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Biomedical subjects

H Dean

Publications and source records attributed to H Dean.

At least 19 recordsLinked to original sources

Pseudorabies virus EPO is functionally homologous to varicella-zoster virus ORF61 protein and herpes simplex virus type 1 ICPO.

Pseudorabies virus (PRV) early protein O (EPO) is the homolog of varicella-zoster virus (VZV) open reading frame 61 (ORF61) protein and herpes simplex virus type 1 (HSV-1) ICPO. A PRV EPO deletion mutant grows poorly in cell culture, suggesting that EPO plays a critical role in the viral replicative cycle. In this study, we have shown that the growth defect of an EPO deletion mutant was complemented in Vero cells expressing VZV ORF61 protein or HSV-1 ICPO. In transient expression assays PRV EPO, like VZV ORF61 protein and HSV-1 ICPO, transactivates a variety of promoters from PRV, VZV, HSV, and unrelated viruses. These data indicate that PRV EPO is functionally homologous to VZV ORF61 protein and HSV-1 ICPO.

Animals

Weight change and lung cancer: relationships with symptom distress, functional status, and smoking.

The pattern of weight change (at five 6-week intervals beginning 2 months after diagnosis of advanced disease) is described in adults with progressive lung cancer (N = 60). Weight loss of 10% or more at study entry occurred in 35% of subjects; 37% lost weight at three or more intervals; and 25% lost weight at only one interval. Pre-illness weight loss was moderately correlated with subsequent decreased functional status (Enforced Social Dependency Scale) at Times 1, 2, and 3 (r = -.49, r = -.43, r = -.48, p < .001). Weight loss correlated with subsequent increased symptom distress (Symptom Distress Scale, SDS) at three times (Times 2, 4, and 5: r = -.34, r = -.30, r = -.43, p < .05). Chemotherapy (50% of subjects) and smoking (25% at study entry) predicted weight loss from Time 1 to 5, explaining 28% of the variance.

Adenocarcinoma

Basal and post-ACTH cortisol levels in preterm infants following treatment with dexamethasone.

Dexamethasone (DEX) has been shown to decrease ventilator dependence in bronchopulmonary dysplasia (bronchopulmonary dysplasia). Abnormal metapyrone tests have been reported in 50% of infants who were weaned from a 45-day course of dexamethasone. We postulated that such infants would have adrenal suppression and would not respond to Cosyntropin (ACTH). We examined morning cortisol levels in 14 premature infants who had been treated with dexamethasone for 36 +/- 4 (mean +/- SEM) days, starting at 38 +/- 6 days of life, and performed ACTH stimulation tests in 12 of them. Morning cortisol levels were 87 +/- 36 nmol/L (range undetectable: 543; n = 14). Random basal cortisol levels were 109 +/- 42 nmol/L (range 34-540; n = 12). The mean cortisol level was 568 +/- 63 nmol/L (range 117-934) 60 min after adrenocorticotrophic hormone. In all cases, cortisol level increased three-fold after adrenocorticotrophic hormone. Low cortisol levels are almost universal in infants after treatment with dexamethasone, but the adrenal gland remains responsive to adrenocorticotrophic hormone stimulation. We speculate that dexamethasone causes secondary adrenal suppression at the hypothalamic-pituitary level. Normal adrenal function in the preterm infant needs to be defined.

Adrenal Glands

Nutritional intake, weight change, symptom distress, and functional status over time in adults with lung cancer.

The purpose of this descriptive longitudinal study was to describe the relationship of nutritional intake to weight change, symptom distress, and functional status over a six-month period in 28 subjects with progressive lung cancer. The majority of the subjects had non-small cell lung cancer and had lost less than 10% of their body weight at the time of study entry. Body weight, hunger, symptom distress, and functional status were measured every six weeks, beginning two months after diagnosis, for a six-month period. Three-day diet records, which were completed immediately prior to each time point, were averaged to obtain nutrient intake data. Average weight change and nutritional intake showed little variation over time, but the ranges were large. Lower intake of kilocalories was moderately related to functional status at Times 1 and 5 (r = -0.56; r = -0.66, respectively). Kilocalorie intake at a previous time was related to subsequent functional decline at two of the six-week data points (r = -0.71; r = -0.75). Weight change was not directly related to kilocalorie intake. Percentage of weight loss over time was greater in subjects younger than 65 years of age, in those with small cell lung cancer, and in those who received chemotherapy. Symptom distress and symptoms of hunger, nausea, and appetite disturbance showed subtle fluctuations over the six-month period and had inconsistent relationships with food intake over time. Further study is needed to describe nutritional changes that follow a diagnosis of lung cancer and to identify areas for nursing intervention.

Activities of Daily Living

Effects of the dipyridamole test on left ventricular function in coronary artery disease.

The dipyridamole stress test is used with thallium-201 to detect areas of inhomogeneity of blood flow that point to coronary artery disease (CAD). It is unclear whether dipyridamole produces inhomogeneous perfusion only or whether it actually decreases net flow in the obstructed vessels and produces true ischemia. It is also unclear what effect dipyridamole has on global and segmental left ventricular function. Therefore, ejection fraction, segmental wall motion and ventricular volume equivalents were measured before and after dipyridamole in 113 patients and 32 normal subjects. Ejection fraction responded in an abnormal fashion in 98 patients (87%), decreasing from 49 +/- 11% to 43 +/- 13% (p less than 0.0001), whereas it increased in 29 normal subjects (90%) from 57 +/- 6% to 64 +/- 10% (p less than 0.0001). Wall motion worsened distinctly in 75 patients (66%), and pressure/volume ratio deteriorated in 72%. The effect of dipyridamole lasted between 10 and 25 minutes, but was promptly reversed by aminophylline. These findings indicate that dipyridamole generally induces true ischemia in CAD. Furthermore, the degree of dysfunction is related to the angiographically assessed severity of CAD. The shortness of breath (seen in 10% of patients) may be partially explained by the findings, and it seems advisable to give aminophylline to every patient in order to promptly correct left ventricular dysfunction.

