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Biomedical subjects

S Crane

Publications and source records attributed to S Crane.

At least 19 recordsLinked to original sources

Un-cross-linked fibrin substrates inhibit keratinocyte spreading and replication: correction with fibronectin and factor XIII cross-linking.

Wound repair is characterized by the presence of a fibrin-rich matrix, but the effect of fibrin on re-epithelialization remains unclear. In this study, we determined the effects of different fibrin matrices on cultured human neonatal keratinocytes. Using purified fibrinogen and fibrin gels generated by the enzymatic action of thrombin, batroxobin (it leads to retention of fibrinopeptide B), or Agkistrodon contortrix thrombin-like enzyme (ACTE; it leads to retention of fibrinopeptide A), we determined the effect of each of these matrices on keratinocyte morphology, attachment, spreading, and replication as compared to tissue culture plastic. Morphologically, keratinocytes seeded on fibrin surfaces were more rounded and formed three-dimensional structures. Specific cell attachment, as measured at either 37 degrees C or 4 degrees C, was not altered on the different fibrin substrates (P > .05) but was increased on fibrinogen and factor XIII cross-linked fibrin (P < .01). However, keratinocytes seeded on fibrin, regardless of the presence or absence of fibrinopeptides A or B, showed a marked decrease (up to 71%) in cell numbers by days 5 (P = .0357) and 10 (P = .0114). Keratinocyte spreading was decreased by 78.8% (P = .0006), 80.3% (P = .0001), and 89.2% (P = .0001) on thrombin-, batroxobin-, and ACTE-generated fibrin, respectively, but not on fibrinogen-coated dishes. However, either the addition of fibronectin or cross-linking of fibrin with factor XIII allowed full keratinocyte spreading to occur (P = .0002 and P = .0013, respectively). We conclude that fibrin inhibits keratinocyte spreading in the absence of other matrix or plasma proteins or cross-linking by factor XIII.

Cell Adhesion

Influences on nursing care volume.

This study explores influences on nursing care volume per case in four DRGs and five hospitals. After accounting for the effects of length of stay, patient characteristics, and severity of illness, the direct effect of factors describing the nursing staff and hospital was assessed. Skill mix and standing orders each were significant in one or more DRGs, but there was no significant association between the volume of nursing care and occupancy or staff availability. The management and research implications of the findings are discussed.

Adolescent

Preparing for Post-Registration Education and Practice (PREP): the support role of the library.

A survey of 5% of trained nursing staff in the Plymouth area provided indications of the impact of changes in post-registration education and practice on the library service of the Tor & South West College of Health in Plymouth. The survey comprised, first, a structured interview to obtain details of professional development plans and preferences, number of courses attended recently, learning styles, use made of ward/unit resources (particularly journals) and optimum periods for library opening. The second part of the survey was a vignette information problem. The responses (written by the participants) provided an indication of information-seeking skills and perceptions of various information sources, both formal (publications) and informal (colleagues and organizations). Analysis indicated that the most popular method of learning was attending a study day, and the most popular combination of learning styles was study day combined with further reading. Reading or journals was selective. Most staff would have to rely on a library for journal literature, particularly the new journals. One third of the sample appeared lacking in information-seeking skills. One third appeared confident in information-seeking skills, and this group was associated with the use of more than two sources of information and use of a library. No single library in Plymouth would be adequate for the sources of information required, indicating the need for better networking and/or integration.

Education, Nursing, Continuing

Child sexual abuse: evaluation and treatment.

Child sexual abuse and its disturbingly high prevalence have received increased attention during the past 2 decades, but the availability of adequate training and support services for this complex problem remain deficient. The identification of victims and early, effective intervention are necessary goals. This review provides a brief summary on the subject of child sexual abuse with an emphasis on recent progress in optimal evaluation.

Child

Treatment of obstetrical hemorrhagic emergencies.

The common hemorrhagic complications of pregnancy remain among the leading causes of maternal mortality. We review new methods of diagnosis and offer suggestions for management. Abruptio placenta, disseminated intravascular coagulation, placenta previa, uterine rupture, and postpartum hemorrhage are included in this review.

Abruptio Placentae

Effect of oatbran on mild hyperlipidaemia.

