Biomedical subjects

W Sawyer

Publications and source records attributed to W Sawyer.

25 records · Page 2Linked to original sources

PubMed1989

A prospective study comparing the haemodynamic with the cross-sectional echocardiographic diagnosis of rheumatic tricuspid stenosis.

The value of cross-sectional echocardiography in the diagnosis of tricuspid valve stenosis is not clearly established. We prospectively studied by cardiac catheterization 42 consecutive patients, with a mean age of 29 +/- 11 years, who exhibited the cross-sectional echocardiographic features of tricuspid valve stenosis, defined as: diastolic doming of all three tricuspid leaflets and leaflet thickening with restrictive motion. To expose occult and amplify borderline tricuspid diastolic gradients, simultaneous right atrial and right ventricular pressures were recorded in the basal state, after incremental infusions of normal saline to 200, 400, 500, 700 or 1000 ml until a mean right atrial pressure of 12 mmHg was achieved, and finally after intravenous administration of 0.6 mg of atropine. Eighteen patients, Group 1, (43%) exhibited mean tricuspid diastolic gradients greater than 2 mmHg after saline infusion, increasing from a mean of 4 +/- 2 to 9 +/- 3 mmHg, (P less than 0.001), 14 (33%) having gradients greater than 2 mmHg in the basal state, together with four (10%) increasing from 1.7 +/- 0.2 to 4.5 +/- 1.2 mmHg (P less than 0.01) after provocation with fluid challenge. In the remaining 24 patients, Group 2, (57%) the mean tricuspid diastolic gradient was less than 2 mmHg, both at rest and after provocative manoeuvres. We conclude that the cross-sectional echocardiographic features of tricuspid valve stenosis are not a precise indicator of tricuspid valve stenosis. Provocative manoeuvres during haemodynamic studies are required to expose occult or amplify borderline tricuspid diastolic gradients in a minority of patients with the cross-sectional echocardiographic features of tricuspid stenosis.

Adolescent↗

PubMed1985

Objective comparison of physical dysfunction after neck dissection.

Thirty-five patients who underwent a total of 44 neck dissections of various types were prospectively studied to compare differences in postoperative shoulder function. Those who underwent a radical neck dissection suffered the greatest reduction in shoulder movement and had severely abnormal electromyograms. Those who underwent modified neck dissection with preservation of the spinal accessory nerve suffered less loss of shoulder function than the radical neck dissection group, but not to a significant degree at 16 weeks; however, the electromyograms of patients who underwent modified neck dissection were significantly better than those of the radical neck dissection group, which suggests that these patients may improve with time. Indeed, a reevaluation of several patients at 1 year showed improvement in both shoulder function and electromyograms in those who underwent modified neck dissection. Patients who underwent supraomohyoid neck dissection that involved minimal dissection of the spinal accessory nerve had minimal loss of shoulder function and usually, normal electromyograms at 16 weeks that documented less injury to the spinal accessory nerve. Again, these patients had improvement with time. A correlational analysis revealed that the physical parameters correlated well with the electromyographic findings, whereas each patient's perception of disability did not. These findings suggest that, in patients in whom it is oncologically sound, a neck dissection that spares the spinal accessory nerve offers significant benefit in terms of shoulder function.

Accessory Nerve↗

PubMed1977

[1-(L-2-hydroxy-3-mercaptopropanoic acid)] analogues of arginine-vasopressin, [8-D-arginine]vasopressin, and [4-valine,8-D-arginine]vasopressin.

[1-(L-2-Hdroxy-3-mercaptopropanic acid)]arginine-vasopressin (hydroxy-AVP), [1-(L-2-hydroxy-3-mercaptopropanoic acid),8-D-arginine]vasopressin (hydroxy-DAVP), and [1-(L-2-hydroxy-3-mercaptopropanoic acid),4-valine,8-D-arginine]vasopressin (hydroxy-VDAVP) were synthesized by a combination of the solid-phase and solution methods of peptide synthesis. Protected octapeptides synthesized by the solid-phase method were further acylated by 1 + 8 couplings in solution to furnish the key intermediates. Hydroxy-AVP has antidiuretic potency of 470 units/mg and activity in the rat vasopressor assay of 550 units/mg, representing a small enhancement of activity over that of arginine-vasopressin (AVP) in each case. Hydroxy-DAVP and hydroxy-VDAVP have essentially the same high antidiuretic activity (900 units/mg) and very low vasopressor potencies (0.9 and less than 0.02 units/mg, respectively). Hydroxy-AVP, hydroxy-DAVP, and hydroxy-VDAVP thus have antidiuretic-pressor selectivity (A/P) of 1, 1000, and greater than 45 000, respectively. These data are compared with those of other vasopressin analogues. Hydroxy-VDAVP is a highly specific antidiuretic peptids and may be useful in pharmacological studies of antidiuresis.

Arginine Vasopressin↗

PubMedDate not supplied

Impact of long-term complications on quality of life in patients with type 2 diabetes not using insulin.

