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Biomedical subjects

L Perry

Publications and source records attributed to L Perry.

At least 37 records · Page 2Linked to original sources
PubMed1998

Nondisruptive, in vivo method for biomechanical characterization of linear incision wound healing: preliminary report.

Previous work on in vivo biomechanical characterization of soft tissues and wound healing has led to the development of a methodology for nondisruptive, in vivo biomechanical analysis of linear incision wounds. The purpose of this preliminary study was to define nondisruptive biomechanical parameters that characterize progressive healing and compare them with an in vivo disruptive parameter of ultimate pressure at failure (in vivo strength). Male Sprague-Dawley rats (n = 60), each weighing 250 to 300 gm, were anesthetized and underwent creation of paired full-thickness linear incision wounds. The rats were divided into three groups (n = 10/group per time period): control group, nothing applied to either wound; carrier group, bovine serum albumin applied to each wound; transforming growth factor-beta2 group, transforming growth factor-beta2 in bovine serum albumin applied to each wound. On postoperative days 5 and 10, rats from each group underwent in vivo biomechanical testing using the Dimensional Analysis System (Dimensional Analysis Systems, Inc., Nashville, Tenn.). This computer-driven device integrates a video camera and processor with a vacuum controller, valve, and transducer to provide measurements of tissue deformation (in millimeters) and negative pressure (mmHg) as a multiaxial stress (vacuum) is applied to a wound. On each rat, one incision was tested disruptively and the other incision was tested nondisruptively. Disruptive data were measured as ultimate pressure (mmHg) at failure, or the amount of pressure required to disrupt the wound. Nondisruptive data were measured for tissue stiffness (kiloPascals) during application of negative pressure (maximum, 80 mmHg). On postoperative day 5, wounds treated with transforming growth factor-beta2 had significantly increased in vivo wound strength compared with carrier wounds. The nondisruptive parameter of tissue stiffness was also significantly increased for the transforming growth factor-beta2 treated wounds, thus supporting the disruptive data. On postoperative day 10, there was no difference in mean wound strength or mean tissue stiffness among any of the groups. These preliminary data represent the first report of in vivo, nondisruptive biomechanical characterization of linear incision wounds. The results suggest that through in vivo measurements of tissue stiffness, differences can be detected between treatment groups. Because the healing wound may be characterized without the need for disruption, this methodology should allow for consecutive, in vivo biomechanical testing of wounds in future wound healing studies.

Animals↗
PubMed1998

Adjustment in patients with rheumatoid arthritis and their children.

OBJECTIVE: To assess everyday life stress and emotional adjustment in patients with rheumatoid arthritis (RA) and their children. METHODS: We conducted a 6 month study of 14 patients with RA with children aged 4-16 years (25 children) and 24 control families (53 children). Life event stress and functional capacity were assessed at the beginning and end of the study, and minor stressors (hassles), positive events (uplifts), and salivary cortisol were recorded weekly. Emotional adjustment was measured monthly in adults by self-report, and bimonthly in children using the Child Behavior Checklist (completed by parents). Social support and psychological coping responses were also measured. RESULTS: Patients with RA experienced fewer positive events than did controls, and they tended to have smaller support networks. Daily hassle levels correlated with severity of disability, and differences in psychological coping were also observed. Children from RA families reported nearly 50% more hassles per week than did controls, and their social networks were significantly smaller. They were rated as having greater problems of social adjustment than controls. Cortisol concentration was greater among children who experienced more life event stress over the study period, but did not differ between groups. CONCLUSION: The patients with RA in this study showed good adaptation, but experienced less pleasure in their daily lives. The children of patients with RA may have heightened vulnerability to stress related problems, with fewer social resources and difficulties in behavioral adjustment.

Adolescent↗
PubMed1997

Fishing for understanding: nurses knowledge and attitudes in relation to nutritional care.

