Improved exercise performance after exchange transfusion in subjects with sickle cell anemia

Ten patients with sickle cell anemia underwent partial exchange transfusion with hemoglobin-A-containing cells using a technique that allowed hemoglobin concentration and blood volume to remain constant. The mean fraction of hemoglobin-A in these patients increased from 9% to 55%, but the mean hemoglobin concentration increased by only 1.44 g/dl. The exchange resulted in a large improvement in submaximal exercise capacity: the mean of the anaerobic threshold (the work at which lactic acid begins to accumulate in the blood) increased from 68 to 114 W. The mean work performed at a heart rate of 170/min, an estimation of maximal work capacity, increased from 128 to 187 W. Improved exercise performance after partial exchange transfusion may result from the superior flow properties of hemoglobin-A-containing red cells. Furthermore, we believe that exercise testing in sickle cell anemia has great potential utility as a means to monitor therapy and to evaluate the benefits of exchange transfusion.

Automated partial exchange transfusion in sickle cell anemia

Partial exchange transfusion is used to manage several of the complications of sickle cell anemia. Automated exchanges have been performed successfully in thirteen homozygous (SS) sickle cell patients and in one patient with hemoglobin SC. Although the expected acute increase in whole blood oxygen affinity occurred in each patient, there was no clinical evidence of detrimental effects during or immediately after each procedure, and in each case the patient was unchanged or improved when evaluated by exercise testing. By using a discontinuous-flow cell separator, it is possible to decrease the time required to achieve a 50 per cent exchange in an adult to approximately two hours. Transfusion of blood with an antigenic marker permits rapid evaluation of exchange efficiency during the procedure. When partial exchange transfusion is indicated, the discontinuous-flow cell separator provides a safe, rapid, and effective procedure.

Computer-aided head film analysis: the University of California San Francisco method

Computer technology is already assuming an important role in the management of orthodontic practices. The next 10 years are likely to see expansion in computer usage into the areas of diagnosis, treatment planning, and treatment-record keeping. In the areas of diagnosis and treatment planning, one of the first problems to be attacked will be the automation of head film analysis. The problems of constructing computer-aided systems for this purpose are considered herein in the light of the authors' 10 years of experience in developing a similar system for research purposes. The need for building in methods for automatic detection and correction of gross errors is discussed and the authors' method for doing so is presented. The construction of a rudimentary machine-readable data base for research and clinical purposes is described.

Electrophysiology of Acanthocephalan Body Wall Muscles

Body wall muscles of an acanthocephalan Macracanthorhynchus hirudinaceus were studied by means of scanning and light microscopy and intracellular recording of potentials. Three types of spontaneous potential changes were found: larger (L) potentials which usually exhibited overshoot and were as large as 65 mV; smaller symmetric (A) potentials approximately 15 mV in amplitude; and even smaller asymmetric (S) potentials which sometimes reached 10 mV. The potentials recorded depended upon the position of the electrode in the anterior-posterior, as well as the medialateral, axis. Tetrodotoxin eliminated L but not S potentials. Ouabain lengthened the time for depolarization of L potentials and depolarized the membrane potentials. It is suggested that the rete system activates the body wall muscles in Acanthocephala.

Location of the sugar-binding site of L-arabinose-binding protein. Sugar derivative syntheses, sugar binding specificity, and difference Fourier analyses

The sugar-binding site of the L-arabinose-binding protein, an essential component of the high affinity L-arabinose uptake system in Escherchia coli, is located deep in a cleft formed by the asymmetric contributions from both of the two similar domains. The site was unambiguously identified with the electron-rich substrate analog 6-bromo-6-deoxy-D-galactose in a difference Fourier analysis. The observation that the original native structure might have been solved with bound L-arabinose necessitated the synthesis of a heavy atom analog, its structure consistent with the known sugar-binding specificity of the protein. Difference Fourier maps (3.5 A) of crystals soaked in 46 mM analog showed a peak 3.5 times background, which is attributed to the -CH2Br moiety of the analog. Superposition of a difference map onto a 2.8-A native electron density map indicated that the difference peak is 6 to 7 A from the reactive single cysteine (Cys-64) and partially coincident with an "extraneous" density found in the native map. This "extraneous" peak was previously attributed to a bound L-arabinose molecule, and its presence accounts for the early failures of difference Fourier analyses of crystals soaked in or co-crystallized with L-arabinose to locate the sugar-binding site.

Distal displacement of the maxilla and the upper first molar

Data from a sample of 198 Class II cases treated with various appliances which deliver distally directed forces to the maxilla were examined to determine the frequency of absolute distal displacement of the upper first molar and of the maxilla. Analysis revealed that such distal displacement is possible and that it is, in fact, a frequent finding following treatment. Long-range stability of distal displacement was not assessed.

A new universal anaesthetic circuit using a preferential-flow T-piece

A new co-axial anaesthetic circuit, employing a preferential-flow T-piece which eliminates the need for valves in the circuit, has been designed. Its efficiency has been shown to compare favourably with that of conventional circuits for use in spontaneous respiration and under conditions of controlled ventilation. The proposed system has the advantage of convenience, in that there is no need to disconnect the system from the patient nor from the anaesthetic machine when it is necessary to change from spontaneous to controlled ventilation or should a circle absorber be incorporated within the circuit. The system has been shown to offer lower resistance than the Mapleson A circuit.

