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J M Baron

Publications and source records attributed to J M Baron.

72 records · Page 4Linked to original sources
PubMed1980

[The influence of pethidine on uterine activity and dilatation of the cervix in spontaneous labour (author's transl)].

Two series of patients, randomly selected, 29 of whom had pethidine and 29 of whom had a placebo, were compared in order to study the influence of intra-muscular pethidine on uterine activity and on the speed with which the cervix dilated. The experiment was a double blind one. A significant increase in the basal tone of the uterine muscle was found 40 minutes after the injection in the group that received pethidine, although there was no other significant difference in the other parameters which were intensity, frequency, length, surface of the contractions [half the height multiplied by (X times) the base on the monitor recording], uterine activity in Montevideo and in Toulouse units and the speed of dilatation. These results do not bear out the classical hypotheses of the muscle relaxing effect of pethidine, and in particular that the uterus relaxes better between contractions, nor that there is relaxation of the cervix in labour. The indication for the use of pethidine is perhaps justified because of its analgesic effect, but as far as favouring dilatation of the cervix in labour is concerned is at best worthy of discussion.

Cervix Uteri↗
PubMed1979

The use of bone core biopsies for cytogenetic analysis.

Cultures of bone core specimens have proved satisfactory for cytogenetic analysis in patients from whom it was impossible to obtain a bone marrow aspirate, or in whose peripheral blood dividing myeloid cells were absent or insufficient in number. The quality of the metaphase chromosome is adequate for banding studies.

Adult↗
PubMed1979

Combined therapy for patients with mycosis fungoides.

In a comprehensive mycosis fungoides program, 60 patients have been seen with a pathologic diagnosis of this disease. Forty-four patients with advanced disease were referred for radiation therapy. Three treatment techniques were identified in which 14 patients were treated with localized fields using electrons or whole-body electron-beam therapy with doses of less than 3000 rads, 21 patients were treated using the Stanford technique with tissue doses of between 3000 and 4000 rads, and nine patients were treated with six cycles of mechlorethamine, vincristine, prednisone, and procarbazine or cyclophosphamide, vincristine, prednisone, and procarbazine following the electron-beam therapy. The actuarial survival rate was 45% at 1 year for the 14 patients with localized electron-beam therapy, whereas the actuarial survival rates were 83% for patients treated with whole-body electron-beam therapy and 100% for patients treated with whole-body electron-beam therapy followed by four-drug chemotherapy. The recurrence-free interval for these three groups correlates with these observations. A central nervous system recurrence has been observed in the combined-therapy group.

Adult↗
PubMed1975

Osteosclerosis in primary hyperparathyroidism.

Osteosclerosis in adults with primary hyperparathyoidism is rare; the usual skeletal manifestation, when presented, is diffuse osteropenia. We describe a patient with generalized osteosclerosis in association with primary hyperparathyroidism. The findings are documented by conventional and fine-detail radiography, absorptiometric bone mineral analysis, quantitative microradiography and histologic examination of bone. The unique features are contrasted with the manifestations recorded in a recently studied group of 87 hyperparathyroid patients. The data presented here support a causal relationship in this patient between parathyroid hormone excess and the development of densely sclerotic bones.

Adenoma↗
PubMed1969

Synthesis of 10,11-dihydrofarnesyl pyrophosphate from 6,7-dihydrogeranyl pyrophosphate by prenyltransferase.

The syntheses of 6,7-dihydrogeraniol and of its pyrophosphate are described. It is shown that this analogue of geranyl pyrophosphate is a substrate for liver prenyltransferase and that the product synthesized by this enzyme from it and isopentenyl pyrophosphate is 10,11-dihydrofarnesyl pyrophosphate. The K(m) value for 6,7-dihydrogeranyl pyrophosphate was determined to be 1.11+/-0.19mum as compared with 4.34+/-1.71mum for geranyl pyrophosphate. The maximum reaction velocity with the artifical substrate was, however, only about one-fourth of that observed with geranyl pyrophosphate. The binding of isopentenyl pyrophosphate to the enzyme was not affected by the artificial substrate.