Many studies have demonstrated that malnutrition is a significant problem amongst hospital patients, but little is known about what nurses actually do, and what factors influence this. This study aimed to explore the nutritional attitudes, knowledge base and nursing care of qualified nurses in an acute hospital. A survey of nurses' records for documented nutrition related activities was carried out for all (141) patients from five wards for two weeks, followed by a questionnaire, focused on nutrition-related attitudes, activities and knowledge, to all qualified nurses of these and a further four wards (110 nurses). Results revealed evidence of some knowledgeable and pro-active attitudes and nursing care; however, there was little association between knowledge, stated attitudes and behaviour and discrepancies were observed between questionnaire responses and documented activities. Ajzen and Fishbein's (1980) theory relating beliefs, attitudes, intentions and behaviour was not supported although this might be attributed, in part at least, to nurses not regarding weighing patients as nutritional assessment. Behaviour appeared to have been influenced by a variety of factors and relationships between attitudes, knowledge and activities seemed far from straightforward.

Attitude of Health Personnel↗
PubMed1997

Helicobacter rodentium sp. nov., a urease-negative Helicobacter species isolated from laboratory mice.

A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the intestines of laboratory mice. The organism grew at 37 and 42 degrees C under microaerobic and anaerobic conditions, did not hydrolyze urea, was weakly positive for catalase and oxidase, reduced nitrate to nitrite, did not hydrolyze indoxyl acetate or hippurate, and was resistant to cephalothin and nalidixic acid. This is the first urease-negative, murine Helicobacter spp. isolated from intestines. Also, Helicobacter pullorum and this bacterium are unique among the genus Helicobacter in having nonsheathed flagella. The new bacterium appears to be part of the normal intestinal flora; although its pathogenic potential is unknown, this organism was also isolated from scid mice with diarrhea that were co-infected with Helicobacter bilis. On the basis of 16S rRNA gene sequence analysis data and biochemical and phenotypic criteria, the new organism is classified as a novel helicobacter, for which we propose the name Helicobacter rodentium. The type strain is MIT 95-1707 (= ATCC 700285).

Animals↗
PubMed1997

A combined test using desmopressin and corticotropin-releasing hormone in the differential diagnosis of Cushing's syndrome.

To assess the ability of desmopressin to differentiate between pituitary and ectopic ACTH-dependent Cushing's syndrome and to determine whether diagnostic accuracy could be improved by administering it together with human sequence CRH, we examined its effects on cortisol and ACTH secretion when given alone or in combination with CRH in patients with Cushing's syndrome of varied etiology and compared these data to the results of a standard CRH test in the same individuals. Each patient was studied on three occasions, in random order, separated by at least 48 h. At 0900 h, via an indwelling forearm cannula, 10 micrograms desmopressin, 100 micrograms CRH, or a combination of the two were given as an iv bolus; thereafter, blood was drawn every 15 min for 2 h. The responses to the individual agents were determined according to the timing and calculation criteria suggested by Nieman et al. (1993). A total of 25 patients with Cushing's syndrome were studied: 17 patients with pituitary-dependent Cushing's syndrome, Cushing's disease (CD); 5 patients with occult ectopic ACTH secretion (EC); and 3 patients with primary adrenal (ACTH-independent) Cushing's syndrome. In this series, the best discrimination among ACTH-dependent patient groups was achieved using the combined test. Using the responses of plasma cortisol, all 17 patients with CD showed a rise greater than any of the 5 patients with EC, whereas 1 patient with CD showed a plasma ACTH response within the range seen in the patients with EC. Plasma cortisol responses to desmopressin alone were seen in 14 of 17 patients with CD and 1 of 5 patients with EC and, after CRH alone, in 15 of 17 patients with CD but in no patient with EC. In contrast, plasma ACTH responses after CRH alone were seen in 14 of 17 patients with CD and 2 of 5 patients with EC and, after desmopressin alone, in 12 of 17 with CD and 3 of 5 with EC, thus indicating overlapping responses between the groups and poorer discrimination. No responses were seen in the ACTH-independent group. These data indicate that desmopressin causes the secretion of ACTH and cortisol in patients with ACTH-dependent Cushing's syndrome, and that in combination with CRH, it may provide an improvement over the standard CRH test in the differential diagnosis of ACTH-dependent Cushing's syndrome. Furthermore, these data suggest that there may be abnormalities in vasopressin receptor function or number in ACTH-secreting tumors.

