Cryptosporidium parvum biliary tract infection in adult immunocompetent and immunosuppressed mice.

Biliary tract infection by Cryptosporidium parvum is a frequent complication of intestinal cryptosporidiosis in immunosuppressed patients. Although biliary tract infection can be produced in immunosuppressed models as a late complication of intestinal infection, there is no infection model in immunocompetent animals. A murine model of biliary tract cryptosporidiosis was developed by direct intra-gall bladder injection of C.

Evaluation of high-dose regimen of paromomycin against cryptosporidiosis in the dexamethasone-treated rat model.

In the dexamethasone-treated rat model of cryptosporidiosis, paromomycin was effective at a dosage of 50 mg/kg/day or more for ileal infection and 200 mg/kg/day or more for cecal infection. At 1 and 3 weeks after treatment, a persistent infection was demonstrated in all rats. These results confirm the anticryptosporidial activity of paromomycin and underscore the limitations of this compound because of its potential toxicity at such high dosages and its inability to eradicate the infection.

Evaluation of curative anticryptosporidial activity of paromomycin in a dexamethasone-treated rat model.

A dexamethasone-treated rat model of cryptosporidiosis was used to evaluate the curative activity of paromomycin. Although eradication of the parasite could not be demonstrated, statistically significant decreases in oocyst excretion and in the intensity of ileal parasitism were observed in animals receiving 100 mg of paromomycin per kg of body weight per day.

Attempts at in vitro cultivation of Pneumocystis carinii from human bronchoalveolar lavage fluids without feeder cells.

We attempted to cultivate Pneumocystis carinii obtained from two bronchoalveolar lavage fluids of AIDS patients with P. carinii pneumonia, in a system wherein cysteine and 2-mercaptoethanol were substituted for the feeder cells. The presence of P.

Effects of rebreathing conditions and body size on normal human lung tissue volume.

To evaluate the consequences of breathing pattern variations inherent to lung disease on the rebreathing measurement of lung tissue volume (Vt), we carried out a study of ten normal human subjects in whom we assessed the effects of changes in rebreathing volume (Vreb), additional deadspace volume (AVD), respiratory rate (RR), and body height. Vt and alveolar volume (VA) were determined from the end-tidal concentrations of acetylene and helium. We performed Vt measurements using different combinations of Vreb (20, 30 and 50% of predicted vital capacity), of AVD (0, 100, and 200 ml) and of RR (10, 25, and 40 br.

[Study of myocardial metabolism of NADH by laser fluorimetry during cardiac catheterization].

Laser fluorimetry of reduced nicotinamide-adenine-dinucleotide (NADH) p6 a new technique used for in situ and real-time study of myocardial metabolism. We have evaluated its applicability to clinical situations in 5 patients undergoing haemodynamic exploration. An optic fibre was inserted in a catheter the end of which was positioned in the postero-diaphragmatic part of the left ventricle.

NADH in situ laser fluorimetry: effect of pentobarbital on continuously monitored myocardial redox state.

NADH laser fluorimetry was applied to in situ monitoring of pentobarbital overload effect on myocardial redox state in rats. Experiments were carried out on open-chest rats anesthetized with pentobarbital. Use of very thin optical probes allowed measurements of NADH fluorescence directly within the myocardial wall.

[Diagnosis of cellular respiratory arrest by NADH laser fluorimetry. Applications in heart surgery and in experimental pharmacology].

The continuous measurement of intratissular NADH concentration allows early detection of cellular respiration arrest during clinical situations, i.e. allows a non-destructive, in situ, continuous measurement of ATP formation.

Pulmonary and systemic effects of increased negative inspiratory intrathoracic pressure in dogs.

Croup and epiglottitis, which cause greater than normal negative inspiratory intrathoracic pressure (NIIP), have been associated with pulmonary edema. To examine the effects of increased NIIP per se on blood gases, hemodynamics, and lung water content, we carried out 2 types of experiments in 18 anesthetized dogs. Short-term, low-pressure experiments (6 control dogs and 6 dogs that generated intratracheal pressures of -12 cm H2O during inspiration for 3 h) and long-term, high-pressure experiments (6 dogs that generated -20 cm H2O during inspiration for 6 h).

[In situ evaluation of tissue metabolism by laser fluorimetry].

Laser fluorimetry is a new technique which provides continuous information on tissue metabolism in situ and without destruction. For the moment, it is mainly applied to the study of changes in redox gradients in various organs, including the heart, brain, liver, kidney and skeletal muscle, in cases with imbalance between oxygen supply and oxygen consumption. Other metabolisms, such as that of the crystalline lens with incipient cataract, can also be investigated by this technique.

Ventilatory adaptation to metabolic alkalosis in adult awake potassium restricted rats.

The resting ventilation of awake rats, developing metabolic alkalosis as a result of sustained dietary potassium (K) restriction, was compared to that of age-matched controls. Extending the measurements over 17 weeks and using adult rats indicated, as soon as the third week, a significant progressive fall in the minute ventilation of low K rats, which previous studies limited to a single time determination did not consistently ascertain. The ventilatory adaptation observed in all groups, as well as the superimposed respiratory compensation to metabolic alkalosis in low K rats, resulted only from frequency changes.

Measurement of pulsatile flows and variable volumes by bolus injection of indicator in a model of the pulmonary circulation.

The reliability and accuracy of the bolus injection-dye dilution technique were assessed for a physiological range of frequencies (13-49 min-1) and stroke volumes (60-160 ml) on a glass model where flows and volumes varied as a preset function of time (n = 320). We found that the technique overestimates flow by about 8% with a 95% confidence interval of +/- 10% for one measurement. Mean transit times are accurate within a +/- 7% confidence interval for one measurement.

Ventilation in awake rats with permanent arterial catheters.

Respiratory frequency (f), tidal volume (VT) and minute ventilation (VE) were measured in restrained awake rats using a volumetric body plethysmograph excluding the head. An arterial catheter was then implanted and ventilatory measurements performed again two or three days later. Arterial blood gases and acid-base status were measured before entry in the plethysmograph (control values) and after, accompanying each ventilatory measurement.

[Gamma function extrapolation of dilution curves for pulmonary blood volume determination in chronic bronchitis (author's transl)].

The risk of incorporating inapparent recirculation under the extrapolated downslope of dye dilution curves is greater with exponential than gamma function extrapolation since the latter makes use of ascending and early descending limbs of the curve. Extrapolation of a true gamma function is not affected by the level at which extrapolation begins. With curves obtained in eight normal subjects, cardiac output (phi) was comparable by exponential and gamma extrapolation if the latter began between 75 and 55% of the peak concentration (Cmax.

Splanchnic blood flow, O2 consumption, removal of lactate, and output of glucose in highlanders.

An impairment of gluconeogenesis has been proposed to explain the low arterial blood glucose of highlanders. Therefore, we studied splanchnic blood flow, splanchnic uptake of oxygen and lactate, and output of glucose in nine normal and six anemic highlanders at an altitude of 3,750 m. Splanchnic blood flow, arteriovenous difference for oxygen, and oxygen consumption were comparable at rest in both groups and in lowlanders from the literature, whereas splanchnic output of glucose, and uptake of lactate were approximately twice those in lowlanders.