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Biomedical subjects

M McCall

Publications and source records attributed to M McCall.

At least 37 records · Page 2Linked to original sources
PubMed1994

An evaluation of three methods for determining colloid osmotic pressure.

Plasma colloid osmotic pressure (COP) is an important determinant in edema formation. Three methods for assessing the COP were evaluated. Direct measurement of COP using the 4420 Wescor Colloid Osmometer was compared to the estimation of COP from both serum total protein and total serum solids (TSS) determinations. Blood samples from twenty adult patients (mean age = 64 years) undergoing cardiopulmonary bypass surgery were collected for COP assessment. Sample collection was performed prior to heparinization/hemodilution, during hypothermic bypass and at the conclusion of bypass following protamine administration. The results obtained from each method were analyzed by a two-way analysis of variance. The Bonferroni technique was used for comparison of sample means when the difference was significant (p less than 0.05). Correlations were reported by linear regression analysis. A statistically significant difference (p less than 0.01) was found between the three methods. A regression equation for the estimation of COP from total serum solids is offered: COP = (3.02 * TSS) + 0.65. Prospective clinical testing between the direct COP measurement and the estimation of COP from TSS using the equation (n = 38) revealed a significant correlation (R2 = .932) and no significant difference between the two (p greater than 0.05).

Albumins↗
PubMed1994

Head-and-neck surgery.

Explore the source record for details and available documents.

Education, Nursing, Continuing↗
PubMed1992

Obstetric care and cesarean birth rates: a program to monitor quality of care.

OBJECTIVE: To study the quality of obstetric care in relation to rising cesarean rates, a Task Force was formed in New York state by the Department of Health and ACOG District II. The Task Force also included the Organization of Obstetric, Gynecologic, and Neonatal Nurses and the Hospital Association of New York State. The goals were to enhance hospitals' in-house review processes, standardize terminology, and improve the quality of care. A premise of the program was that if quality of care improved, cesarean rates would fall. METHODS: A Dictionary of Terms was developed to standardize clinical and diagnostic terminology. A two-tiered review process was instituted, using internal and external hospital reviews. A format for in-house review of obstetric care was developed and recommended to hospitals. External reviews were conducted at 24 hospitals during 1989-1990. Review teams, composed of obstetrician-gynecologists and obstetric nurses in active obstetric practice, assessed obstetric facilities, staffing, medical care, and the in-house review process. Contacts continued with the hospitals after site visits to follow up on implementation of recommendations. General recommendations to improve care, based on the overall program experience, were distributed to hospitals and physicians as part of educational efforts to improve quality of care. RESULTS: The state cesarean rate reversed. Statistics for 1989 and 1990 showed a stronger downward trend in reviewed hospitals than in non-reviewed hospitals. A survey of reviewed hospitals reported a positive response to the review process. CONCLUSION: A successful quality assurance program can be jointly developed by a state regulatory agency and a medical specialty society.

Cesarean Section↗
PubMed1988

Fetal heart rate monitoring by telephone. II. Clinical experience in four centres with a commercially produced system.

A commercially produced domiciliary fetal monitoring (DFM) system was assessed in four centres in the UK (Bristol, Glasgow, London and Nottingham) chosen to allow for comprehensive assessment in various settings in many different women. Overall, 825 recordings were made from 368 women (2.24 per woman). There were 56 unsuccessful attempts at transmission (6.8%), most were due to problems with telephone equipment. The system worked most efficiently when a dedicated direct line was used. The data transmission time varied between 40 and 60 s. The median telephone time (including data transmission and conversation) with a dedicated direct line was 7 min. Mean acceptance times from the four centres were between 70 and 80%. All recordings with acceptance times of 40% or more were interpretable. Ten recordings were abnormal. The women and mid-wives were equally proficient at using the DFM system. The DFM system represents an important addition to current methods of fetal assessment. Specific guidelines are outlined.

England↗
PubMed1985

The crystal structure of d(G-G-G-G-C-C-C-C). A model for poly(dG).poly(dC).

The structure of the DNA oligomer d(G-G-G-G-C-C-C-C) has been determined at a resolution of 2.5 A by single-crystal X-ray methods. There are two strands in the asymmetric unit, and these coil about each other to form a right-handed double-helix of the A-type with Watson-Crick hydrogen bonds between base-pairs. The helix has a shallow minor groove and a deep, water-filled major groove; almost all exposed functional groups on the DNA are hydrated, and 106 ordered solvent molecules have been found. The two d(G-G-G-G).d(C-C-C-C) segments in the octamer exhibit similar and uniform structures, but there is a slight discontinuity at the GpC step between them. A recurring feature of the structure is the overlap of adjacent guanine bases in each GpG step, with the five-membered ring of one guanine stacking on the six-membered ring of its neighbour. There is little or no overlap between adjacent cytosine rings. Conformational parameters for these GpG steps are compared with those from other single-crystal X-ray analyses. In general, GpG steps exhibit high slide, low roll and variable twist. Models for poly(dG).poly(dC) were generated by applying a simple rotation and translation to each of the unmodified d(G-G-G-G).d(C-C-C-C) units. Detailed features of these models are shown to be compatible with various assays of poly(dG).poly(dC) in solution, and are useful in understanding the polymorphic behaviour of this sequence under a variety of experimental conditions.

