Amphotericin B lipid complex therapy of experimental fungal infections in mice

The amphotericin B lipid complex (ABLC), which is composed of amphotericin B and the phospholipids dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol, was evaluated for its acute toxicity in mice and for its efficacy in mice infected with a variety of fungal pathogens. ABLC was markedly less toxic to mice when it was administered intravenously; it had a 50% lethal dose of greater than 40 mg/kg compared with a 50% lethal dose of 3 mg/kg for Fungizone, the desoxycholate form of amphotericin B. ABLC was efficacious against systemic infections in mice caused by Candida albicans, Candida species other than C. albicans, Cryptococcus neoformans, and Histoplasma capsulatum. ABLC was also efficacious in immunocompromised animals infected with C. albicans, Aspergillus fumigatus, and H. capsulatum. Against some infections, the efficacy of ABLC was comparable to that of Fungizone, while against other infections Fungizone was two- to fourfold more effective than ABLC. Against several infections. Fungizone could not be given at therapeutic levels because of intravenous toxicity. ABLC, with its reduced toxicity, could be administered at drug levels capable of giving a therapeutic response. ABLC should be of value in the treatment of severe fungal infections in humans.

Complications of treatment for cryptosporidial diarrhoea

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Preliminary characterization of phosphotyrosine phosphatase activities in human peripheral blood lymphocytes: identification of CD45 as a phosphotyrosine phosphatase

A preliminary characterization of the protein phosphotyrosine phosphatase (PTPase) activity in human peripheral blood lymphocytes (PBL) has been made using two tyrosine-containing peptides and the epidermal growth factor receptor from A-431 cells as substrates. High PTPase activity with a pH optimum near 7.4 was observed in both the membrane and the cytosolic fractions. At least three distinct fractions with PTPase activity were separated on DEAE cellulose columns, indicating that the enzyme is heterogeneous. Vanadate, molybdate, and salts of zinc, copper, and mercury were all effective enzyme inhibitors, although the inhibition was generally incomplete and showed some variation with the enzyme preparation. The difficulty in completely inhibiting PTPase activity in lymphocytes may help explain the variation between laboratories in studies of tyrosine phosphorylation in these cells. Studies with highly purified T lymphocytes obtained by filtration of PBL through nylon wool columns indicated that the activity is present in T cells. Absorption with agarose containing anti-HLe-1, a mouse monoclonal IgG1 antibody specific for the leukocyte-specific surface protein T-200 (CD45), removed up to 40% of the PTPase activity. Enzyme activity was recovered on the immunoadsorbent after extensive washing, confirming that the enzyme was being bound to the beads. Immunoabsorbents containing other mouse IgG1 antibodies failed to bind PTPase activity, indicating that the binding to beads with anti-HLe-1 antibody is specific. Further characterization of the CD45 and PTPase activities in lymphocytes may provide a better understanding of the role of protein tyrosine phosphorylation in the regulation of proliferation and differentiation in these cells.

In vitro phosphorylation of bovine adrenal chromaffin cell tyrosine hydroxylase by endogenous protein kinases

