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Biomedical subjects

S Kendall

Publications and source records attributed to S Kendall.

At least 19 recordsLinked to original sources
PubMed1997

Impact of an easy-access VA clinic-based program for patients with bipolar disorder.

OBJECTIVE: The study examined the impact of easy access to ambulatory services for patients with bipolar disorder in a clinic-based program at a Veterans Affairs medical center. Core program components included medication administration based on treatment algorithms, standardized psychoeducation, and easy access to a single primary nurse provider to enhance continuity of care. The program had no community outreach or extensive rehabilitation components. METHODS: The study used a mirror-image design to compare patients' data from the year before program entry when patients received standard clinical care with data for the first year in the program. Process and outcome data from the first 103 patients to complete one year are reported. RESULTS: The findings indicated increased patient satisfaction and increased intensity of medication treatment without increased side effects at one year. Although scheduled ambulatory clinic visits increased as expected, use of the emergency room and the psychiatric triage team decreased significantly. Patients who were high utilizers of care before program entry experienced significant reductions in psychiatric hospital days and total mental health expenditures. CONCLUSIONS: Easy access to ambulatory care, even if limited to clinic-based services, may have beneficial effects on important process and outcome measures for bipolar disorder. These effects may be attributable to on-demand access to services, continuity of care with a single primary provider, or improved medication delivery to reduce the "efficacy-effectiveness gap" for patients with bipolar disorder. Results indicate that augmenting, rather than limiting, access to ambulatory care for patients with major mental illnesses such as bipolar disorder may reduce overall mental health expenditures.

Adult↗
PubMed1995

The measurement of permeability in single rat venules using the red cell microperfusion technique.

The red cell microperfusion-micro-occlusion technique has been used to measure fluid filtration and reabsorption (Jv/A) at known microvascular pressures (Pc) in single mesenteric venules of anaesthetized rats. The relation between Jv/A and Pc is linear over the range of Pc from 15 to 50 cmH2O and its slope is the hydraulic permeability, Lp. Reproducible estimates of Lp can be made in the same venule in separate microperfusions. The value of Pc at Jv/A = 0 varies linearly with perfusate oncotic pressure and is the effective oncotic pressure of the perfusate, sigma delta pi, when the hydrostatic pressure in the pericapillary fluid is zero. The mean value for Lp (+/- S.E.M.) in forty venules was 2.43 (+/- 0.2) x 10(-7) cm s-1 cmH2O-1. Two potential errors of the micro-occlusion technique (vessel distensibility and marker red cell size) were investigated. It was found that the effects of vessel distensibility had little effect on red cell movements at times later than 2 s after a step change in Pc. Red cell size had a potentially large effect on estimates of the absolute values of Lp. Cooling the mesenteric tissues from 37 to 7 degrees C reduced Lp in proportion to the change in the reciprocal of water viscosity with temperature. Rat venular permeability was shown to be sensitive to histamine, with Lp increasing and sigma delta pi falling in a concentration-dependent fashion with histamine concentrations of 1.6 x 10(-5) to 3.3 x 10(-4) mol l-1 in the perfusate.

Animals↗
PubMed1995

Clinical experience with a collagen impregnated woven Dacron graft.

Vascular grafts continue to evolve. Recent developments have been aimed at decreasing porosity, increasing strength of prosthesis, increasing ease of handling and suturing and optimising flow characteristics. This study describes results with a recently developed collagen impregnated polyester prosthesis Hemashield Woven Double Velour, which does not require pre-clotting. Between January 1988 and December, 1991 such prostheses were used in 90 patients at Papworth Hospital. Fifty-eight, were used to replace the ascending aorta, 10 for the arch of the aorta and 28 for the descending aorta seven of whom were for coarctation and four for traumatic transections. In 60 cases the underlying disease was a dissected or ruptured aorta requiring emergency operation. There were 66 survivors with X-ray and CT follow-up of 6-52 months. Median blood loss was 630 ml range 380-1800 ml. There was no leakage from any of the grafts during surgery despite full perioperative heparinisation. For emergency/elective operations (N = 60/30) early mortality was 25%/10% (15/3) and late mortality 5%/6.6% (3/2). Of 15 patients who had interposition grafts for Type A dissection CT scans at 5-47 months showed one with chronic dissection proximal to the repair and 11 with persistent distal dissection. There was no evidence of late bleeding, seroma impaired healing or thickened neointima formation. It is concluded that there are no clinical disadvantages associated with collagen impregnation to set against the notable convenience of initial impermeability.

