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Biomedical subjects

D Jensen

Publications and source records attributed to D Jensen.

At least 91 records · Page 5Linked to original sources

Anti-LSP antibodies in acute liver disease.

Sera from 71 patients with acute liver injury have been tested for antibodies to hepatocyte membrane lipoprotein complex (LSP) using a sensitive radioimmunoassay. Two main patterns of anti-LSP response were seen. In the first, seen in patients with type A and B viral hepatitis, anti-LSP antibodies were detectable at presentation, with the highest titres two to 10 days before the peak in serum aminotransferases and, in the hepatitis B patients, when viral DNA polymerase concentrations were still high, indicating active viral replication. These findings are consistent with the anti-LSP response being consequent on an interaction between T cells and neoantigens on the liver cell surface. A similar pattern was found in halothane hepatitis where immune responses to a halothane-altered liver membrane antigen are present early in the course of the disease. In the second type of response, exemplified by cases with paracetamol-induced hepatic necrosis, anti-LSP was only occasionally detectable at presentation, although present in very low titre later in the clinical course. This may be due to the release of altered antigen at the time of hepatocellular injury. The same pattern was found in a selected group of patients with uncomplicated acute alcoholic hepatitis, suggesting that in both these groups of patients the liver damage may have been due to a direct toxic effect on liver cells.

Acetaminophen↗

Agreement in human interpretation of analog thallium myocardial perfusion images.

To assess the agreement of human interpretation of analog thallium myocardial perfusion images, four experienced interpreters evaluated 100 images on two occasions using a form designed to limit reader variability. A high intraobserver agreement (agreement by same observer at separate times) of 89--93% was found when films were interpreted as normal or abnormal (a dichotomous decision). Interobserver agreement for a majority grouping of observers (three or four) was 75% for an abnormal and 68% for a normal interpretation. However, agreement ranged from 11--79% when interpreters were asked to read the anatomic location of defects. Posterior and lateral wall defects were interpreted with the least amount of agreement. These results indicate that caution must be taken when interpreting defect location. Using a scale of 1--10 to grade the severity of a defect, correlations of 0.82--0.86 were found when reading defects in the lateral and anterior projections. Higher correlations, from 0.86--0.94, were found in left anterior oblique views. Use of reporting forms with specific criteria, multiple observers at one occasion, and/or computer processing may improve agreement. A brief review of the agreement of cardiology testing procedures is also presented.

Angina Pectoris↗

Uninhibited neurogenic bladder treated with Prazosin.

The effect of the new alpha-adrenoreceptor blocking agent prazosin on hypermotility of the urinary bladder was investigated, using controlled cystometry in neurological patients with normal bladder or with uninhibited neurogenic bladder. In short-term administration of prazosin, the bladder capacity was markedly increased and the uninhibited detrusor contraction was diminished. Long-term treatment with prazosin gave subjectively improved micturition in patients with detrusor-sphincter dyssynergia. The cystometrograms then showed less pronounced improvement than in short-term medication. Prazosin offers a valuable supplement to the existing choice off therapeutic agents for uninhibited neurogenic bladder. Side effects of the drug were few.

Adult↗

Pharmacological studies of the uninhibited neurogenic bladder. III. The influence of adrenergic excitatory and inhibitory drugs on the cystometrogram of neurological patients with normal and uninhibited neurogenic bladder.

In order to elucidate the sympathetic activity of the uninhibited neurogenic bladder, controlled cystometry before and during the influence of alpha- and beta-adrenergic agonists and antagonists was performed on patients with normal and uninhibited neurogenic bladder. Alpha-agonist increased the pathological findings in the cystometrogram of the uninhibited bladder with increase in intravesical pressure, decrease in capacity and increase in the amplitude of the uninhibited contraction, but had no effect whatsoever on the normal bladder. Alpha-antagonists improved the uninhibited bladder with decrease in intravesical pressure, increase in capacity and decrease in amplitude of the uninhibited contraction, and decrease in intravesical pressure in normal bladder. Beta 2-agonist improved the uninhibited bladder too, but was proved to be inactive on the normal bladder. Unselective beta- and selective beta 1-antagonists deteriorated the uninhibited bladder and had only minor effect on the normal bladder. The decreased capacity and forcible uninhibited detrusor contraction seem to be due to a reduction of inhibitory beta-adrenergic impulses as well as an increased contractile alpha-adrenergic action on the bladder wall in uninhibited neurogenic bladder.

