Biomedical subjects

R E Gleason

Publications and source records attributed to R E Gleason.

At least 19 recordsLinked to original sources

PubMed2001

Fibrinogen and factor VII levels improve with glycemic control in patients with type 1 diabetes mellitus who have microvascular complications.

To determine whether the hypercoagulable state of patients with complications of diabetes can be reversed toward normal, a group of insulin-dependent individuals with proteinuria was treated with intensive insulin protocols. A statistically significant (P<.001) improvement in control of diabetes was achieved (mean +/- SEM glycosylated hemoglobin, 9.51% +/- 0.35% at baseline to 8.36% +/- 0. 39% at 12 months; and mean +/- SEM advanced glycosylated end products, 14.8 +/- 2.8 U/mL at baseline to 8.4 +/- 1.5 U/mL at 12 months). There were statistically significant decreases in 2 procoagulant factors: mean +/- SEM baseline elevated plasma factor VII, 128.69% +/- 5.63% at baseline to 106.24% +/- 3.43% at 12 months (P =.002); and mean +/- SEM plasma fibrinogen, 12.3 +/- 0.7 micromol/L (417.3 +/- 24.7 mg/dL) at baseline to 10.2 +/- 0.7 micromol/L (348.8 +/- 22.6 mg/dL) at 12 months (P =.04). Throughout the study, lipid fractions did not change significantly. Because plasma factor VII and fibrinogen concentrations were elevated while cholesterol and triglyceride concentrations were not, more attention should be paid to procoagulants as markers for thromboembolic complications in diabetic patients undergoing intensive insulin therapy.

Adult↗

PubMed2000

Improved glycemic control and platelet function abnormalities in diabetic patients with microvascular disease.

Patients with diabetes mellitus have a variety of platelet and coagulation system dysfunctions. At least theoretically, these can contribute to microvascular complications. Intensive glycemic control has been demonstrated to decrease microvascular complications in type 1 diabetics. We studied 16 patients with type 1 diabetes mellitus (11 men and five women; mean age, 39 years) with albuminuria greater than 0.1 g/d and/or proteinuria greater than 0.3 g/d and a creatinine clearance rate higher than 30 mL/min. They received a regimen including three to four injections of insulin per day with or without a weekly infusion of intravenous insulin, and were evaluated for 6 months. We compared the plasma level of von Willebrand factor, platelet aggregation responses to adenosine diphosphate (ADP), epinephrine, and collagen, and platelet adhesion at the beginning of the study and at follow-up intervals. Glycemic control improved significantly. There were no significant differences in the platelet aggregation responses to ADP (1.59 +/- 0.34 v 1.88 +/- 0.23 mmol/L, P = .3; normal, 4.6 +/- 0.2), epinephrine (0.50 +/- 0.20 v 1.11 +/- 0.31 mmol/L, P = .06; normal, 7.6 +/- 1.5), or collagen (92.4 +/- 6.61 v 82.60 +/- 3.78 seconds, P = .6; normal, 79.1 +/- 3.1) or in platelet adhesion (126.31 +/- 16.95 v 195.08 +/- 30.2 platelets, P = .34; normal, 68.6 +/- 1.4). Baseline von Willebrand factor increased, but not significantly (166.38% +/- 10.6% v 142.72% +/- 14.73%, P = .21; normal, 102.0% +/- 6.0%). In type 1 diabetic patients with established microvascular complications of nephropathy, a statistically significant improvement in glycemic control did not improve the in vitro platelet function abnormalities. Improved glycemic control delays the progression of microvascular disease through mechanisms not measured by tests of platelet function.

Adenosine Diphosphate↗

PubMed2000

Effects of pulsatile intravenous insulin therapy on the progression of diabetic nephropathy.