Chemical Phenomena↗
PubMed1984

Use of specific antibody for rapid clearance of circulating blood background from radiolabeled tumor imaging proteins.

A major problem that arises when radiolabeled serum proteins are used for tumor imaging is the presence of a large amount of circulating background activity that persists for several days. This delays imaging for at least 2 days following injection and necessitates computer subtraction of simulated background (second radiopharmaceutical injection) which introduces artifacts that are difficult to control. We propose here the injection of specific antibody immediately before imaging as an alternate way of reducing blood background through clearance of the immune complex by the liver. 111In-alkyl human transferrin and IgG were injected IV in BALB/c tumor mice, and followed in 18 h by anti-human transferrin and anti-human IgG antibody IV. Two hours later, the tumor and organ distribution of activity was compared with control mice not receiving antibody. 111In-transferrin blood activity was reduced to 1/48 of control with no decrease in tumor concentration: as a result, the tumor to blood ratio increased from 1.4:1 to 78:1. 111In-IgG blood activity was reduced to 1/17 of control, again with no decrease in tumor. The tumor to blood ratios increased from 0.7:1 to 17:1. The liver picked up most of the blood activity with none of the complex going to spleen, bone marrow, or kidney. Dog experiments showed clearance of blood was 90% complete in less than 15 min following antibody injection. Simultaneous scintillation images showed complete clearance of activity from the heart and great vessels in the chest and neck, and over the abdomen, with a concomitant increase in liver activity but no increase in spleen, kidney, or bone marrow activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

A comparison of populations self-selected and randomly selected for coronary risk factor screening.

Levels of coronary risk factors in 3,090 adults who sought screening over a 2-year period in Perth, Western Australia, were compared with those in 722 subjects who were selected at random to attend the screening center. Self-referred (SR) subjects were less likely than random-sample (RS) subjects to have suffered from, or be on treatment for, heart disease, hypertension, gout, or diabetes but were more likely to have a family history of premature heart disease. They were less likely to be current smokers and overweight (women only) but more likely to be sedentary at work and have higher mean serum cholesterol levels. SR also had more knowledge about coronary heart disease (CHD) and its causes and were more likely to believe that this knowledge had influenced their behavior, but were less likely than RS to be satisfied with their knowledge level. Smokers among SR were more likely to express a wish to give up smoking than smokers in the RS. These findings are consistent with previous observations. The differences, although statistically significant, were generally small and did not clearly favor one group with respect to total risk of CHD. Therefore the effectiveness of risk factor modification following screening should not be greatly affected by self-selection for screening. Effectiveness may be greater in self-selected subjects because of their apparently greater motivation toward risk factor change.

Adult↗
PubMed1983

Coping with the negative therapeutic response in psychosocial problems in family medicine.

Four brief case reports are presented from a series of Balint-type seminars on psychosocial problems at a university Family Medicine Centre. These cases illustrate the difficulties encountered by family practitioners when faced with a negative therapeutic response. When confronted by this outcome, it is important for the physician to define the dependency relationship which exists between himself/herself and the patient. It is often necessary to negotiate an explicit therapeutic contract. In doing so the physician should consider his own limitations of time, expertise and inclination and gather enough information to allow him to identify the focus of therapy and to consider his options for dealing with that specific focus.

Adult↗
PubMed1981

Two mutant forms of human insulin. Structural consequences of the substitution of invariant B24- or B25-phenylalanine by leucine.

In 1979 the first abnormal human insulin was discovered. With the minute samples from the patient a Phe leads to Leu replacement could be established in either position B24 or B25. For the unequivocal localization of the substitution both the Leu analogues had to be prepared by semisynthesis. While another laboratory did this with the sequence of porcine insulin, here we are dealing with the true analogues of human insulin. In the present paper the structural consequences of the substitutions are investigated. Human insulin obtained by total synthesis served as a reference. Its CD spectral properties are herewith documented. According to the substantial deviations of the CD spectrum of [Leu B24]insulin, the introduction of the new side-chain forces conformational changes to occur not only in its immediate surrounding but also in the peptide chain. The failure to give the typical CD spectral response to variations of protein and zinc concentration indicates that the ability to form quaternary structure is impaired. Though dimerization was confirmed by gel chromatography to be largely reduced, it is concluded that, in addition, interactions normally responsible for the increase in tyrosine-CD with association are weakened. [Leu B25]insulin, on the other hand, does exhibit all CD spectral effects characteristic of the native hormone, though quantitatively somewhat reduced. The CD spectroscopic results are in full agreement with the computergraphic analysis of the sterical consequences of the substitutions. For B24-leucine an acceptable packing without movements of the mainchain and/or B15-leucine and without affecting dimerization is impossible, whereas B25-leucine can be accommodated without causing bad contacts either in the monomer or in the dimer. The structural results do not explain why [Leu B25]-insulin should have a lower biological activity than the B24 analogue, 2.1 +/- 0.3% versus 20.9 +/- 2.8%, in the fat cell test. They suggest, however, an important but not critical stereospecific role for the B25-phenylalanine in binding.

