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Biomedical subjects

M Martin

Publications and source records attributed to M Martin.

At least 739 records · Page 41Linked to original sources
PubMed1988

Interleukin 1 and the glomerular mesangium. III. IL-1-dependent stimulation of mesangial cell protein kinase activity.

Interleukin 1 (IL-1) exerts a number of biologic actions upon cultured glomerular mesangial cells (MC). These include stimulation of cellular proliferation and induction of prostaglandin and type IV collagenase secretion. It was determined that this activity, as with other polypeptide growth factors, was associated with the activation of specific MC plasma membrane protein kinases. Plasma membranes from cycling MC were incubated with purified IL-1 and (32P) ATP in the absence of calcium and cyclic nucleotides. Macrophage IL-1 stimulated the rapid phosphorylation of several plasma membrane proteins, the most significant of which were 52-55 kd, 46 kd, and 20 kd in size. Macrophage IL-1 induced specific membrane phosphorylation in concentrations as low as 1.5 x 10(-12) M, an effect obtained with equivalent concentrations of purified MC IL-1. The 46 kd phosphoprotein, which was the most prominent, was alkali-resistant and contained phosphotyrosine when examined by phosphoamino acid analysis. The 52-55 kd and 20 kd phosphoproteins were alkali-labile and contained phosphoserine. The 46 kd phosphoprotein was the major phosphoprotein recovered from Con A-Sepharose and IL-1 affinity columns. Induction of plasma membrane-associated protein kinase activity may represent one mechanism whereby IL-1 initiates mesangial cellular activation.

Animals↗
PubMed1988

The relative effects of therapy and periodontal disease on loss of probing attachment after root debridement.

This study investigated the immediate effects, and the effects during 12 months, of a single episode of root debridement in 1248 sites in 9 periodontitis patients. Single recordings for probing depths and probing attachment levels were made at baseline, and at 3, 6, 9 and 12 months. In addition, triplicate recordings of attachment levels were made for all sites by 3 independent examiners immediately prior to debridement, immediately post debridement, and at 3 and 12 months. It was found that a mean loss of probing attachment of 0.5 to 0.6 mm occurred as a result of instrumentation, irrespective of initial probing depth. Individual sites were identified as having lost probing attachment using a site-specific standard deviation for measurement variability and a greater than or equal to 1.0 mm change. 5% of all sites lost probing attachment from pre-instrumentation to 12 months. Approximately half of these had probing attachment loss inflicted during instrumentation. 23 sites (2% of all sites) were identified as having lost probing attachment from the post-instrumentation time point to 12 months. The majority of these sites seemed to undergo this probing attachment loss as a result of a remodelling process during the healing phase. Over the observation period used in this study, the majority of the attachment loss identified seems to be either directly attributable to instrumentation or to a remodelling process as a result of the therapy rather than to progressive periodontitis.

Adult↗
PubMed1988

Treatment of periodontal furcation defects. (I). Review of the literature and description of a regenerative surgical technique.

This report provides an abbreviated review of the literature on treatment and prognosis of periodontal furcation lesions. In addition, it describes a surgical technique designed to accomplish bone regeneration in class II furcation defects, together with the rationale for the development of this procedure. Results of treatment of 30 defects with this technique are presented in a subsequent report.

Bone Regeneration↗
PubMed1988

Treatment of periodontal furcation defects. (II). Bone regeneration in mandibular class II defects.

A total of 30 mandibular, buccal class II furcation defects were treated in 22 subjects using a regenerative surgical therapy that included citric acid root conditioning and coronally positioned flaps secured by crown-attached sutures. In addition, grafts of freeze-dried, decalcified allogenic bone were placed in 16 of the 30 defects. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. These measurements demonstrated notable improvement 12 months following therapy. On the average, 67% of the defect volume became filled with bone. 43% of treated defects were completely closed by bone fill. No difference was observed between defects treated with and without bone grafts.

Adult↗
PubMed1988

Combination of chemotherapy and radiotherapy in limited small cell lung carcinoma: results of alternating schedule in 109 patients.

