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Biomedical subjects

J Jacob

Publications and source records attributed to J Jacob.

At least 145 records · Page 8Linked to original sources
PubMed1990

Identification of Campylobacter jejuni and Campylobacter coli from waste water by SDS-disc-page of whole cell protein.

Analysis of the electrophoretic profiles of whole cell proteins of Campylobacter strains from waste water was used to differentiate C. jejuni from C. coli. The results show, that biotyping of campylobacters from waste water may results in a false species differentiation. Some of the Campylobacter strains originally typed as C. coli, were proved to be atypical C. jejuni strains. Therefore, in addition to biotyping and serotyping, electrophoretic typing is recommended to ensure correct identification of Campylobacter, especially from environmental sources.

Bacterial Proteins↗
PubMed1989

Axonal transport of neurofilament is accelerated in peripheral nerve during 2,5-hexanedione intoxication.

The neurotoxic compound 2,5-hexanedione (2,5-HD) causes an axonopathy characterized by the presence of neurofilament (NF)-containing enlargements in the preterminal segments of central and peripheral axons. The 2,5-HD axonopathy is a good model for human acquired and inherited giant axonal neuropathies. Recently, we reported that following 2,5-HD administration, axonal transport of NF is markedly and selectively accelerated in the primary visual system. We have now studied slow axonal transport in the sciatic system of rats intoxicated with 0.5% 2,5-HD in drinking water. Following radiolabeling, transported proteins were examined after polyacrylamide gel electrophoresis and fluorography. The bulk of radiolabeled NF subunits was located 30-50 mm from the spinal cord in 2,5-HD treated animals and 10-25 mm in controls. The rate of transport of the three NF subunits was 0.7 mm/day in controls and 1.2 mm/day in 2,5-HD treated animals. The rate of transport of tubulin was not significantly changed. Electrophysiological studies of soleus nerve and muscle showed no evidence of denervation after 6 weeks of intoxication. It is concluded that, following 2,5-HD administration, transport of NF is preferentially accelerated in both central and peripheral axons. A pathogenetic mechanism based on the acceleration of NF transport is proposed, which may explain the formation and the distal or proximal location of NF-containing axonal enlargements in giant axonopathies.

Action Potentials↗
PubMed1989

Urinary and faecal excretion of pyrene and hydroxypyrene by rats after oral, intraperitoneal, intratracheal or intrapulmonary application.

The urinary and faecal excretion of pyrene and 1-hydroxypyrene after oral (53.4%), intraperitoneal (3.1%), intratracheal (30-37%) and intrapulmonary application (0.003%) to rats has been determined by means of gas chromatography/mass spectrometry and the excretion rates were found to depend on the mode of application. With regard to the low urinary excretion rates, 1-hydroxypyrene seems not to be very suitable as a biological marker for PAH exposure to man.

Animals↗
PubMed1989

Growth factor production by sarcoma cells in primary culture.

Cell lines derived from human sarcomas have been previously shown to produce a protein growth factor which, similar to platelet-derived growth factor (PDGF), can induce competence for mitosis in fibroblasts. Whether this factor production is an important feature of sarcomas in vivo or simply an artefact caused by long-term culture conditions is unclear, however. We demonstrated growth factor activity in conditioned medium from six of 11 primary sarcoma cultures, utilizing flow cytometric analysis of DNA to monitor the presence of sarcoma cells in cultures. Cells isolated from control tissues failed to show a similar mitotic effect.

Cells, Cultured↗
PubMed1989

Changes in the polynuclear aromatic hydrocarbon content of wheat grain and pasture grassland over the last century from one site in the U.K.