OBJECTIVES: The complications of diabetes have the potential to greatly impact the health-related quality of life (HRQOL) of patients with type 2 diabetes. The effect of diabetic complications on HRQOL was assessed in 1233 patients with type 2 diabetes who were not using insulin. METHODS AND DATA: Patients were aged 35 and older and had stable fasting serum glucose (FSG) after washout of antidiabetic therapy. Patients who required insulin or suffered from severe cardiovascular or hepatic disease, neuropathy, or retinopathy were excluded. Patients completed the SF-36 generic quality of life questionnaire. Demographic data, including body mass index (BMI), blood glucose hemoglobin A1c (HbA1c), FSG, and the presence and severity of eight specified diabetic complications were also collected. A linear regression analysis was performed for each of the SF-36 domains and for the physical and mental health summary scales. RESULTS: The most prevalent diabetic complications were hypertension (46% of patients), peripheral sensory neuropathy (PSN; 12%), coronary artery disease (CAD; 8%), retinopathy (8%), and peripheral vascular disease (PVD; 7%). Most (73%) of the complications were assessed to be mild. PSN was associated with significantly lower scores (i.e., worse quality of life) in the mental health scale; CAD was associated with significant reductions of all but role-emotional and mental health scales of the SF-36; and PVD was associated with significantly lower physical and social functioning scales. Hypertension did not have an independent effect on HRQOL. CONCLUSIONS: The presence of even mild diabetic complications has a significant impact on patients' quality of life. Early diagnosis and treatment is essential to help prevent deterioration of HRQOL in these patients.

Adult↗

PubMedDate not supplied

Medical high-technology assessment and implementation in a community hospital: nuclear magnetic resonance.

Health care administrators and physicians are under intense pressure from the government, industry, and the public at large to contain the escalating cost of health care. Operating margins of hospitals are averaging about 1%, and some hospitals are closing their doors. Health care providers are thus faced with the dilemma of how to bring costly high technology to a community hospital in a timely and effective manner without incurring serious financial setbacks. Despite all these pressures, we have presented several reasons why a community hospital should bring costly technology to its medical staff, and thus to its patients. We have described Kettering Medical Center's approach to this problem and our success in bringing it to the community early and cost-effectively, which has benefited the local community as well as the medical center. Our desire to be one of the "early adopters" may not work for everyone, since it requires extremely careful and perceptive evaluation of the technologic developments. It requires an intelligent, progressive, and committed board, administration, and medical staff, and it requires clever financing, such as large outside grants and help from a medical school. Such partnerships and research organizations, or liaisons with government agencies such as the Veterans Affairs system, are believed to be the keys in getting costly high technology into a community hospital. To achieve this, administration and key medical staff should constantly be on the lookout, evaluating high-technology developments. Once the hospital decides to get into a costly new high technology, it must seek alliances or partnerships with others. To identify, assess, and acquire new technology is an ongoing process.(ABSTRACT TRUNCATED AT 250 WORDS)

Cost Control↗

PubMedDate not supplied

The value and extent of valve area increase by balloon dilatation of the stenosed bioprosthesis: in vitro studies.

The value and extent in which balloon dilatation increases the valve area in severe bioprosthesis stenosis has not been defined. In-vitro double balloon dilatation, using 15 to 20 mm diameter Meditech balloon catheters, simultaneously inflated to 5 atmospheres, was attempted in 10 intact, stenosed, surgically excised bioprosthetic valves, 7 mitral and 3 aortic, size 21 to 35 mm. Radiological studies and calculation of the valve area, using a conical sizer, were performed both before and after balloon dilatation. After balloon dilatation the valve area was increased from 1.1 +/- 0.4 to 2.0 +/- 0.5 cm2 (p less than 0.001). The valve area increase was due to improved leaflet mobility in all cases. Leaflet calcium fractures were noted in 9 valves, 5 exhibited leaflet tears and the valve annulus was distorted in 3. A control group of balloon dilatation in 10 unused bioprostheses of the same sizes showed no leaflet tears. The mechanism of valve area increase, (80%), of stenotic bioprostheses by balloon dilatation, is improvement in leaflet mobility, partially secondary to leaflet calcium fractures and tears. Despite the marked increase in the bioprosthesis valve area the induction of leaflet tears will limit the clinical use of this technique for the dilatation of stenosed bioprosthetic valve.

Adolescent↗

PubMedDate not supplied

Comparison of PT, aPTT, and factor VII values obtained by concurrent sample collection by direct venipuncture and peripheral venous catheters.

STUDY OBJECTIVE: To compare prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor VII values in concurrent blood samples obtained by direct venipuncture and from a peripheral venous catheter. DESIGN: Concurrent samples obtained from catheters and by direct venipuncture were studied. In a separate crossover bioequivalence assessment of DNA-derived factor VIIa (rFVIIa) from two different batches, sample results of each technique were compared. SETTING: University hospital clinical research unit. PATIENTS: Six patients with hemophilia A under nonbleeding conditions. INTERVENTIONS: The patients received a single dose of rFVIIa 70 micrograms/kg administered by intravenous push over 2 minutes. Concurrent blood samples were collected at 2, 3, 4, 6, 8, 10, and 12 hours after rFVIIa administration. Catheter blood samples were drawn from a three-way stopcock attached to an 18-gauge peripheral venous catheter in the patient's forearm and connected to an intravenous solution of 5% dextrose with half normal saline maintained at a rate of 30 ml/hour. Venipuncture samples were drawn from the opposite arm. MEASUREMENTS AND MAIN RESULTS: The PT and aPTT values were determined by using a BBL Fibrometer (PT) and a Coagamate X-2 with automated aPTT reagent. Blood samples were analyzed for factor VII concentration using the Novo Clot assay. The mean venipuncture-obtained PT (8.9 +/- 1.0 sec) and aPTT (48.7 +/- 13.6 sec) values were numerically equivalent to mean catheter-derived PT (9.0 +/- 1.0 sec) and aPTT (48.3 +/- 12.5 sec) results, as were mean venipuncture and catheter-obtained FVII:C values. CONCLUSIONS: The PT and aPTT values determined after venipuncture and through the peripheral catheter were not statistically different (p > 0.05) when compared by paired or unpaired analysis. Similarly, values of FVII:C measured after venipuncture were statistically equivalent to those after sampling through the peripheral catheter. All six patients preferred the catheter method of blood collection over venipuncture.

Adult↗