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Biomedical subjects

S D Jones

Publications and source records attributed to S D Jones.

At least 37 records · Page 2Linked to original sources
PubMed1996

Adenosine effectively controls pulmonary hypertension after cardiac operations.

BACKGROUND: Pulmonary hypertension secondary to increased pulmonary vascular resistance may greatly complicate the perioperative management of patients having cardiac operations. Adenosine may have a therapeutic role as a selective pulmonary vasodilator. The purpose of this study was to examine the pulmonary hemodynamic effects of a central venous infusion of adenosine in cardiac operative patients with pulmonary hypertension. METHODS: Ten cardiac patients with pulmonary hypertension (age, 62 +/- 6 years) were studied in the operating room under general anesthesia after weaning from cardiopulmonary bypass. Cardiac output, pulmonary vascular resistance, systemic vascular resistance, mean pulmonary arterial pressure, and mean systemic arterial pressure were determined before, during, and after central venous infusion of adenosine (50 micrograms x kg-1 x min -1) for 15 minutes. Statistical analysis was by analysis of variance, and significance was accepted at p < 0.05. RESULTS: Adenosine produced significant pulmonary vasodilation. Mean pulmonary arterial pressure was lowered from 36 +/- 1 to 28 +/- 2 mm Hg (p < 0.05), and pulmonary vascular resistance was lowered from 560 +/- 30 to 260 +/- 30 dynes x s x cm-5 (p < 0.05) during adenosine administration. At the same time, cardiac output rose from 4.0 +/- 0.6 to 6.2 L/min (p < 0.05). Pulmonary vascular resistance, mean pulmonary arterial pressure, and cardiac output returned to baseline after the adenosine infusion was stopped. There was no change in systemic mean arterial pressure during adenosine infusion. CONCLUSIONS: Adenosine may be used clinically as a selective pulmonary vasodilating agent to optimize pulmonary hemodynamic indices without adverse systemic hemodynamic effects in patients with pulmonary hypertension having cardiac operations. It may be particularly valuable in patients with right heart dysfunction by selectively lowering right ventricular afterload.

Adenosine↗
PubMed1996

Effective control of pulmonary vascular resistance with inhaled nitric oxide after cardiac operation.

Increased pulmonary vascular resistance may greatly complicate the perioperative management of cardiac surgical patients. Inhaled nitric oxide may be a promising new therapy to selectively lower pulmonary vascular resistance. The purpose of this study was to examine the effects of inhaled nitric oxide on pulmonary and systemic hemodynamics in cardiac surgical patients. Twenty patients (age 57 +/- 6 years) were studied in the operating room after weaning from cardiopulmonary bypass. Mean pulmonary artery pressure, pulmonary vascular resistance, systemic vascular resistance, and mean aortic pressure were determined at four points of data collection: before nitric oxide, with 20 ppm nitric oxide, with 40 ppm nitric oxide, and after nitric oxide. Statistical analysis was by analysis of variance; significance was accepted for p < 0.05. Inhaled nitric oxide produced selective pulmonary vasorelaxation. Pulmonary vascular resistance was lowered from 343 +/- 30 before nitric oxide to 233 +/- 25 dynes.sec-1.cm-5 with 20 ppm nitric oxide. Pulmonary vascular resistance was not further lowered by 40 ppm nitric oxide (p < 0.05). Mean pulmonary arterial pressure was 29 +/- 1 mm Hg before nitric oxide and was lowered to 22 +/- 1 mm Hg by 20 ppm nitric oxide and 21 +/- 1 mm Hg by 40 ppm nitric oxide (p < 0.05). Both pulmonary vascular resistance and mean pulmonary arterial pressure returned to baseline after withdrawal of inhaled nitric oxide. Inhaled nitric oxide produced no changes in either systemic vascular resistance or mean aortic pressure. We conclude that nitric oxide may be used as an effective pulmonary vasodilator after cardiac operations. It may be particularly valuable for selectively lowering right ventricular afterload in patients with right ventricular dysfunction.

Administration, Inhalation↗
PubMed1996

The Bath Ankylosing Spondylitis Patient Global Score (BAS-G).