ACTH Syndrome, Ectopic↗
PubMed1997

Critical incidents, crucial issues: insights into the working lives of registered nurses.

The critical incident technique has been used in nursing in a number of ways: in developing understanding of the nursing role, as a quality assurance strategy, as an assessment and evaluation tool, and as an aid in the fostering of reflective practice. This article describes how the technique, used as a theoretical course assessment for a group of students studying long ENB courses, could be used to shed light upon issues regarded as crucial in the daily working lives of this group of registered nurses, and upon the reflective skills which they were able to employ.

Conflict, Psychological↗
PubMed1997

Nutrition: a hard nut to crack. An exploration of the knowledge, attitudes and activities of qualified nurses in relation to nutritional nursing care.

Provision of adequate nutrition is recognized as essential, yet malnutrition continues to be reported in patients admitted to hospital. The effects of malnutrition in hospital patients have been well documented; however, most work relating to nutritional management has been produced by members of Nutrition Support Teams, nurse specialists and interested clinicians, whilst the majority of hospitals are still without such specialist posts. This study used two data collection methods to gain information about the attitudes, nutritional knowledge base and nutrition-related nursing care in a large trust hospital in the South of England. A survey of care plans for documentation of nutrition-related nursing activities, carried out on the day of discharge for all patients from five wards over a period of a fortnight (totalling 141 sets of documentation), was followed by a questionnaire to all qualified nurses on these and a further four wards (110 nurses). Results demonstrated that nurses generally felt that nutritional assessment was primarily their responsibility. Whilst there was evidence of knowledgeable and proactive nursing care, it also appeared that there were fairly widespread deficiencies in the knowledge, communication and co-ordination required to ensure consistent good practice.

Adult↗
PubMed1996

Delayed repair: the role of glutathione in a rat incisional wound model.

Glutathione is a low molecular weight tripeptide that is a major intracellular antioxidant, modulates DNA synthesis, and may regulate signal transduction mechanisms. Our previous studies in rats suggested that intracellular stores of glutathione were sensitive to skin ischemia and, therefore, may regulate the early temporal course of wound healing. A 4-cm incision was placed on a rat's back and in vivo wound strength was measured over time. Animals were depleted of glutathione using L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of the enzyme gamma-glutamylcysteine synthetase. Some animals were treated in combination with allopurinol/BSO or with allopurinol alone. The data demonstrated at 4 days that BSO treatment produced a fourfold reduction in glutathione (3.51 +/- 1.78) over baseline (16.15 +/- 2.18) levels and twofold reduction (5.0 +/- 1.1) over untreated sham controls (11.1 +/- 2.3) (P < 0.05). Allopurinol provided no protection to glutathione levels. BSO treatment alone reduced wound burst strength compared to the other groups (P < 0.05). Allopurinol treatment enhanced wound strength over sham controls and BSO groups at 9 days after wounding (P < 0.05). Hydroxyproline content in wounds accumulated faster by Day 4 in the BSO-treatment groups compared to sham controls (P < 0.05), whereas the BSO-treatment groups had lower hydroxyproline levels measured at Day 6 (P < 0.05). These data provide the first evidence that wound healing is related to the temporal course of glutathione metabolism. The effect may not be related to oxidant stress since allopurinol provided enhanced wound burst strength without protecting wound glutathione levels.

Allopurinol↗
PubMed1996

Growth hormone treatment in hypopituitary GH deficient adults reduces circulating cortisol levels during hydrocortisone replacement therapy.