Fatty acids in female Macracanthorhynchus hirudinaceus (Acanthocephala)

Neutral lipids and phospholipids in the body wall, lemnisci and pseudocoel and neutral lipids of fluid found in the "tube" system of the lemnisci and the lacunar system of the body wall of Macracanthorhynchus hirudinaceus (Acanthocephala) were determined by the technique of thin layer chromatography and gas chromatography (GC). Sixteen different fatty acids from nonpolar lipids were identified as follows: 8:0, 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 18:0, 18:1, 18:2 and/or 20:0, 18:3 and/or 20:1, 20:3, 22:1, 24:1 and 22:6. In addition, there were three unidentified GC peaks corresponding to chain lengths greater than 20 carbons. Sixteen different fatty acids from phospholipids were identified in each of the three fractions analyzed. They were as follows: 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2 and/or 20:0, 20:2, 20:3, 22:1, 24:1 and 22:6. Four unidentified peaks were also observed. There was a significant difference in the percentage of lipid as well as the concentration of particular fatty acids when each fraction was compared. There was also an abundant supply of sterols and glycerides in each fraction.

The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis

The kinetics of the uptake and efflux of 3-O-methyl-glucose in sporidia of Ustilago maydis were measured, both in active cells and in cells whose metabolic activity had been inhibited by azide and iodoacetate. The de-energized transport system proved to be carrier mediated with apparent affinity constants 13 +/- 2 mM outside (Ko) and 18 +/- 2 mM inside (K1). The apparent maximum rate constants for the same system were 0.66 +/- 0.05 mmol/1 cell water per min for uptake (V+) and 0.53 +/- 0.04 mmol/l cell water per min for efflux (V-). For the active system K0 = 0.08 +/- 0.01, K1 greater than 40, V+ = 9.7 +/- 0.5 and V- = 1.1 +/- 0.9 (in equivalent units). These results are discussed in the context of the carrier mechanism as proposed by Regen and Morgan (Regen, D.M. and Morgan, H.E. (1964) Biochim. Biophys. Acta 79, 151--166). The antifungal compound carboxin had no effect on de-energized transport but was shown to decrease both K0 And V+ in the active system. Phloretin and phlorizin were also found to be without effect on de-energized cells but the former enhanced while the latter inhibited active uptake.

Anatomy of the genital ganglion of the male acanthocephalan, Moniliformis moniliformis

Male Moniliformis moniliformis possess paired genital ganglia each measuring approximately 280 micron long by 80 micron wide by 25 micron thick. They are located on either side of Saefftigen's pouch on the ventral surface of the ejaculatory duct where it joins the bursal cap. The cellular organization consists of externally located soma and a poorly developed internal neuropile. Most of the 19 cells in each ganglion exit via axons from the anterior and posterior extremities. A single dorsal commissure connects the 2 ganglia. No ventral commissure was observed. Many cells contained large nuclei with perinuclear rings but no cell had 2 nuclei.

A new ganglion in male Moniliformis moniliformis (Acanthocephala)

A new ganglion identified as the bursal ganglion is described from male Moniliformis moniliformis. This ganglion is located adjacent to the pseudocoel and longitudinal muscle fibers and medial to the dorsal lacunar canal about 1 mm from the posterior end of males with non-everted bursa. The ganglion consists of four large club-shaped cells with single nuclei and bipolar neurons. The ganglion cells are paired with one neuron from each cell innervating the opposite side of the worm.

Effects of music-listening contingencies on arithmetic performance and music preference of EMR children

A five-phase experiment was designed to investigate (a) whether contingent music-listening would act as a reinforcer to increase arithmetic performance of EMR children and (b) whether this contingent reinforcement would affect preference for that reinforcer. During the three baseline (no reinforcement) phases, subjects returned to their classrooms at the end of the arithmetic work period. During the two treatment phases, experimental subjects meeting criterion were permitted to remain and listen to either rock (high preference) or music classics (low preference). Statistical analyses revealed significant differences between the no-reinforcement and contingent-reinforcement conditions and between the control and four experiment groups during the contingent reinforcement phases. No differential effect between the more or less preferred contingencies was found. Analyses of the music-selection data indicated that the contingencies did not influence music preference.

Ion metabolism in a halophilic blue-green alga, Aphanothece halophytica

The intracellular ion content of the halophilic blue-green alga, Aphanthece halophytica was studied as a function of age, external sodium and external potassium concentration. Intracellular Na+ was found to be about 0.38 millimoles/g dry mass. Intracellular K+ concentrations were as high as 1 M and varied directly with external salinity. Intracellular Ca++ and Mg++ were in the range previously reported for fresh water blue-green algae despite their extremely high extracellular concentrations. Average cell size is consistent at room temperature with two exceptions. When the outside K+ is lower than 6.5 mM the cells tend to be smaller with less intracellular K+ and high Ca++. In stationary phase cultrues the cells are larger with high intracellular Mg++ and low K+.