The purpose of this study was to assess the effects of pulsatile intravenous insulin therapy (PIVIT) on the progression of diabetic nephropathy in patients with type 1 diabetes mellitus (DM). This 18-month multicenter, prospective, controlled study involved 49 type 1 DM patients with nephropathy who were following the Diabetes Control and Complications Trial (DCCT) intensive therapy (IT) regimen. Of these, 26 patients formed the control group (C), which continued on IT, while 23 patients formed the treatment group (T) and underwent, in addition to IT, weekly PIVIT. Blood pressure in all patients was maintained below 140/90 mm Hg on antihypertensive medication, preferentially using angiotensin-converting enzyme (ACE) inhibitors. All study patients were seen in the clinic weekly for 18 months, had monthly glycohemoglobin (HbA1c), and every 3 months, 24-hour urinary protein excretion and creatinine clearance (CrCl) determinations. The HbA1c levels declined from 8.61% +/- 0.33% to 7.68% +/- 0.31% (P = .0028) in the T group and from 9.13% +/- 0.36% to 8.19% +/- 0.33% (P = .0015) in the C group during the study period. CrCl declined significantly in both groups, as expected, but the rate of CrCl decline in the T group (2.21 +/- 1.62 mL/min/yr) was significantly less than in the C group (7.69 +/- 1.88 mL/min/yr, P = .0343). We conclude that when PIVIT is added to IT in type 1 DM patients with overt nephropathy, it appears to markedly reduce the progression of diabetic nephropathy. The effect appears independent of ACE inhibitor therapy, blood pressure, or glycemic control.

Adult↗

PubMed1999

Prospective evaluation of autonomic dysfunction in aggressive management of diabetic microangiopathy.

Twenty-six type I diabetic nephropathy patients in a rigorous schedule for glucose control to preserve kidney function were studied to determine autonomic functional changes during 18 months. Intercurrent and nonrelated acute illness, withdrawal from the study for personal reasons, or failure to undergo testing on schedule resulted in complete data at 1 year for 26 of the original 41 patients enrolled, 24 patients completing a further 6 months. Glycohemoglobin A1c dropped for the total group from 9.0 to 7.9 at 6 months, 8.0 at 12 months, and 8.1 at 18 months (P<.01). Autonomic function tests revealed baseline results that were below the anticipated normals for age in 38% to 56% of patients. Timed ventilatory heart rate variations measured for the total group were 1.11, 1.13, 1.10, and 1.09 (normal > or =1.20). Valsalva heart rate variations for the total group were 1.27, 1.30, 1.255, and 1.35 (normal > or =1.50). Assumption of upright posture-related heart rate variations for the total group were 1.10, 1.07, 1.07, and 1.06 (normal > or =1.20). Mean arterial pressure day/night ratios for the total group were 1.04, 1.05, 1.05, and 1.08 (normal > or =1.10). Group analysis based on differences in insulin treatment programs, levels of blood pressure, and levels of renal function revealed no significant differences from the total group or companion groups during 18 months. Patients with a glycohemoglobin A1c of <8.0% were more likely to normalize mean arterial pressure day/night ratios than those with glycohemoglobin A1c > or =8.0%. We conclude that aggressive glucose control in diabetic patients with proteinuria for a period of 18 months resulted in a reproducible pattern of autonomic function tests during that period of time with neither worsening nor improvement. The restoration of day/night mean arterial pressure variation in a minority of patients should be studied with a larger cohort.

Adult↗

PubMed1998

Relationship between autonomic function and progression of renal disease in diabetic proteinuria: clinical correlations and implications for blood pressure control.