OBJECTIVES: Patients with GH deficiency frequently have multiple hormone deficiencies and require hydrocortisone replacement. We have investigated whether GH treatment alters circulating cortisol levels in hypopituitary patients receiving stable replacement therapy. DESIGN: Subjects were studied during 6 or 12 months of s.c. GH at a dose of 0.25 IU/kg/week (0.125 IU/kg/week for the first 4 weeks), and after a wash-out period of at least 2 months off GH (range 2-5 months). PATIENTS: Fourteen hypopituitary patients (2F:12M) receiving stable hydrocortisone replacement and thyroxine, gonadal steroids and bromocriptine therapy as required. MEASUREMENTS: Serum cortisol values were measured throughout the day over 10.5 hours. Thyroid hormones and cortisol binding globulin (CBG) were measured in the baseline sample. Comparisons of the serum cortisol peak after receiving the first dose of hydrocortisone, the time when the serum cortisol peak was obtained, the area under the curve (AUC) for the cortisol values and the levels of unbound cortisol on and off GH therapy were made. The results are expressed as mean +/- SEM. Comparisons were carried out within individuals, using the Wilcoxon signed rank test. A P-value less than 0.05 was considered statistically significant. RESULTS: During GH therapy, there was a significant reduction in the mean cortisol peak (662.2 +/- 61.1 vs 848.0 +/- 58.6 nmol/l; P = 0.001), and in the AUC for cortisol (185.3 +/- 18.3 vs 230 +/- 17.9 nmol/l/10.5h; P = 0.03), but there was no significant change in the time of the cortisol peak (55.7 +/- 7.6 vs 57.8 +/- 4.9 minutes; P = NS). During GH therapy there was a significant reduction in CBG levels (33.64 +/- 1.16 vs 40.86 +/- 1.34 mg/l; P = 0.001); however, no changes were found in the levels of calculated unbound cortisol on and off GH (2.87 +/- 0.38 vs 2.90 +/- 0.30 nmol/l; P = NS). During GH therapy, there was a significant increase in serum triiodothyronine (T3) (1.88 +/- 0.15 vs 1.44 +/- 0.11 nmol/l; P = 0.01), and a significant decrease in thyroxine (T4) levels (74.9 +/- 11.1 vs 97.6 +/- 10.9 nmol/l; P = 0.02) but levels remained within the normal range. No change was observed in serum TSH levels (0.29 +/- 0.13 vs 0.83 +/- 0.71 mU/l; P = NS). CONCLUSIONS: These results suggest that GH therapy in GH deficient adults produces an alteration in the measured serum cortisol profile, with a reduction in concentration of total cortisol in blood after orally administered hydrocortisone. These changes in circulating cortisol probably depend primarily on the fall in CBG levels, as no changes were found in the levels of calculated unbound cortisol on and off GH. Our data show that when measuring circulating cortisol levels, the results should be interpreted with caution in GH deficient patients on GH replacement, and different criteria may have to be applied to the circulating cortisol profile of these patients. The results highlight the importance of ensuring adequate corticosteroid replacement in patients starting GH therapy.

Adult↗
PubMed1996

Cardiovascular risk and responsivity to mental stress: the influence of age, gender and risk factors.

