Kinetic constants of alpha-methyl-D-glucoside transport in the chick small intestine during perinatal development

The kinetic parameters of alpha-methyl-D-glucoside (alpha Glc1Me) have been determined in the small intestine in order to establish developmental and regional changes in the apical transport in embryos and newly hatched chicks. Results show that the apparent Michaelis constant (Km) values did not change during the period studied in each region of the small intestine. However, the ileum showed a smaller Km than that of the duodenum and jejunum, indicating an increase of the affinity of the carrier in the distal portion of the intestine and a significant contribution of the ileum to overall sugar absorption in the perinatal period. There were important changes in the diffusional component and in the mediated transport system capacity during this period, as well as in the different regions of the intestine. Significant increases in the maximal rate of transport (Vmax) were observed in all regions during the embryonic period until the second day after hatching, followed by a decline during the first week. During all the period studied, Vmax values from the jejunum were significantly greater than those from both the duodenum and the ileum at every age studied showing that the jejunum is the segment that is best suited for Na(+)-mediated uptake. Such changes which occur when the need for nutrients for rapid development are at their highest are not solely a result of diet composition, but rather in accordance with a genetic programme.

Cutaneous botryomycosis. Report of the two first Uruguayan cases

The first two Uruguayan cases of botryomycosis were diagnosed in white adult male patients with cutaneous lesions. Staphylococcus aureus was the etiologic agent in both cases. In one of them, however, Pseudomonas aeruginosa was also identified during relapse. General comments on diagnosis and pathogenesis of the disease are made.

Distribution of the predominant hepatitis B virus precore variants in hepatitis B e antigen-positive children and their effect on treatment response

Little is known about the distribution of precore hepatitis B virus mutants and their influence on the outcome of interferon therapy in children with chronic hepatitis B. In this study, serum samples were analyzed from 60 children with chronic hepatitis B e antigen+ (HBeAg+) hepatitis. Fifty-two of these children underwent different interferon trials, and a second serum sample was taken from 25 of them at the end of therapy. Fifty-six of the original 60 children were simultaneously infected by wild-type and precore mutant hepatitis B virus variants. The remaining four children were infected by the wild type alone. In 50/56 of children with a mixed viral population, the wild-type variant comprised more than 50% of the total viremia. With respect to the influence of precore variants on the outcome of interferon treatment, the prevalence of mixed viral population was similar in responders and nonresponders (96 versus 88%, respectively). However, precore mutant variants were prevalent (> 50% of the viral population) in 21% of the nonresponders, but in none of the responder children (p < 0.05). Viremia levels were significantly higher in nonresponder than in responder children (p < 0.05). No substantial changes in the prevalence of mutants were observed throughout the interferon therapy. In conclusion, mixed viral infection is found in a high percentage of children with chronic B HBeAg+ hepatitis. Response to interferon therapy does not seem to be related to the presence of hepatitis B virus precore mutants, but rather to the levels of viremia.

Influence of topical cyclosporine A and dissolvent on corneal epithelium permeability of fluorescein

The corneal stroma is the major barrier to penetration for the lipophilic Cyclosporine A (CsA) molecule and prevents the use of the common ophthalmic solvents. At present, corn oil, castor oil and olive oil are the three most commonly used vehicles. The aim of this study was to determine the effect that topically applied CsA dissolved in different oils has on corneal epithelial permeability measured by fluorophotometry. Forty healthy volunteers, with absence of ocular or systemic disease and not receiving topical or systemic drugs were enrolled. Measurements were taken before and 45 min after the instillation of 40 microliters of a 2% aqueous solution of sodium fluorescein without preservatives. Basal corneal permeability and the permeability 24 h after the instillation of 2% CsA-olive oil, olive oil alone, 2% CsA-castor oil, castor oil alone, 2% CsA-corn oil and corn oil alone, were calculated. To prepare the topical 2% CsA, a Sandimmun oral solution (Sandoz, Basel, Switzerland) was employed under sterile conditions. We found that epithelial permeability 24 h after the instillation of any CsA formulations or solvents increased more than 6.62 times (p <0.001). No differences in corneal permeability values were found between any of the CsA formulations and the vehicles. We conclude that oils used to dissolve CsA are mainly responsible for the increased corneal epithelial permeability. No differences were found in the effects of the tested solvents on corneal epithelial permeability.