Under phosphorylating conditions, addition of Ca2+ or cyclic AMP to the 100,000 g supernatant of purified bovine adrenal chromaffin cells increases both the incorporation of 32P into tyrosine hydroxylase and the activity of the enzyme. Combining maximally effective concentrations of each of these stimulating agents produces an additive increase in both the level of 32P incorporation into tyrosine hydroxylase and the degree of activation of the enzyme. The increased phosphorylation by Ca2+ is due to stimulation of endogenous Ca2+-dependent protein kinase activity and not inhibition of phosphoprotein phosphatases. When the chromaffin cell supernatant is subjected to diethylaminoethyl (DEAE) chromatography to remove calmodulin and phospholipids, tyrosine hydroxylase is no longer phosphorylated or activated by Ca2+; on the other hand, phosphorylation and activation of tyrosine hydroxylase by cyclic AMP are not affected. Subsequent replacement of either Ca2+ plus calmodulin or Ca2+ plus phosphatidylserine to the DEAE-fractionated cell supernatant restores the phosphorylation, but not activation of the enzyme. Reverse-phase HPLC peptide mapping of tryptic digests of tyrosine hydroxylase from the 100,000 g supernatant shows that the Ca2+-dependent phosphorylation occurs on three phosphopeptides, whereas the cyclic AMP-dependent phosphorylation occurs on one of these peptides. In the DEAE preparation, either cyclic AMP alone or Ca2+ in the presence of phosphatidylserine stimulates the phosphorylation of only a single phosphopeptide peak, the same peptide phosphorylated by cyclic AMP in the crude supernatant. In contrast, Ca2+ in the presence of calmodulin stimulates the phosphorylation of three peptides having reverse-phase HPLC retention times that are identical to peptides phosphorylated by Ca2+ addition to the crude unfractionated 100,000 g supernatant. Rechromatography of the peaks from each of the in vitro phosphorylations, either in combination with each other or in combination with each of the seven peaks generated from phosphorylation of tyrosine hydroxylase in situ, established that cyclic AMP, Ca2+/phosphatidylserine, and Ca2+/calmodulin all stimulate the phosphorylation of the same reverse-phase HPLC peptide: in situ peptide 6. Ca2+/calmodulin stimulates the phosphorylation of in situ peptides 3 and 5 as well. Thus, tyrosine hydroxylase can be phosphorylated in vitro by protein kinases endogenous to the chromaffin cell. Phosphorylation occurs on a maximum of three of the seven in situ phosphorylated sites, and all three of these sites can be phosphorylated by a Ca2+/calmodulin-dependent protein kinase.

High frequency oscillations and mucociliary transport

Mucociliary transport is influenced by high frequency oscillation of air within the lungs. While some studies suggest that high frequency ventilation may be detrimental, with appropriate techniques, there is no doubt that this has potential as a means of improving the clearance of secretions from the lung.

Supplemental oxygen and exercise ability in chronic obstructive airways disease

The influence of supplemental oxygen on exercise performance was assessed in 17 patients with severe airflow obstruction. Exercise capacity was measured by the six minute walking distance, by an endurance walking test, and by an endurance cycling test and comparison was made with performance when the patient was breathing air. In addition, the relation between the flow rate of supplemental oxygen and cycling endurance time was studied. Portable oxygen (41 min-1) carried by the patient increased the mean endurance walking time by 59% and the six minute walking distance by 17%. The endurance time for cycling at a constant work load was increased by 51% with oxygen at a flow rate of 21 min-1, by 88% at 41 min-1, and by 80% at 61 min-1. Supplemental oxygen prolonged the length of time that the patients were able to walk at a fixed speed. It also increased the mean speed achieved during a six minute walk but this was variable and did not occur in all the subjects. The benefit from supplemental oxygen was not cancelled by the effort of carrying the portable cylinder.

Aerosol deposition in the human lung: effect of high-frequency oscillation on the deposition characteristics of an inhaled nebulized aerosol

1. Oral high-frequency oscillation (OHFO) may have important effects on aerosol deposition in the lungs. In order to investigate these, a technique was devised to measure regional deposition rates of a nebulized radiolabelled aerosol in the lungs during normal tidal breathing. 2. The effect of three frequencies of OHFO on pulmonary aerosol deposition rate (PADR) in four normal subjects and five patients with chronic airways obstruction (CAO) were assessed using the technique. 3. In separate experiments employing three normal subjects, the effect of OHFO was studied on the deposition rate of aerosol on the oropharynx and delivery apparatus, and on the amount and characteristics of aerosol inhaled by the subjects. 4. Total PADR was significantly reduced by OHFO at 8 Hz and 16 Hz in the normal subjects, and by all three frequencies of OHFO in the CAO patients. In the normal subjects, the regional distribution of aerosol deposition was unchanged, but in the CAO patients a larger proportion of total aerosol deposition occurred in peripheral lung. 5. OHFO reduced the oropharyngeal aerosol deposition rate, increased the loss of aerosol to the atmosphere before inhalation, and increased the deposition of aerosol on the delivery apparatus. The end result was a reduction in the amount of aerosol inhaled, and in the particle sizes measured at the mouthpiece. 6. We conclude that OHFO reduces the amount of aerosol inhaled, but may improve peripheral deposition of inhaled aerosol in patients with CAO. This effect may be of value in the clinical administration of nebulized drugs.