The objective of this study was to test the relationship between neurologic and microvascular complications of type 1 diabetes mellitus. It was hypothesized that the mechanisms operative in autonomic dysfunction seen in diabetic patients with microangiopathy play a role in the rapidity of progression to renal failure. Twenty-six type 1 diabetic patients with proteinuria were studied with computerized monitoring of heart rate variation during timed ventilation, assumption of upright posture, and Valsalva maneuver and with 24-h ambulatory blood pressure monitoring at baseline. Renal function was evaluated over the ensuing 12 months of intensive insulin therapy. Blood pressure was treated so as to achieve consistent 24-h readings < 140/90 mm Hg. Angiotensin converting enzyme inhibitors were the preferred antihypertensive agents. Serial serum creatinine concentrations were compared using repeated measures analysis of variance. Over 12 months there were no significant serum creatinine changes for any autonomic test group with normal results at baseline. Groups with abnormal autonomic results at baseline demonstrated statistically significant increases in serum creatinine over 12 months compared to their baseline. Of the tests, Valsalva separated groups of patients with similar degrees of baseline renal impairment. Each of the sympathetic plus Valsalva combinations demonstrated a significant difference in progression of serum creatinine increase over 12 months. In each instance, if both sympathetic and Valsalva results were abnormal, there was a statistically significant increase in serum creatinine over 12 months when compared to groups in which one or both test results were normal. There is a relationship between autonomic function and the progression of renal dysfunction. The inability to vary the heart rate to a Valsalva maneuver identifies a degree of parasympathetic dysfunction that permits unopposed sympathetic tone, heralding more rapid renal destruction. A simple inexpensive bedside laboratory test discerned a relatively low-risk group of diabetic patients with proteinuria that demonstrated no deterioration in renal function over 12 months. When the Valsalva maneuver was markedly abnormal the presence of a mean arterial pressure > 100 mm Hg was associated with a greater likelihood of rapid renal deterioration. This group at higher risk of renal deterioration should undergo aggressive lowering of mean arterial blood pressure to < 95 mm Hg.

Adult↗

PubMed1998

Twenty-four-hour L-[1-(13)C]tyrosine and L-[3,3-(2)H2]phenylalanine oral tracer studies at generous, intermediate, and low phenylalanine intakes to estimate aromatic amino acid requirements in adults.

Daily pattern and rates of whole-body tyrosine oxidation and phenylalanine hydroxylation were determined in young adults (15 men, 1 woman) receiving [13C]tyrosine and [(2)H2]phenylalanine via primed, constant oral infusion and [(2)H4]tyrosine by vein (five subjects also received [(2)H3]leucine simultaneously by vein) continuously for 24 h (12 h fast then 12 h fed). Subjects were given a diet supplying 96.6 (n = 5), 35.6 (the proposed requirement; n = 5), and 18.5 mg phenylalanine x kg(-1) x d(-1) (n = 6) based on an otherwise adequate L-amino acid mixture for 6 d before the 24-h tracer study began. [Each diet was low in tyrosine: 6.79 mg x kg(-1) x d(-1).] Our hypothesis was that subjects would be in tyrosine equilibrium, positive balance, or both, at the 96.6- and 35.6-mg intakes and in distinctly negative balance at the 18.5-mg intake. The diurnal pattern in phenylalanine and tyrosine kinetics was dependent on the intake and, presumably, on the adequacy of dietary phenylalanine. Wholebody tyrosine balances, determined from rates of phenylalanine hydroxylation and tyrosine input and oxidation were negative (0.05 < P < 0.1 from zero balance) with the low (18.5 mg) phenylalanine intake [total aromatic amino acid (AAA) intake: 25.3 mg x kg(-1) x d(-1)] but at equilibrium (P > 0.05 from zero balance) with the two higher phenylalanine intakes. Whole-body AAA balance (AAA intake - tyrosine oxidation) was negative (P < 0.05 from zero balance) with the low intake, at equilibrium with the intermediate intake, and apparently distinctly positive (P < 0.05) with the generous intake. Despite model limitations, as discussed, these findings lend further support for a proposed, tentative value for a total mean requirement of 39 mg AAA x kg(-1) x d(-1).

Adolescent↗

PubMed1998

Tetanus toxoid stimulation of the hypothalamic-pituitary-adrenal axis correlates inversely with the increase in tetanus toxoid antibody titers.