Circular Dichroism↗
PubMed1980

Duration of action of beta blockers.

Three randomized, placebo-controlled, crossover experimental designs were used to define a suitable interdose interval and to study the adequacy of once-daily administration for applications in preventive trials on manifest or latent ischemic patients. Suppression of exercise tachycardia was used as the major effect variable. All measurements were made at different intervals after the last dose when the healthy subjects had been treated for at least 1 wk. Reductions of exercise tachycardia were found 24 hr after the last dose for atenolol, metoprolol, penbutolol, pindolol, propranolol, sotalol, and timolol. Penbutolol and propranolol induced equal reduction of exercise tachycardia at the end of the dose interval regardless of whether the total daily dose was given once daily or divided in 2 daily doses. Atenolol and sotalol, both with long half-lifes (t1/2s), were not superior to other beta blockers. Neither were slow-release preparations of metoprolol and propranolol markedly more effective 24 hr after the preparation than after ordinary tablets. Plasma concentration-time patterns after slow-release preparations may be important in patients with adverse experiences during peak plasma levels after conventional tablets.

Adrenergic beta-Antagonists↗
PubMed1979

Influence of a myocardial infarction on blood pressure and serum cholesterol.

Blood pressure (BP) was measured before and after acute myocardial infarction (MI) in 21 men aged 49--60 years from a random population sample. Men on drugs affecting BP before MI or during follow-up were excluded. Pre- and postinfarction cholesterol levels were analyzed in 49 men not on hyperlipidemic treatment recruited from the same population sample. The mean fall in systolic BP (SBP) was 14 mmHg both five weeks and one year after the acute event, but 10 mmHg after two years. The mean fall in diastolic BP (DBP) was 10 mmHg five weeks after the MI and remained at this level for two years. The decreases in SBP and DBP were significant. There was a positive correlation between the maximum rise in SGOT during the acute phase of MI and the decrease in DBP between preinfarction readings and readings five weeks after the MI. Serum cholesterol was unchanged three months, and one and two years after the MI as compared to the preinfarction level.

Aged↗
PubMedDate not supplied

The crystal structure of d(GGATGGGAG): an essential part of the binding site for transcription factor IIIA.

Most genes in higher organisms are activated by the binding of proteins called transcription factors. One such protein, transcription factor IIIA (TFIIIA) from the frog, activates the gene for 5S RNA by binding to the region of the gene between nucleotides 45 and 97. This binding site has been defined by a variety of biochemical studies, including base-deletion experiments and DNase I footprinting. The protein also binds to the gene product: in immature frogs it is stored as a complex with 5S RNA. From the observation that TFIIIA can bind to either double-helical DNA or RNA, and from their own measurements, Rhodes and Klug have proposed that the DNA-binding site for TFIIIA has an RNA-like structure. Here we present the crystal structure analysis of a part of the DNA-binding site (nucleotides 81-89 of the gene) which forms a particularly strong interaction with the protein, and show that it has a conformation similar to the A' form of double-helical RNA.

Base Sequence↗
PubMedDate not supplied

Use of resuscitation skills by paramedics caring for critically injured children in Oregon.

OBJECTIVES: 1) To perform a statewide analysis of the frequency of major pediatric trauma cases and the use of resuscitation skills by paramedics (EMT-Ps). 2) To determine whether EMT-Ps use resuscitation skills less frequently for injured children than for older patients. METHODS STUDY DESIGN: Retrospective, database analysis of major trauma cases. SETTING AND POPULATION: 1995 statewide trauma registry data for patients with EMT-P scene care. OBSERVATIONS: The database included patient demographics, field vital signs, field procedures [e.g., intravenous (i.v.) line placement, chest compressions, needle thoracostomy, endotracheal intubation], field medication, and vital signs at ED presentation. DATA ANALYSIS: Patients aged < or = 12 years ("pediatric") were compared with those aged > 12 years ("older"). Analyses of patients with tachycardia, hypotension, and obtundation were performed using chi 2 analysis (alpha = 0.05). RESULTS: Of 3,502 trauma patients managed by an EMT-P, only 297 (8%) were aged < or = 12 years. Fewer pediatric patients (18%) than adults (27%) had an injury severity scale score > or = 16, p < 0.005. The frequency of most resuscitation skills and the administration of medications were not statistically different between patient groups. However, i.v.s were four times more likely to be placed in adults (76%) than in pediatric patients (42%), p < 0.001. Subanalyses indicated fewer pediatric patients with tachycardia (p = 0.02) or hypotension (p = 0.02) received an i.v., compared with adults who had similar physiologic parameters. Obtunded patients were equally likely to receive endotracheal intubation, although the procedure was rarely used (20%). CONCLUSIONS: EMT-Ps infrequently manage seriously injured children. i.v.s are less frequently placed in pediatric trauma patients, even in the setting of physiologic abnormalities. The contributions of these field procedures to patient outcomes should be evaluated further.

Adolescent↗