Adult

Is ascites caused by impaired hepatic inactivation of blood borne endogenous opioid peptides?

Methionine enkephalin and catecholamines were measured in carefully collected plasma samples from 25 patients with cirrhosis and ascites, and 25 with cirrhosis without ascites, 15 disease and 15 healthy controls. Methionine enkephalin was invariably raised in the ascites group, the median value being 4.6-6.9 times that of the other three groups. Similarly, in the ascites group, median noradrenaline was increased 2.5-4.2 and median adrenaline 1.8-2.5 times that of the other groups. Plasma methionine enkephalin is considerably raised in patients with cirrhotic ascites and has actions which could enable it to be an initiating factor of ascites formation.

Ascites

Increased intensity of the murmur of hypertrophic obstructive cardiomyopathy with carotid sinus pressure.

In a prospective study murmurs increased in intensity with carotid sinus pressure in 18 of 26 patients with hypertrophic obstructive cardiomyopathy (HOCM) (sensitivity, 69.2 percent for the 26 patients, 85.7 percent for the 21 patients in whom heart rate and blood pressure decreased with carotid sinus pressure). On the other hand, the murmur remained constant or decreased in all but one of 104 patients with valvular aortic stenosis, mitral insufficiency, hypertrophic nonobstructive cardiomyopathy, and systolic murmurs of miscellaneous origins (specificity, 99 percent; positive predictive value, 94.7 percent). Catheterization, indirect arterial pressure tracings, and echocardiographic studies indicated that carotid sinus pressure-induced bradycardia was associated with increased left ventricular outflow tract obstruction. The carotid sinus pressure-induced increase in the murmur is probably multifactorial: decreased aortic pressure and impedance; increased contractility immediately on sudden slowing of heart rate; further increase in obstruction as the mitral valve systolic anterior movement is enhanced; and delayed vasodilatation maintaining the obstruction even after return of heart rate to precarotid sinus pressure values. An increase in a systolic murmur with carotid sinus pressure is characteristic of HOCM.

Aortic Valve Stenosis

Echocardiographic and hemodynamic correlates of diastolic closure of mitral valve and diastolic opening of aortic valve in severe aortic regurgitation.

Acute severe aortic regurgitation (AR) is characterized by a steep increase in left ventricular end-diastolic pressure, exceeding left atrial pressure and occasionally equilibrating with aortic diastolic pressure. These pressure phenomena correlate with the M-mode echocardiographic (echo) findings of diastolic closure of the mitral valve (DCMV) and diastolic opening of the aortic valve (DOAV). Six men, aged 23 to 48 years, with recent-onset, severe AR were evaluated by M-mode echo and pressures at cardiac catheterization. DCMV was seen in all 6 patients and DOAV in 4. Near-constant time intervals from the preceding R wave of the electrocardiogram to DCMV and DOAV were seen, even in 3 patients with varying RR intervals (1 with atrial fibrillation and 2 with asynchronous and demand atrial pacing). When the RR intervals were shorter than these intervals, DCMV and DOAV did not occur. Increasing the heart rate in the 2 patients by atrial pacing resulted in a marked decrease in left ventricular end-diastolic pressure. In conclusion, DCMV and DOAV have a near constant relation to the preceding R wave of the electrocardiogram, DCMV with competence of the mitral valve must be present for DOAV to occur, DOAV indicates that the diastolic blood pressure equals left ventricular end-diastolic pressure, and heart rate is an important factor influencing the hemodynamic and echocardiographic parameters in recent-onset, severe AR.

Adult

Metabolic response to insulin induced hypoglycaemia in lean and obese subjects.

Metabolic response to insulin induced hypoglycaemia was examined in 8 lean and 11 obese subjects. The metabolic rate increased in lean and obese subjects during the hypoglycaemia. The mean response (as the sum of all the values above basal) was not significantly different between lean and obese subjects. The mean decrease in blood glucose and the mean hormonal response (increase in cortisol, adrenaline and noradrenaline) were not different between lean subjects and obese subjects. However, the metabolic response and noradrenaline response were variable in obese subjects and some obese subjects showed a poor response. These results suggest that in some obese subjects, there may be reduced thermogenic response to insulin induced hypoglycaemia.

Adult

Maternal and cord blood glycated albumin and total serum proteins: correlation with maternal glycemic control and birth weight.

Maternal and cord blood glycated albumin and total protein levels were measured in three groups: normal women (nondiabetic women who gave birth to infants that were normal for gestational age), test women (women who had no evidence of glucose intolerance with screening procedures and who gave birth to large for gestational age infants), and women with gestational diabetes. In all cases the cord glycated albumin and total protein levels were 20% to 30% less than the corresponding maternal levels, and no correlation could be detected between cord and maternal blood concentrations. There was no significant difference in cord and maternal glycated albumin and total protein levels among the three groups, although there was a slight upward trend detected in the test and diabetic groups. There was no significant correlation between birth weight ratio and either cord or maternal values for any of the groups except the diabetic cord samples, where a significant negative correlation between glycated albumin and total protein and birth weight ratios was found. The implications of these findings are discussed in respect to the usefulness of cord and maternal glycated albumin and total protein in retrospective screening for gestational diabetes.

Adult