OBJECTIVE: To determine whether adding 60 g oatbran per day to a low saturated fat, low cholesterol diet has any additional effect of lowering serum lipids. DESIGN: A double blind, prospective, randomised, placebo controlled crossover study. SETTING: Lipid clinic in a teaching hospital. SUBJECTS: Thirty-seven subjects (16 men, 21 women) with serum cholesterol of 5.5-8.0 mmol/L were recruited from staff and medical clinics. All subjects were aware of their hyperlipidaemia and no subject was previously treated with lipid lowering agents. INTERVENTIONS: After an eight-week diet period subjects were randomised to receive two muffins per day containing either 60 g of oatbran or the equivalent amount of fibre from wheatbran in a double blind crossover study. MAIN OUTCOME MEASURES: Measurement of lipids, lipoproteins and biochemical parameters at the end of each eight-week period. RESULTS: Mean serum lipid levels at the end of the oatbran and wheatbran periods were significantly different from each other only for low density lipoprotein (LDL) cholesterol (oatbran, 4.67 mmol/L; SD, 0.85; and wheatbran, 4.95 mmol/L; SD, 0.81; P < 0.01), the LDL/HDL (high density lipoprotein) ratio (oatbran, 3.68; SD, 1.25; and wheatbran, 4.01; SD, 1.25; P < 0.001) and apoprotein B (oatbran, 1.03 g/L; SD, 0.21; and wheatbran, 1.08 g/L; SD, 0.19; P < 0.05). CONCLUSION: Oatbran fibre is more effective than wheatbran fibre in lowering cholesterol in subjects with mild hyperlipidaemia who are already on a low saturated fat, low cholesterol diet.

Adult

Quantitation of canine plasma von Willebrand factor antigen using a commercial enzyme-linked immunosorbent assay.

The purpose of this study was to evaluate a commercial enzyme-linked immunosorbent assay (ELISA) for human von Willebrand factor antigen (vWF:Ag) with respect to its potential value in quantitating the protein in canine plasma. The assay was a sandwich technique using F(ab')2 fragments specific for von Willebrand factor (vWF) and a peroxidase conjugated rabbit anti-vWF second antibody, with a microplate as the support surface. Canine plasmas were assayed by ELISA, and by Laurell electroimmunoassay (EIA), our reference methodology. The ELISA had a within-day variation of 1.21-4.44% and a between-day variation of 0.85-4.88% depending on the level of vWF:Ag. The sensitivity of the assay was less than 0.1% vWF:Ag. The range of vWF:Ag concentrations in plasmas from 24 clinically normal dogs compared favorably with the range for the same plasmas when assayed by EIA (ELISA = 60-152% of normal; EIA = 50-142% of normal). In 121 canine plasmas with vWF:Ag concentrations (as assessed by EIA) ranging from undetectable levels (less than 6% of normal) to 142% of normal, there was good correlation with measurements made by ELISA (correlation coefficient = 0.835). It was concluded that this commercial ELISA technique could be used to provide reliable, same-day measurements of canine plasma vWF:Ag. Since it requires no special equipment other than a microplate reader and washer it is particularly suitable for laboratories lacking the electrophoretic expertise or equipment required for EIA.

Animals

Hemostatic studies in racing standardbred horses with exercise-induced pulmonary hemorrhage. Hemostatic parameters at rest and after moderate exercise.

The purpose of this study was to determine whether a defect in hemostasis might be a factor in the etiology of exercise-induced pulmonary hemorrhage (EIPH). Hemostatic parameters were evaluated in 22 EIPH-positive and ten EIPH-negative racing horses while in a rested state. Nineteen EIPH-positive and ten EIPH-negative horses were further evaluated just before and immediately after a 15 min exercise period on a 260 m oval track. When EIPH-positive and EIPH-negative horses were compared at rest, there was no significant difference in any of the coagulation and fibrinolytic parameters studied. There was however, a significant difference in platelet function as assessed by aggregometry. The platelets from affected horses were significantly less responsive than those from nonaffected horses when exposed in vitro to the platelet agonists adenosine diphosphate, collagen and platelet activating factor. Exercise tended to increase the packed cell volume and factor VIII/von Willebrand factor and to decrease platelet aggregation responses to low concentrations of adenosine diphosphate. These effects of exercise however were quantitatively similar in both EIPH-positive and EIPH-negative horses. Reduced platelet function may therefore be a contributing factor in the bleeding characteristic of horses with EIPH.

Adenosine Diphosphate

First year medical students' attitudes and knowledge about AIDS.

Medical students attitudes and resulting behaviors about treating HIV-infected patients are critical and will become increasingly so in the years ahead. An anonymous self-administered questionnaire of 135 first year medical students at Boston University School of Medicine conducted in May 1988 queried students' knowledge of HIV transmission; concerns about contracting HIV; ethical and legal responsibilities; attitudes about testing for HIV and treatment of HIV-infected patients; the effect the epidemic poses for their medical careers; changes in personal sexual and drug use practices. Results indicate that students' careers are being affected because they are worried about contracting HIV, that the epidemic will affect their final choice of specialty, and that they believe they should be allowed to refuse to treat AIDS patients during their medical school training. The findings raise serious questions concerning why medical students hold these beliefs and suggest that students' willingness to care for AIDS patients may be a function of their level of knowledge and understanding of HIV infection and the disease AIDS. The results have implications for curriculum reform to address the AIDS crisis.

