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Biomedical subjects

L Jacobs

Publications and source records attributed to L Jacobs.

At least 37 records · Page 2Linked to original sources
PubMed1990

Investigation by scintigraphic methods of platelet kinetics under normal and septic shock conditions in the experimental baboon model.

This study concerned the correlation of platelet kinetics with the pathogenic course of septic shock and adult respiratory distress syndrome (ARDS) in the anesthetised baboon model. 111In-tropolonate platelets were traced in vivo in normal baboons (n = 7) and in Escherichia coli-infected baboons, which were reinjected with the labeled autologous platelets either 2 hr after the onset of the E. coli infusion (procedure A: n = 4) or simultaneously with the infusion (procedure B; n = 3). One minute images were taken hourly for 5 hr, using a gamma camera and data processor. Time-activity curves were obtained for platelet clearance from the blood and the lungs and for platelet accumulation in the liver and spleen. A significant retention of platelets in the lungs of baboons with E. coli-induced septic shock was noted, as well as an accelerated clearance from the circulation. Platelets were distributed mainly to the spleen after induction of bacteremia, later substantially moved to the liver, and even later moved back to the spleen.

Animals↗
PubMed1990

Preparation and biokinetic evaluation of various halogenated iminodiacetic acid-type compounds labeled with technetium-99m for hepatobiliary scintigraphy in the baboon (Papio ursinus) model.

In an evaluation of various 99mTc-labeled halogenated (F, Cl, Br, I) iminodiacetic acid (IDA) derivatives for hepatobiliary scintigraphy, it was found that, in the baboon model, none of these compounds performed as well as did disida. F-IDA was least effective, with the lowest biliary excretion and highest renal participation, but multihalogen substitution as in penta-F-IDA increased the biliary specificity and reduced urinary excretion to the extent that penta-F-IDA scored second to disida and even above I-IDA, with its high molecular weight. Surprising also was the relatively good performance of Cl-IDA compared to Br-IDA and I-IDA.

Animals↗
PubMed1989

Using the "integral spleen" method of radiorenogram analysis and a baboon model to compare the diagnostic usefulness of technetium-99m-diethylenetriamine pentaacetic acid to that of various technetium-99m-mercaptoacetyltriglycene formulations and iodine-123-hippuran.

In light of the high price of commercially available mercaptoacetyltriglycene (MAG3) it was decided to attempt a local MAG3-formation and to test this against diethylenetriamine pentaacetic acid (DTPA), 123I-Hippuran, and commercial MAG3 for diagnostic radiorenographic capabilities also in conjunction with furosemide and captopril. A baboon model (n = 6) was used, and the parameters evaluated were obtained by the "integral spleen" method of radiorenogram analysis. Although the images and parameters pointed to 123I-Hippuran and commercial MAG3 as the ideal renal scanning agents and to DTPA as the least so, with the local product an acceptable alternative, the differences were not significant enough to warrant either the purchase of the commercial product or the extensive development of the local product. Inexpensive 99mTc-DTPA in conjunction with modern computer techniques will probably supply most of the answers.

Animals↗
PubMed1989

Left ventricular volume and function changes during beta-blockade and accompanying atrial pacing.

Radionuclide ventriculography was performed at rest and during transoesophageal pacing on nine anaesthetized baboons (Papio ursinus), alternatively with and without administration of a beta-blocker. Left ventricular volumes, cardiac output, and ejection fraction were determined at each heart rate. A gradual decrease in end-diastolic, end-systolic, and stroke volume followed with increasing heart rate, significantly more pronounced under beta-blockade. Cardiac output and ejection fraction showed no significant changes, although tendencies to increase were observed without beta-blockade. Comparisons of these parameter changes were drawn to those previously observed during the first 5 h of septic shock (E. coli). We conclude that the tachycardia present during this phase of shock is not the only contributory factor to cardiac function changes but that other depressant influences prevail as the added effect of the beta-blocker seems to suggest.

Adrenergic beta-Antagonists↗
PubMed1989

Changes in phase analysis patterns of radionuclide ventriculograms obtained from baboons during atrial pacing, septic shock, and induced myocardial infarction.