Intraaortic balloon entrapment

A review of intraaortic balloon pump use at the University of Miami/Jackson Memorial Medical Center over the past 21 years identified 2 cases where a balloon was found to be entrapped. The balloon catheters had been in place for approximately 10 days when this complication occurred. The retained balloons were torn, filled with clotted blood, and impacted in the vasculature. In our first case, forceful removal of the intraaortic balloon was complicated by unintentional extraction of the external iliac and common femoral arteries. In the second case, clot within the balloon was dissolved with tissue plasminogen activator injected into the drive lumen of the catheter before removal. The prevention and management of this rare but serious complication of intraaortic balloon pumping is reviewed.

Late complications of plombage

Plombage was used commonly in the management of tuberculosis before the early 1950s. From 1977 through 1990, 4 patients were seen with complications of plombage performed decades previously. Lucite spheres were used in 3 patients and paraffin in 1. One patient had bilateral apical plombage. In all cases, complications were related to infection or migration of the foreign material. Two patients had extrusion of foreign material or fluid into the chest wall. One patient had hemoptysis and infection due to erosion of a Lucite sphere into the lung. Another had intestinal obstruction subsequent to erosion into the esophagus. The patient with bilateral plombage had development of asynchronous complications on both sides. Treatment consisted of removal of the foreign material and individualized management of the remaining space. There were no operative deaths and the outcome was good in all cases.

Characteristics of a presynaptic plasma membrane Ca2(+)-ATPase activity from electric organ

Ca2(+)-ATPase activity was measured in electric organ synaptosomal homogenates and their derived presynaptic plasma membranes using a low ionic strength medium, low in Ca2+ and Mg2+, and devoid of K+. The enzyme activity showed a high apparent affinity for Ca2+ (KCa:0.5 microM) and was: (1) 5-fold stimulated by 120 nM calmodulin, (2) highly sensitive to LaCl3 inhibition, and (3) not affected by 20 mM NaN3 or 0.1 mM ouabain. The addition of Mg2+ promoted the disappearance of Ca2(+)-ATPase activity. Incubation of synaptosomal homogenates in the above-mentioned assay medium with [gamma -32P]ATP resulted in the appearance of a 140 kDa band as revealed by SDS-gel electrophoresis. Labeling of this band with 32P was inhibited by 1 mM EGTA or 10 mM NH2OH, indicating that the isotope incorporation required the presence of Ca2+ and the formation of an acyl-phosphate derivative. The results indicate that the Ca2(+)-ATPase activity from synaptosomal homogenates had characteristics corresponding to those of the enzyme that catalyzes an outward transport of Ca2+ in nerve terminals. Preincubation of synaptosomes in Ca2+ plus K+, a depolarizing procedure, induced a large and rapid decrease in the Ca2(+)-ATPase activity, possibly mediated via Ca2+ entry through voltage-gated Ca2+ channels. Furthermore, the muscarinic cholinergic agonist oxotremorine (at 15 microM concentration) did not significantly affect either the enzyme activity or the intensity of the Ca2(+)-dependent 32P incorporation into the 140 kDa band, suggesting that the enzyme is not coupled to muscarinic binding sites.

Successful treatment with ketoconazole of Cushing's syndrome in pregnancy

Patients with Cushing's syndrome rarely become pregnant. This is a high risk situation both for the fetus and the mother, if untreated. We report a patient with Cushing's syndrome due to adrenocortical adenoma who became pregnant and was successfully treated with ketoconazole during the last period of pregnancy.