Adult↗
PubMed1993

Effects of hydroxyethylrutosides on the permeability of microvessels in the frog mesentery.

1. We have investigated the effects of a standardised mixture of hydroxyethylrutosides (HR, Venoruton), a mixture of five of its main components (M) and each of the five components separately (7-mono-HR, 7,4'-di-HR, 7,3',4'-tri-HR, 5,7,3',4'-tetra-HR and 7,3'4'-tri HQ) upon the permeability of single perfused capillaries and venules in the mesenteries of pithed frogs. 2. In each experiment, the hydraulic permeability (Lp) of a single perfused microvessel and the effective osmotic pressure (sigma delta pi) exerted by macromolecules across its walls were estimated by a microcclusion technique, first during control perfusion and then in the presence of a known concentration of test substance. 3. HR, M and 7,4'-di-HR reduced Lp in a similar concentration-dependent manner over the range of 1 microgram ml-1 to 1 mg ml-1 (maximum reduction was to 40% of control Lp at 1 mg ml-1). At perfusate concentrations greater than 1 mg ml-1, these substances reduced Lp to a lesser extent. While the four other test substances reduced Lp significantly when their perfusate concentrations equalled or exceeded 100 micrograms ml-1, they were all less potent than 7,4'-di-HR. 4. The reduction in Lp induced by the mixture of flavonoids was only slightly reversed by subsequent perfusion with flavonoid-free solutions. 5. When permeability was increased by perfusing with protein-free solutions, both HR and 7,4'-di-HR reduced and then reversed the increase in Lp in a concentration-dependent manner over the range of 1 microgram ml-1 to 100 micrograms ml-1. None of the other component flavonoids was effective in restoring Lp under these conditions.

Animals↗
PubMed1993

Complement activation during CAPD.

Complement activation was monitored in 20 CAPD patients and 20 normal individuals using markers of the alternative (Bb fragment), classical (C4d fragment), common (iC3b) and terminal pathways (SC5b-9, the soluble form of the membrane attack complex, MAC), together with C3, C4 and factor B. CAPD plasma SC5b-9 was higher than normal although this was not due to increased complement activation in the plasma. The calculated cleavage for C3, C4 and factor B to iC3b, C4d and Bb respectively, due to spontaneous activation, was similar in both groups. C3, C4 and factor B in dialysate were less than 1% of plasma concentration, consistent with vascular leakage, whereas iC3b, Bb and SC5b-9 were at higher concentrations, suggesting generation in the peritoneum by the alternative pathway. 2.4% C4d is consistent with leakage of this small molecule but may indicate slight classical activation. It is concluded that complement activation occurs in the peritoneum during CAPD. MAC and the anaphylatoxins which are also generated may contribute to an increased risk of infection and other inflammatory complications.

Blood↗
PubMed1991

A peripherally implanted permanent central venous access device.

Totally implanted central venous access devices provide reliable delivery of repetitive chemotherapy courses. However, placement of these ports requires special expertise and facilities, and is not without risk of major complications. This paper reports the technique of placing a new peripherally accessed, totally implantable, central venous port in 22 patients for the repeated administration of systemic chemotherapy. All ports were successfully placed under local anesthesia, with catheter tip location determined by an electronic sensor wand. The ports have been in use for a total of 387 patient-weeks. One port required removal secondary to an infection at the port site. Twenty-one ports have remained functional for infusion and blood sampling through 99 courses of chemotherapy. Acceptance by patients, nurses, and physicians has been excellent.

Antineoplastic Agents↗
PubMed1990

Helping people to stop smoking: a study of the nurse's role.

Sixteen trained nurses from various clinical backgrounds participated in a project designed to describe the process and assess the outcome of their attempts to help a range of patients and clients to stop smoking. A case-study approach was employed and the nurses initiated 68 health education interventions related to smoking cessation. All interventions were tape-recorded and data on patients' and clients' characteristics, smoking history, health beliefs and motivation to give up smoking were also collected. Forty-two patients were followed up 1 year post-intervention. Data collected at this time revealed that 17% had successfully given up smoking, while a further 12% had substantially reduced their cigarette consumption. These findings compare very favourably with those of previous studies in which general practitioners have attempted to help patients stop smoking. The results of the research reported here therefore suggest that nurses have enormous potential for fulfilling a highly effective health education function.

Attitude to Health↗
PubMed1990

Longitudinal study of proteins in plasma and dialysate during continuous ambulatory peritoneal dialysis (CAPD).