Changes in intraventricular phase delays, phase angle histograms, amplitude images, and electrocardiograms (ECG) were investigated during oesophageal pacing with and without beta-blockade, after induced myocardial infarction, and during septic shock in the anaesthetized baboon model. Unavoidable triggering from the pacemaker spike and to a lesser extent increased heart rate were responsible for parameter changes during pacing. Myocardial infarction changed contraction patterns, which did not always correlate with conduction changes from the ECG's. Cardiac volume changes during septic shock could be responsible for the abnormal trends in phase angle spread and electrocardiographic data.

Animals↗
PubMed1988

The comparative recidivism rates of voluntary- and coerced-admission male alcoholics.

The outcomes of inpatient alcoholics who reported that they had been coerced into treatment by commitment or pressure from others were compared in a follow-up study to those of alcoholics who described themselves as voluntary admissions. Ten assessments of control over drinking, number of drinking days in the past week, and intoxication since previous appraisal were made by collaterals between 2 weeks and 18 months after treatment. Even though the data were analyzed in several ways, the number of significant differences did not exceed chance expectations. This suggests that the prognoses of alcoholics who present for treatment under court order or interpersonal pressure were not substantially different from those of men who claim to have entered without coercion. However, the differences between the groups' Control over Drinking ratings, even though not statistically significant, consistently favored the coerced admissions, which raises the possibility that their outcomes may have been slightly better than those of the voluntary admissions.

Adult↗
PubMed1988

Neuropsychological improvement following endarterectomy as a function of outcome measure and reconstructed vessel.

30 patient receiving right or left carotid reconstruction and 15 medically matched controls were compared pre- and post-surgically on measures of motor speed, sustained vigilance, verbal memory and verbal and nonverbal intellectual function. The group receiving right sided vessel reconstruction demonstrated the largest post-operative improvement in intellectual function in any of the groups. The findings suggest that increased blood perfusion following right sided endarterectomy facilitates the right hemisphere's exclusive control of bilateral attention/arousal responses. In addition, findings suggest that detection of post-endarterectomy improvement may be dependent on the specific task dimension sampled, e.g., speed vs. cognitive ability and verbal-graphic vs. nonverbal symbol manipulation.

Carotid Arteries↗
PubMed1988

Scintigraphic phase analysis of abnormal A-V conduction in a baboon.

During an interventional cardiac investigation on an anaesthetised baboon (Papio ursinus) the animal developed A-V block. Scintigraphic phase analysis leading to quantified intraventricular delays and histogram characteristics pointed to abnormalities which persisted even after A-V block was replaced by nodal tachycardia as was reflected by the electrocardiogram. This indicated towards an increased diagnostic sensitivity with the use of phase analytical methods.

Animals↗
PubMed1988

Cholesterol screening in general practice.

Serum cholesterol levels were measured in 250 men and 250 women aged 25-60 years attending a general practice. Seventy three per cent of the sample had levels above 5.2 mM and of these 98 patients agreed to follow a low cholesterol/low saturated fat diet for six months. The overall reduction in serum cholesterol level among these patients was 13%, suggesting that lipid screening in general practice could be worthwhile.

Adult↗
PubMed1988

Central nervous system lupus erythematosus: the value of magnetic resonance imaging.

Magnetic resonance imaging was sued to examine the brains of 13 patients with systemic lupus erythematosus (SLE) who had experienced symptoms and signs of encephalopathy. All the patients had normal computerized tomographic scans. Four patients with abnormal magnetic resonance imaging studies had active central nervous system disease. None of the 9 patients with normal scans had active nervous system involvement at the time of study. Parenchymal lesions were usually located in the region of the corticomedullary junction or in the deep periventricular white matter. In coronal sections, some of the corticomedullary lesions extended centripetally as thin irregular lines into the white matter approximating the course of penetrating arterioles of the brain. The parenchymal lesions resolved in 4 months in 1 patient, but persisted unchanged in the others despite clinical improvement or a stable clinical course. It is likely that the parenchymal lesions of these patients represent intrinsic vasculopathy of small cerebral vessels and perivascular microinfarctions associated with SLE.

Adult↗
PubMed1987

Intrathecally administered natural human fibroblast interferon reduces exacerbations of multiple sclerosis. Results of a multicenter, double-blind study.