BACKGROUND: Exaggerated cardiovascular and neuroendocrine responses to mental stress may enhance cardiovascular disease risk. Coronary heart disease and hypertension increase in prevalence with advancing age, whereas the excess male/female ratio declines in later middle age. Psychosocial factors may contribute to these changing risk profiles. The hypothesis that cardiovascular and neuroendocrine stress responses are associated with age and gender differences in cardiovascular disease risk was tested. METHOD: 132 healthy men and women from younger (30-40 years) and older (55-66 years) age bands were selected at random from general practice lists. They performed a series of mental stress tests during which blood pressure, heart rate, cardiovascular baroreflex sensitivity, cortisol, respiration patterns and electrodermal activity were monitored. A submaximal exercise test was performed and psychological characteristics were assessed by questionnaire. RESULTS: At rest, systolic and diastolic blood pressure was higher in men than in women, while cardiac baroreflex sensitivity was greater in younger than in older participants. Blood pressure responses to tasks were substantial, with changes from the baseline averaging 18.6/8.11, 26.0/13.5 and 40.7/19.0 mmHg for computerized problem solving, mirror drawing and speech tasks, respectively. Men and women in the older age band did not differ from each other in blood pressure, heart rate or baroreflex sensitivity responses. Systolic blood pressure responses (mean +/- SEM) were larger in older than in younger women (mean peak difference 6.87 +/- 2.67 mmHg), and in the younger male compared with the younger female groups (mean peak difference 7.20 +/- 2.97 mmHg). Diastolic blood pressure and heart rate responses to mental stress were larger in younger than in older age participants of both sexes. Baroreflex sensitivity was inhibited during behavioural tasks, with significantly greater suppression in younger than in older groups (5.28 +/- 0.52 and 2.62 +/- 0.35 ms/mmHg, respectively). Cortisol responses were greater in men than in women, but did not vary with age. Across the entire sample, systolic blood pressure responsivity was negatively related to the expression of anger. Among older men, heightened blood pressure responses were associated with elevated fasting low-density lipoprotein cholesterol levels, and with lower concentrations of high-density lipoprotein cholesterol. CONCLUSIONS: Systolic blood pressure stress responsivity increases with age in women but not in men. Other data do not support the notion that stress responsivity mediates age and gender differences in cardiovascular disease risk. However, in middle-aged men, ex-aggerated cardiovascular stress responsivity is associated with an unfavourable risk profile.

Adult↗
PubMed1995

Continuing professional education: luxury or necessity?

The author sets out to define what is meant by continuing professional education, the implications of the terminology and the contribution that it makes to nursing. She then moves on to discuss the distinction between education and learning, and the importance of 'life-long learning' to nursing. The relative merits of voluntary and compulsory education are considered and the attitudes and expectations of both nurses and their managers are examined. Obstacles to the up-take of educational opportunities are outlined, and some of the issues behind this are explored. The assessment of educational requirements and the evaluation of educational offerings are reviewed, along with the importance of assuring quality, not only in the context of proposals for postregistration education and the current market ethos in the United Kingdom, but also with regard to the potential benefits to be gained in the health care of the general public.

Education, Nursing, Continuing↗
PubMed1995

A single sleeping midnight cortisol has 100% sensitivity for the diagnosis of Cushing's syndrome.

OBJECTIVE: The diagnosis of Cushing's syndrome remains a major challenge in clinical endocrinology. Various screening tests are commonly used to support a biochemical diagnosis in the context of clinical suspicion. The aim of this study was to compare the sensitivity in the diagnosis of Cushing's syndrome of a single in-patient sleeping midnight cortisol to a standard 48-hour in-patient low-dose dexamethasone suppression test (LDDST) during the same admission. DESIGN: A retrospective analysis was performed on 150 patients investigated in our department between the years 1970 and 1994 with a confirmed diagnosis of Cushing's syndrome. PATIENTS: One hundred and fifty patients with a diagnosis of Cushing's syndrome were analysed: 110 with Cushing's disease; 12 with tumours with ectopic ACTH secretion; 8 with ACTH dependent Cushing's syndrome of so far undetermined origin; 17 with cortisol secreting adrenal tumours; 3 with adrenocortical nodular hyperplasia. Twenty normal volunteers and nine patients with non-endocrine conditions were also investigated as controls. MEASUREMENTS: Plasma cortisol was measured by radioimmunoassay (RIA) in the 122 patients presenting after 1980, and by fluorimetry prior to this date. RESULTS: In all the control subjects the sleeping midnight cortisol was < 50 nmol/l, below the lowest standard of the routine in-house RIA. In every patient with Cushing's syndrome the sleeping midnight cortisol was detectable with a value greater than 50 nmol/l, with a range of 70-2000 nmol/l. In contrast, in three cases, all of whom had proven Cushing's disease on histology, there was uncharacteristic complete suppression of plasma cortisol to < 50 nmol/l following the LDDST. CONCLUSION: In this series of 150 cases, a single in-patient sleeping midnight cortisol above 50 nmol/l had a 100% sensitivity for the diagnosis of Cushing's syndrome, clearly different from normal subjects. In contrast, the low-dose dexamethasone suppression test had a sensitivity of 98% even when the drug was administered as an in-patient. We recommend that a low-dose dexamethasone suppression test should not be used alone for confirmation of Cushing's syndrome since it may miss 2% of cases.