In humans, endotoxin activates the hypothalamic-pituitary-adrenal (HPA) axis, and the resulting increase in cortisol modulates the immune response. There is little information on the HPA axis response to other antigens. We examined the effect of the protein antigen tetanus toxoid on HPA axis activity in 10 healthy, premenopausal women (aged 28.6 +/- 2.6 yr). Subjects received im injections of placebo and tetanus toxoid at 1600 h on consecutive days. Blood samples for ACTH and cortisol were obtained every half-hour from--1 to 6 h and at 8, 12, and 16 h after each injection. Compared to placebo, tetanus toxoid administration stimulated significant increases in plasma ACTH and serum cortisol, with the maximum cortisol increase of 1.6-fold occurring 4.5 h after drug administration. Urinary free cortisol increased 1.8-fold in the 8 h after tetanus toxoid administration compared to that after placebo administration. Additionally, there was a significant inverse correlation (r = 0.87; P < 0.005) between the tetanus toxoid-induced increase in serum cortisol and the increase in tetanus antibody levels measured 1 month postvaccination. Thus, administration of the protein antigen tetanus toxoid activated the HPA axis in healthy, premenopausal women. This activation of the HPA axis correlated inversely with the antibody response to tetanus toxoid.

Adrenal Glands↗

PubMed1997

Screening for lung cancer. Another look; a different view.

PURPOSE: There is widespread acceptance that screening for lung cancer is not indicated, to our knowledge, because no randomized trial has demonstrated a reduction in mortality as a result of screening. The objectives of this work are to review prospective studies on lung cancer screening and to analyze the extent to which known biases may have influenced observed results. BACKGROUND: Four randomized controlled trials have been conducted. The Memorial-Sloan Kettering and Johns Hopkins Lung Projects compared annual chest radiographs (CXRs) in a control group with CXRs and sputum cytologic findings in an experimental group. Although both studies failed to demonstrate any difference in outcome by the addition of cytologic study to CXR, long-term survival in both studies was approximately three times that predicted by other data. Accordingly, these results are at least consistent with the hypothesis that the screening CXRs may have improved survival. Two randomized trials, the Mayo Lung Project and the Czechoslovak study, compared regular and frequent rescreening CXRs in an experimental group with sporadic and/or infrequent rescreening in a control group. RESULTS: Both the Mayo and Czech studies demonstrated a striking advantage for screening with respect to stage distribution, resectability, survival, and fatality. Nevertheless, mortality was somewhat higher in the screened groups in both studies. Survival and fatality comparisons in randomized trials can be confounded by overdiagnosis bias, lead-time bias, and length bias, while mortality is not subject to these biases. Accordingly, it is believed that a mortality reduction represents the strongest evidence for screening efficacy. Mortality is directly proportional to cumulative incidence. In both the Mayo and Czech studies, incidence of lung cancer was higher in the screened group. The higher cumulative incidence (which in the Mayo Lung Project was statistically significant) made possible the discordant findings of superior survival/fatality and inferior mortality in the screened populations. Overdiagnosis has been widely accepted to account for the "missing cases" in the control populations in the Mayo and Czech studies. However, epidemiologic and autopsy evidence as well as an outcome analysis of unresected early-stage screen-detected lung cancer demonstrates that screening does not lead to the overdiagnosis of lung cancer. Similarly, lead-time bias and length bias cannot account for the outcome differences in the Mayo Lung Project or Czech study. If survival and fatality comparisons (which suggest a striking benefit from screening) are not biased, then mortality comparisons (which suggest no benefit) cannot accurately reflect lung cancer death rates in these trials. Population heterogeneity may provide an explanation for how outcome differences may have been misrepresented by mortality comparisons in these two trials, as well as other large population-based randomized studies. CONCLUSIONS: Periodic screening CXRs lead to clinically meaningful improvements in stage distribution, resectability, survival, and fatality in lung cancer. Mortality reductions have not been demonstrated, but mortality did not accurately reflect lung cancer death rates in the Mayo Lung Project and Czechoslovak study. Accordingly, reconsideration of the desirability of periodic CXR screening may be appropriate for individuals at high risk of lung cancer.

Bias↗

PubMed1997

Relationship between autonomic function and plasma fibrinogen, viscosity, and elements of fibrinolytic activity in diabetic nephropathy.