[Effect of active metabolites of vitamin D on manifestations of primary hyperparathyroidism]

We have evaluated the serum levels of 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D (1.25-OHD) in 33 patients with primary hyperparathyroidism and normal renal function, relating them with the clinical expression of the disease and other biochemical parameters. The level of 1.25-OHD of the patients was significantly higher than in healthy controls [51 +/- 18 vs 36 +/- 10 pg/ml (122 +/- 43 vs 86 +/- 24 pmol/l), p less than 0.001], although it was higher than the upper limit of the normal range in only 36% of patients. By contrast, the level of 25-OHD was diminished [11.0 +/- 6.3 ng/ml (27.5 +/- 15.7 nmol/l) in the patients and 19.9 +/- 10.5 ng/ml (49.7 +/- 26.2 nmol/l) in the controls, p less than 0.01]. A positive correlation was found between PTH and 1.25-OHD (r = 0.40, p less than 0.05) and a negative one between PTH and 25-OHD (r = -0.40, p less than 0.05). Calcemia was correlated with PTH (r = 0.77, less than p 0.001) but not with 1.25-OHD (partial r = 0.22). There was no correlation between vitamin D metabolites and calciuria, nor between the former and the biochemical indexes of bone remodelling. There were no significant biochemical differences between patients with renal calculi and those without them. It was concluded that PTH level appears as the major determinant factor of 1.25-OHD serum level. The serum level of vitamin D metabolites does not seem to clearly influence calcemia, calciuria, bone remodelling or the development of calculi.

Antidiuretic responses to osmotic cutaneous stimulation in the toad, Bufo arenarum. A possible adaptive control mechanism for urine production

Osmotic stimulation of the skin of the toad Bufo arenarum with isotonic (115 mM) or hypertonic (400 mM) NaCl solutions produced a marked and reversible antidiuresis within 5 min. No changes in plasma osmolarity were detected in the course of this response. Hypophysectomized animals exhibited a lower and delayed antidiuresis when exposed to a hypertonic environment (400 mM NaCl). This antidiuretic response was drastically reduced in normal toads after ten consecutive days of administration of the sympatoplexic guanethidine. The existence of a feed-forward control of urine production initiated by cutaneous osmotic sensors and involving an adrenergic component is proposed.

Anti-adrenal action of a subanaesthetic dose of etomidate

The effects of subanaesthetic doses of etomidate on corticosteroid synthesis have been studied in vivo. In the group of patients who received etomidate (n = 10), cortisol and aldosterone responses to adrenocorticotrophic hormone were blunted, while 11-de-oxycortisol response was increased, as compared to a control group (n = 10). These results suggest that a single bolus of 0.04 mg/kg etomidate, which produces sedation, without loss of consciousness, is able to block adrenal 11 hydroxylase.

Study of appendicitis in children treated with four different antibiotic regimens

This is a prospective and randomized study of 100 patients with acute appendicitis who were less than 10 years old, in which four different antibiotic regimens commonly in use against gram-negative and anaerobic bacteria were compared in terms of postoperative septic complications. The antibiotics were begun immediately preoperatively and continued for five days. Ten percent of the patients developed infection complications, with 4% requiring further surgery. The best results were obtained with cefoxitin (4% of infection), metronidazole plus amikacin and latamoxef (8%), while the regimen of clindamycin plus amikacin was associated with the greatest number of complications (20%). On analyzing the main microbiologic findings of the study, we conclude that some sort of antibiotic treatment is indicated in all types of appendicitis, due to the occult presence of bacteria in the peritoneal cavity, even without clinical evidence of gangrene or perforation. Further, we emphasize the significance of Streptococcus faecalis as being responsible, along with Escherichia coli and Bacteroides fragilis, for serious postoperative complications.

Calcium and calcitonin responses to calcium infusion in type I diabetes mellitus

We studied calcium and calcium and calcitonin responses to intravenous calcium infusion (3 mg of elemental calcium/kg of body weight in 10 minutes) in 21 type I diabetic males and 17 age-matched normal males. Baseline total calcium, parathyroid hormone and calcitonin levels were normal in the diabetic group, but ionized calcium was lowered. Cortical bone status and osteocalcin levels were normal, suggesting a normal osteoblastic function. Total calcium and ionized calcium responses to calcium infusion were lowered in the diabetic group. Despite these lowered calcaemic responses, calcitonin secretion was normal.

[Degos' syndrome. Intestinal involvement as demonstrated by digital angiography. A case]

Degos' syndrome consists in a generalized vasculitis with frequent affectation of the gut and the skin. The arteriographic findings in a patient with the diagnosis of Degos' syndrome and severe affectation of the gut are reported.