In the absence of an ideal objective measure for assessing ankylosing spondylitis (AS), self-administered measures of disease activity (the Bath Ankylosing Spondylitis Disease Activity Index, BASDAI) and function (the Bath Ankylosing Spondylitis Functional Index, BASFI) have been developed, in addition to an objective measure of spinal mobility (the Bath Ankylosing Spondylitis Metrology Index, BASMI). However, a more global assessment is also desirable. We report on the design and validation of a global measure (the Bath Ankylosing Spondylitis Patient Global Score, BAS-G) which reflects the effect of AS on the patient's well-being. A pilot study was performed to select the most appropriate wording for BAS-G. Using 392 patients with AS, BAS-G's construct and predictive validity and test-retest reliability were assessed. Correlations between BAS-G and BASDAI/BASFI were calculated, and multiple regression was used to examine the significant correlates. The distribution of the responses covered the whole scale. As predicted, BAS-G correlated best with BASDAI (r=0.73), followed by BASFI (r=0.54). The best fitting regression equation included these scales as well as patients' gender and current age. One week and 6 month scores were significantly different (P<0.001). Construct validity was good: BAS-G correlated more strongly with each component of BASDAI and BASFI than with BASMI or with gender. Predictive validity was satisfactory: there was an improvement (mean=29%) in in-patient BAS-G scores over a 2 week treatment period (P<0.001). Test-retest reliability was excellent (1 week r=0.84, 6 months r=0.93). BAS-G correlates well with both BASDAI and BASFI, suggesting that disease activity and functional ability play a major role in patients' well-being, whereas metrology does not. The score is sensitive to change, reliable, and meets face, predictive and construct validity criteria.

Adult↗
PubMed1996

Adenosine is a selective pulmonary vasodilator in cardiac surgical patients.

OBJECTIVE: The purpose of this study was to examine and compare the systemic and pulmonary hemodynamic effects of a central venous infusion of adenosine in cardiac surgical patients. DESIGN: Prospective; each subject served as his/her own control. SETTING: University Hospital and Veteran's Affairs Medical Center. PATIENTS: Ten cardiac surgical patients (age 56 +/- 6 years) were studied in the operating room under general anesthesia after weaning from cardiopulmonary bypass. Pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), mean pulmonary arterial pressure (MPAP), and mean systemic arterial pressure (MAP) were determined before, during, and after central venous infusion of adenosine (50 micrograms/kg/min) for 15 min. Statistical analysis was by analysis of variance; significance was accepted at p < 0.05. RESULTS: Adenosine produced selective vasodilation of the pulmonary vascular bed: both PVR and MPAP were significantly reduced during adenosine infusion without changes in either SVR or MAP. PVR and MPAP returned to preinfusion levels after cessation of the infusion. Adenosine effectively reduced PVR and pulmonary arterial pressure without decreasing SVR or systemic arterial pressure. CONCLUSIONS: Adenosine may be used clinically as a selective pulmonary vasodilator to optimize pulmonary hemodynamics without adverse systemic hemodynamic effects in cardiac surgical patients. It may be particularly valuable in patients with right heart dysfunction by selectively lowering right ventricular afterload.

Adenosine↗
PubMed1996

Adenosine for refractory pulmonary hypertension.

We report 2 patients with refractory acute pulmonary hypertension. In both, a central venous infusion of adenosine into the circulation effectively lowered pulmonary arterial pressure when standard treatment measures had failed, and reversed the clinical state of shock by achieving pulmonary vasodilatation. We conclude that adenosine may help lower pulmonary arterial pressure without lowering systemic arterial pressure in the setting of acute pulmonary hypertension when standard measures have failed.

Adenosine↗
PubMed1996

Fatigue in ankylosing spondylitis: its prevalence and relationship to disease activity, sleep, and other factors.