Alkenes↗
PubMed1969

Artificial substrates for prenyltransferase.

Four out of 16 new allylic pyrophosphates synthesized were found to be artificial substrates for liver prenyltransferase (EC 2.5.1.1). These were the trans-and the cis-3-ethyl-3-methylallyl, the 3,3-diethylallyl and the (mixture of cis and trans) 3-methyl-3-n-propylallyl pyrophosphates. The products synthesized from these substrates and isopentenyl pyrophosphate were the appropriate homo- and bishomo-farnesyl pyrophosphates. Substitution of 3,3-dimethylallyl pyrophosphate at C-2 with a methyl group destroyed its reactivity with the enzyme. Neither the unsubstituted allyl pyrophosphate nor the cis- or trans-3-methylallyl pyrophosphate could be condensed with isopentenyl pyrophosphate. Thus the simplest allylic substrate for prenyltransferase is 3,3-dimethylallyl pyrophosphate.

Animals↗
PubMedDate not supplied

Myocardial single-photon emission computed tomographic quality assurance.

In this era of cost constraints in health care and the growing demand for cost-effective clinical strategies, the nuclear cardiologist is under increasing pressure to show clear evidence that myocardial imaging studies compete favorably with other modalities. This underlines the need for ensuring consistently high image quality and accuracy using optimally chosen standardized protocol. Nuclear medicine imaging has not yet reached the level of standardization, automation, and built-in quality control of imaging modalities such as ultrasound or x-ray computerized tomography, where the press of a button guarantees a consistent high-quality image. This is due to the large number of parameters and other factors affecting image quality that each individual operator still has to choose or be aware of before commencing imaging. Of crucial importance is ensuring the correct collection of the raw data. Processing can be repeated, but errors in the raw data, if detected at all, require repeating the entire study. These errors can cause artifacts that are difficult or impossible to recognize and are the major causes of incorrect reporting. Examples are a poorly prepared radiopharmaceutical, a poor injection, scatter from "hot" areas outside myocardium, an undetected change in the photopeak window, uniformity, or center of rotation, insufficient acquisition time, camera too far from the patient, etc. The first step to guarantee consistent image quality and accuracy is the preparation and strict implementation of a quality assurance program covering all the individual stages of the procedure starting from preparation of the radiopharmaceutical and ending with processing, display, and reporting. The next step is the standardization of optimally chosen protocols with maximization of automation. Rapid built-in automated software-driven equipment quality control checks should be developed. Finally, attenuation and scatter correction, gated single-photon emission computed tomography, and the advent of digital cameras will no doubt improve quantitation and accuracy even further following clinical evaluation in close cooperation with manufacturers who have the incentive to accelerate all the above steps.

Heart↗
PubMedDate not supplied

Changes in plasma factor VIII complex and serum lipid profile during atherogenesis in cynomolgus monkeys.

If endothelial injury plays a prominent role in early atherogenesis, the plasma levels of von Willebrand factor (VWF), which is made within and normally released from endothelial cells, might be expected to rise as a marker of the cellular damage. To evaluate this hypothesis, we measured plasma VWF (as VIIIR:Ag), factor VIII:C, and serum lipids serially up to 37 weeks in 29 adult male cynomolgus monkeys on an atherogenic diet. Factor VIII:C peaked at 113% above baseline by week 10 (p less than 0.0001), then fell and remained 53% below baseline (p less than 0.04) during weeks 20 to 37. However, the overall rise in VWF was not significant. In contrast, serum cholesterol continued to rise after week 21. Serum phospholipids (PL), triglycerides (TG), and free fatty acids (FFA) showed a temporal pattern similar to VIII:C. Significant positive correlations with VIII:C were noted for PL (r = 0.59, p = 0.0001) and TG (r = 0.36, p = 0.0096). At autopsy, small to moderately advanced atherosclerotic lesions were distributed throughout the aortas of the majority of the animals. We conclude that changes in plasma VIIIR:Ag do not correlate with atherogenesis in this model. However, the similar course of VIII:C, TG, and PL suggests that these substances may be involved and perhaps interrelated early in atherogenesis.

Animals↗