Twenty-three insulin-dependent diabetics with proteinuria (3.3 g/day: range 0.3 to 8.9) and azotemia (creatinine clearance: 58 mL/min, range 30 to 112) were tested for 24-h mean arterial blood pressure; instantaneous heart rate variations to a computerized protocol involving timed ventilation, assumption of upright posture, and Valsalva maneuver; plasma fibrinogen, viscosity, fibrinolytic activity, and plasminogen activator inhibitor. These were to test the hypothesis that autonomic dysfunction is associated with altered concentrations of plasma fibrinogen, fibrinolytic activity, viscosity, and plasminogen activator inhibitor. We have previously shown the absence of a correlation between level of blood pressure, clinical and standard laboratory testing, and the results of the autonomic function testing protocol used in this study. In this group of patients, plasma fibrinogen concentration was correlated (positively) with mean arterial pressure and (negatively) with heart rate variation in response to the Valsalva maneuver. The greater the mean arterial pressure or the worse the Valsalva results, the higher the plasma fibrinogen concentration. In addition, patients with one or no abnormal autonomic function tests had a mean fibrinogen of less than 400 mg/dL compared to the group of patients with two or more abnormal tests who had a mean fibrinogen of 500 mg/dL. In patients with demonstrated parasympathetic abnormalities, postural heart rate variation testing also discerned a differential in plasma fibrinogen. Lower concentration of plasminogen activator inhibitor throughout the day, and greater fibrinolytic activity in the morning were also noted to be present in patients with abnormal heart rate response to the Valsalva maneuver. We conclude that there are relationships between high blood pressure, autonomic function, and hemostatic factors favoring thrombogenesis that may be related by common mechanisms and treatments in the diabetic with kidney disease.

Adult↗

PubMed1995

Autonomic function in type I diabetes mellitus complicated by nephropathy. A cross-sectional analysis in the presymptomatic phase.

The purpose of this study was to determine the prevalence of parasympathetic and sympathetic autonomic dysfunction in long-standing type I diabetics with established nephropathy and to correlate autonomic function with cardiac risk factors. We used prospective analysis of heart rate variations to standardized testing and 24-hour blood pressure control prior to enrollment in a study utilizing various methods of intense diabetic control to prevent deterioration of kidney function. The settings were outpatient clinical research units. The patients were 42 type I diabetics with proteinuria (total urinary protein > or = 300 mg/day or urinary albumin > or = 100 mg/day) and creatinine clearance > or = 30 mL/min. Heart rate variation during respiratory cycles with change in posture from supine to upright, and during the Valsalva maneuver was recorded by a computerized method. Mean arterial blood pressure was recorded for 24 h by a computerized method. Heart rate variations in this group were abnormal during timed respiratory cycles in 26 of 40 patients (56%), during changes in posture in 15 of 40 patients (38%), and during Valsalva maneuver in 13 of 34 patients (38%) whose retinal disease permitted Valsalva testing. Blunted day/night mean arterial pressure ratios occurred in 18 of 41 (44%) patients and were more severe in men than in women (1.00 v 1.06, P < or = .05). Absence of deep tendon reflexes was associated with an increased incidence of both parasympathetic (respiratory rate variation) and sympathetic (postural rate variation) abnormalities (both P < or = .05). Loss of vibration sensation was not associated with autonomic functional abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

The 24-h kinetics of leucine oxidation in healthy adults receiving a generous leucine intake via three discrete meals.

