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Biomedical subjects

S Crane

Publications and source records attributed to S Crane.

At least 37 records · Page 2Linked to original sources

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↗

Antithrombin III (ATIII) activity in plasmas from normal and diseased horses, and in normal canine, bovine and human plasmas.

Plasma Antithrombin III (ATIII) activity was quantitated in 24 clinically normal Standardbred/Thoroughbred horses using a clotting time technique. ATIII activity ranged from 80 to 106% of the pooled reference standard plasma, with a mean of 94%. Horses presenting with impaction or spasmotic colic (n=17) had normal plasma ATIII activity, while 15 horses presenting with acute diarrhea/colitis had significantly lower plasma ATIII activity with a mean of only 74% of the reference plasma. Seven horses presenting with liver disease had significantly higher plasma ATIII activity with a range of 127 to 177% of the pooled reference plasma. Fifty-seven equine plasmas were retested using a rapid chromogenic substrate technique for quantitating plasma ATIII activity. A good correlation (r =+0.83) existed between clotting time and chromogenic determinations of ATIII. Pooled normal canine, human and bovine plasmas had only 65, 62 and 79%, respectively, of the ATIII activity of the equine reference plasma.

Journal Article↗

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↗

The effects of desmopressin on plasma factor VIII/von Willebrand factor activity in dogs with von Willebrand's disease.

Eight unanesthetized normal dogs and seven dogs with von Willebrand's disease (vWD) were given desmopressin (0.6 micrograms/kg, IV) in order to determine the effects of this drug on plasma Factor VIII/vWF activity. Seven of the normal dogs and four of the vWD dogs were administered an equal volume of saline (control infusion) on another occasion. The other three vWD dogs underwent major surgery after treatment with desmopressin. Plasma FVIII coagulant activity (FVIII:C), von Willebrand factor antigen (vWF:Ag), and FVIII-ristocetin co-factor activity (FVIII:RC) were quantitated before infusion and at 60 minutes postinfusion. Activities were expressed as a percentage of the activity of a pooled canine plasma (12 dogs) arbitrarily designated as having 100% FVIII:C, vWF:Ag, and FVIII:RC activity. Plasma FVIII:C activity increased by 28% in the normal dogs and by 37% in the dogs with vWD. Plasma vWF:Ag increased more than twofold in normal dogs after desmopressin treatment. In the vWD dogs the average increase was also twofold, however there was much greater variability between dogs with increases ranging from 1.2 fold to 2.4 fold. Plasma FVIII:RC activity almost doubled in normal dogs, however like vWF:Ag, the increases in vWD dogs were more variable. One vWD dog had no increase in FVIII:RC while in the remaining six dogs FVIII:RC increases ranged from 1.8 to 2.9 fold. The results of this study indicate that a single intravenous dose of desmopressin (0.6 micrograms/kg) causes a significant elevation in plasma vWF:Ag and FVIII:RC activity and a much lesser increase in FVIII:C activity in normal unanesthetized dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Mnemonic correlates of unit activity in the hippocampus.

The role of the hippocampus in memory processing was examined by recording single unit activity while rats performed two different types of memory tasks. The same apparatus was used for all tasks; it consisted of two goal boxes, side by side, on the end of a runway. One goal box was white, the other was black. Experiment I used a working memory, delayed match-to-sample (DMTS) task. A trial began with a sample phase in which the rat was forced to a goal box containing a reward. The rat was then placed at the beginning of the runway again for the choice phase and allowed to enter either of the two goal boxes. Entering the goal box with the same color as that entered during the sample phase was rewarded. Experiment II used a within-subjects, within-units, design to test rats in two reference memory tasks, a cue task and a spatial task. During the cue task, the rat was rewarded for choosing the same colored goal box on each trial regardless of its spatial location. During the spatial task, the rat was rewarded for choosing the goal box in a specific location on each trial regardless of its color. During all tasks, the location of the goal boxes was changed between trials in a pseudorandom, counterbalanced fashion so that each colored goal box was on the right for half of the trials and on the left for half of the trials. During performance of the DMTS task, activity of most units was correlated with a combination of factors such as color and location, or color and phase. For example, most units showing differential activity in one of the colored goal boxes fired more when that box was in a certain spatial location, or during either the sample or choice phase. During performance of the reference memory tasks, the activity of most units was not correlated with behavior. However, the rate for some units changed between the cue and spatial tasks. When unit activity was correlated with behavior, it was dependent on a combination of dimensions such as color and spatial location. These results demonstrate that units in the hippocampus respond to combinations of stimulus dimensions such as color and spatial location, and to the temporal context necessary to solve a working memory task.

