Search PubMed⌕ Search

Biomedical subjects

L Jacobs

Publications and source records attributed to L Jacobs.

At least 109 records · Page 6Linked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

Nuclear magnetic resonance imaging in patients with stroke.

In contrast to CT, NMR imaging revealed a high percentage of abnormalities in the TIA-RIND population studied. The various patterns of abnormalities identified should provide further insight into the pathophysiology of ischemic cerebrovascular disease. Age and hypertension appeared to be the most significant clinical risk factors for TIA-RIND. Although periventricular hypodensities have been visualized by CT for many years, their clinical significance has only recently been appreciated. NMR shows the same periventricular changes as increased signal (long T2), but shows it in a more dramatic fashion. These periventricular abnormalities, seen both by CT and NMR, have been shown in some cases to be compatible with the pathologic diagnosis of SAE, or Binswanger's disease. Watershed abnormalities both with and without corresponding cerebral infarctions have been presented. At present, this appears to be a ubiquitous group of cerebrovascular disease with multiple underlying causes. NMR is superior to CT for demonstrating watershed infarctions, not only because it reveals ones missed by CT, but also because it shows a fuller extent of involvement than does CT. The evolution of cerebral infarctions as seen by CT and NMR has been presented. NMR demonstrates abnormalities earlier than CT. The region of infarction appears more extensive than by CT and chronic infarctions show an associated rim of prolonged T2 that may correspond to the ischemic penumbra or regions of ischemic demyelinization. CT phenomena, such as fogging and GME, have their NMR correlates. To date, all regions of GME shown by CT have also been demonstrated by NMR. Cortical infarctions, thought in many instances to be due to emboli have been frequently demonstrated by NMR. NMR imaging is clearly superior to CT for recognizing these lesions because it is not hampered by artifact from bone adjacent to cortex, as is CT. Similarly, posterior fossa and brainstem infarctions may be seen to advantage by NMR.

Aged↗

Characterization and translation of transmissible gastroenteritis virus mRNAs.

Three protein species were identified in purified transmissible gastroenteritis virus particles (strain Purdue). They are thought to represent constituents of the peplomer (E2; molecular weights of 280,000 and 240,000), the envelope (E1; molecular weights of 28,000, 31,500, and 33,000), and the nucleocapsid (N; molecular weight of 48,000). In infected cells, proteins with molecular weights of 195,000 (E2), 48,000 (N), and 28,000 (E1) were detected. Tunicamycin, an inhibitor of N glycosylation, prevented the appearance of polypeptides with molecular weights of 195,000 and 28,000 in infected cells; instead, proteins with molecular weights of 160,000 and 25,000 were observed. One minor and five major mRNA species were detected in porcine cells after infection. Their size was determined to be 23.6 kilobases (kb) (RNA1), 8.4 kb (RNA3), 3.8 kb (RNA4), 3.0 kb (RNA5), 2.6 kb (RNA6), and 1.9 kb (RNA7). The RNAs were translated in vitro. RNA7 was shown to code for the N protein. Although complete separation of RNA6 could not be achieved, it was shown to encode an unglycosylated (molecular weight of 25,000) precursor of E1 (molecular weight of 28,000). RNA4 was translated into a nonstructural protein with a molecular weight of 24,000. Translation of RNA3 resulted in proteins with molecular weights of 250,000 and 130,000 and smaller molecules which could be precipitated with a monoclonal antibody directed against E2.

Animals↗

Correlations of nuclear magnetic resonance imaging, computerized tomography, and clinical profiles in multiple sclerosis.

Nuclear magnetic resonance (NMR) imaging was superior to CT for imaging the brain lesions of 27 patients with MS. The incidence of abnormal examinations was 78% by NMR and 63% by CT. In cases in which both studies were abnormal, NMR usually demonstrated many more lesions and more extensive involvement than CT. The appearance and locations of lesions identified by NMR were similar to those of autopsy studies of MS and may be relatively specific for this disease. Some lesions identified by CT disappeared during serial examinations, but lesions identified by NMR did not resolve over time. Seventy-five percent of the lesions were clinically "silent"; only 5% were definitely related to the clinical symptoms and signs. All of those lesions were located in the brainstem or cerebellar peduncles and were identified by NMR, but missed by CT.

Adult↗