OBJECTIVE: To assess the symptom of fatigue in patients with ankylosing spondylitis (AS) with regard to its prevalence and its relationship to disease activity and other factors. METHODS: A self-administered questionnaire, including visual analog scales to assess fatigue, other components of disease activity, and functional ability (the Bath AS Functional Index, BASFI) was sent to 350 patients with AS. Questionnaires were completed and returned by 295 patients (84% response rate). Statistical analyses were descriptive and predictive and included t tests, chi-squared tests, and multiple regression. RESULTS: Sixty-five percent of the patients (n = 192) described fatigue as a major symptom (F+ group) while 31% (n = 91; F- group) did not consider it to be important (4% noncommittal). Excluding fatigue, the mean of a disease activity composite score was significantly higher in the F+ group (5.26, standard deviation (SD) + or - 2.33) than in the F- cohort (3.67, SD + or - 2.09, p <0.001). The former group also had significantly worse scores on the functional index (BASFI mean 5.87, SD + or - 2.42 vs 4.29. SD + or - 2.46, p <0.001). Of the total, 55% had, on occasion, suffered fatigue without accompanying pain or stiffness. After controlling for other factors, pain (p <0.001), functional disability (BASFI, p <0.001) and stiffness (p <0.05) were significantly associated with level of fatigue. The F+ group reported more sleep disturbance, with 41 % (compared to 26% of the F- group) waking more than 3 times a night (p = 0.04). In addition, usual fatigue on waking was more common in the F+ group (71 vs 36%, p <0.001). CONCLUSION: (1) Fatigue is a major symptom in the majority of patients with AS, in particular those with more severe disease; (2) fatigue is more likely to occur with active disease but may also occur as a lone symptom. (3) those with severe fatigue function less well; and (4) the management of fatigue remains an enigma - exercise, for example, having only an equivocal effect.

Adult↗
PubMed1995

Heart transplantation in children and young adults: early and intermediate-term results.

The purpose of this article is to report our short- and intermediate-term follow-up of cardiac transplantation for congenital heart disease and cardiomyopathy in children (age greater than 6 months), adolescents, and young adults. Thirty patients (ages 8 months to 24 years) with end-stage heart failure have undergone cardiac transplantation in our program: 12 (40%) for postoperative end-stage heart failure, 9 (30%) as primary treatment for congenital heart disease, 5 (17%) for dilated cardiomyopathy, and 4 (13%) for restrictive/hypertrophic cardiomyopathy. Nineteen patients (63%) had undergone prior operations; 4 patients received transplants for failed Fontan procedures. Induction therapy with antithymocyte therapy was used routinely, and long-term immunosuppression was by cyclosporine and azathioprine alone. Rejection surveillance/diagnosis was based on echocardiographic criteria. Posttransplantation follow-up ranges from 3 to 78 months. Operative mortality was 3.3% (1/30). No patients have been diagnosed with either accelerated allograft atherosclerosis or posttransplantation lymphoproliferative disease. We conclude that cardiac transplantation may be performed with excellent early and intermediate-term results.

Adolescent↗
PubMed1995

Cardiac allograft failure: successful use of biventricular assist device.

Nonspecific primary allograft dysfunction is an important cause of perioperative death in cardiac transplant recipients. We report a case of severe nonspecific allograft dysfunction that was ultimately reversible after 18 days of biventricular mechanical circulatory support. Allograft recovery was echocardiographically recognized by a positive inotropic response to isoproterenol and milrinone. This case illustrates the potential for recovery of even extreme allograft dysfunction.

Adult↗
PubMed1995

Failure of ambulance crew to initiate cardiopulmonary resuscitation.

The Utstein style of reporting out-of-hospital cardiac arrests requires that all confirmed cardiac arrests considered for resuscitation are analysed and that a record is made of the number of cases where no resuscitation is attempted. We report a series of 942 confirmed cardiac arrests considered for resuscitation by South Glamorgan Emergency Medical Service (EMS). There were 370 (39.3%) cases where no resuscitation was attempted by the EMS. The ages, male/female ratio and EMS response times were similar in both the group that received ambulance resuscitation and those that did not. Those not receiving resuscitation were less likely to have had an arrest of cardiac aetiology (51.3% vs. 75%, P < 0.00001). Rigor mortis or decomposition of the body was present in 50.8% of cases and in 20% a doctor had already confirmed the patient dead. In the remainder the ambulance crew failed to start resuscitation for a variety of reasons.

Aged↗
PubMed1995

Respiratory arrest outside hospital.

Of 954 attempted resuscitations outside hospital performed by ambulance personnel, 48 patients (5%) had primary respiratory arrest. Comparing this group with those manifesting cardiorespiratory arrest, patients with primary respiratory arrest were significantly more likely to be female (25 of 48 vs 269 of 906-P < 0.005), were more likely to have a non-cardiac cause (67% vs. 22%-P < 0.00001) and more likely to have witnessed arrest. Of all arrests witnessed by ambulance crew, 35% were respiratory arrests. Basic and advanced life-support was delivered sooner. Outcome was significantly better, with 19 patients (40%) being discharged compared to only 49 patients (5.1%) discharged in cases of cardiorespiratory arrest (p < 0.00001). Considering that many respiratory arrests were witnessed by ambulance crew, the type of crew (EMT or paramedic) made no difference to outcome. Our findings suggest that patients manifesting respiratory arrest outside hospital are a heterogeneous group who have a relatively good prognosis regardless of the type of ambulance crew that attends.