The aim was to evaluate plasma proteins during continuous ambulatory peritoneal dialysis (CAPD) in relation to dialysis losses, membrane permeability, renal insufficiency, and time on CAPD. Ten male patients, established on CAPD for at least 14 months, were studied every 8 weeks for 56 weeks. Blood and dialysate from the morning exchange were analysed for urea, creatinine, and 7 proteins, and used to calculate dialysate to plasma concentration ratios (D/P). These ratios were not significantly changed suggesting that permeability remained constant. However, there was a trend for beta 2-microglobulin, creatinine, and urea to increase progressively. After 56 weeks, beta 2-microglobulin had increased from 27.9 to 31.3 mg/L (p less than 0.05) and creatinine 1006 to 1099 mumoL/L (p less than 0.05) and both correlated with time on CAPD (p less than 0.001). Plasma alpha 1-acid glycoprotein, albumin, transferrin, IgG, IgA, and complement C3 were not significantly changed, although IgA and complement C3 were each negatively correlated with time on CAPD (r = -0.70 and -0.67, respectively), creatinine (r = 0.51 and -0.54), and urea (r = -0.61 and -0.61) (p less than 0.001 for all). It is concluded that increases in beta 2-microglobulin, creatinine, and urea are not due to loss of membrane permeability but reflect a slight increase in uraemia. Long-term decreases in immunological proteins may be caused by uraemia or progressive depletion.

Adult↗
PubMed1989

A longitudinal study of the effects of amino acid-based CAPD fluid on amino acid retention and protein losses.

During the evaluation of 1% amino acid solution as an alternative osmotic agent to glucose, we measured amino acids and proteins in dialysate, urine and plasma to evaluate the uptake of amino acids and their effects on membrane permeability. Eight patients (plasma albumin less than 35 g/l) were on 21 exchanges of glucose fluid for 4 weeks before and after 12 weeks, during which a solution of 15 amino acids (Baxter '151') was used for the morning exchange. The absorption of amino acids from the single daily '151' exchange increased during the study: 16.4 g at 4 weeks and 17.1 g after 12 weeks (P less than 0.01) with increases in eight amino acids. Amino acid uptake was related to the permeability characteristics of the patients. Following each '151' exchange, 1% of the amino acids absorbed were dialysed into subsequent glucose exchanges. Consequently the net daily gain was 15.0 g increasing to 15.6 g, whereas daily depletion during glucose exchanges was 1.8 g both before and after '151'. Clearance of five proteins increased both at the start and after 12 weeks of '151'. Total protein and prealbumin loss into dialysate increased by about 20%, and when glucose was restored loss of transferrin, albumin and immunoglobulin G decreased. Urinary concentrations were similar throughout. Amino acid uptake from '151' greatly exceeded all losses although our results suggest small reversible increases in macromolecular permeability of the peritoneum.

Absorption↗
PubMed1986

Structure of proteoheparan sulfates from fibroblasts. Confluent and proliferating fibroblasts produce at least three types of proteoheparan sulfates with functionally different core proteins.

[3H]Leucine- and [35S]sulfate-labeled proteoheparan sulfates were isolated from postconfluent or proliferating cultures of human skin fibroblasts. Cell layers were solubilized by Triton X-100, and transferrin-binding macromolecules were isolated by affinity chromatography. Proteoglycans with no affinity for transferrin were purified by using ion-exchange and gel permeation chromatography. Postconfluent cells synthesize a proteoheparan sulfate of Mr 350,000 (as determined by gel permeation chromatography) which has affinity for transferrin as well as for octyl-Sepharose. Its core protein (Mr 180,000) consists of two disulfide-bonded polypeptides of Mr 90,000. This species was not detected in cultures of proliferating cells. Proliferating and confluent cells also synthesize other forms of proteoheparan sulfates (Mr 200,000-400,000) which have no affinity for transferrin. However, most of them have affinity for octyl-Sepharose. The core protein of proteoheparan sulfates made by proliferating cells has Mr 50,000. A smaller form (Mr 250,000) of this proteoglycan was solubilized by Triton X-100, whereas a larger form (Mr 400,000) remained associated with the pericellular matrix. A third type of proteoheparan sulfate (Mr 200,000) without affinity for transferrin nor octyl-Sepharose was associated with postconfluent cell layers but not with proliferating ones. Its core protein has Mr 35,000. Heparan sulfate oligosaccharides (Mr 6,000 or higher) were found in proliferating cells but not in postconfluent ones.

Cell Division↗