Adolescent↗
PubMed1995

Primary hyperaldosteronism due to an adrenal adenoma in a 14-year-old boy.

Conn's syndrome due to an adrenal adenoma is very rare in children. This paper reports a 14-year-old boy with primary hyperaldosteronism due to an adrenal adenoma. His biochemistry data were compatible with either bilateral adrenal hyperplasia or an adrenal adenoma. A dexamethasone test did not suppress aldosterone levels. Venous catheter sampling and 75Se-selenomethylcholesterol scanning suggested that the hyperaldosteronism originated at the right adrenal. Computed tomography showed an 8-mm low-density nodule in the right adrenal gland and magnetic resonance imaging confirmed the nodule which had high signal intensity on T2-weighted images consistent with a functioning adenoma. Surgery confirmed the right adrenal adenoma, and the patient was cured by right adrenalectomy. This case illustrates the difficulty of defining the aetiology of primary hyperaldosteronism and we review the biochemical and scanning techniques available to aid in diagnosis. Hypertension is unusual in children and endocrine causes are very rare, but Conn's syndrome should always be considered in the differential diagnosis.

Adenoma↗
PubMed1995

Portal vein: US-guided localization prior to transjugular intrahepatic portosystemic shunt placement.

To mark the portal vein prior to transjugular intrahepatic portosystemic shunt (TIPS) placement, metallic coils adjacent to (n = 18) and a wire within (n = 18) the portal vein were placed with ultrasonographic (US) guidance. The mean number of punctures for successful portal vein entry was 3.0 with coils and 2.9 with a wire, and the mean total procedure time was 127.5 and 110.0 minutes, respectively (differences, not significant), and mean time at US was 20 and 10 minutes, respectively.

Adult↗
PubMed1995

Diagnosis and selective cure of Cushing's disease during pregnancy by transsphenoidal surgery.

The diagnosis of Cushing's Disease during pregnancy is complex because the biochemical features are obscured by changes in the normal hypothalamo-pituitary-adrenal axis that occur during gestation. To date, treatment has not been successful and there is a high incidence of maternal and fetal complications. We report the case of a 24-year-old woman with Cushing's disease who presented during her 16th week of pregnancy. Diagnosis was confirmed by the finding of elevated serum and urinary free cortisol levels with loss of the normal circadian rhythm of serum cortisol. Cortisol levels failed to suppress after a low-dose dexamethasone test but suppressed after a high-dose test. There was an exaggerated serum cortisol and plasma adrenocorticotrophin (ACTH) response to corticotrophin-releasing hormone (CRH). Magnetic resonance (MR) scanning demonstrated a pituitary tumour and cure was effected by transsphenoidal surgery where tumour immunostaining for ACTH was removed. Postoperatively the patient made an uncomplicated recovery; serum cortisol and plasma ACTH levels were undetectable at 9 days following surgery and recovery of the hypothalamo-pituitary axis occurred at 99 days after surgery. Caesarean section was performed at 38 weeks of pregnancy and a healthy but small female infant was delivered. This case illustrates the biochemical features of Cushing's disease during pregnancy and is the first report of the use of CRH testing and MR scanning in this clinical situation. The cure by surgery and successful outcome for mother and infant, with preservation of normal anterior pituitary function, suggest that transsphenoidal surgery may be the treatment of choice.

Adrenocorticotropic Hormone↗