Thoracoscopy: assessment of a physician service and comparison of a flexible bronchoscope used as a thoracoscope with a rigid thoracoscope

The practicality of physicians performing thoracoscopy for diagnostic purposes was assessed in 30 patients with pleural effusions of unknown cause. A rigid thoracoscope was compared with a fibreoptic bronchoscope used as a flexible thoracoscope and the diagnostic adequacy of biopsy specimens obtained with the two instruments assessed. The two instruments were inserted by a physician in the bronchoscopy suite using local anaesthesia. The procedure proved safe, acceptable, and diagnostically effective. The rigid thoracoscope proved a more satisfactory instrument but the fibreoptic bronchoscope, with minor adaptations, may be used for thoracoscopy.

An oxygen conserving nasal cannula

Oxygen administration via a nasal cannula incorporating a small collapsible reservoir (Oxymizer, Chad Therapeutics Inc, California) was compared with delivery via a standard nasal cannula. Twelve patients with chronic, stable hypoxaemia (arterial oxygen tension less than 60 mm Hg (8.0 kPa)) were studied. Transcutaneous oxygen and carbon dioxide tensions were recorded by skin electrodes and oxygen saturation by ear oximetry. Baseline measurements during the breathing of air were compared with those made during the breathing of oxygen at flow rates of 0.5, 1.0, and 2.0 l/min via each device. Increases in saturation and transcutaneous oxygen tension were significantly greater at each flow rate with the reservoir device than with the conventional cannula. To produce similar improvements in oxygenation the reservoir device required an oxygen flow rate about half that of the conventional cannula. Use of the reservoir device may reduce the inconvenience and perhaps the cost of supplying domiciliary oxygen, and prolong the time during which patients may rely on a portable cylinder.

Effect of oral high frequency ventilation by jet or oscillator on minute ventilation in normal subjects

Normal subjects were asked to breathe through an open ended tube while high frequency oscillations were superimposed on tidal breathing via a side arm, either an eight inch (20 cm) loudspeaker or a jet ventilator being used. Both systems were comfortable and well tolerated. Spontaneous minute ventilation fell by 19-46% at frequencies up to 33 Hz without a rise in transcutaneous PCO2. Maximum ventilatory savings occurred at 1.6 Hz with the jet ventilator (p less than 0.01) and at a frequency corresponding to respiratory system resonance with the loudspeaker. This suggests that during oral high frequency ventilation pulmonary gas exchange is improved and leads to more efficient carbon dioxide excretion for a given minute ventilation. This technique provides a practical and simple method of supplementing breathing in conscious subjects, and it may also have application in the management of patients with acute or chronic respiratory failure, where intubation and conventional ventilation might be avoided.