Nerves originating from the cerebral ganglion of Moniliformis moniliformis (Acanthocephala)

Extending from the cerebral ganglion are the following 6 pairs of nerves: 2 pairs of anterior medial nerves, 2 pairs of lateral medial nerves, 1 pair of anterior proboscis nerves, 1 pair of lateral medial nerves. The dorsal anterior medial nerve and the ventral anterior medial nerve are unpaired nerves. The dorsal anterior medial nerve supplies the apical sensory device on the proboscis. The ventral anterior medial nerve supplies the retractor and protrusor muscles of the proboscis and the lateral posterior nerve supplies the longitudinal and circular muscles of the body wall. This last nerve is the largest of the nerves and is enclosed by the retinacular muscle as it extends through the pseudocoel to the body wall where it divides into a posterior and anterior nerve. The anterior medial nerve originates from 2 different levels along the dorsal anterior surface of the ganglion. These nerves serve the anterior presoma. The anterior proboscis nerve originates from the apical cells of the ganglion and is found between the proboscis retractor muscles throughout their length.

Anatomy of the cerebral ganglion of the male acanthocephalan, Moniliformis dubius

An atlas of the cerebral ganglion of Moniliformis dubius has been constructed and the cells identified by number. There is a total of 88 cells, two of which are binucleate. These cells (20 and 90) are located in the frontal plane. The cell population is equally distributed between each half of the ganglion, there being 41 cells on each side with six cells centrally located between the two halves. Most cells give rise to bilateral processes and are organized in such a way that there is an outer coat of somata or cell bodies. Cell bodies predominate on the ventral surface, but the dorsal surface is more of a mixture of cell bodies and nerve processes. The core or neuropile occupies the central part of the ganglion and is the site for cross over for many cell processes which then exist from the side opposite the cell body. The cytoarchitecture of these cells varies considerably. Most have a large round nucleus with well defined nucleoli.

The kinetics of selective biological transport. V. Further data on the erythrocyte-monosaccharide transport system

Measurements of the rate of loss of sugar from human erythrocytes into sugar-free solutions were made as a function of sugar concentrations. The half-saturation concentration of this process was found to be different from those half-saturation concentrations previously measured by other methods. These data, together with a number of similar data from former publications, are summarized in tabular form and their use in assessing postulated transport mechanisms is illustrated by consideration and rejection of a mechanism in which the transport process is assumed to be the result of a protein conformational change.

The kinetics of selective biological transport. 3. Erythrocyte-monosaccharide transport data

The simplest biological transport system so far extensively investigated is that of monosaccharides in human erythrocytes. Despite its simplicity there is still considerable doubt and divergence of opinion concerning its mechanism. Some confusion may arise as a result of the comparison of diverse data obtained by different workers using a variety of experimental techniques. To minimize this problem, an attempt is made here to repeat, under standard conditions and with as much care as possible, five of the more definitive types of experiments previously performed on this system. It is hoped that the result of this effort is an internally consistent set of data with which the quantitative predictions of various proposed mechanisms may be compared as a primary criterion for their acceptability.

The kinetics of selective biological transport. IV. Assessment of three carrier systems using the erythrocyte-monosaccharide transport data

An assessment is made of the possible validity of three transport mechanisms proposed to describe the movement of monosaccharides in human erythrocytes. These mechanisms consist of a simple carrier system and two mechanisms derived from it, one of which postulates that the free carrier moves more slowly than the complexed carrier, and the other that slow diffusion steps occur at each surface of the membrane. None of these schemes provides an adequate quantitative description of the data so that all must be discarded, leaving the question of the mechanism still open to speculation.

Hexokinase isoenzymes in liver and adipose tissue of man and dog

A hexokinase, with a low Michaelis constant, not previously described, has been found in extracts of human and dog liver but not of rat liver. Earlier reports are contradicted in that glucokinase occurs in extracts of liver from well-nourished humans and dogs; it is absent, or almost so, during states of poor nutrition.

d-tubocurarine chloride: effect on insects

Injection of d-tubocurarine chloride into certain insects produces complete flaccid paralysis. The site of injection is closely related to the region of primary paralysis. The effect depends on concentration, with distinct differences in the optimum concentrations for various species so far tested. A dose-response curve has been prepared for Calliphora erythrocephala.

The kinetics of selective biological transport. II. Equations for induced uphill transport of sugars in human erythrocytes

Equations describing the movement of sugars during induced uphill transport were derived on the assumption of a simple carrier transport mechanism and subjected to experimental verification. Since there was good agreement between the experimental points and the theoretical curves, no changes in the original postulates were required.

The kinetics of selective biological transport. I. Determination of transport constants for sugar movements in human erythrocytes

A method for the determination of the affinity constants and transfer rate constants of an equalizing selective transport system is derived from the simple transport mechanism, and applied to monosaccharide movements in human red cells. It is similar to the method of Widdas but does not require his approximations. Results are compared with those of the other workers.