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Biomedical subjects

P Martin

Publications and source records attributed to P Martin.

At least 847 records · Page 47Linked to original sources
PubMed1985

Effect of age, malnutrition and renutrition on free secretory component and IgA in secretions.

The development of free secretory component (FSC) was studied in the tears of normal infants, children and adults. The level of FSC in tears was higher in older adults than in children. Free secretory component was also measured in the tears of normal, moderately and severely malnourished Colombian children. Children suffering from kwashiorkor, combined protein-calorie malnutrition or marasmus were studied before and after renutrition. No change was detected in the concentration of FSC in tears of moderately malnourished (Grade I and II) children. There was a significant difference between normal and severely malnourished children which improved with renutrition. The levels of tear IgA were decreased in the moderately malnourished children. These results indicate that reduction in secretory IgA levels in moderate malnutrition may not be explained by a lack of available free secretory component in tears, but that severe malnutrition may impair the S-IgA system by significantly reducing the availability of free secretory component.

Adolescent↗
PubMed1985

Effects of loading conditions and inotropic state on rapid filling phase of left ventricle.

Afterload, activation sequence, inotropism, and extent of shortening affect the time constant (T) of left ventricular (LV) isovolumic pressure decay, yet it is unknown if they modify peak lengthening velocity of the LV minor axis [(dD/dt)/D]. Accordingly, we studied their effects on (dD/dt)/D, measured by sonomicrometry, in nine anesthetized open-chest dogs during atrial pacing at 2 Hz. Afterload was increased 20-40 mmHg by 1) constricting the ascending aorta and 2) occluding the descending aorta for four beats. Activation was altered by right ventricular pacing. These interventions, plus constriction of venae cavae, were studied during four inotropic states. Aortic stenosis increased (dD/dt)/D (P less than 0.05), whereas occlusion of the descending aorta, vena caval constriction, and right ventricular pacing decreased (dD/dt)/D (P less than 0.05). Left atrial pressure was constant except during vena caval constriction. Alterations in inotropic state modified (dD/dt)/D (P less than 0.001). Extent of shortening and (dD/dt)/D were directly related (r = 0.80, P less than 0.001). Changes in (dD/dt)/D and T were inversely related (r = 0.70, P less than 0.001), and alterations in the interval from -dP/dtpeak to the end of rapid filling were directly related to changes in T (r = 0.75, P less than 0.001). We conclude that (dD/dt)/D can be modified by systolic and diastolic load perturbations, activation sequence, and inotropic interventions. These effects relate to changes in extent of shortening, time course of inactivation, or both.

Animals↗
PubMed1985

[Chemotherapy of embryonal carcinoma of the testis with lymph node invasion and/or pulmonary metastases. Results of a VBP type protocol].

Fourteen patients with histologically proven embryonal carcinoma of the testis with pulmonary metastasis (10 pts) or para-aortic nodal involvement (4 pts) were treated by a chemotherapy regimen including vinblastine, bleomycin and cisplatin. Extreme ages were 19 and 51 years with a median age of 32 years. Median duration of treatment was 6 months (6 cycles of chemotherapy) without maintenance treatment. After completion of chemotherapy, 6 patients in complete remission received para-aortic node irradiation (45 Grays in 25 fractions). One patient had a para-aortic node dissection, histologically negative. With a median follow-up of 47 months (maximum 92 months, minimum 12 months), eleven patients are in complete remission (78.6%). Three patients are dead from the disease, in spite of salvage chemotherapy. There were no toxic deaths. Disease-free actuarial survival is 74% at 4 years. Our results confirm the excellent therapeutic results of this chemotherapy regimen in embryonal carcinoma of the testis with pulmonary metastasis and/or para-aortic nodal involvement.

Adult↗
PubMed1985

Donor cell leukemia developing six years after marrow grafting for acute leukemia.

A patient who developed recurrent leukemia more than six years after marrow grafting from an HLA-identical same-sex sibling is reported. Difference in DNA restriction fragment length polymorphisms between donor and host demonstrated that the DNA in the recurrent leukemia sample was probably of donor origin. Possible mechanisms that could explain the long latent period between transplantation and expression of leukemic transformation are discussed. We conclude that future cases of late leukemic recurrence after marrow grafting should be studied to determine whether, in contrast to early relapses, late relapses occur in donor cells in most or all instances.

Adult↗
PubMed1985

Evidence for clonal development of childhood acute lymphoblastic leukemia.

To determine whether acute lymphoblastic leukemia (ALL) is a clonal disease and to define the pattern of differentiation shown by the involved progenitor cells, we studied the glucose-6-phosphate dehydrogenase (G6PD) types in the cells of 19 girls heterozygous for this X chromosome-linked enzyme. Lymphoblast immunophenotypes were those of HLA-DR+, CALLA+ ALL (six patients); HLA-DR+, CALLA- ALL (four patients); pre-B cell ALL (two patients); T cell ALL (four patients); and undefined ALL (three patients). Malignant blast cells at diagnosis from ten patients displayed a single G6PD type, indicative of clonal disease. In contrast, both A and B G6PD in ratios similar to those found in skin were observed in morphologically normal blood cells from the same patients. The leukemic cells of three patients were examined at both diagnosis and relapse; in each instance the same G6PD type was found, consistent with regrowth of the original leukemic clone at relapse. Results of studies of cells from nine additional patients tested only at relapse were similar. Our results indicate that childhood ALL is a clonally derived disease involving progenitor cells with differentiation expression detected only in the lymphoid lineage.