Adrenergic Fibers↗

Pharmacological studies of the uninhibited neurogenic bladder. I. The influence of repeated filling and various filling rates on the cystometrogram of neurological patients with normal and uninhibited neurogenic bladder.

The influence on the cystometrogram of repeated filling and varying filling rates was studied in two groups of neurological patients, one with normal and one with uninhibited neurogenic bladder. A technique which permits an even bladder filling and a continuous recording of the intravesical pressure was used. The effect of repeated bladder filling without interval at a rate of 50 ml per min resulted in the following findings: In the normal bladder the intravesical pressure decreased at the second filling in three of the five patients. The bladder capacity remained unchanged in four of the five patients. In the uninhibited bladder, only a slight tendency to pressure decrease could be observed at the second filling in the 14 patients studied. The bladder capacity increased significantly (14 patients), while the amplitude of the uninhibited contraction was reduced (17 patients). These changes of the cystometric parameters cold be avoided in both groups when an interval of 20 min was interposed between the fillings. Varying filling rates (range 10 to 90 ml per min) resulted in the following findings: The normal bladder responded to higher filling rates partly with pressure increase (3 out of 6 patients), partly with pressure decrease (2 patients) or with unchanged pressure (1 patient). The capacity was independent of the filling rate. In the uninhibited neurogenic bladder, the pressure response to higher filling rates was either unchanged (11 out of 16 patients), higher pressure (3 patients) or a reduced pressure (2 patients). The capacity of the uninhibited bladder was not influenced by the filling rate in 10 out of 16 patients. The capacity increased at higher filling rates in four patients, and decreased in one. The amplitude of the uninhibited detrusor contraction was not influenced by the filling rate in nine out of 18 patients. The amplitude increased in five and decreased in four patients at higher filling rates. The present results show that an interval of at least 20 min has to be interposed between the fillings when cystometry with high and non-physiological filling rates is used for pharmacological studies. Otherwise, non-specific results will frequently be obtained. The influence of the rate of filling is of less importance as long as one and the same rate is used in the same experiments.

Adult↗

Pharmacological studies of the uninhibited neurogenic bladder. II. The influence of cholinergic excitatory and inhibitory drugs on the cystometrogram of neurological patients with normal and uninhibited neurogenic bladder.

In order to elucidate the parasympathetic activity of the uninhibited neurogenic bladder, controlled cystometry before and during influence of cholinergic and anticholinergic drugs has been performed on patients with normal and uninhibited neurogenic bladder. Cholinergic stimulation proved to increase the intravesical pressure to a great extent; to a higher degree in the normal than in the uninhibited bladder. In two patients with normal bladder, uninhibited detrusor contractions were induced by cholinergic stimulation. Cholinergic inhibition had only minor influence on the intravesical pressure during the filling phase. Opposite effects were obtained on the uninhibited detrusor contractions which are regarded as a part of the expulsive phase. Cholinergic stimulation increased the amplitude of the uninhibited bladder to some degree, but cholinergic inhibition markedly reduce the amplitude. Conclusively, the uninhibited neurogenic bladder is at least partly caused by an overactivity in cholinergic stimulation.

Adult↗

Hormone-sensitive lipase of rat adipose tissue: correlation of activity with a protein of molecular weight 84 000.

Hormone-sensitive lipase of rat adipose tissue was partially purified. The enzyme retained its capacity to be activated by cyclic AMP-dependent protein kinase throughout purification. When the partially purified 32P-labeled preparation was subjected to two-dimensional gel electrophoresis, the enzyme activity was found to be associated with a 32P-labeled protein of molecular weight 84 000. The result suggests that this 32P-labeled protein represents hormone-sensitive lipase or the catalytic subunit of the enzyme.

Adipose Tissue↗

Improvement in ventricular function during exercise studied with radionuclide ventriculography after cardiac rehabilitation.

A heterogeneous group of 19 consecutive patients with coronary artery disease were studied with radionuclide ventriculography before and after a mean of 6 months of exercise training. Ejection fraction was measured at rest, at matched submaximal supine work loads and during maximal supine bicycle exercise. After training there was no change in mean ejection fraction at rest or during maximal exercise, but a higher maximal mean systolic blood pressure, heart rate and work load were achieved. At equivalent submaximal work loads after training, similar levels of mean heart rate and systolic blood pressure were reached but a statistically greater mean ejection fraction was obtained. These preliminary results suggest that exercise training may improve cardiac function during exercise in selected patients with coronary disease. A randomized study using similar techniques has been initiated.

Adult↗

Radionuclide perfusion images before and after cardiac rehabilitation.

