1160/1586) (95% confidence interval for difference 17.5 to 22.7%) for intervention and control groups respectively. For patients with hypertension the figures were 97% (104/107) v 69% (80/116) (18.2 to 38.2%). For women the proportion who had had a cervical smear in the preceding three years were 76% (606/799) v 49% (392/806) (22.5 to 31.9%). Recording of smoking, family history of ischaemic heart disease, and serum cholesterol concentrations was also higher in the intervention group compared with the control group. CONCLUSION: An organised programme, which includes a nurse with specific responsibility for adult prevention, is likely to make an important contribution to recording of risk factors and follow up of those patients with known risks.

Adult↗
PubMed1989

The effect of local controlled release of sodium fluoride on the stimulation of bone growth.

This study was performed to test the feasibility of using a biodegradable delivery system for the local controlled release of sodium fluoride as a mechanism for the stimulation of local bone growth. Sodium fluoride grains were mixed with poly-DL-lactic acid (PLA), and the mixture was then dissolved in acetone. After driving off the solvent, sheets of this material were rolled into rods 3.2 mm in diameter and 28.6 mm long. These were inserted into the intramedullary canals of the right femora of adult New Zealand White rabbits. A sham implant, made the same way but containing no fluoride, was inserted into the contralateral left leg. The effects of three different concentrations of sodium fluoride, 0.125 g NaF/g PLA, 0.250 g NaF/g PLA, and 0.500 g NaF/g PLA, were determined after a 4-week implantation period. In a second set of experiments, the concentration was fixed at 0.500 g NaF/g PLA with implantation durations of 4, 8, and 16 weeks. Expressed in terms of property ratios (experimental/control), bending strengths of the femora were significantly raised in most groups with the notable exception of Group 3 (0.500 g NaF/g PLA, 4 weeks). Cross-sectional area ratios in the distal femora were increased in all groups compared to right/left values for a normal unoperated group (p less than 0.05), with the highest ratio being 1.50 (SD = 0.44) for Group 4 (0.500 g NaF/g PLA, 8 weeks). Only Group 4 animals showed significant (p less than 0.05) increases in midshaft area ratio and none had responses proximally. Growth rates, measured by sequential fluorochrome labeling of bone followed the area ratio data and were only significant for the distal femora.

Animals↗
PubMed1988

Comparative mechanical properties of various Kirschner wire configurations in transverse and oblique phalangeal fractures.

A biomechanical study assessed the comparative mechanical properties of various wire configurations used in transverse and oblique phalangeal fractures. The configurations included crossed, oblique, and intramedullary wire techniques using 0.028-inch diameter (d) or 0.035-inch d Kirschner (K) wires. Six different configurations were tested in both the oblique fracture pattern and in the transverse fracture pattern. The mechanical properties were determined after either oblique or transverse osteotomy and fixation of the proximal phalanx. Each fixation technique was tested in apex palmar, apex dorsal, and lateral bending, as well as in torsion and distraction. The results showed that of the configurations tested, four crossed 0.028-inch d Kirschner wires obtained the highest rigidity in the transverse fracture pattern and three oblique 0.035-inch d Kirschner wires obtained the highest rigidity in the oblique fracture pattern.

Aged↗
PubMed1988

CT diagnosis of circumcaval ureter.

Variability in the normal course of the ureter makes it difficult to differentiate a normal variant from a congenital anomaly or deviation caused by a mass. CT can be useful in making this distinction. We present five cases of circumcaval ureter in which contrast-enhanced CT, by showing the ureter passing posterior and medial to the inferior vena cava (IVC), provided the definitive diagnosis. In addition, we studied the position of the inferior vena cava in the midlumbar region in 100 consecutive contrast-enhanced CT scans and compared the results with the position of the IVC in our five cases of circumcaval ureter plus one case of circumcaval ureter taken from the literature. Whereas only 6% of the normal patients had an IVC lateral to the right pedicle of the third lumbar vertebra, all of the patients with a circumcaval ureter and the one case in the literature had the IVC lateral to the pedicle. Therefore, the finding of a laterally placed IVC on CT is suggestive but not pathognomonic of circumcaval ureter. Contrast-enhanced CT can be used to prove the diagnosis of circumcaval ureter, and lateral placement of the IVC on non-contrast-enhanced CT suggests the diagnosis.

Adult↗
PubMed1987

The effect of implant axial and torsional stiffness on fracture healing.

A study was performed to compare the mechanical properties of healing transverse femoral osteotomies fixed with either (a) plates of high or low axial stiffness (compression or slotted plates) but equivalent bending and torsional stiffnesses, or (b) rods of high or low torsional stiffness (solid or slotted rods) but equivalent bending and axial stiffnesses. Compression and slotted plates were implanted contralaterally in one group of adult mongrel dogs and solid or slotted rods were implanted contralaterally in a second group as fixation for transverse osteotomies. We found that the compression-plated femora regained strength and stiffness earlier than the slotted-plated femora and healed with less callus formation. The femora fixed with rods healed with no significant differences in properties at any time interval. Also, the femora fixed with rods had mechanical properties close to those of the slotted-plated femora and lower than those of the compression-plated femora at the same time intervals. We concluded that contact compression caused the differences in the healing results and was more important than differences in torsional or axial rigidity of the implant.

Animals↗
PubMed1977

Metabolic and endocrine studies in a case of lipoatrophic diabetes.

A 20-yr-old female with congenital lipoatrophic diabetes was studied, with the following findings: (1) Serum insulin levels increased after both oral glucose and intravenous arginine administration; there was no growth hormone response to the latter. (2) The infusion of insulin (0.1 units and 0.5 units/kg) during the fed state and following at 110-hr fast produced only minimal changes of various fuels measured, with the exception of a decrease in the branched-chain amino acids. (3) There was a minimal production of ketones during the 110-hr fast. (4) Matabolic expenditure was markedly increased during the postabsorptive state (65-75 kcal/hr/sg m); it fell into the normal range during the 110-hr fast (31-35 kcal/hr/sq m). (5) Following meals, the patient experienced complaints ranging from cold and shivering to feeling hot with gross diaphoresis. These findings were associated with intermittent lability of her skin temperature, which varied 1 degree - 2 degrees F during a 3-hr period. (6) Progressive increases in doses of regular insulin before each meal resulted in up to a total of 9000 units/day being required before normal blood glucose levels were achieved. (7) A 2-wk therapeutic trial of pimozide provided no significant changes in a variety of hormones and fuels in the basal state or following insulin perturbations. (8) A variety of pituitary hormones and pituitary target organ hormones were studied in both the hypothyroid (Hashimoto's thyroiditis) and euthyroid state (following thyroid replacement). All the hormone responses were normal except that growth hormone did not rise during the slow wave sleep in either thyroid state.

Adult↗