The significance of meal size and frequency for the 24-h leucine tracer-balance technique was examined. Continuous measurements of leucine oxidation throughout a 24-h d were performed in six healthy, young adults who were given a weight-maintaining diet (188 kJ.kg-1.d-1; 1 g protein.kg-1.d-1) for 6 d followed by primed, continuous intravenous infusions of L-[1-13C]leucine and [15N-15N]urea. The 24-h study was started at 1800 on day 6 and three equal discrete meals were given at 2000, 0600, and 1200. Leucine oxidation was assessed from plasma [13C]alpha-ketoisocaproate enrichment and 13CO2 excretion. The mean (+/- SD) leucine oxidation after each meal (over 6 h) was not significantly different (P > 0.5) among the three discrete meals: 20.0 +/- 3.9, 20.2 +/- 1.9, and 20.3 +/- 2.4 mg.kg-1.d-1 for the meals given at 2000, 0600, and 1200, respectively. Twenty-four-hour leucine oxidation was 75.0 +/- 7.8 mg.kg-1.d-1 for a leucine dietary intake of 80 mg.kg-1.d-1 (and approximately 9.7 mg tracer.kg-1.d-1). The 24-h pattern in leucine oxidation was paralleled by plasma leucine concentrations. Further, leucine oxidation and urea excretion predicted relatively similar values for 24-h protein oxidation. These data are compared with results from our similar previous studies using a multiple-small-meal feeding protocol.

Adult↗

PubMed1995

Effect of acute ethanol ingestion on prolactin in menopausal women using estradiol replacement.

Epidemiologic studies suggest that women who consume ethanol are at an increased risk for developing breast cancer. Two randomized, crossover studies were performed to examine the effects of ethanol on prolactin in menopausal women using transdermal estradiol. In study 1, transdermal estradiol patches (0.15 mg) were administered to menopausal women (n = 7) the day before ethanol administration. At 8.00 h, the women ingested ethanol (1 ml/kg, 95% ethanol) or an isocaloric carbohydrate drink. Prolactin levels were measured frequently for 6.3 h. Serum ethanol levels reached a broad peak from 40 to 100 min after initiation of ethanol ingestion. Serum prolactin levels were significantly higher after ethanol ingestion than after the isocaloric carbohydrate drink ingestion (p < 0.03). Study 2 was identical to study 1 except that the transdermal estradiol patches were removed after completion of ethanol or carbohydrate ingestion. In study 2, serum prolactin was greater after ethanol ingestion than after carbohydrate ingestion (p < 0.001). In menopausal women using transdermal estradiol, acute ethanol ingestion is associated with an increase in serum prolactin.

Administration, Cutaneous↗

PubMed1995

Chest X-ray screening improves outcome in lung cancer. A reappraisal of randomized trials on lung cancer screening.

It is believed that population-based screening for cancer should be advocated only when screening reduces disease-specific mortality. Four randomized controlled studies on lung cancer screening have been conducted in male cigarette smokers, and none has demonstrated reduced mortality. Accordingly, no organization that formulates screening policy advocates any specific early detection strategies for lung cancer. Yet, despite this public policy against screening, there is considerable evidence that chest x-ray screening is associated with earlier detection and improved survival. Two randomized trials, the Memorial Sloan-Kettering and Johns Hopkins Lung Projects, were specifically designed to evaluate the effectiveness of sputum cytologic study. Both evaluated the efficacy of the addition of sputum cytologic studies to annual chest radiographs, and both demonstrated that cytologic study did not favorably influence outcome. All individuals in experimental and control groups in both studies had annual chest radiographs. Because survival rates observed in both studies were about three times higher than predicted, based either on the National Cancer Institute's Surveillance Epidemiology and End Results database or based on the American Cancer Society's annual Cancer Statistics, raises the possibility that the periodic chest radiographs performed in all patients in both studies contributed to an improved outcome. In the Mayo Lung Project and in the Czechoslovak study on lung cancer screening, the experimental groups underwent a program of relatively intensive and regular rescreening with chest radiographs and sputum cytologic study, while the control groups underwent either less-frequent rescreening or no rescreening. In both studies, the screened groups achieved meaningful improvements in stage distribution, resectability, and survival. However, increases in cumulative incidence of lung cancer in the experimental group in both studies (which in the Mayo Lung Project reached statistical significance) prevented significant improvements in survival from translating into corresponding reductions in mortality. The possibility that screening may be associated with lung cancer "overdiagnosis" has been widely postulated to account for higher survival and incidence rates and equivalent mortality rates. However, analysis of autopsy information and of disease outcome in individuals with screen-detected early stage lung cancer who do not undergo surgical resection strongly supports the conclusion that screening does not lead to overdiagnosis of lung cancer. Similarly, lead-time and length bias do not adequately account for the differences in cumulative incidence observed in the Mayo and Czech studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Bias↗

PubMed1995

The effects of ethanol on the clearance of estradiol in postmenopausal women.