Improvement in cardiac perfusion has not been demonstrated in man to explain the increased functional capacity secondary to exercise training. Thallium imaging is a noninvasive method of evaluating myocardial perfusion and scaring. Therefore, using thallium exercise tests, we studied 17 patients with coronary heart disease before and after a mean of 6 months participation in cardiac rehabilitation program emphasizing exercise training. Interobserver variability in imaging interpretation was considered by reading images blinded both individually and in consensus. Agreement with defects called by consensus occurred at least 51% of the time individually and normal readings agreed at least 90% of the time. By consensus reading, seven patients showed improved perfusion, seven showed no change, and three worsened following training. Our study shows that thallium scans may be used to demonstrate central changes in myocardial perfusion after cardiac rehabilitation, but larger controlled studies considering redistribution and utilizing image enhancement are necessary to see if such changes are truly secondary to this intervention.

Adult↗

Cardiac rehabilitation: evidence for improvement in myocardial perfusion and function.

Sixteen patients with coronary heart disease (CHD) were studied with rest and exercise thallium scans and gated radionuclide ventriculography before and after 3 to 12 months of exercise training. The 5 patients presented in this report showed improvement in both the ejection fraction and exercise thallium images after training while achieving a higher maximal workload and an equivalent double product. These radionuclide techniques have provided the 1st documentation of improvement in both myocardial perfusion and function in CHD patients after exercise training. A controlled study using advances in imaging technology with patients matched according to postmyocardial infarction time and by the severity of disease is underway to confirm these findings.

Adult↗

Laparoscopic diagnosis of peritoneal mesothelioma. Report of a case and review of the diagnostic approach.

This is the second report of a malignant peritoneal mesothelioma diagnosed by laparoscopy and guided needle biopsy and the first with photographic documentation of the lesion. The case illustrates the following points: (1) diagnosis of peritoneal mesothelioma should be considered in the evaluation of exudative ascites; (2) the only definitive diagnostic procedure is to obtain tissue for histology; and (3) laparoscopy with biopsies under direct vision is an accurate and safe technique which is underutilized and should be considered as the diagnostic procedure of choice when peritoneal disease is suspected.

Ascitic Fluid↗

Effect of exercise on left ventricular ejection fraction in men with coronary artery disease.

Left ventricular ejection fraction (LVEF) was measured at rest and during supine bicycle exercise in 31 men with arteriographically defined coronary disease and in 15 normal men. LVEF was calculated from a left ventricular time vs activity curve (collimated scintillation probe, 99m Technetium) as the fracitonal fall in count-rate divided by the background-corrected left ventricular end-diastolic count-rate. In normal men LVEF at rest averaged .59 +/- .06 (+/-SD) and during exercise was .72 +/- .08. LVEF did not increase with exercise in men with coronary disease (.55 +/- .03 to .57 +/- .03; N = 31; AVE +/-SEM; NS). In 17 men with coronary disease who had ST segment depression with exercise, LVEF either decreased or was unaltered in all (55 +/- .04 to .49 +/- .03; P less than 0.05); whereas in 14 without ST depression, LVEF increased in 10 (71 per cent) and was unaltered in 4 (29 per cent) (.54 +/- .04 to .66 +/- .04; P less than 0.01). Results suggest that LVEF during exercise normally increases, but in men with coronary disease LVEF either fails to increase or actually decreases. In addition there appears to be a relationship between ST segment changes during exercise and ejection fraction.

Adult↗

Respiration during the first six months of life in normal infants: II. The emergence of a circadian pattern.

The objective of the present study was to investigate the emergence of circadian patterns in respiratory rates. Twenty-five neurologically normal infants were monitored for 12-hours during the first week of life and at one, two, three, four and six months of age. Each minute of the recordings of EEG, eye movements, somatic activity, respiration, ECG and temperature was coded into Active sleep (AS), Quiet sleep (QS), Indeterminate (IN) and Awake (AW). The night was divided into four equal intervals and a computer program calculated the mean respiratory rate for each interval as a function of state and age. During the first week of life group means of respiratory rates increased linearly with each interval in all states. A circadian pattern with lowered respiratory rates between 10:00 p.m. and 1:00 a.m. emerged at different ages in different sleep states. This pattern was first seen at one month of age in AS and IN, and at three months in QS. It was also observed in AW at three months of age, suggesting that the circadian rhythm is not solely an expression of the sleep wakefulness cycle. Feeding patterns contributed to but did not explain these observations.

Age Factors↗