Age Distribution↗
PubMed1994

Transmission of Lactobacillus pneumonia by a transplanted lung.

Herein we report Lactobacillus pneumonia in a lung transplant recipient. The organism may have been normal flora in the donor but was a pathogen in the immunosuppressed recipient. Antibiotic therapy should include penicillin or clindamycin.

Anti-Bacterial Agents↗
PubMed1993

The Xenopus platelet-derived growth factor alpha receptor: cDNA cloning and demonstration that mesoderm induction establishes the lineage-specific pattern of ligand and receptor gene expression.

We have cloned the Xenopus PDGF alpha receptor cDNA and have used this clone, along with cDNA encoding PDGF A, to examine their expression pattern in Xenopus embryos and to determine the factors responsible for lineage specificity. Recombinant Xenopus alpha receptor expressed in COS cells exhibits PDGF-A-dependent tyrosine kinase activity. We find that receptor mRNA is present in cultured marginal zone tissue explants and in animal cap tissue induced to form mesoderm either by grafting to vegetal tissue or by treatment with recombinant activin A. In contrast, PDGF A mRNA is expressed in cultured, untreated animal cap tissue and is suppressed by mesoderm induction. These results suggest that ectodermally produced PDGF A may act on the mesoderm during gastrulation and that mesoderm induction establishes the tissue pattern of ligand and receptor expression.

Amino Acid Sequence↗
PubMed1993

An automatized computer-method utilizing Procomm Plus and DataEase (4.2) PC and SAS (6.06) mainframe software for isolated, perfused guinea-pig heart studies.

A powerful, time sharing and automatized method of a comprehensive data analysis for isolated, perfused guinea-pig heart studies is described. Data are collected using DataEase PC software (version 4.2) into forms with data fields specified for vital parameters consistently recorded in isolated, perfused heart studies (HR, CBF, PEAKPRESSURE, DPDT, MVO2). After running, DataEase reports the data and information is uploaded to an IBM 3081D mainframe computer on each day of heart experiment and data collection. The uploading process, the data archival and the statistical analyses are automatized by Procomm Plus commands written in Aspect Source Program (.ASP) Files for logging, data transforming and file management procedures. The ASPCOMP.EXE compiler compiles these .ASP files into Aspect Script eXecutable (.ASX) programs, which run on the PC in our laboratory and activate WYLBUR (IBM 3081D Batch-job service and Command file processor) edited files in the mainframe's electronic devices then upload, backup and save data into these files. SAS EXE files containing program instructions for the data analyzing system are then forced by Procomm Plus to operate over the data just uploaded. SAS reads the DATA files by its INFILE facility and performs comprehensive statistical analyses and produces hard output including graphics and JOB reports of dose-response- and logaritmic scale curves for delivery to team members. This computerized and automatized method developed for isolated, perfused guinea-pig heart studies is capable of performing multiple file transfer, sophisticated statistical analyses and graphic procedures after one keystroke on the PC (Alt-F5 in Procomm Plus section) and also facilitates a consistent and convenient method for planning, controlling and standardizing experiments. The method is based on an interactive computer conversation between the PC in the laboratory and the remote's WYLBUR editor. No human presence is needed; however, in case of failure, Procomm Plus gives one of the team members supervising the system a phone call in order to get human help.

Animals↗
PubMed1993

Production of monoclonal antibodies recognising different epitopes present on insulin-like growth factor 1.

Monoclonal antibodies (MAbs) were generated against recombinant human insulin-like growth factor 1 (IGF-1) by fusion of NS-1 myeloma cells with spleen cells from BALB/c X DBA mice immunised with recombinant IGF-1 and synthetic peptide sequences derived from the published amino acid sequence of IGF-1. MAbs were produced that recognised four distinct epitopes including two defined segments of the C and D domains. All MAbs were IgM mouse immunoglobulins. These results indicate the feasibility of producing MAbs to highly conserved proteins.

Amino Acid Sequence↗