One hundred nine patients with limited small cell lung carcinoma were entered in a phase II study of treatment consisting of alternating 6 cycles of combination chemotherapy and 3 courses of mediastinal radiotherapy. Chemotherapy consisted of 40 mg doxorubicin/m2 on day 1; 75 mg etoposide/m2 on days 1, 2, and 3; 300 mg cyclophosphamide/m2 on days 3, 4, 5, and 6; and 400 mg methotrexate/m2 on day 2 (plus folinic acid rescue) or 100 mg cisplatin/m2 on day 2. The total mediastinal radiation dose was 45 or 55 Gy. A 6- to 8-cycle maintenance chemotherapy followed this induction protocol. The complete remission rate at the end of the induction therapy was 79%. The local recurrence rate was 25%, and the distant metastases rate was 52%. Median survival is 17.2 +/- 1.2 months and survival rate at 3 years is 26%. Lethal toxicity occurred in 3% of the patients, and long-term survivors are being evaluated. Our results justify further investigations with this alternating schedule.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Valproate-induced stimulation of renal ammonia production and excretion in the rat.

Administration of valproate, a widely used antiepileptic drug, markedly stimulated the production of ammonia by the rat kidney, resulting in an increase in both the renal venous release and the urinary excretion of ammonia. These effects were associated with a diminution of the plasma concentration of urea which was not accompanied by a stimulation of the urinary excretion of urea. These results indicate that the kidneys, together with the liver, might contribute to the hyperammonaemia caused by valproate.

Ammonia↗
PubMed1988

5 alpha-cholest-8(14)-en-3 beta-ol-15-one, a potent regulator of cholesterol metabolism: occurrence in rat skin.

5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of cholesterol biosynthesis which has significant hypocholesterolemic activity upon oral administration to animals. Described herein are the results of experiments that indicate the presence of the 15-ketosterol in rat skin. The 15-ketosterol was, after purification by medium pressure liquid chromatography on Lichroprep RP-8 columns, thin-layer chromatography on silica gel G, and reverse phase high performance liquid chromatography, characterized by gas-liquid chromatography-mass spectrometry in the form of its trimethylsilyl ether derivative. The use of an internal standard containing both tritium and deuterium permitted the determination of the levels of the 15-ketosterol by mass fragmentography. The results of five separate analyses of portions of the skin of a male Sprague Dawley rat showed a mean value of 84.5 +/- 4.1 (SEM) ng per g. Analyses of hair samples of ten male Sprague Dawley rats indicated a mean level of 143 +/- 19 (SEM) ng per g of hair. Most (approximately 72%) of the 15-ketosterol in hair was esterified. This report constitutes the first isolation of the 15-ketosterol from animal tissues.

Animals↗
PubMed1988

[The therapeutic value of second-look laparotomy in advanced ovarian carcinoma].

42 patients with advanced epithelial ovarian carcinoma who were clinically free of disease after completed postoperative chemotherapy were submitted to second-look laparotomy at the University clinics of Bilbao and Santander, in Northern Spain, between 1980 and 1987. Tumor was demonstrated in 22 of the cases (52.3%). This paper deals with the question of whether this knowledge and the ensuing change in therapy resulted in a longterm benefit for the patients or not. In our experience, this was not the case. All second-look-positive patients either died during the follow-up period, or showed tumor progression if they survived more than 6 months. Survival sank to 50% after only 24 months, and steadily thereafter to 0% after 78 months. The therapeutical value of second-look laparotomy is heavily questioned by these results.

Adenocarcinoma↗
PubMed1988

Effect of oxodipine and nifedipine on guinea-pig ileum.

1. The effects of oxodipine, a new dihydropyridine, were studied and compared with those of nifedipine in guinea-pig ileum. 2. Oxodipine and nifedipine, 10(-8)-10(-7) M, produced a dose-dependent inhibition of the contractile responses induced by single pulse stimulation, acetylcholine and histamine. 3. From these experiments it is concluded that oxodipine like nifedipine produced a similar and potent inhibitory effect of the contractile responses induced in guinea-pig ileum.

Acetylcholine↗