Biomedical subjects
Publications and source records attributed to G Sanchez.
We report two patients with vitiligo-like lesions caused by contact with compounds containing phenols and toluene. The clinical, histopathologic and ultrastructural findings are compared with vitiligo. Two mechanisms may be present: one from direct enzymatic or cytotoxic action on melanocytes and the other through immunologic reaction.
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The influence of intestinal transit time on the release of 5-aminosalicylic acid (5-ASA) from a peroral, slow-release preparation (Pentasa) was studied at steady state in seven healthy volunteers. Daily dose was 1500 mg Pentasa, normal transit time (NTT) was 24 h (16-26 h) and accelerated transit time (ATT), caused by a laxative, was 5 h (4-9 h). Median total recovery (24 h, 5-ASA + acetyl-5-ASA) was 87% (61-129%) (NTT) and 81% (56-100%) (ATT), respectively, (P greater than 0.10). The total faecal excretion of 5-ASA (per cent of dose) increased from 16%, (9-21%) (NTT) to 29%, (16-38%) (ATT) (P less than 0.02). Free 5-ASA rose from 12% (4-19%) to 17% (10-25%), the retained part (in granules) from 4% (2-5%) to 12% (4-24%). Urinary excretion decreased correspondingly from 32% (19-59%) to 21% (11-38%), predominantly as Ac-5-ASA (P less than 0.05). Mean plasma Ac-5-ASA concentration decreased from 1.42 micrograms ml-1 to 0.86 microgram ml-1 (P less than 0.05). An almost complete release of 5-ASA from Pentasa takes place during NTT. At ATT conditions about 88% is released, indicating Pentasa to be an acceptable source of 5-ASA in diarrhoeal states.
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The liquid antacid Novaluzid (10 ml seven times daily) was compared with ranitidine (150 mg twice daily) and with placebo in 57 patients with symptoms and endoscopic signs of oesophagitis and gastro-oesophageal reflux. A randomized three-period change-over design with the double-dummy technique was used. Each treatment period lasted 6 weeks. Only 37 patients (64.9%) completed the entire trial. In retrospect, five patients receiving placebo were withdrawn because of insufficient effect, six patients because of side effects while taking Novaluzid and two while taking ranitidine. The remaining seven dropouts/withdrawals were for reasons without evident relationship to the treatment given. Statistical analyses based both on the 37 completers and on the 43 patients who had at least two treatment periods showed that ranitidine and Novaluzid were superior to placebo with regard to pain score (p less than 0.005) but not with regard to regurgitation, dysphagia, histology, and appearance on endoscopy (p greater than 0.05). It was impossible to distinguish statistically between ranitidine and Novaluzid. In conclusion, ranitidine and high-dose antacids are of equal effectiveness in the short-term treatment of reflux oesophagitis, and both are superior to placebo with regard to symptomatic relief.
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An optic-ultrastructural study is realized, emphazising the presence of: a) Intermediate lymphocytes, that we interpret as T-activated; b) Activated endothelial cells (prominent, rich in Weibel-Palade's bodies, well developed nuclei- and cytoskeletons); c) Classic and native myofibroblasts, partially responsible for the cicatricial contraction. We postulate that the changes in the connective-vascular tissue of the chorion represent an anarchic and reactive fibroangioblastic hyperplasia and favors the typical recurrences of this process.
To characterize biochemical traits associated with various forms of epidermolysis bullosa (EB), we used skin fibroblast cultures to measure a gelatin-specific neutral metalloprotease. Compared to normal cultures, levels of this gelatinase were 7-fold decreased in cell cultures from 3 patients from 3 kindreds with generalized dominant EB simplex of the Koebner type (DEBS-K) (p less than 0.001). The specificity of this trait was shown in several ways. The growth kinetics and total protein synthesis of the cells were unaltered. The activity of lactic dehydrogenase, a cytoplasmic enzyme, was also unaltered, indicating the integrity of the cells was not compromised. The decrease in gelatinase activity is specific for generalized DEBS-K, since cultures from recessive dystrophic EB, recessive junctional EB, dominant dystrophic EB, and a second genetic type of DEBS all fail to show this defect. However, since it has been suggested that DEBS-K and the localized form of DEBS, the Weber-Cockayne type (DEBS-WC), may represent allelic mutations of varying severity, we measured gelatinase activity in cell cultures of 13 patients of this type. The levels displayed a biphasic segregation in which 7 of 13 values were equal to, or greater than, the mean activity of control cells. Cultures from the remaining 6 patients were greater than 1 SD below the mean control value and approximated those seen in the generalized DEBS-K patients. These studies suggest that the decrease in gelatinolytic activity is a marker for DEBS-K and that DEBS-K and DEBS-WC may be closely related genetic disorders in which the defect in gelatinolytic protease represents a pleiotropic effect of the gene for DEBS or is genetically linked to the DEBS gene.