Animals↗

Haemostatic abnormalities in horses with colic--their prognostic value.

The incidence and nature of coagulation abnormalities in horses presented with colic and the possible prognostic value of these abnormalities was investigated. A coagulogram was performed on each of 24 adult Thoroughbred or Standardbred horses. A coagulogram consisted of measurements of eight parameters; platelet count, plasma fibrinogen, plasma antithrombin III (AT), partial thromboplastin time (PTT), prothrombin time (PT), thrombin clotting time (TCT), soluble fibrin monomer (SFM) and fibrin-fibrinogen degradation products (FDP). Retrospective determination of the cause of the colic and outcome (survival vs non-survival) was carried out. All patients examined had at least one abnormal parameter with the frequency being: Increased SFM 67 per cent; prolonged PTT 63 per cent; prolonged TCT 50 per cent; elevated plasma fibrinogen 46 per cent; reduced platelet count 29 per cent; reduced plasma AT 29 per cent; prolonged PT 25 per cent; and elevated serum FDP 21 per cent. When survivor and non-survivor groups were compared there was little difference in the frequency of abnormalities such as elevated SFM, elevated fibrinogen and prolonged PTT. The abnormalities which had the greatest frequency difference between non-survivors and survivors, and therefore the greatest prognostic value, were decreased AT greater than prolonged TCT = prolonged PT greater than elevated FDP greater than reduced platelet count. The frequency of these abnormalities in non-survivors compared to survivors was 8.6:1, 7.1:1, 5.7:1 and 3.6:1, respectively. The average number of abnormal parameters in non-survivors (five) was significantly greater than in survivors (two).

Animals↗

The effects of desmopressin on hemostatic parameters in the normal dog.

Seven normal unanesthetized dogs were infused with desmopressin in saline (doses 0.2, 0.4 and 0.6 micrograms/kg i.v.) or saline alone, on separate occasions in order to determine the effects of desmopressin on circulating factor VIII coagulant and factor VIII-related antigen activities, on partial thromboplastin times and prothrombin times, on blood platelet count and packed cell volume, and on serum osmolarity. Desmopressin caused a rapid dose-dependent elevation in both factor VIII activities peaking at 30-60 minutes postinfusion. At a dosage of 0.6 microgram/kg desmopressin induced rises in factor VIII coagulant activity and factor VIII-related antigen of 150% and 198% of the preinfusion levels respectively, while the half disappearance times were approximately five and six hours respectively. The other parameters were not significantly affected by even the highest dose of desmopressin used. These results indicate that normal dogs respond to desmopressin in a manner similar to man. The major differences are in the dosage required to produce comparable effects (higher in dogs), and in the fact that the factor VIII-related antigen activity consistently responds to a greater degree than the coagulant activity. It is concluded that desmopressin may have particular value in stimulating elevations in plasma factor VIII-related antigen in dogs deficient in this plasma protein. Six dogs were pretreated with the endorphin inhibitor, naloxone, (0.04 mg/kg I.V.) or sterile saline, three minutes prior to infusion with desmopressin at a dose of 0.6 microgram/kg i.v.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Hemostatic abnormalities in equine colic.

Hemostatic profiles were determined in 30 horses with clinical colic. Blood samples were obtained at the time of the animal's admission, and the following hemostatic tests were done: blood platelet count, plasma fibrinogen, plasma antithrombin, prothrombin time, partial thromboplastin time, thrombin time, protamine sulfate test for soluble fibrin monomer, and fibrin-fibrinogen degradation products. The patients were categorized in retrospect, according to the cause of the colic: group 1--colic associated with colitis and/or severe diarrhea, group 2--colic associated with torsion or obstruction of the intestine, and group 3--colic associated with impaction of the intestine or the presence of enteroliths. Of the 30 horses with colic, 28 had at least 1 abnormality in their coagulogram--the most frequent abnormalities being high plasma fibrinogen concentration, high circulating soluble fibrin monomer, or a long partial thromboplastin time or thrombin time. The horses in group 1 seemed to have the most severe coagulopathies, as indicated by the average number of demonstrable abnormalities. The horses in group 3 showed the fewest abnormalities--usually a high plasma concentrations of fibrinogen and/or soluble fibrin monomer. The results indicated that hemostatic abnormalities are not uncommon in horses with gastrointestinal disease and colic--the degree of severity depending to some extent on the cause of the colic.

Animals↗