OBJECTIVE: To determine whether acute alcohol ingestion affects the pattern of decline of circulating E2 levels after removal of transdermal E2 patches. DESIGN: A randomized, placebo-controlled, crossover study. SETTING: The study was performed in the Clinical Research Center of the Brigham and Women's Hospital. PARTICIPANTS: Twelve healthy postmenopausal women were enrolled. INTERVENTIONS: Transdermal E2 patches, 0.15 mg, were applied 13 hours before subjects ingested alcohol (1 mL/kg 95% ethanol) or carbohydrate placebo punch. The patches were removed immediately after drink ingestion. MAIN OUTCOME MEASURES: Estradiol, estrone (E1), and ethanol levels were measured. RESULTS: Serum samples were obtained for 40 minutes before drink ingestion and 5 hours after drink ingestion and E2 patch removal. At the time of patch removal, E2 levels rose acutely over 10 minutes and then decreased rapidly, suggesting a bolus effect that was more marked after ethanol ingestion. After ethanol ingestion and patch removal the half-life of E2 was calculated to be 378 minutes, and after carbohydrate punch and patch removal 245 minutes. There were no significant changes in E1 concentrations over the time course of the study between groups. CONCLUSIONS: Ethanol ingestion may decrease E2 clearance after removal of transdermal E2 patches.

Administration, Cutaneous↗

PubMed1995

Role of calcium channel blockers in diabetic renal transplant patients: preliminary observations on protection from sepsis.

BACKGROUND: Diabetic recipients of kidney transplants have an excessively high risk of allograft loss, infectious complications with sepsis, cardiovascular events and early death. This study was designed in order to determine whether post-transplantation medical management influenced long-term results. METHODS: Seventy consecutive diabetic recipients of cadaveric renal allografts were followed from the time of transplant. Treatment regimens were based on the clinical judgement of transplant nephrologists and surgeons, not by the study team. Patients were followed for 2 to 9 years (mean follow-up of 50.85 months, one lost to follow-up). Groups were classified by HLA match, type of immunosuppression, prior cardiovascular history, type of antihypertensives (36 on calcium channel blockers, 32 on beta blockers, 8 ACE inhibitors). Events were defined as myocardial infarction, CVA, graft loss with return to dialysis, life-threatening sepsis, or death. RESULTS: Twenty allografts failed during the study, 24 patients died. Potentially cardioprotective drugs did not impact significantly on cardiac death, MI or CVA. Survivals were better when calcium channel blockers were used (mean 71.7 vs 38.6 months, p < 0.05; 4-year survival 84 vs 58%). When both beta and calcium channel blockers were used (n = 20), patients mean survival was 72.5 months vs 36.8 months for 21 patients who were not treated with blockers (p < 0.005). There was a lower incidence of graft loss when beta blockers and calcium channel blockers were used: at mean patient survival of 36.8 months, the no-blockers group had a mean graft survival of 19.3 months vs 72.5 months for blocker-treated patients (p < 0.002). Reinstitution of dialysis occurred less often with calcium channel blockers (17 vs 42%) or beta blockers (19 vs 38%) used either individually or together (5 vs 42%), all p < 0.05. Calcium channel blocker treated patients had 1/9 the number of septic deaths, fewer patients had multiple septic episodes, all p < 0.02. CONCLUSION: Allograft success and patient survivals may be improved and sepsis related events diminished when diabetic renal allograft recipients are treated with calcium channel blocking agents, plus or minus beta blockers. Considerable savings can be accomplished and graft results with these drugs can approach non-diabetic and live-related transplant results.