Ventilatory saving by external chest wall compression or oral high-frequency oscillation in normal subjects and those with chronic airflow obstruction

Oscillation of the air within the lungs at high frequency is associated with an increased clearance of CO2. Because of the high frequency and low volume of these oscillations, spontaneous breathing is unhindered and the technique has potential value as a supplement to ventilation. High-frequency oscillations were superimposed upon tidal breathing by using a loudspeaker attached to a mouthpiece (oral high-frequency oscillation, OHFO) or by external chest wall compression (ECWC). We set out (a) to compare the changes in ventilation and breathlessness by using OHFO and ECWC in normal subjects with those in patients with chronic airflow obstruction (CAO), and (b) to relate the pattern of saving to the resonant frequencies of the respiratory system as a whole (for, 5-10 Hz in normal subjects, 16-26 Hz in CAO) and those of the ribcage (foc, 70 Hz). OHFO reduced minute ventilation (VE) by up to 46% in normal subjects (P less than 0.01) and 29% in CAO (P less than 0.01) without any rise in CO2. ECWC reduced VE by 27% in normal subjects (P less than 0.01) and 16% in CAO (P less than 0.01) without a rise in CO2. High-frequency oscillation by either method relieved breathlessness in those with CAO and was comfortable and well tolerated. In normal subjects for was discrete and varied little with respiration. Maximum savings occurred around for (5-10 Hz). In CAO, there was no obvious single resonant frequency and flow and pressure signals were intermittently in phase over a band of about 10 Hz. Thus the reductions in minute ventilation were only loosely related to for (13-26 Hz). Neither group reduced VE at foc (65-75 Hz). OHFO has considerable potential in the management of patients with CAO, where it may be of value as an assistance to breathing and in the relief of breathlessness. ECWC, although effective in principle, is impractical by our methods and awaits the development of an acceptable delivery system.

Duodenal perforation associated with tolazoline

A neonate, managed with tolazoline for pulmonary hypertension after repair of a congenital diaphragmatic hernia, developed a duodenal perforation. The role of tolazoline in this condition is discussed, and possible measures to reduce its gastrointestinal side effects are proposed.

Increase in mucociliary clearance in normal man induced by oral high frequency oscillation

Data on the effect on mucociliary clearance of oral high frequency oscillation is conflicting. By means of a technique to superimpose high frequency oscillation on tidal breathing, changes in mucociliary clearance during high frequency oscillation were studied in seven normal non-smokers by monitoring the clearance of inhaled radiolabelled aerosol from the lungs. After inhalation of 5 microns technetium 99m labelled particles under controlled conditions, whole lung clearance was monitored by scintillation counters half hourly for six hours with a final count at 24 hours, from which tracheobronchial deposition and clearance could be calculated. Control and high frequency oscillation studies were performed on separate days in random order. Oral high frequency oscillation was applied by a bass loudspeaker through a mouthpiece to superimpose sinewave oscillations (RMS input pressure 1.2 cm H2O, mean pressure zero) on normal breaths. On high frequency oscillation days 30 minutes of oscillation alternated with 30 min of rest. Between 3 and 4.5 hours mucociliary clearance with high frequency oscillation exceeded control by about 10% (p less than 0.05). The mean time taken to eliminate 90% of deposited radioaerosol from the tracheobronchial tree fell from 4 hours 50 minutes (range 1 h 52 min-6 h 50 min) during control to 3 hours 43 minutes (range 2 hr 28 min-5 hr 54 min) during the high frequency oscillation run (p less than 0.05). Possibly this comfortable, simple technique would be of therapeutic benefit to patients with chronic sputum retention and merits further investigation.

High frequency ventilation

What is high frequency ventilation? Is it useful or just another transatlantic fad? Apart from appearing to break all the rules of physiology, this technique has definite advantages over conventional ventilation in certain areas and great potential in others.

The effects of theophylline and salbutamol on right and left ventricular function in chronic bronchitis and emphysema

We have compared the effects of oral theophylline and salbutamol on right and left ventricular function in twelve patients with chronic bronchitis and emphysema. Right and left ventricular ejection fraction (RVEF and LVEF) were measured using multiple gated radionuclide ventriculography. Theophylline 600 mg and salbutamol 4 mg both produced increases in RVEF and LVEF. There were no significant changes in blood gases after either drug. The clinical significance of the effects of oral bronchodilators on cardiac function in patients with chronic bronchitis and emphysema has yet to be determined.