A randomized, double-blinded, placebo-controlled, two-year multicenter study demonstrated that natural human fibroblast interferon (interferon beta) administered intrathecally (IT) is effective in reducing the exacerbations of exacerbating-remitting multiple sclerosis (MS). The mean reduction in exacerbation rate of 34 patients with MS who received interferon beta administered IT was significantly greater during the study than that of 35 control patients who received placebo. The prestudy exacerbation rates were comparable for both patients who received interferon beta and control patients, but the exacerbation rate of patients receiving interferon beta at the end of the study was significantly lower than that of the control patients. Interferon beta was administered by nine or ten lumbar punctures for the first six months of the study, and observations were continued for two years. In 95% of the recipients, interferon beta therapy was well tolerated, and the side effects experienced were clearly acceptable for the benefits achieved. Low doses of indomethacin dramatically reduced the toxicity of interferon beta therapy and played an important role in successful double blinding. This study confirms a preliminary report on 20 patients that initially suggested that interferon beta administered IT was of benefit in patients with MS. The number of treatments was fewer and the dosage of interferon beta administered was less in the present study than in the preliminary one. It is possible that even fewer treatments with lower doses of interferon beta administered might provide a similar degree of prophylaxis against exacerbations.

Adult↗
PubMed1987

The nucleotide sequence of the peplomer gene of porcine transmissible gastroenteritis virus (TGEV): comparison with the sequence of the peplomer protein of feline infectious peritonitis virus (FIPV).

The amino acid sequence of the peplomer protein of transmissible gastroenteritis virus (TGEV) has been derived from the cloned cDNA sequence. The gene encodes a protein of 1447 amino acids with a molecular weight of 159 574. Comparison with the primary structure of the peplomer protein of feline infectious peritonitis virus (FIPV) (de Groot et al., 1987b) revealed one domain, from amino acids 1 to 274, in which the nucleotide homology was 39%, whereas in the second domain (from residues 275 to 1447) the homology was 93%.

Amino Acid Sequence↗
PubMed1987

Cardiopulmonary complications after major surgery: a role for epidural analgesia?

Improvement in postoperative pulmonary mechanics with epidural analgesia has been described. Data on the hemodynamic effects of this technique are absent from the surgical literature. To provide such data we have evaluated two groups of patients undergoing aortic reconstruction: group I (n = 25), general anesthesia and group II (n = 6), general anesthesia with adjunctive epidural analgesia. The groups were comparable preoperatively as judged by the incidence of cardiac history, preoperative ejection fraction, and measured hemodynamic parameters. Postoperatively there were no significant differences in the pressure-related parameters; however, rate-related factors including heart rate and double product were significantly decreased in group II with no reduction in cardiac index. Postoperative increases in total body oxygen consumption were also markedly attenuated by epidural analgesia. Epidural analgesia reduces the hemodynamic demands on the heart after major surgery and is a useful adjunct, especially in patients with coronary artery disease.

Aged↗
PubMed1986

Silent brain lesions in patients with isolated idiopathic optic neuritis. A clinical and nuclear magnetic resonance imaging study.

Eight of 16 patients with isolated idiopathic optic neuritis were found to have one to several brain lesions by nuclear magnetic resonance scanning. The brain lesions were predominantly located in the periventricular white matter; their appearances, locations, and extents were similar to those seen in recent nuclear magnetic resonance studies of patients with definite multiple sclerosis. All of these brain lesions were clinically silent and were missed by computerized tomography. Idiopathic optic neuritis may be the only manifestation of a multicentric disease process that is disseminated in the central nervous system in the majority of cases.

Adolescent↗
PubMed1986

Isolated idiopathic optic neuritis. Analysis of free kappa-light chains in cerebrospinal fluid and correlation with nuclear magnetic resonance findings.

There is controversy about the frequency with which patients with isolated optic neuritis (ON) subsequently develop clinically definite multiple sclerosis. Furthermore, at the time of isolated ON, there are no features that are both sensitive and accurate in predicting which patients will develop clinically definite multiple sclerosis. We analyzed cerebrospinal fluid (CSF) samples from eight patients with isolated ON and compared the result with the presence of clinically silent brain lesions demonstrated by nuclear magnetic resonance imaging. The single most common laboratory abnormality was an elevated level of free kappa-light chains in CSF. This abnormality was present in five (63%) of eight patients with isolated ON and correlated with the presence of clinically silent brain lesions demonstrated in four of the five patients by nuclear magnetic resonance. The only other laboratory abnormality that correlated with disseminated disease was the presence of oligoclonal bands, but this finding was observed less frequently than was an elevated level of free kappa-chains. Thus, the presence of free kappa-chains in CSF appears to correlate with disseminated disease in patients with isolated ON and may have prognostic value.

Adolescent↗