Adrenergic beta-Antagonists↗

PubMed1994

Use of exercise test parameters to predict presence and duration of ambulatory ischemia in patients with coronary artery disease.

Myocardial ischemia is an indicator of adverse prognosis. In patients with stable angina and positive exercise tests, prolonged cumulative ischemia on ambulatory electrocardiographic monitoring identifies a high-risk group with severe coronary artery disease and poor survival. To determine whether features of the exercise test can accurately (1) predict the occurrence of ambulatory ischemia, and (2) classify patients into subgroups at varying levels of risk for ambulatory ischemia, we studied 48 patients with a history of angina and documented coronary disease who underwent the standard Bruce protocol and ambulatory monitoring. All patients had a positive exercise treadmill test, and 26 had ischemia on Holter monitoring (total of 2,922 minutes, 173 episodes, 94% with silent ischemia). The remaining 22 patients did not have ischemia. The exercise test parameters showing significant differences between the 2 groups were (1) time to > or = 1 mm ST-segment depression (p < 0.0003), (2) maximal ST-segment depression (p < 0.004), and (3) exercise capacity (p < 0.037). These data were used to develop a model for predicting the presence and the severity of ambulatory ischemia. Time to onset of > or = 1 mm ST-segment depression and maximal ST-segment depression on exercise treadmill testing can be used to determine the likelihood of mild (1 to 5 episodes or lasting < or = 60 minutes) or severe prolonged (> 5 episodes or lasting > 60 minutes) ambulatory ischemia. Patients with a very high or very low probability of ischemia on Holter monitoring can be identified by certain exercise test parameters and may not need to undergo monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Acute and delayed effects of corticotropin-releasing hormone on dopamine activity in man.

Interactions between the hypothalamic-pituitary-adrenal (HPA) axis and central dopamine systems have been hypothesized to play a role in the pathophysiology of psychosis, but the normal physiology of HPA axis-dopamine interactions has not been fully defined. We report results from two uncontrolled pilot studies which explored the effects of ovine corticotropin-releasing hormone (CRH) on dopamine activity in healthy human subjects. Administration of CRH did not produce changes in plasma levels of homovanillic acid (HVA), the major dopamine metabolite, over the subsequent 3.5 hours. However, when the effects of CRH were followed over a longer period in a small subgroup, we found that CRH administration produced a two-fold rise in plasma HVA levels 20 hours later, without affecting plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), a major metabolite of norepinephrine. Thus, the findings of these pilot studies suggest that CRH may exert delayed but not acute effects on dopamine activity in man.

Adrenocorticotropic Hormone↗

PubMed1994

Validation of the tracer-balance concept with reference to leucine: 24-h intravenous tracer studies with L-[1-13C]leucine and [15N-15N]urea.

The validity of tracer-derived estimates of whole-body leucine balance was investigated. Seven healthy young adult subjects received an adequate protein diet for 6 d; at 1800 on the last day, L-[1-13C]leucine and [15N-15N]urea were given as primed, continuous intravenous infusions for 24 h. Subjects were in a fasting state for the first 12 h and at 0600 on day 7 they then received hourly 10 equal meals to achieve a fed state. Total leucine intake (diet plus tracer) was 89.4 mg.kg-1.d-1. Mean daily leucine oxidation was equivalent to 89.5 +/- 3.3 mg leucine/kg. The predicted daily oxidation rate, from measurements made during the last hour of the fast and the fifth hour of the fed period, was 91.2 +/- 5.8 mg/kg (P = 0.25 from measured). Measured and predicted whole-body leucine balances were 0.76 +/- 2.99 and -0.98 +/- 5.54 mg/kg, respectively (P = 0.25). Urea production exceeded urea excretion by 20%; daily protein oxidation was the same when estimated from leucine oxidation or nitrogen excretion. Thus, the tracer-balance concept is valid, and reliable predictions of total daily leucine oxidation and whole-body leucine balance can be obtained from short-term measurements of leucine oxidation during fasted and fed states.

Adult↗