Crops harvested and stored from two long-term agricultural experiments started in the 1840-1850s at Rothamsted Experimental Station (U.K.) have been analyzed for polynuclear aromatic hydrocarbons (PAHs) because PAHs have increased four-to-five fold in the underlying 0-23 cm depth of soil over the last century due to atmospheric deposition. Bulked samples of herbage and wheat grain were analyzed for 16 compounds by gas chromatography-mass spectrometry for groups of years between 1860 and 1986. The sigma PAH (16 PAH) concentrations in herbage ranged between 110 and 6900 micrograms kg-1 dry weight, with fluoranthene, pyrene, benzofluoranthenes (b + j + k), chrysene and triphenylene consistently the most abundant. Benz[a]anthracene, benzo[ghi]perylene, benzo[a]pyrene, benzo[e]pyrene and indeno(1,2,3-cd)pyrene were also all important constituents. PAH concentrations in wheat grain ranged from 4 to 46 micrograms sigma PAH kg-1; the mixture of individual compounds was similar to that in herbage. Correcting for yield differences these corresponded to 37-1500 and 2.4-8.8 micrograms sigma PAH m-2 for herbage and wheat grain respectively. The lowest values were found in the most recent samples (1980s) and the highest for samples collected in 1879-81. Generally, there was a decline in the PAH burden of the vegetation with time. The temporal trends of PAHs in the samples are discussed in the context of possible sources of PAHs. Various lines of evidence indicate that the PAH concentrations in vegetation are an indication of atmospheric deposition directly onto the above-ground plant portions, and that uptake and translocation of soil-bound PAHs is of minor importance.

Animal Feed↗
PubMed1989

[Sternocostoclavicular osteoarthritis].

On observation of a case of infectious osteoarthritis which was remarkable both because of its site, the sternoclavicular joint, and of the germ involved, which was Salmonella paratyphi A is reported.

Adult↗
PubMed1989

[Arteriographic aspects of Buerger's disease. Apropos of 18 cases].

Arteriosclerosis obliterans occurring in a young man in an impressive clinical presentation which requires a precise diagnosis. There are no clinical, radiological, laboratory or histological signs of Buerger's disease. In arteriography, all of the suggestive negative and positive elements are important and must be well known as the diagnostic orientation large depends on recognition of their association. Arteriography is still the fundamental examination for assessment of the course of the disease.

Adult↗
PubMed1988

Linear gramicidin activates neutrophil functions and the activation is blocked by chemotactic peptide receptor antagonist.

The activation of functional responses in rabbit peritoneal neutrophils by gramicidin and the chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine methyl ester, was studied. Gramicidin activated superoxide generation, lysosomal enzyme release and a decrease in fluorescence of chlortetracycline-loaded cells, as for the chemotactic peptide. The maximum intensities of the responses by gramicidin were lower than that by chemotactic peptide. Responses by both these peptides could be inhibited by t-butyloxycarbonyl-methionyl-leucyl-phenylalanine, a chemotactic peptide receptor antagonist. Gramicidin gave responses at low doses comparable to that of the chemotactic peptide.

Animals↗
PubMed1988

Ca2+ ionophores inhibit superoxide generation by chemotactic peptide in rabbit neutrophils and the correlation with intracellular calcium.

Effects of Ca2+ ionophores, A23187 and lasalocid, on superoxide anion generation by chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine methyl ester, in rabbit peritoneal exudate neutrophils were studied. The ionophores by themselves did not activate superoxide anion generation in these neutrophils. When preincubated with the cells for 2 min, both the ionophores inhibited superoxide generation induced by chemotactic peptide. The inhibition was present even in the absence of extracellular Ca2+ and the inhibition was better then. Lasalocid produces a dose-dependent chlortetracycline fluorescence decrease response in neutrophils loaded with chlortetracycline. This response is independent of extracellular Ca2+ concentration and is related to release of Ca2+ from intracellular storage sites. The dose-range at which lasalocid gives this response is same as the dose-range at which it causes inhibition of superoxide response. It may be concluded that the inhibition of superoxide generation by these ionophores is correlated to intracellular Ca2+ modulation.

Animals↗
PubMed1988

Urinary and faecal excretion of chrysene and chrysene metabolites by rats after oral, intraperitoneal, intratracheal or intrapulmonary application.

The urinary and faecal excretion of chrysene and its phenolic metabolites after oral, intraperitoneal, intratracheal, and intrapulmonary administration to rats have been studied by means of gas chromatography/mass spectrometry. The metabolite profile was found to depend on the mode of excretion and on the route of administration. In all cases the oxidation of chrysene in the 1,2- or 3,4-position predominates, whereas oxidation in the 5,6-position (K-region) seems be a minor pathway.

Administration, Inhalation↗
PubMed1988

Novel GABA agonists depress the reward effect of lateral hypothalamic stimulation in rats.