Adolescent↗
PubMed1985

A randomized trial of antihuman thymocyte globulin versus murine monoclonal antihuman T-cell antibodies as immunosuppressive therapy for aplastic anemia.

A prospective randomized trial was undertaken to compare the efficacy and toxicity of murine antihunman T-cell monoclonal antibody (mcAb) therapy to that of horse antihuman thymocyte globulin (ATG) in the treatment of severe aplastic anemia (AA). Patients were randomized into one of the two treatment groups as well as to receive or not receive androgens. Median duration of aplasia prior to treatment was 1.5 and 2.2 months for the mcAb and ATG groups, respectively. One of 12 patients who received mcAb therapy had a partial response, whereas four of 13 patients receiving ATG had a complete or partial response. Of the 11 patients who failed mcAb treatment, six were subsequently treated with ATG and two improved. Ten of 13 patients who received ATG are surviving compared with seven of 12 patients who received mcAb. Toxicity of mcAb therapy was less than that of ATG. Future studies are needed to determine whether mcAbs known to be immunosuppressive are of benefit as therapy for patients with AA.

Adolescent↗
PubMed1985

[Concentrations of antibiotics (josamycin, trioleandomycin and amoxicillin) in the secretions of the ear, sinus and adenoids].

This was a comparative study of antibiotics in the pus of otitis and from the sinuses as well as in the adenoids. Three antibiotics were chosen: Trioleandomycin, Josamycin, Amoxicillin. The study protocol was strict. Results obtained were as follows: high concentrations of macrolids in discharge of otitis and the sinuses as well as in the adenoids. Concentrations were higher than serum concentrations. By contrast, in the case of amoxicillin tissue concentrations were lower than the serum concentration. This leads to the conclusion that there is good penetration of infectious ENT sites by macrolids.

Adenoids↗
PubMed1985

[Traumatic tricuspid insufficiency. Review of the literature, apropos of a case].

The authors report a case of traumatic tricuspid incompetence due to rupture of an anterior pillar and the chordae, associated with pericardial rupture, a first degree atrioventricular block, a persistent complete right bundle branch block and acute recurrent pericarditis. The diagnosis, suggested by echocardiography was confirmed by right cardiac catheterisation. The patient underwent tricuspid plasty six months after the accident. On the basis of a review of the literature, the authors discuss traumatic tricuspid incompetence (its symptoms and associated lesions), the diagnostic methods and the therapeutic approach.

Adult↗
PubMed1984

Hydrolysis of the synthetic chromophoric hexapeptide Leu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe catalyzed by bovine pepsin A. Dependence on pH and effect of enzyme phosphorylation level.

Steady-state kinetic parameters for the hydrolysis of the chromophoric hexapeptide Leu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe catalyzed by bovine gastricsin and pepsin A were determined. It was shown that the phosphate content of bovine pepsin A is without any significant effect on that parameters. At pH 4.7, the specificity constant (kcat/Km) was 2455 and 2150 mM-1 X s-1 for the most phosphorylated bovine pepsin A (2.58 phosphate groups per molecule), before and after treatment by potato acid phosphatase, respectively. The kcat/Km ratio found for bovine gastricsin (1314 mM-1 X s-1) was closer to that of bovine pepsin A than that previously reported for chymosin (25 mM-1 X s-1). The spectral properties of the chromophoric tripeptide Leu-Ser-Phe(NO2) in the pH range 1-3.6 were investigated. We have shown that the hexapeptide hydrolysis could be followed by difference spectrophotometry at 295 nm (delta epsilon = -235 M-1 X cm-1 at pH 1.0) thus allowing to study the effect of pH on bovine pepsin A activity in a pH range which could not be explored earlier. The pH-dependence of kcat/Km ratio of unphosphorylated bovine pepsin A indicated that enzyme activity was dependent upon the ionization of two groups of the enzyme whose pK are 1.2 and 5.0. These pK values strongly suggest the involvement of two carboxyl groups probably corresponding to the two reactive aspartyl residues (Asp32 and Asp215) identified through active site-directed reagents for all the aspartic proteinases so far tested.

Animals↗
PubMed1984

Protective effects of diazepam and valproate on beta-vinyllactic acid-induced seizures.

GABA level and the activity of L-glutamate-1-decarboxylase (GAD) (EC 4.1.1.15) were studied in brains of mice treated with beta-vinyllactic acid, a new, selective and pyridoxal phosphate-independent GAD inhibitor. Valproate and diazepam protected mice against convulsions caused by beta-vinyllactic acid although both anti-epileptic drugs antagonized neither the decrease in GABA concentrations nor the inhibition of GAD observed after treatment with beta-vinyllactic acid alone. Assuming that the anticonvulsant effect measured with both antiepileptics is GABA mediated, these results support the hypothesis of a postsynaptic enhancement of GABAergic transmission by diazepam and valproate.

Animals↗