High frequency oscillations improve nasal mucociliary transport

The saccharin clearance time technique was used to determine the effect upon nasal mucociliary transport of sine wave oscillations. Nasal air was oscillated at 8 Hz, 14 Hz, and 20 Hz by a loudspeaker attached to a nasal mask. Mucociliary transport was significantly increased at all frequencies with an overall mean rise of 161%. Because sine waves have zero mean pressure and flow, the improvement is more likely to be caused by changes in mucus viscoelasticity or ciliary function rather than by a direct physical effect on mucus velocity. This simple and comfortable technique may have practical application in patients with overproduction or retention of mucus within the nasal passages or intrathoracic airways.

Self-administered home intravenous antibiotic therapy in bronchiectasis and adult cystic fibrosis

10 patients (mean age 23.1, range 17.1-40.5 years), 8 with cystic fibrosis (CF), and 2 with advanced bronchiectasis without CF, were taught, while being treated in hospital for exacerbations of pseudomonas infection, how to continue to give themselves intravenous antibiotics at home. They were discharged after satisfactory antibiotic levels had been achieved, and 22 courses were given at home over a total of 116 patient-days. In 14 of these, the greater part of the course was given at home (mean duration 6.6, range 5-10 days); 2 of these were given without admission to hospital. In the 8 patients with two or more infective exacerbations within a 12-month period there was no difference between home and hospital treatments in clinical improvement or in relapse time, defined as the interval between completion of treatment and subsequent antibiotic therapy. Self-administration of antibiotics intravenously at home for selected adults with cystic fibrosis and severe bronchiectasis reduces hospital stay and does not seem to be associated with an increased rate of recurrent infection.

Pretreatment extraperitoneal surgical staging in primary carcinoma of the cervix uteri

Sixty-one patients with invasive carcinoma of the cervix uteri underwent extraperitoneal pelvic and para-aortic lymph node sampling along with the exploratory laparotomy. Using the adverse surgical effects criteria modified from the G.O.G., the clinical course of this group of patients was analyzed, retrospectively. The demonstration of metastases had an adverse effect upon survival whether the metastatic disease occurred in the para-aortic or pelvic node regions. No substantial delay in the initiation of radiotherapy occurred regardless of the severity of toxicity.

Multiple site phosphorylation of tyrosine hydroxylase. Differential regulation in situ by a 8-bromo-cAMP and acetylcholine

Suspension cultures of purified bovine adrenal chromaffin cells incorporated 32P from exogenous 32Pi into a protein of approximately M4 = 60,000 (isolated by discontinuous, sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis). Phosphorylated tyrosine hydroxylase, purified from chromaffin cell supernatants by immunoprecipitation, co-migrated with the Mr = 60,000 band. Tryptic fragments prepared fom either the Mr congruent to 60,000 band or the immunoprecipitated tyrosine hydroxylase band were analyzed after separation with two-dimensional electrophoresis/chromatography. Two distinct 32P-peptides were present in either sample. After a 2-3-min lag period. 32P incorporation into both peptides was relatively linear with time for at least 20 min. In the presence of calcium, exogenous acetylcholine (100 microM) increased 32P incorporation into both of the 32P-labeled tryptic peptides whereas 8-bromo-cAMP (1 mM) increased 32P incorporation into only one of the two. Ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid and MnCl2 inhibited the acetylcholine-induced phosphorylation of both tryptic peptides. Thus, tyrosine hydroxylase is phosphorylated in situ at more than one site, and the phosphorylation of these sites is affected differently by acetylcholine and 8-bromo-cAMP. The data imply that kinase activity other than (or in addition to) cAMP-dependent protein kinase activity attends tyrosine hydroxylase in the intact chromaffin cells and that multiple kinase activities may be involved in the short term regulation of catecholamine biosynthesis by afferent activity.

Acute right heart failure complicated by hypovolaemia

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