Rats were given systemic injections of one of a series of novel GABA compounds which can penetrate the blood-brain barrier to release GABA into the brain. They were then tested on lateral hypothalamic self-stimulation behavior using a rate-frequency paradigm to discriminate effects on reward from those on motor/performance. Both reward and, to a lesser extent, motor/performance impairments were found with all GABA compounds. In more extensive testing with one compound, LG2, no differences in the effects of three salts (acetate, ascorbate, and tartarate) were found except that the tartarate salt effects decayed more rapidly.

Animals↗
PubMed1988

Subsequent pregnancies in previously infertile women with endometriosis.

Sixty-eight previously infertile patients with endometriosis who had delivered a child tried to conceive again. Fifty-two of them were successful, 28 within 1 year, and 16 were not. The ability to conceive a second child was uniformly good regardless of the stage of the previous disease, the method of treatment, the duration of the initial sterility, or the age of the patient. Patients with endometriosis and infertility who deliver should be reassured concerning their chances of completing their families.

Adult↗
PubMed1988

Rheumatoid arthritis: similarity of radiographic abnormalities in men and women.

To test the hypothesis that there are significant differences in the radiographic appearance of rheumatoid arthritis between men and women, the authors blindly evaluated bilateral hand and wrist radiographs in 32 men with definite rheumatoid arthritis and 32 age- and disease duration-matched women (mean age, 56.4 years; mean disease duration, 10.5 years). Radiographically, disease distribution and severity were identical in these matched groups. Superimposed osteoarthritis was frequent in both groups and related to age. Ill-defined bone proliferation was present in 13 of 64 hands in both groups. Cystic changes and well-defined erosions were present in 12 of 64 male hands and six of 64 female hands, but this difference was not statistically significant. In women, presence of cysts and bone proliferation was related to disease duration, whereas men exhibited these atypical features independent of disease duration. There was no statistically significant difference in the frequencies of typical and atypical features of rheumatoid arthritis between the two sexes, and the authors postulate that previously reported differences relate to patient selection and lack of adequate matching.

Arthritis, Rheumatoid↗
PubMed1988

A randomized trial of standard chemotherapy v a high-dose chemotherapy regimen in the treatment of poor prognosis nonseminomatous germ-cell tumors.

We performed a prospective randomized trial of a high-dose chemotherapy regimen v standard cisplatin-based chemotherapy in poor prognosis nonseminomatous germ-cell cancer patients. The high-dose regimen consisting of twice the standard dose of cisplatin (P), along with vinblastine (Ve), bleomycin (B), and the epipodophylotoxin etoposide (VP-16) (V) (PVeBV) was compared to the classic regimen with normal dose cisplatin, vinblastine, and bleomycin (PVeB). Eligibility criteria included large abdominal masses, liver metastases, multiple pulmonary metastases, brain metastases, marked elevations in serum tumor markers (alpha-fetoprotein greater than 1,000 ng/mL or the beta-subunit of human chorionic gonadotropin greater than 10,000 mIU), unfavorable histology (pure choriocarcinoma), or extragonadal germ-cell tumors. Fifty-two consecutive patients with poor prognostic features were randomized to receive either PVeBV or PVeB. The median follow-up is 4 years. Treatment with the high-dose regimen increased the complete remission rate (88% v 67%, P = .14) and was associated with a lower relapse rate (17% v 41%, P = .2). The median survival of patients receiving standard therapy was 30 months, while the median survival for patients receiving the high-dose regimen has not been reached. Actuarial 5-year survival for patients treated with the high-dose regimen is 78%, compared with 48% for patients receiving standard therapy (two-sided Mantel-Cox test = .06). Disease-free survival was also superior for patients randomized to PVeBV (P = .03). Sixty-eight percent of patients (23 of 34) randomized to PVeBV are alive and continuously disease-free, compared with 33% (six of 18) for PVeB (P = .02). The major difference in toxicity between the high-dose regimen and standard therapy was the severity of myelosuppression and the incidence of severe hearing loss. Ninety-one percent of patients treated with PVeBV had a WBC count less than 1,000/microL, compared with 50% of patients receiving PVeB (P less than .05). Hearing aids were recommended for 12 patients who received PVeBV and two who received PVeB. The increased effectiveness of the PVeBV regimen in poor prognosis germ-cell cancer patients may relate to the double-dose cisplatin, the addition of VP-16, or to a synergistic effect of these two drugs.

Antineoplastic Combined Chemotherapy Protocols↗