Acquired Immunodeficiency Syndrome

Breed, age, and gender differences in plasma antithrombin-III activity in clinically normal young horses.

Plasma antithrombin-III activity was quantitated in plasma samples obtained from 165 clinically normal horses 3 years old or younger. In the horses as a group, antithrombin-III activity ranged from 63 to 131% of a species-specific reference plasma. Thoroughbred horses had significantly higher antithrombin-III activity (103.3 +/- 18.3; mean +/- SD) than did Standardbred horses (92.3 +/- 14.2). The plasma antithrombin-III activities were significantly lower in horses younger than 16 months old when compared with those in more mature horses (3 years old). There was no statistically significant gender-related effect on plasma antithrombin-III activity. Breed and age factors should therefore be taken into consideration when interpreting plasma antithrombin-III activity in horses.

Age Factors

Failure of sodium pentobarbital anesthesia to alter 1-desamino-8-D-arginine vasopressin-induced elevations of plasma factor VIII/ von Willebrand factor in normal dogs.

The vasopressin analog 1-desamino-8-D-arginine stimulates elevations in plasma Factor VIII/ von Willebrand factor in normal dogs. In order to study the effects of general anesthesia on this response, six dogs were anesthetized with sodium pentobarbital or given an equivalent amount of saline then challenged with an intravenous dose of 1-desamino-8-D-arginine (0.6 micrograms/kg body weight). Factor VIII coagulant activity, von Willebrand factor antigen, and ristocetin cofactor activity were quantitated before anesthesia (or saline infusion), 20 min after induction (pre-1-desamino-8-D-arginine), and at 30 and 60 min post-1-desamino-8-D-arginine. Anesthesia did not significantly affect the elevations in plasma Factor VIII/ von Willebrand factor induced by 1-desamino-8-D-arginine. Sodium pentobarbital appeared however to prevent the rise in Factor VIII coagulant activity seen following saline treatment. The results of this study suggest that when 1-desamino-8-D-arginine is to be used in normal dogs to boost basal plasma von Willebrand factor levels, it is not necessary to administer it prior to induction of general anesthesia with sodium pentobarbital.

Anesthesia, Intravenous

Identification of chromaffin granule-binding proteins. Relationship of the chromobindins to calelectrin, synhibin, and the tyrosine kinase substrates p35 and p36.

At least 23 soluble proteins (chromobindins) bind to chromaffin granule membranes in the presence of Ca2+. In order to further the identification of the chromobindins and to determine the roles they may play in exocytosis or other aspects of chromaffin cell biology, several of these proteins were compared to other known membrane-binding proteins. Chromobindin 4 was identified as a 32-kDa protein called calelectrin or endonexin. Immunologically related proteins were detected in bovine brain and human platelets. Chromobindin 20 was identified as a 67-kDa variant of calelectrin and was found to have the activities of the synexin inhibitory protein, synhibin. Chromobindin 8 was identified as p36, a substrate for the tyrosine-specific kinase, pp60v-src. Chromobindin 8 was also demonstrated to undergo phosphorylation predominantly on alkali-sensitive sites during stimulation of the chromaffin cell with 20 microM nicotine. Chromobindin 6 was identified as p35, a substrate for the tyrosine kinase activity associated with the epidermal growth factor receptor. Chromobindin 9, which is known to be a substrate for protein kinase C (Ca2+/phospholipid-dependent enzyme), was found to be immunologically related to p35 and may be a precursor of chromobindin 6. The identification of these proteins from the chromaffin system may be useful in the characterization of similar, complex groups of membrane-binding proteins that have been observed in other systems.

Amino Acids

Feeding the handicapped child--a review of intervention strategies.

Feeding the handicapped child occurs three or four times per day, every day of the year, despite the child's feeding problems and, in the vast majority of cases, without life threatening consequences. Yet the need for adequate feeding therapy for these children is becoming increasingly recognised. This paper seeks to explore why intervention is so important. The complex causes of feeding problems will be reviewed briefly followed by a discussion of the reasons for intervention. Feeding therapy techniques, strategies and approaches will be reviewed with the need for parent involvement, early intervention and a 'feeding-team' being stressed throughout. This paper highlights the need for intervention in feeding problems, whether or not they are life threatening, particularly in view of their effect upon quality of life of both the child and his family.

Child