Plasma digoxin measurements have proved unserviceable as a means of differentiating between toxic and non-toxic patients. In order to assess the value of a biological effect of digoxin in this discrimination, intraerythrocytic sodium and potassium concentrations were determined in 55 chronically digitalized patients of whom 10 were digoxin-intoxicated according to ECG criteria. Digitoxicity was associated with elevated intraerythrocytic sodium concentration (mean +/- SEM 19.3 +/- 1.2 versus 11.3 +/- 0.3 mmol/l, p less than 0.001) and reduced intraerythrocytic potassium concentration (94.6 +/- 2.3 versus 100.0 +/- 0.6 mmol/l, p less than 0.001) compared to non-toxic patients. Mean (+/- SEM) plasma digoxin concentrations in the two groups were 3.14 +/- 0.41 and 1.57 +/- 0.09 nmol/l, respectively (p less than 0.001). When diagnosing toxicity in chronically digitalized patients, plasma digoxin and intraerythrocytic sodium determinations showed sensitivities of 60 and 100%, respectively. The predictive values of a positive test were 75% for plasma digoxin and 83% for intraerythrocytic sodium.
The authors report a case of Libman-Sacks endocarditis of the posterior mitral leaflet in a child treated for disseminated lupus erythematosus for 8 years. Mitral valve replacement was performed. Libman-Sacks vegetations are hardly ever recognised in vivo and have never been previously reported in a child. The incidence of this cardiac complication of lupus erythematosus is probably higher than indicated in the literature. Attentive cardiac examination and systematic echocardiography should be part of routine follow-up of patients with disseminated lupus erythematosus.
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To assess the cellular effects of digoxin, intraerythrocytic sodium and potassium concentrations were measured in 17 patients during the early phase of digitalization, in 45 patients on long-term therapy and in 64 non-digitalized control patients. Acute digitalization raised intraerythrocytic sodium from 11.6 +/- 0.4 to 16.7 +/- 1.0 mmol/l (mean +/- SEM) (p less than 0.01) and reduced intraerythrocytic potassium from 100.1 +/- 1.3 to 95.9 +/- 1.8 mmol/l (p less than 0.01). These changes were strongly correlated with the steady-state plasma digoxin concentration. During a few weeks of digoxin therapy, the intraerythrocytic cation composition normalized gradually. In patients on chronic treatment, neither intraerythrocytic sodium (11.3 +/- 0.3 mmol/l) nor potassium concentrations (100.0 +/- 0.6 mmol/l) differed significantly from the values of the control group (11.4 +/- 0.2 and 99.9 +/- 0.5 mmol/l, respectively). The changes in intraerythrocytic cation concentrations, induced by acute digitalization, seem to disappear during chronic administration of the drug.
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The synaptic region and nerve endings have been studied both in the outer and inner hair cells by using optic and electron microscopy, nerve staining and Acetyl Cholinesterase activity. The findings are described, with a discussion of the results.
In patients with cerebrospinal fluid internal shunts, immune complex glomerulonephritis sometimes develops. Of two new cases the first was classic, while the second was in an adult who had had a ventriculoatril shunt for 8 years; furthermore, the patient had acute renal failure and is the first to have been reported to have Peptococcus septicemia. Shunt glomerulonephritis is characterized by the following: (a) its occurrence following, most often, Staphylococcus albus infection in a patient who usually has a ventriculoatrial shunt; (b) transitory improvement of the symptoms by antibiotherapy only; and (c) full recovery if the prosthesis is removed. Laboratory studies show a low serum concentration of the C3 component of complement, the presence of cryoglobulins and a positive rheumatoid factor test. These abnormalities are reversible with removal of the prosthesis. Optical microscopy of a renal biopsy specimen in the two cases showed cellular proliferation of the glomerular tuft, electron microscopy demonstrated subepithelial deposits and immunofluorescent studies revealed intramembranous and intramesangial immune complexes. These features are similar to those observed in experimental nephritis induced in animals by foreign protein.